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Proceedings of the INTERNATIONAL CONFERENCE ON INNOVATIONS IN CIVIL ENGINEERING ICICE-2013

MAY 9th & 10th, 2013 SSET, KOCHI, KERALA, INDIA

CONTRIBUTORY PAPERS

Organised by

DEPARTMENT OF CIVIL ENGINEERING SCMS SCHOOL OF ENGINEERING TECHNOLOGY

In association with

Copyright, Civil Engineering Department, SSET, Karukutty, 2013 All rights reserved. No part of this publication may be reproduced or transmitted in any form or by any means without prior permission.

First published 2013 Publishers: Civil Engineering Department, SSET, Karukutty, Kochi, Kerala, India.

Printed at Kochi Maptho Printers Kochi.

The proceedings in this volume are meant for research and academic purposes. The authors of the papers in this volume have declared the originality of their contributions and affirmed that their works do not contain materials whose publication would violate any copyright, trademark, intellectual property rights or other personal or proprietary rights of any private person or entity or governmental or quasi- governmental entity. In addition, the authors have declared that the papers have been submitted only to ICICE-2013 and that those have neither been published nor have they been under consideration for publication or in press anywhere else. Having thus exercised all reasonable care against infringement/violation of copyright or intellectual property right, the organizers do not accept any responsibility or liability of claim for damages in these regards. The statements and opinions expressed in the papers in this volume are purely those of the authors and do not necessarily reflect the opinion of the editors and the organizers of the International Conference on Innovations in Civil Engineering 2013. Any mention of the name of any company or the trade name of any product or process does not imply endorsement by the Conference organizers. Errors/ omissions, if any, are unintentional and regretted.

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PATRON Dr. G.P.C. Nayar Chairman, SCMS Group ADVISORY COMMITTEE Dr. Tan Kiang Hwee Dr. Fwa Tien Fang Dr. Johannes Fritsch Dr. S. Mohan Dr. Eldho.T.I

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NUS, Singapore. NUS, Singapore. UAS, Germany. IIT, Madras. IIT, Bombay.

TECHNICAL COMMITTEE Dr. S. Sreekumar Dr. K. Balan Dr. G. Madhu Dr. K.S Beena Dr. Renu Powels Dr. Mathews M Paul Dr. Soosan George.T Dr. Meera.V Shri. S. Suresh

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Professor, CET. Professor, CET. Professor, CUSAT. Professor, CUSAT. Professor, CUSAT. Professor, MACE, Kothamangalam. Professor, MACE, Kothamangalam. Asst. Professor, GEC, Thrissur. ASC, Cochin.

ORGANIZING COMMITTEE Prof. P.C.Pillai Prof. M. Madhavan Er. Shelly Fernandes Er.Mohan Kumar Shamarao Dr. E.M.S.Nair Dr. C.K.Rajan Smt. Meril George Smt. Sanju Sreedharan Shri.Santhosh G

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Group Director, SCMS. Director, SSET. Chairman, ICI-Cochin. Secretary, ICI-Cochin. Professor, SSET. Professor, SCMS. Associate Professor, SSET. Associate Professor, SSET. Associate Professor, SSET.

ICICE 2013 is grateful to its Panel of Reviewers

1.

Meril George

2.

Sanju Sreedharan

3.

Santhosh G

4.

Shiji P V

5.

Rakhi Premachandran

6.

Sreedevi V M

7.

Jini Jacob

8.

Nandita Mohan

9.

Sanya Maria Gomez

10. Sweeta Francis 11. Airin M G 12. Ayona S Nair 13. Sandeep T N 14. Indu N

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MESSAGE We live in a technology driven world. Twentieth century is considered the century of information technology. This century is said to be the century of biotechnology. Even soothsayers cannot predict what is in store for us in the future. However, the basic technology has not lost its luster a bit. Civil, Mechanical and Electrical Engineering technologies rule the roost even today. Without them other technologies cannot move forward. Of all technologies Civil Engineering is the most important as it paves the foundation for development and growth of other technologies. I am happy our Civil Engineering Department has decided to organize a Conference to discuss and analyse issues involved in structural engineering, concrete technology, environmental and water resources engineering, geotechnical engineering and traffic and transportation engineering. These are vital engines of growth in a fast developing economy like that of India. We have some of the top experts from across the world to speak on the innovation in technology in these areas. I congratulate Ms.Meril George, Associate Professor for taking the lead in organizing this International Conference. Her team members Ms.Sanju Sreedharan and Mr.Santhosh are also reported to be ably assisting her. I have pleasure in congratulating them on their laudable effort.

Dr.G.P.C.Nayar Chairman SCMS Group of Educational Institutions

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MESSAGE I am happy to know that the Department of Civil Engineering of SCMS School of Engineering & Technology is organizing an International Conference on Innovations in Civil th th Engineering on the 9 and 10 May, 2013. This is a laudable initiative taken by the college to focus on new developments in the field of civil engineering and how innovations can contribute to expand the frontiers of civil engineering technology. This is also an opportunity for the faculty Members and students to get experience in organizing national and international conferences. Civil Engineering is already an advanced field of engineering. To my mind, at this stage of nation building, it is not innovations which are important, but more stress on fundamentals ofcivil engineering to ensure our designs are robust and execution perfect. We come across a number of cases of civil structures failing due to faulty designs, specifications notbeing enforced and inordinate delays incompletion of projects with inevitable cost overruns. Let us get our fundamentals right and ensure, civil structures are safe and durable. Our designs also have to be construction friendly. It is my hope the conference will debate on thesubject in a fruitful and constructive manner. I am sorry, I am not able to be present in the conference, but send my best wishes for its success.

Dr. E. Sreedharan Principal Advisor vii

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ICICE -2013

PREFACE Civil Engineering is co-evolving with the integrated global marketplace. Technology is spurs innovation and accelerates productivity. Global capital impacts infrastructure construction and the global supply chain affect project delivery. Dynamic discussions will unravel the changes that shape the profession today and in the future. Civil engineers equipped with enhanced skills, advanced knowledge and imaginative vision can easily interact with multi-national teams spanning cultural boundaries about global socio-technological problems. It is with immense pride that we, SCMS School of Engineering and Technology, place on record the “International Conference on Innovations in Civil Engineering – 2013”, a venture meant to give impetus to novel innovations and contributions in the field of civil engineering. The principal aim of the conference is to provide a platform for academicians, students, and researchers to interact with international scholars, learn the latest industry breakthroughs and impart , a new dimension to the profession The conference covers the following themes; 1. Structural Engineering: Analytical and design methods, Special Structures, Case studies, Innovations in design and new technologies, Repairs and rehabilitation, Stability Engineering, Optimization, Soil-Structure Interaction, Standards and Codes of Practice, Solid Mechanics, Experimental Studies and Testing Technologies and Structural Dynamics 2. Concrete Technology: Properties and performance of concrete and concrete structures, Advanced and improved experimental techniques, Concrete waste management. 3.Environmental and Water Resources Engineering: Water Supply and Sanitary Engineering, Soil, Air and Water pollution, Sustainability in Waste Management, Watershed Management, Water Resources Planning and Irrigation Engineering. 4. Geotechnical Engineering: Advances in Geotechnical Characterization, Instrumentation and Monitoring, Design and Construction of Foundations, Geomechanics, Environmental Geotechnics, Earthquake Geotechnical Engineering, Risk Assessment and Disaster Reduction. 5. Traffic and Transportation Engineering: Intelligent Transport Systems, Pavement Engineering, Transportation Planning, Traffic Engineering. ix

The concerted efforts of the organizers were given an overwhelming response by the civil engineering community. From the 110 submissions, 70 papers were selected for presentation and publication in ICICE-2013 and 68 will be published in the International Journal of Scientific and Engineering Research (IJSER) after a stringent double blind review process. On behalf of the organizing committee I thank and appreciate the sincere efforts and support of the technical and review committee for ensuring the quality of the proceedings. I wish to extend my sincere gratitude to all the authors and delegates and all who have contributed their time and skill and make ICICE – 2013 a milestone. The publication of the proceedings has been made possible through the concerted efforts of several individuals besides the advisory committee and technical committee. With immense gratitude I acknowledge the selfless service of all those who extended their whole-hearted cooperation in making this program a grant success. On behalf of the organising committee, I express our sincere thanks to the SCMS Group of Educational Institutions, Kerala State Council for Science, Technology and Environment, Indian Concrete Institute and International Journal of Scientific and Engineering Research and all the sponsors and delegates, and all those who have worked behind the scenes and for their continuous support in the making of ICICE-2013.

M. MADHAVAN, Director,SSET.

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CONTENTS Page Nos Preface 1

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Removal of Cr (VI) in aqueous solution using iron oxide coated sand (IOCS) Aditya Dhagat, Bhushan Goyal, Lalsangzela Sailo

1

Prediction of PM, SO2 & NOX - GLC’S from Point Source Emissions Using Air Modeling M.S.Priyanka Yadav, Ravi Kumar Gaurav, Jahnavi.B, Dr.G.Dasartha Ram

5

Heavy Metal Removal from Water using Moringa oleifera Seed Coagulant and Double Filtration Ravikumar K, Prof.Sheeja A K

9

An Experimental Study on Duckweed For Improving Pond Water QualityS.Vanitha, NVN.Nampoothiri, C.Sivapragasam, Anitha Menon.M

13

Reduction of COD of Pulp and paper mill effluent using Sequencing batch reactor Afzal Husain Khan, Iqbal Khan, Nadeem Ahmad khan, Misbahul Islam, Arshad Husain

17

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Suitability of Sludge as a Building MaterialKrishna Priya Nair, Vivek J M, Prof.Shibu K

21

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Cyclic Response of Stone Columns K.V.S.B. Raju, L.Govinda raju, Chandrashekhar A.S

27

Capacity evaluation of Lead cell foundation K. Subhashini, C. Harikumar, C. Sivathanu Pillai

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Effect of fly ash on the properties of expansive soil Mahesh G. Kalyanshetti, Satish Basavaraj Thalange

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Analysis of Geotextile Reinforced Embankment on Difficult Subsoil Condition Jigisha M. Vashi, Atul K. Desai, Chandresh H. Solanki

39

Design of Amended Soil Liner Emy Poulose, Prof. Ajitha A. R., Dr. Sheela Evangeline Y.

43

Role of Moulding Water Content on the Strength Properties of Red Earth treated with Mine tailings Dr. H.N.Ramesh, Mr. A.J.Krishnaiah, Mrs.M.D. Supriya

45

Effect of Fly Ash on CBR and DCPT Results of Granular Sub Base Subjected to Heavy Compaction Ratna Prasad, R., Darga Kumar, N., and Janardhana, M.

49

Strength Behaviour of Randomly Distributed Fibre Reinforced Natural Sand Dr.T.Sambaiah

55

Effect of Fibre Content on Strength Behaviour of Geosynthatic Reinforced Medium Sand Dr.T.Sambaiah

61

Effect of reinforcement Spacing on the Performance of Embedded Circular Footing in Reinforced FlyAsh S. Gangadara, H.C. Muddaraju

67

Effect of Elevated Temperatures on Physical and Residual Strength Properties of HPC Kishor S. Kulkarni, K S Babu Narayan and Subhash C. Yaragal xi

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18

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Fracture Properties of Fibre Reinforced Geopolymer Concrete Deepa Raj S., Ruby Abraham, N. Ganesan, Divya Sasi Experimental Study on Combined Effect of Fly Ash and Pond Ash on Strength and Durability of Concrete S.A. Haldive, Dr. A. R. Kambekar

81

Feasibility Study of Fly Ash as a Replacement for Fine Aggregate in Concrete and its Behaviour under Sustained Elevated Temperature Parvati V. K, Prakash K.B.

87

Effect of Wollastonite micro fiber addition in mortar and concrete mixes Shashi Kant Sharma, G.D.Ransinchung R.N., Praveen Kumar

91

Use of Blast Furnace Slag Aggregate in Concrete K.G. Hiraskar and Chetan Patil

95

Soil-structure interaction analysis of RC frame shear wall buildings over raft foundations under seismic loading 99

H.K Chinmayi, B.R Jayalekshmi. 24

25

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75

Challenges in design and construction of building housing 100 T shake table C. Harikumar, R. preetha, Davy Herbert, C. Sivathanu Pillai

103

Parametric Investigations on Behaviour of Square CFST Columns Ziyad A. Khaudhair, P.K. Gupta,A.K. Ahuja

107

Effect of Corrosion on Load Deflection Behaviour of OPC concrete in NBS Beam Akshatha Shetty, Katta Venkataramana, Babu Narayan K. S

111

Assessment of First Order Computational Model for Free Vibration Analysis of FGM Plates K. Swaminathan, D. T. Naveenkumar

115

Higher order computational model for the thermo-elastic analysis of cross-ply laminated composite plates K. Swaminathan, Reginald Fernandes

119

Ductility Behavior of reinforced high volume flyash concrete beams R.Preetha, Joanna.P.S, Jessy Rooby,C.Sivathanu Pillai

123

Investigations on Elastic Behaviour of Corrugated Plates Lathi Karthi, C.G.Nandakumar

127

Strength Parameters Of Self Compacting Concrete With Partial Replacement of Cement By Rice Husk Ash And Natural Sand By Filtered Sand Praveen.G.Suryavanshi, Dr. B. P. Annapurna, Dr. K Chethan, Manjunath N.K, Chandrashekar H.S

131

Response of a 3-Dimensional 2 X 3 Bays Ten Storey RC Frame with Steel Bracings as Lateral Load Resisting Systems Subjected To Seismic Load Venkatesh S.V., Sharada Bai H., Divya S.P.

137

Review of Particle Packing Theories Used For Concrete Mix Proportioning Mangulkar M. N., Dr. Jamkar S.S.

141

Influence of Horizontal Reinforcement on Ultra High Performance Concrete Wall Panels under Two way in plane action N Ganesan , Ruby Abraham , Beena P.R , Anil R

147

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Forensic Investigation For Sustainability Issues In Structure Prof. D.S.Bhosale

151

Fibre Reinforced Light Weight Aggregate (Natural Pumice Stone) Concrete N. Sivalinga Rao, Y.Radha Ratna Kumari, V. Bhaskar Desai, B.L.P. Swami

155

Dynamic Buckling of Composite Cylindrical Shells subjected to Axial Impulse Chitra V., Priyadarsini R.S.

159

Spline Finite Strip Bending Analysis of Functionally Graded Plate using Power-law Function Parvathy U, Beena K.P.

163

Numerical Modeling of Rectangular Concrete-Filled Steel Tubular Short Columns Heaven Singh, P.K. Gupta

167

Performance Assessment of Sandwich Structures with Debonds and Dents Anju Mohanan, K.R. Pradeep , K.P. Narayanan

171

Seismic Fracture Analysis In Concrete Gravity Dams Deeja Alora, Indrani Gogoi

177

Seismic Soil-Structure Interaction Studies on Tall Chimneys Ansu Thomas, B. R. Jayalekshmi, R. Shivashankar

185

Coupled Layerwise Theories for Hybrid and Sandwich Piezoelectric Beams Akil Ahmed

189

Prediction of elastic modulus of high strength concrete by Gaussian Process Regression Ishan Saini, Pranav Chandramouli

193

Vibration of laminated composite cylindrical shells with cutouts using higher order theory Ajay Kumar, Anupam Chakrabarti , Pradeep Bhargava

195

Reactive Powder Concrete Properties with Cement Replacement Using Waste Material Mr.Anjan kumar M U, Dr. Asha Udaya Rao, Dr. Narayana Sabhahit

199

Catalytic use of Laterite Iron for Degradation of 2-Aminopyridine Using Advanced Oxidation Processes Rahul Karale, Basavaraju Manu and S.Shrihari

203

Strengthening of Existing Building Column Using FRP Wrap& GI Wire Mesh Engr. Azam Amir, Dr. AmjadNaseer, Engr. Orooj Azam

207

Fatigue life estimation of ship structure Emil Mathews, C G Nandakumar

213

Reliability analysis of response surface based damage identification method Tanmoy Mukhopadhyay, Rajib Chowdhury, Anupam Chakrabarti

217

Seismic Reliability Assessment of Typical Soft-storey RC Building In Manipur Region Monalisa Priyadarshini, Robin Davis P, Haran Pragalath D C and Pradip Sarkar

221

A Numerical Model of Externally Prestressed Concrete Beam Jafar Sadak Ali, Soumendu Bagchi, Sumit Gupta

225

Design and Development of High Strength Heavyweight Concrete Using SBRS. P. Jadhao, M. G. Shaikh

229

Effect of Soil Structure Interaction in Seismic Loads of Framed Structures Shiji P.V, Suresh S., Glory Joseph

233

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Sustainable Concrete using Waste Paper Ash249 as Partial Replacement for Cement Dr.P.B.Sakthivel, C.B.Yaamini, T.Vidhya

237

An Innovative Method of Replacing River Sand by Quarry Dust Waste in Concrete for Sustainability Dr. P.B.Sakthivel, C.Ramya, M.Raja

241

Analysis of Self-supported Steel Chimney with the Effects of Manhole and Geometrical Properties Kirtikanta Sahoo, Pradip Sarkar, Robin Davis P.

245

Fracture Parameters of Steel Fibre Reinforced High Strength Concrete by Size Effect Method K.S. Prebhakumari , P. Jayakumar

249

Mechanical and Durability properties of Self Compacting Concrete with recycled concrete aggregates C.Sumanth Reddy, K.V.Ratna Sai, Dr.P.Rathish Kumar

255

Simplified Analysis of Reinforced Concrete Framed Structures for Progressive Collapse Ayush Singhania, Vikas Khatuja, Vikram Singh Thakur, Dr. C.B.K. Rao

259

Toughness of Ferrocement Confined Reinforced Self Compacting Concrete(FCRSCC) Under Axial Compression VikasKhatuja, Vikram Singh Thakur,Ayush Singhania,Dr.C.B.K. Rao

267

Different Techniques of Seismic Control of Structures Ch.Avinash, K.Dharmateja, T.P.Balaji, K. Jagadeesh Reddy, Dr. P Saha

275

A study on shear strength of sand reinforced with glass fibres Shivanand Mali and Baleshwar Singh

279

Improvement in Properties of Subgrade Soil by Using Moorum and RBI Grade 81 B.M.Patil, K.A.Patil

283

OD Matrix Estimation from Link Counts Using Artificial Neural Network Remya K P, Samson Mathew

287

Application of ASTER DEM in Watershed Management as Flood Zonation Mapping in Koyana River of the Western Ghats. V. M.Shinde, P. K. Deshpande, M.B.Kumthekar

291

Assessment of Surface Water Chemistry of Jakkur Lake, Bangalore, Karnataka, India M. Inayathulla and Jai M. Paul

295

Desertification, the global environmental problem and it’s impact on food & water resources

299

Er. S. Venkateswara Rao, Dr. P.G. Sastry, Dr. Vaishali Ghorpade 69.

70

Factors influencing the Prediction of Resistance in a Meandering Channel Saine S. Dash, Kishanjit K. Khatua, Prabir K. Mohanty

303

Experimental Analysis of Energy Dissipation in Small Diameter Nitinol wires Chandra Mouli Vemury, Scott Renfrey

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CONTRIBUTORY PAPERS

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INTERNATIONAL CONFERENCE ON INNOVATIONS IN CIVIL ENGINEERING 9th and 10th of May 2013

Removal of Cr (VI) in aqueous solution using iron oxide coated sand (IOCS) Aditya Dhagat, Bhushan Goyal, Lalsangzela Sailo Abstract— In the present study, Iron Oxide Coated Sand (IOCS) was applied to treat water contaminated with chromium. The effect of adsorbent dosage and pH on the removal of chromium (Cr) from aqueous solution using IOCS has been investigated. Batch mode experiment was carried out to assess the adsorption kinetics and equilibrium studies. The kinetics study was best described by pseudo second order. Moderate fitting of Elovich model and intra-particle diffusion model suggested complex adsorption i.e. surface sorption and intra-particle diffusion as rate controlling steps. The adsorption isotherm data fitted well to Freundlich isotherm. Index Terms— Adsorption isotherm, Chromium,Dosage, Effect of pH , Elovich, Intra-particle diffusion model, Iron oxide coated sand, Kinetics, Pseudo second order.

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1

INTRODUCTION

P

ollution of water by chromium is of considerable concern; as this metal is widely used in leather tanning industries and chromate manufacturing located in the industrial development area of Ranipet, Tamil Nadu, which is situated only 20 km from Vellore. Extensive efforts and works have been directed towards the water chemistry, environmental mobility, and toxicity of chromium. Since, the Ranipet has numbers of tanneries which discharge high concentration of chromium, so there is a potential risk for ecology and environmental pollution. Tamil Nadu Pollution Control Board (TNPCB, 1996) reported that 150,000 tons approx. of solid waste (sodium, chromium, chromate salt, basic chromium sulfate tanning powder) accumulated over two decades of plant operation has been stacked in the open yard on 3.5 ha of land within Tamil Nadu Chromate and Chemical Limited (TCCL) [1]. The leachate from this stack infiltrates into the soil and pollutes the groundwater due to rain. Rao et al. (2011) reported groundwater Cr concentration in Ranipet as high as 220 mg/l suggesting the extensiveness of the pollution in the area. For the removal of chromium from water, various water treatment technologies like adsorption, ion-exchange, filtration, reverse-osmosis and electro-dialysis have been used. However, the existing technologies are not tailored fit for rural community in developing countries because of high capital cost and maintenance by skilled labors. Consequently, adsorption processes has been found to be most effective and economical treatment for the removal of Cr from the aqueous solution for household as well as small communities. Therefore, in order to remove chromium effectively from the water iron oxide coated sand (IOCS) was used. It is used to remove both soluble and particulate fraction from water through a column packed with IOCS filter media [2, 3]. IOCS has be effective use for treatment of water and wastewater containing variety of heavy metal over a wide range of concentrations [3]. •

Aditya Dhagat, Bhushan Goyal are currently pursuing B-Tech degree program in civil engineering in VIT University, India,.MOB-08870511706 E-mail: [email protected], [email protected].

•

Lalsangzela Sailo , Assit. Prof ,S.M.B.S. VIT UniversityIndia, MOB-09597095385 E-mail: [email protected]

ICICE-2013

The surface characteristics of IOCS are physically and chemically heterogeneous and are expected to change with time viz. porosity, specific surface area etc. Adsorption of Cr(VI) onto the sand coated with iron oxide from ferric chloride solution gave better result and the media have longer life time when less alkaline solution is employed for the regeneration [3]. The objective of the present study was to find the potential adsorption of Cr(VI) from the aqueous solution by IOCS under various kinetics and equilibrium conditions at optimum dosage and pH conditions.

2. MATERIALS AND METHODS 2.1 Preparation of Iron Oxide Coated Sand (IOCS): Sand passing through 1.2 mm and retaining on 0.6mm sieve was taken and washed with 0.1N HNO3 and kept for 24 hr. Then the sand sample was washed with distilled water and oven dried at 105æ%C for 5-6 hrs. Then a 1M sample of Fe(III) was prepared by dissolving FeCl3 in distilled water and the sample of sand was added to it. Then the pH was reduced to 8-9 by adding 6M NaOH into it and allowed to remain undisturbed for 24 hrs. On reducing pH, iron molecules settle on sand thereby enhancing adsorption phenomena. After keeping it for 24 hrs, the sample was washed with distilled water and oven dried at 105æ%C for 56 hrs.

2.2 Effect of pH The effect of pH on the adsorption processes was studied by taking initial Cr(VI) concentration of 10 mg/l. A soil solution ratio of 1:50 (1gm: 50ml) was taken and the pH was regulated by using NaOH solution and H2SO4 solution to have a pH of 4 different set to 4.5, 5.5, 7, 8.5 respectively. These samples with different pH were placed in a mechanical shaker for 90 minutes. After shaking, amount of Cr(VI) adsorbed was determined using UV spectrophotometer.

2.3 Dosage study To each 50 ml Cr(VI) solution different amount of IOCS viz. 0.25 gm, 0.5 gm, 0.75gm, 1gm and 1.25gm were added respectively. These samples with optimum pH of 7.5 were placed in a mechanical shaker for 90 minutes. After shaking, amount of Cr(VI) adsorbed was determined using UV spectrophotometer. 1


2.4 Kinetics study A sample of Cr(VI) contaminated water was prepared from K2Cr2O7 (Merck) and initial solution for the kinetic study was taken as 10 mg/l Cr(VI). Samples were prepared by adding 1 gm of iron oxide coated sand (IOCS) to 50 ml of 10 mg/l Cr(VI) sample and each sample was rotated in a mechanical shaker for 5mins, 10mins, 15mins, 20mins, 30mins, 45min, 60mins, 90mins, 120mins and 180 minutes. After shaking for predefined interval, the samples were filtered to remove sand particles and tested for concentration of Cr(VI) removed using UV spectrophotometer. For the study of adsorption isotherm, various concentrations of Cr(VI) was shaken in horizontal shaker (Neolab Orbit Shaker Incubator) at 120 rpm till the equilibrium. And the isotherm data was fitted into the model. The concentration of Cr(VI) present in different solutions was determined by UV spectrophotometer (CyberLab) using Diphenyl Carbazide method-3500 CR (APHA, 1998).

3. RESULTS AND DISCUSSIONS: 3.1 Effect of pH on adsorption of Cr(VI) According to the experiment conducted, amount of Cr(VI) adsorbed is found to be higher at a lower pH than higher pH; similar trend has been reported in various studies. The adsorption takes place till 5.5 and then desroption takes place as we increase pH which indicates that acidic medium is optimum for reduction of maximum amount of Cr(VI) from the solution ranging from pH 5-6. Since, Cr(VI) solution is in oxy-anionic form, therefore, the increase in pH of the solution will induce repulsion due to higher electro negativity at greater pH [2] as shown in Fig 1.

Fig 2: Effect of dosage of IOCS on adsorption of Cr (VI) 3.3 Kinetics of Cr(VI) adsorption In order to determine the rate of different processes and factors which influence them, kinetics studies have been conducted. Through these studies possible mechanism of adsorption and the different transition states on the way to the formation of the final adsorbate–adsorbent complex have been evaluated. These reaction rates are dependent on the respective concentrations of adsorbate and adsorbent which is given by the equation: R=[A]a[B]b………..

(1)

where k is the rate coefficient and a, b represent the order with respect to the species A and B [4]. The type of soil component can drastically affect the rate of metal sorption. Sorption reaction can involve physical sorption, outer-sphere complexation (electrostatic attraction), inner-sphere complexation (ligand exchange), and surface precipitation. Various kinetic models namely pseudo-secondorder, Elovich model and intra-particle diffusion models have been used to test their validity with the experimental adsorption data. From the kinetic study experiment the adsorption of Cr(VI) on the IOCS was found to be rapid as 90% adsorption took place within the initial 30 minutes as shown in Fig 3. A maximum of 47% of Cr(VI) was found to be removed after shaking for 60 minutes after which equilibrium was attained.

Fig 1: Effect of pH on adsorption of Cr (VI)

3.2 Impact of dosage on adsorption of Cr(VI) Dosage studies determined the optimum quantity of IOCS to be used as an adsorbent. Large number of particles might hinder the adsorption process. According to the experiment, 1 g IOCS comes out to be optimum dosage for maximum removal of Cr(VI) which has been used in subsequent batch analysis. Initially, Cr(VI) concentration reduces till 1gm and becomes which then increases till 1.25g as shown in Fig 2. Cr(VI) reduces by 40% after adding 1 g of IOCS. Increase in IOCS might reduce the available active sites of adsorption or increase desorption rate because of which there is a sudden reduction in Cr(VI) removal. 2

Fig 3: Kinetic Study ICICE-2013


3.3.1 Pseudo-Second-Order kinetic model

3.3.2 Elovich kinetic model

Pseudo second-order kinetic model determines the values of kad and qe which pseudo first order kinetic model doesn’t. The pseudo-second-order model is based on the assumption of chemosorption of the adsorbate on the adsorbents. This model can be represented in the following form:

The Elovich equation has been widely used in adsorption kinetics, which described chemical adsorption in nature. This model assumes that neither the inter-particle interaction nor desorption affects adsorption of Cr(VI) on IOCS at lower surface coverage [4]. The rate decreases with time due to an increase in surface coverage. This equation has also been commonly used to describe the sorption of pollutants from aqueous[5]. The Elovich equation can be written in the form:

dqt/dt = k2(qe-qt)2

(2)

Where, K2 is the second order rate coefficient (g/mg min) and depends on the applied operating conditions namely, initial metal concentration, pH of solution, temperature and agitation rate, etc. The validity of pseudo second order kinetics depends on the linearity of the curve plotted between time/adsorbed amount versus time which is shown in eq(3). t/qt = 1/(k2qe2) + (1/qe).t

(3)

The initial adsorption rate, h, adsorption capacity qe, and rate constant k2, can be determined experimentally from the slope and intercept of a plot of t/qt against t. The various linearized forms of pseudo second order are given in Table 1.

dqt/dt = a exp(-b qt)

(4)

where a represents the rate of chemisorptions at zero coverage (mg/(g min)) and b is the extent of surface coverage and activation energy for chemisorptions (g/mg), the above Eq. 2.24 can be simplified as qt = (1/b)*ln(ab) – (1/b)*ln(t)

(5)

where, constant a and b were calculated from the slope and intercept of plot qt versus ln(t) as in Fig 5.

TABLE 1 Parameters of pseudo-second order kinetics

The experiment conducted determines the amount of chemosorbtion on the sorbate. The graph shows to be best fitting with pseudo second order kinetics. The initial sorption rate (h) obtained from the experiment performed was found to be 0.19 whereas, the adsorption capacity qe and rate constant k 2 were 0.23 (g/mg) and 3.68 (g/mg min) respectively from the Fig 4. The linearity of curve has a good agreement between the amounts of Cr(VI) adsorbed per unit mass (qe) obtained from second order model.

Fig 5: Elovich plot Elovich equation helps determine the values of a and b which from the performed experiment come out to be 103227.4 (mg/(g min)) and 90.90 (g/mg) respectively. From the graph, the value r2 which is 0.784 which is lower than pseudo second order kinetics. All the above data hereby, support the chemosorption property of the IOCS and Cr(VI) particles. 3.3.3

Intra-particle diffusion model

The IOCS being a heterogeneous in terms of its composition as well as sizes therefore surface sorption and diffusion, transport mechanism was suspected. This theory suggests the diffusion on ions into pore spaces of adsorbent using suitable kinetic model[7]. The most-widely applied intraparticle diffusion equation is given: qt = Kidt0.5+ C

Fig 4: Plot for Pseudo second order adsorption kinetic ICICE-2013

(6)

Where Kid is the intra-particle diffusion rate constant (mg/ (mg min0.5)) and the intercept C, obtained by extrapolation of the linear portion of the plot of qt versus t0.5, back to the axis is taken to be proportional to the extent of the boundary layer thickness as shown in Fig 6. 3


4

Fig 6: Intraparticle diffusion 2

The value of r from the curve is 0.65 (Fig 6) which suggested the likelihood of intra-particle diffusion being a minor mechanism of adsorption. Therefore, the rate limiting steps for kinetic study can be attributed to intra-particle diffusion. 3.4

Adsorption Isotherm

The Freundlich adsorption model which is based on multilayer adsorption was found to fit better than the Langmuir isotherm which is based on monolayer adsorption[6]. The Freundlich adsorption isotherm model (adsorbed mass per mass of adsorbent (mg/g)) is expressed by a power law function of the solute concentration:

log qe = log Kf +1/n* logCe

(7)

where, qe is the adsorption of Cr(VI) in mg/g and Ce is the equilibrium concentration (mg/l). The plot of log qe versus log Ce (Fig 7) has a slope with the value of 1/n and an intercept magnitude of log Kf. Freundlich parameters log Kf and 1/n were found to be 1.92 and 0.89 respectively. The r2 obtained from freundlich adsorption isotherm modal was found to be 0.803.

CONCLUSION

Utilization of iron oxide coated sand (IOCS) was investigated for the removal of chromium in batch experiment from water as a low cost adsorbent for use in small community and household unit. The maximum percentage removal of Cr(VI) was found to be 47% with an initial concentration of 10 mg/ l. The optimum pH for the removal of Cr(VI) was found to be in the range of 5-6 and the dosage test at this pH suggested 1g in 50 ml of solution (1:50, IOCS: Solution). The adsorption kinetics study revealed that rapid sorption takes place at the initial 30 minutes where 90% of the adsorption occurs. Pseudo-second order kinetics was the best fit model for the study confirming chemosorption as the main adsorption mechanism. The intra-particle diffusion model exhibits moderate relationship in the sorption kinetics model, thus suggesting the rate limiting factor to be transport mechanism. Freundlich adsorption isotherm model was found to be the best fit model for the Adsorption isotherm.

REFERENCES [1] Rao, T.G., Rao, V.V.S.G., Ranganathan, K., Surinaidu, L., Mahesh, J., Ramesh, G. 2011. Assessment of groundwater contamination from a hazardous dump site in Ranipet. Tamil Nadu, India. Hydrogeology Journal 19: 1587-1598. [2] Chang, Y.Y., Lim, J.W., Yang, J.K. 2012. Removal of As(V) and Cr(VI)in aqueous solution by sand media simultaneously coated with Fe and Mn oxides. Journal of Industrial and Engineering Chemistry (18): 188-192. [3] Kumar, T. 2009. Effect of water quality matrix on chromium removal. M.Sc Thesis. UNESCO-IHE Institute for Water Education. Delf. Neitherland. [4] Gupta, S.S., Bhattacharyya, K.G. 2011. Kinetics of adsorption of metal ions on inorganic materials: A review. Advances in Colloid and Interface Science 162: 39–58. [5] Wu, F.C.,Tseng, R.L.,Juang, R.S. 2009. Characteristics of Elovich equation used for the analysis of adsorption kinetics in dye-chitosan systems. Chemical Engineering Journal 150: 366–373. [6] Hsu, J.C., Lin, C.J., Liao, C.H., Chen, S.T. 2008. Removal of As(V) and As(III) by reclaimed iron-oxide coated sands. Journal of Hazardous Materials 153: 817–826 [7] Du, G., Li, Z., Liao, L., Hanson, R., Leick, S., , Hoeppner, N., Jiang, W.T. 2012. Cr(VI) retention and transport through Fe(III)-coated natural zeolite. Journal of Hazardous Materials 221– 222: 118– 123

Fig 7: Plot of Ce (mg/l) Vs qe (mg/g) at eqilibrium 4

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Prediction of PM, SO2 & NOX - GLC’S from Point Source Emissions Using Air Modeling M.S.Priyanka Yadav, Ravi Kumar Gaurav, Jahnavi.B, Dr.G.Dasartha Ram Abstract— Air quality assessment by integrating measurement techniques and modeling tools is a crucial element in pollution mitigation. The air modeling tools are routinely used in the environmental impact assessments, risk analysis, emergency planning, and source apportionment studies. Recent strategies for air pollution control in industries have largely neglected the emission reduction measures which are the prime polluting sources. To accomplish this, various air dispersion models have been developed and used worldwide so far for different applications under different scenarios. The Gaussian plume model is a standard approach for studying the transport of pollutants due to turbulent diffusion and advection by the wind. Applications of such models have been made mandatory. It has therefore assumed greater importance for the academicians, consultants and regulatory authorities. In this study, the AERMOD (the American Meteorological Society/Environmental Protection Agency Regulatory Model Improvement Committee’s Dispersion Model, version 7.0.3 Gaussian dispersion models selected to predict the ground level concentrations (GLC’s) of Particulate Matter (PM) μg/m3, sulphur dioxide (SO2) μg/m3, and oxides of nitrogen (NOx)- μg/m3 from point source emissions will be investigated in the study area (10 Km buffer) from the periphery of the industrial area chosen for case study. In point source emissions, the stacks are subjected to plume rise which again is dependent on force of buoyancy and momentum. The higher is the plume rise or stack, the lesser will be ground level concentrations (GLC’s).The emissions when released into the atmosphere are subjected to transportation, dispersion, transformation, and fall out and wash out and finally reach the ground level at a particular distance and concentrations. The relationship between the source of emissions and its magnitude with the ground level concentrations (GLC’s) at receptor points is governed by air dispersion models which take into the account by the source strength, plume rise, atmospheric stability, mixing height, wind velocity, terrain and other meteorological conditions. The comparison between the predicted and field sampled downwind concentrations for PM, SO2 & NOX (μg/m3) will be carried out in this study to predict the average downwind ground level concentrations (GLC’s). Index Terms— AERMOD, downwind, Gaussian plume model, ground level concentrations (GLC’s),PM, point source emissions, receptor points, NOX, SO2.

—————————— ——————————

ir pollution has long been recognized as a brain storming issue worldwide. The onset of technological and scientific innovations in various fields and diverse activities of human race for its elegance have put extra load on the atmosphere by way of releasing air pollutants like particulate matter (PM10, PM2.5), sulphur dioxide (SO2), oxides of nitrogen (NOx), carbon monoxide (CO), unburned hydrocarbon (HC), hydrogen fluoride (HF) and other organic as well as inorganic pollutants including trace metals responsible for causing health consequences[1]. Entry of pollutants into the atmosphere occurs in the form of gases or particles. Continuous mixing, transformation and trans-boundary transportation of air pollutants make air quality of a locality unpredictable. The growth of population, industry and number of vehicles and improper implementation of stringent emission standards make the problem of air pollution still worse. According to WHO esti-mates, 4-8 per cent of deaths occurring in the world are related to air pollution, whereas a

2005 estimate from WHO indicates that air pollution in major Southeast Asian and Chinese cities ranks among the worst in the world and contributes to the deaths of about 500,000 people annually[2]. Rapid industrialization and vehicular traffic especially in the urban areas of India is a great threat to air quality. Emissions from industrial stacks are one of the major sources of air pollution in recent epoch [3]. Dispersion estimates are determined by using distribution equations and/or air quality models. Gaussian plume equation is simple and widely used to identify the variation of pollutant concentrations away from the centre of the plume. This distribution equation determines ground level pollutant concentrations based on time-averaged atmospheric variables (e.g. temperature, wind speed).One of the Dispersion Model developed base on Gaussian plume equation was AERMOD (The American Meteorology Society-Environmental Protection Agency Regulatory Model) which is recommended for air quality simulations by the US EPA (2005).These models stand for the state-of-thescience in air quality modeling and provide powerful features to simulate various modeling situations and considerations.

•

M.S.Priyanka Yadav is currently pursuing MTech in environmental engineering in Manipal University, India, PH09052882298. E-mail: [email protected]

2 METHODOLOGY

Ravi Kumar Gaurav is currently working as Sr.Energy Engineer in EFS Facilities Services(INDIA)Pvt.Ltd.India, PH09884010435. E-mail: [email protected]

Proposed site is a rural region which falls under tumkur district of Karnataka state. It is chiefly elevated land. This region has emerged as a hub to industrial advancement. This

1

INTRODUCTION

A

•

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2.1 Study Area

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industrial area is located at about 20 Km from Tumkur and 70-75 km from Bangalore. Project Site is situated adjacent to NH 4.

2.2 Meteorological Data AERMOD model requires hourly surface data values for wind speed, wind direction, temperature, relative humidity and cloud cover. Both data files for the surface and profile files were then used to generate the meteorological file required by the AERMOD dispersion model using the AERMET meteorological pre-processor programme. This AERMET programme has three stages to process the data. The first stage extracts meteorological data and assesses data quality through a series of quality assessment checks. The second stage merges all data available for 24-hour periods and writes these data together in a single intermediate file. The third and final stage reads the merged meteorological data and estimates the necessary boundary layer parameters for dispersion calculations by AERMOD. Table 1 : Freqency Distribution for post-monsoon season (0-24 hours)

The estimation and evaluation of atmospheric emissions from proposed activity involves a number of scientific inputs. Emissions from each activity vary from one another greatly with respect to characteristics and quantity of emissions; controlling factors. The screening models were used for designing the Ambient Air Quality Monitoring Network and the monitoring stations were selected based on the occurrence of maximum pollutant concentrations under expected micro meteorological conditions during study period of post-monsoon season and other criteria as described earlier.

2.3 Emission Sources The emission sources are mainly the diesel generator set (DG SET). Their details are as given below.

The meteorological pre-processed data was used to determine its corresponding Wind Rose plot. The Wind rose shows the most predominant wind direction blows from which the wind blows. This means that the emissions plume will be dispersed mainly in that direction. The wind speed and direction for post-monsoon season year 2012 were recorded on continuous basis during study period at proposed site location. The percentage frequencies of occurrence of various wind speed classes in different directions were computed from recorded data on 24 hourly bases and presented in the form of Wind Rose plot (see Figure 1). The wind rose diagram shows the predominant winds are mainly flowing from East, with the secondary wind direction being from the West. Calm conditions are observed for 10.78% of the total time. The wind data were further analyzed to obtain predominant wind direction and average wind speed for 0 to 24 hrs and the same data were used in prediction of impacts on air environment. 6

2.4 AERMOD Dispersion Modeling Hill height scales as well as terrain elevations for all receptor loca-tions AERMOD View dispersion model was developed by Lakes Environmental software. It is used extensively to assess pollution concentration and deposition from a wide variety of sources. It is a regulatory steady-state plume modeling system with three separate components: AERMOD View (AERMOD Dispersion Model), AERMAP (AERMOD Terrain Pre-processor), and AERMET (AERMOD Meteorological Pre-processor). The AERMOD model includes a wide range of options for modeling air quality impacts of pollution sources. Some of the modeling capabilities of AERMOD include the following: •

The model is used to analyze primary pollutants.

•

Source emission rates can be treated as constant or may be varied by month, season, hour-of-day, or other optional periods of variation. These variable emission ICICE-2013


rate factors may be specified for a single source or for a group of sources. For this project all emission rates were treated as constant. •

•

•

•

•

The model can account for the effects of aerodynamic downwash due to buildings that are nearby point source emissions. Receptor locations are specified as gridded and/or discrete receptors in a Cartesian or polar coordinate system. Site location involving elevated terrain,the AERMAP terrain pre-processing program is incorporated into the model to gene ate. The model contains algorithms for modeling the effects of settling and removal (through dry and wet deposition) of large particulates and for modeling the effects of precipitation scavenging for gases or particulates. AERMOD requires two types of meteorological data files, a file containing surface scalar parameters and a file containing vertical profiles. These two files are provided by AERMET meteorological pre-processor programme.

The graph is plotted against the Concentration Vs Distance, where the minimum pollutant concentration was less than 14 μg/m3 and while for a period of time the concentration has increased from 14μg/m3 to 24μg/m3 at 1770m and hence the highest concentration is predicted as 24 μg/m3 at 1770m distance.

3.2 Predicted GLC for SO2

3 RESULTS AND DISCUSSIONS 3.1 Predicted GLC for NOX

The minimum pollutant concentration was less than 0.70 μg/m3 and while for a period of time the concentration has increased from 0.70μg/m3 to 1.2μg/m3 at 1770m and hence the highest concentration is predicted as 1.2 μg/m3 at 1770m distance. ICICE-2013

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3.3 Predicted GLC for PM

4 CONCLUSION This paper presents predictions of air pollutants (SO2, NOx and PM) emitted from a proposed industrial area to be constructed 20 km North-North-West of Tumkur District, Karnataka .AERMOD and local meteorological data were used to predicted concentrations of major air pollutants in the vicinity of the project in order to ensure compliance with the Indian standards (CPCB, 2009) for ambient air quality. Our findings indicate that after the implementation of the proposed project, concentrations of air pollutant are found to be well below the permissible CPCB (Central Pollution Control Board) Standards for ambient air quality. Therefore, the proposed activity is not likely to have any significant adverse impact on the air environment in the vicinity of the proposed project. However, the SO2 concentration is expected to be high due to the NH-4.which is adjacent to the project area. Implementing proper Environmental Management Plan along with mitigation measures like Water sprinklers, and trees planting, around the industrial area can minimize the pollution and protect the environment from the adverse effects.

REFERENCES

The minimum pollutant concentration was less than 1.6 μg/ m3 and while for a period of time the concentration has increased from 0.6 μg/m3 to 0.0028 μg/m3 at 1770m and hence the highest concentration is predicted as 0.0028 μg/ m3 at 1770m distance. Table 3 summarizes the maximum predicted concentrations for the proposed study area and their comparison with the National Ambient Air Quality Standards-Central Pollution Control Board (NAAQS – CPCB (2009)). The results revealed that the maximum predicted ground level concentrations from the proposed sources of the industrial area did not exceed the Significant Impact Concentrations. Additionally, the maximum predicted ground level concentrations from the proposed industrial area sources and the baseline concentrations (as re-commended in the Air Quality Guideline Document) were all less than the NAAQS.

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[1] Avnish Chauhan and Maynak Pawar, “Assessment of ambient air quality status in Urbanization,Industrilization and Commercial centers of Uttarakhand(India)”, vol 3, no. 7, pp. 85-94, 2010.( Newyork Science Journal) [2] Abhimanyu Singh, Jamshed Zaidi , Shree Ganesh, Swati Gupta, Nitin P.Varma and Pradip K.Maurya, “Monitoring of Air Pollution and their AQI status vis-à-vis Health hazards with the New Approaches for the Granite Mining Terrains of the Jhansi Region in Bundelkhand Massif,India,” vol. 3, no. 2, pp. 41-68, Jun. 2012. (International Journal of Advanced Scientific Research and Technology) [3] Ankita Shukla, Rajeev Kumar Mishra and Dr.M.Parida “Estimation of Composite Air Quality Index for Lucknow,” vol. 4, no. 7, pp. 45-56, Dec. 2010. (Institute of Town Planners, India Journal) [4] Joshi.P.C and Semwal Mahadev, “Distribution of Air pollutants in Ambient Air of district Haridwar(Uttarakhand),India:A Case study after establishment of State Industrial Developmental Corpporation,” vol. 2, no. 1, pp. 237-258, Sep. 2011. (International Journal of Environmental Sciences) [5] Panda.B.K and Panda.C.K, “Estimation of Ambient Air Qualityy Sta-tus in Kalinganagar Industriual Complex in the district of Jajpur of Odisha,” vol. 3, no. 2, pp. 767-775, Sep. 2012. (International Journal of Environmental Sciences) [6] CPCB (2003), “Guidelines for Ambient Air Quality Monitoring” Report Under Central Pollution Control Board, Ministry of Environment & Forests. [7] Gufran B., Ghude D. S. and Deshpande A. (2010), Scientific Evaluation of Air Quality Standards and Defining Air Quality Index for India, Indian Institute of Tropical Meteorology Research Report No. Rr-127 [8] Dayal H. V. and Nandini S. N. (2000), Vehicular Emissions and Ambient Air Quality in Bangalore City. Poll. Res., 19: 205-209. [9] Lakes Environmental Software. 1996-2005 User’s Guide for ISCAERMOD View. [10] Isikwue B. C., Tsutsu O. O. and Utah E. U. (2010), Estimation of Horizontal Pollution Potential and Mean Ground Level Concentrations of Air Pollutants from an Elevated Source over Makurdi, Nigeria Using Wind Data. International Journal of the Physical Sciences, 5: 2402-2410. [11] CPCB, “National Ambient Air Quality Standards,” 2009. http:/ /www.cpcb.nic.in/National_Ambient_Air_Quality_Standards.php [12] WHO. WHO guidelines for indoor air quality: selected pollutants. WHO Regional Publications 2010; Europe ICICE-2013


Heavy Metal Removal from Water using Moringa oleifera Seed Coagulant and Double Filtration Ravikumar K, Prof.Sheeja A K Abstract— The quality and accessibility of drinking water are of paramount importance to human health. Drinking water may contain disease-causing agents and toxic chemicals and to control the risks to public health, systematic water quality monitoring and surveillance are required. Thousands of chemicals have been identified in drinking water supplies around the world and are considered potentially hazardous to human health at relatively high concentrations. Heavy metals are the most harmful of the chemical pollutants and are of particular concern due to their toxicities to humans. Moringa oleifera seed acts as a natural coagulant, adsorbent and antimicrobial agent. It is believed that the seed is an organic natural polymer. The coagulation mechanism of the Moringa oleifera coagulant protein has been described as adsorption, charge neutralization and interparticle bridging. It is mainly characteristic of high molecular weight polyelectrolyte. Analysis of the heavy metals cadmium, copper, chromium, and lead were performed before and after treatment of water with Moringa oleifera seed coagulant. The results showed that Moringa seeds were capable of adsorbing the heavy metals tested in some water samples. The percentage removal by Moringa seeds were 95 % for copper, 93 % for lead, 76 % for cadmium and 70 % for chromium. In this study the advantage of proposing a sequential process using coagulation with Moringa oleifera seed and double filtration (Up-flow roughing filtration followed by rapid filtration) for the removal of heavy metals from water is analysed. Index Terms—Adsorption, Coagulaion, Double filtration, Heavy metals, Moringa oleifera, Rapid filters, Roughing filters, Turbidity.

—————————— —————————— Literature survey reveals that Moriga oleifera plant is the most inexpensive credible alternative for providing good he need for simple, reliable and effective method of water nutrition and to cure and prevent a lot of diseases [1]. treatment led to the application of plant materials, Aqueous extract of Moringa oleifera showed strong and including seed coagulants of Moringa oleifera. The superior antibacterial activity against bacterial strains such Moringa oleifera (MO) tree grows in tropical and subtropical as Staphylococcus aureus, Bacillus subtilis, Eschreiashia coli regions around the world and its seeds have been used in and Pseudomonas aeruginosa [2]. Moringa oleifera is the drinking water treatment in small scale in Sudan and India for best natural coagulant that can replace aluminium sulphate generations. The coagulant in the seed is a protein that acts as a (Alum) which is widely used all around the world [3]. Acid cationic polyelectrolyte. The soluble particles in the water extract of natural polyelectrolyte Moringa oleifera seed is attaches to the active agent that binds them together creating very effective as a coagulant for removal of fluoride from large flocs in the water. Previous studies indicate that Moringa water [4]. Removal of turbidity and hardness can oleifera is an efficient coagulant for the removal of turbidity in simultaneously be done by using Moringa oliefera seed both water and waste water treatment. extract with 1.0M sodium chloride solution (MO-Nacl) [5]. The Moringa oleifera is one of the natural coagulants that Moringa oliefera seed extract against E. coli by TVC method have been tested over the years as an alternative to the use reduced >99.9% E.coli count [6]. Efficient reduction (80.0% of inorganic and synthetic coagulants. Disadvantages of to 99.5%) of high turbidity produces an aesthetically clear inorganic and synthetic coagulants are it causes Alzheimer’s supernatant, concurrently accompanied by 90.00% to disease and similar health related problems, reduction of 99.99% bacterial reduction [7]. pH, high costs, production of large sludge volume and low Distilled water extract of Moringa oleifera seed powder efficiency in coagulation of cold water. Moringa oleifera achieved 90 to 95% sedimentation of the suspended particles has potential in water treatment- as a coagulant, a soften in underground and surface water samples [8]. Increased agent and bactericidal agent. Advantages of Moringa oleifera dose of Moringa oleifera seed powder showed reduction in as a natural coagulant are its low cost, produces lesser volume turbidity, TDS, TS, hardness, chlorides, alkalinity, acidity, of biodegradable sludge, and it does not affect the pH of the MPN and SPC in ground water samples [9]. Moringa oleifera water. Moringa oleifera is a sustainable, low cost, locally available, simple, reliable, acceptable, eco-friendly and as a coagulant agent provided significant results, which household level point of use water treatment coagulant/ justify its use as an alternative coagulant in the process of technology most suitable for developing countries where coagulation/flocculation of produced water (which is the major population use contaminated water for drinking waste that has the highest volume during the production and purposes. exploration of oil) [10]. Shelled blended Moringa oleifera seed as a biosorbent removes C.I. Acid Orange 7 from the • Ravikumar K is currently pursuing M.Tech degree program in aqueous systems [11].The percentage removal by Moringa Civil Engineering in College of Engineering Trivandrum, India, oleifera seeds were 90% for copper, 80 % for lead, 60 % for PH- 919349495386. E-mail:[email protected]. cadmium and 50% for zinc and chromium [12].Coagulation • Prof.Sheeja A K is currently working as Professor in Civil - flocculation process using Moringa oleifera seeds after Engineering in College of Engineering Trivandrum, India, PHoil extraction (MOAE) as a natural coagulant presents a 919497453986. Email:[email protected]. 1 INTRODUCTION

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viable alternative for the treatment of Palm Oil Mill Effluent (POME) [13].The efficiency of coagulation-photooxidation processes for removing color from a landfill leachate by using Moringa oleifera coagulation as a pre-treatment was effective[14]. The operation of the Hindustan Coca Cola Beverages Private Limited (HCBP) Plant has polluted drinking water by its careless and irresponsible disposal of sludge and treated effluents. Particularly hard hits are the dalits, tribals, women and chidren of the sorrounding area. As the water supply deteriorated, the women have to travel about 5 kms to fetch drinking water. Serious damage caused by the contamination of aquifers and springs had adversely affected agriculture yield and productivity. The water in Plachimada and sorrounding area is contaminated with copper, cadmium, lead and chromium, more than the admissible level by the World Health Organisation. The Kerala Agricultural University has found that the fodder, milk and egg samples collected from Plachimada area contain the above elements at toxic levels. In 2003, the district medical officer advised the people of Plachimada that their water was polluted and unfit for consumption. Cadmium is more toxic than lead and chromium. Cadmium and certain cadmium compounds are listed by International Agency for Research on Cancer (IARC) as carcinogenic. Cadmium at extreme levels causes itai-itai disease and at low levels over prolonged periods causes high blood pressure, sterility among males, kidney damage and flu disorders. Exposure to chromium (VI) by the inhalation route may cause lung cancer (World Health Organisation 2004). Copper is both an essential nutrient and a drinking water contaminant. Recent studies have shown effects of copper in drinking water on the gastrointestinal tract, carriers of the gene for Wilson disease and other metabolic disorders. The toxic effects of lead include nervous system disorders, anemia, decreased hemoglobin synthesis, cardio vascular diseases and disorders in bone metabolism, renal function and reproduction. Concentrations of heavy metals are high in the Periyar river near the industrial estate and the concentration is high in pre monsoon period. The chemical factories discharges their effluents to Periyar river and it eventually reach in to the Cochin estuary. The flow of water discharged through the river is very low in pre monsoon period, which cause the high concentration of metals in lake and river. In Muvattupuzha river the heavy metal concentration is high near the news print factory. At present, water in the open wells in the area is unfit for drinking. Different technologies may be applied to diminish these levels in water for consumption. This study was an effort to investigate the water treatment potential of indigenous plant coagulant Moringa oleifera seeds with double filtration for removal of heavy metals. The objectives of the study were 1. To identify a sustainable, low cost, locally available, simple, reliable, acceptable, eco-friendly, household level point of use water treatment technology most suitable for rural population of developing countries 10

2. To find a process that allowed efficient removal of heavy metals from aqueous systems. 3. To evaluate the up-flow roughing filtration process followed by rapid filtration as a suitable method for the separation of the flocs formed using the Moringa oleifera seed coagulant. 4. To determine the removal efficiency of various heavy metal concentrations in water using Moringa oleifera coagulation and double filtration.

2 MATERIALS AND METHODS 2.1 Preparation of MO Seed Powder Dry MO pods were collected from Varkala, Trivandrum. Pod shells were removed manually; kernels were grounded in a domestic blender and sieved through 600micro meter stainless steel sieve..

2.2 Aqueous Extract Aqueous extract was prepared by using 200ml of distilled water and 25 g of MO seed powder, mixed by a magnetic stirrer for 60 minutes and settled for 20 minutes. Moringa oleifera aqueous extract is finally filtered through 20μm paper filter

2.3 Coagulant Activity Test Jar test was conducted to determine the effective dosage of coagulant to reduce the heavy metals of the samples. The standard procedure was 1 min of rapid mixing (120 rpm) followed by 15 minutes of slow mixing (30rpm) for flocculation and 60 minutes of settling.

2.4 Multistage drinking water filtration By providing roughing filter pretreatment, suspended solids are decreased. Rapid sand filtration is still a viable method of water treatment most suitable for raw water sources with turbidity and suspended solids. Multistage filtration has been shown to be an efficient and effective drinking water treatment technique for source water with high turbidity, organic matter, and suspended solids.

2.4.1Filtration test with roughing filter In vertical-flow roughing filters the water to be treated flows in sequence through the three filter compartments filled with coarse, medium and fine filter material. The size of the three distinct filter material fractions is generally between 25 and 3 mm, and graded, for example, into fractions of 25-16mm, 16-8mm and 8-3mm. Roughing filtration was conducted directly after the coagulation and flocculation processes with Moringa oleifera and separates the suspended solids. Vertical-flow roughing filter was operated at 0.3 to 1.0 m/h filtration rates. The separated solids, which accumulate mainly in the coarse filter fraction next to the filter bottom, can be easily flushed out with the water stored in the filter. Therefore, the use of upflow roughing filter in layers was used.

2.4.2 Filtration test with rapid sand filter In rapid sand filters the water to be treated flows in sequence through the three filter compartments filled with coarse, medium and fine filter material. The size of the ICICE-2013


three distinct filter material fractions is generally between 50 and 0.5 mm, and graded, for example, into fractions of 25-50mm, 13-25mm and 0.5-1mm. Rapid sand filtration was conducted directly after the roughing filtration and separates the last remaining flocs that failed to disappear during roughing filtration. The filtration rate for a rapid filter is 5-10 m/h. 2.4.3Double Filtration Experiments Jar tests were carried out in the following conditions: 1 minute rapid mixing and 10 minutes slow mixing. An upflow roughing filtration stage was chosen because it is a process with a high efficiency in the removal of light flocs. As a second stage a conventional rapid filter was adopted. The washing of the roughing filter was carried out through lower drainage, and the washing of the rapid filter was counter current. The bed of the upflow gravel roughing filter was made up of three layers of gravel of different granule measures.

3 RESULTS AND DISCUSSIONS A.

Coagulation activity test results of synthetic water samples containing heavy metals

Coagulation- flocculation was done using shelled blended, oil extracted and crude extract of Moringa oleifera seed powder. These coagulants were extracted by using a standard preparation method.. Optimum doses of 2 g/L coagulants were used for different water samples containing heavy metals concentrations of 5 mg/l. The optimum dosage is the minimum dosage of coagulant corresponding to the removal of heavy metals present in the water samples. At optimum dosage of 2 g/L of coagulant, the final heavy metal concentrations reduced considerably, but the turbidity increases in all four synthetic heavy metal water samples as shown in Table 1. Table 1. Final Heavy metal concentrations and the respective increase in turbidity levels after coagulation treatment with filtrated Moringa oleifera coagulant Heavy metals Final Heavy with initial metals concentration concentration of 5 mg/l in mg/L

Removal efficiency in %

Final turbidity

Copper

0.25

95

73

Lead

0.35

93

78

Cadmium

1.2

76

86

Chromium

1.5

70

92

B. Test results of synthetic heavy metal water samples after upflow roughing filtration. Samples of water collected from the outlet of roughing filter were used for analyzing the turbidity and heavy metals. Table 2 represents the results of turbidity removal from treated water with various heavy metals of concentration 5mg/l, after upflow roughing filtration. An up-flow roughing filtration stage was chosen because it is a process with a high efficiency in the removal of light flocs. The bed of the upflow gravel roughing filter was made up of three layers of gravel of different granule measures. ICICE-2013

C.

Test results of synthetic heavy metal water samples after upflow roughing filtration and rapid filtration (double filtration)

Samples of water collected from the outlet of rapid filter were used for analyzing the turbidity and heavy metals concentrations. Table 2 represents the results of turbidity removal, after upflow roughing filtration and rapid sand filtration (double filtration). Table 2. Turbidity (NTU) after upflow roughing filtration and double fitration Heavy metals with initial concentration of 5 mg/l

Turbidity after upflow roughing FiltrationNTU

Turbidity after double FitrationNTU

Copper

11

2

Lead

15

2

Cadmium

16

3

Chromium

19

3

The combined coagulation and double filtration process is an alternative for heavy removal, since the coagulation process is effective in removing metal ions and double filtration complements the process by reducing the turbidity to the limits. In this study, the double filtration step was performed just after coagulation in order to remove colour and turbidity caused by the addition of Moringa oleifera coagulant, so as to meet the standards for water potability. Therefore, the utilization of the combined treatment allows for the production of fully treated water. It is known that the filtration process is not efficient for the removal of metal ions, which indicates that heavy metals retention was mainly due to the process of coagulation with the coagulants obtained from Moringa oleifera. Thus, it is more likely that the mechanism of interaction between the Moringa oleifera proteins and heavy metals was ion adsorption and charge neutralisation.The MO seed powder has been termed as potential heavy metal removing agent due to its oxygen and nitrogen donating carboxylate and amino groups.MO seed powder extraction with salt increased the removal efficiency. The adsorption of metals using MO is limited to the adsorption surface. This is because MO is a cationic polyelectrolyte of short chain and low molecular weight. The mechanism that brings about adsorption of heavy metals is through the positive metal ions that forms a bridge among the anionic polyelectrolyte and negatively charged protein functional groups on the colloidal particle surface. There is formation of complexes with the heavy metals and the organic matter of MO seeds such as proteins. Due to hydrophilic character, several hydrogen bonds are formed among polyelectrolyte and water molecules. Polyelectrolyte coagulant aid have structures consisting of repeating units of small molecular weight forming molecules of colloidal size that carry electrical charges or ionisable groups that provide bonding surface for the flocs. Adsorption describes attachment of ions and molecules from seed protein by means of specific mechanism. Metal ions in coagulation react with proteins and destroy them in water. Metal adsorption occurs due to the high protein content of the seeds. The flocculation activities of MO seeds are based on the electrostatic patch 11


charge mechanism. Studies have shown that seeds have the capability to adsorb metal cations and attract highly toxic compounds.

4 CONCLUSION

[7] Michael Lea. 2010. Bioremediation of Turbid Surface Water Using Seed Extract from Moringa oleifera Lam. (Drumstick) Tree, Wiley Interscience (www.interscience.wiley.com), Current Protocols in Microbiology (February 2010), 1G.2.1-1G.2.14.

Moringa oleifera is an environmentally-friendly natural coagulant most suitable for the treatment of water containing undesirable heavy metal concentrations. Based on the experimental test results; the following conclusion can be drawn.

[8] A.O Oluduro and B.I Aderiye. 2007. Impact of Moringa oleifera Seed Extract on the Physicochemical Properties of Surface and Underground Water, International Journal of Biological Chemistry 2007, 1(4): 244-249.

1. The optimum dosage of Moringa oleifera aqueous extract for synthetic water samples containing heavy metal concentrations of 5mg/L was 2g/L and the removal efficiencies were 95%, 93%, 76% and 70% of copper, lead, cadmium and chromium respectively.

[9] Mangale Sapana M., Chonde Sonal G. and Raut P. D. 2012. Use of Moringa oleifera (Drumstick) seed as Natural Absorbent and an Antimicrobial agent for Ground water Treatment, Research Journal of Recent Sciences Vol. 1(3) (March 2012), 31-40.

2. The process of up flow roughing filtration followed by rapid filtration is suitable for the separation of the flocs formed using Moringa oliefera seed coagulant.

[10] Santana C. R., a Pereira D. F., Sousa S. C. S. N., Cavalcanti E. B and Silva G. F. 2010. Evaluation of the Process of Coagulation / Flocculation of Produced Water using Moringa oleifera Lam. as Natural Coagulant, Brazilian Journal of Petroleum and Gas | v. 4 n. 3 | p. 111-117 | 2010 | ISSN 1982-0593.

3. It is an eco-friendly technology that is economically more advantageous than other treatment alternatives. 4. In accordance with the above conclusions, it is suggested that aqeous extract of Moringa oleifera seed powder treatment with coagulation and flocculation followed by double filtration (roughing filters followed by rapid filtration) is considered in the event of expansion or construction of small scale waterworks, presuming that an adequate amount of plantations are established.

REFERENCES [1] Ritu Paliwal, Veena Sharma and Pracheta. 2011.A Review on Horse Radish Tree (Moringa oleifera): A Multipurpose Tree with High Economic and Commercial Importance, Asian Journal of Biotechnology,Vol.3(4), pp.317-328. [2] Abdulmoneim M. Saadabi and I.E.Abu Zaid. 2011. An In vitro Antimicrobial Activity of Moringa oleifera L. Seed Extracts against Different Groups of Microorganisms, Australian Journal of Basic and Applied Sciences, Vol. 5(5).pp.129-134. [3] Eman N. Ali, Suleyman A. Muyibi, Hamzah M. Salleh, Mohd Ramlan M. Salleh and Md Zahangir Alam. 2009. Moringa oliefera Seeds as a Natural Coagulant for Water Treatment, Thirteenth International Water Technology Conference, IWTC 13 2009, Hurghada, Egypt,pp.163-168. [4] Vivek Vardhan.C.M and Karthikeyan.J. 2011. Removal of Fluoride from Water using Low Cost Materials, Fifteenth International Water Technology Conference 2011 IWTC15, Alexandria, Egypt. [5] Muhammad Ridwan Fahmi, Nor Wahidatul Azura Zainon Najib, Pang Chan Ping and Nasrul Hamidin. 2011. Mechanism of Turbidity and Hardness Removal in Hard Water Sources by using Moringa oleifera, Journal of Applied Sciences, Vol.11 (16), pp.2947-2953. [6]

12

Jadhav Swapnali Mohan, Bipinraj N K and Milind R Gidde. 2008. Moringa oleifera - Household Alternative Coagulant for Water Treatment, Paper for National Conference on Household Water Treatment Technology (July 2008) at Hindustan College of Sc. And Tech. Farah, Mathura.

[11] Reza Marandi and Seyedeh Marjan Bakhtiar Sepehr. 2011. Removal of Orange 7 Dye from Wastewater Used by Natural Adsorbent of Moringa oleifera Seeds, American Journal of Environmental Engineering 2011, 1(1): 1-9. [12] Vikashni Nand, Matakite Maata, Kanayathu Koshy and Subramanium Sotheeswaran. 2012. Water Purification using Moringa oleifera and Other Locally Available Seeds in Fiji for Heavy Metal Removal, International Journal of Applied Science and Technology Vol. 2 (May 2012), No. 5. [13] Zalina Othman, Subhash Bhatia and Abdul Latif Ahmad. 2008. Influence of the Settleability Parameters for Palm Oil Mill Effluent (POME) Pretreatment by Using Moringa oleifera Seeds as an Environmental Friendly Coagulant, International Conference on Environment (ICENV 2008). [14] Salwa Mohd Zaini Makhtar, Mahyun Ab Wahab, Mohammad Tamizi Selimin and Norsyazwani Che Mohamed. 2011. Landfill Leachate Treatment by a Coagulation–Photocatalytic Process, International Conference on Environment and Industrial Innovation (IPCBEE) vol.12 2011 © (2011) IACSIT Press, Singapore. [15] R. Sowmeyan, J. Santhosh and R. Latha. 2011. Effectiveness of Herbs in Community Water Treatment, International Research Journal of Biochemistry and Bioinformatics (ISSN-2250-9941) (December 2011), Vol. 1(11) pp. 297-303. [16] Puthenveedu Sadasivan Pillai Harikumar, Chonattu Jaseela and Tharayil Megha. 2012. Defluoridation of water using biosorbents, Water Quality Division, Centre for Water Resources Development and Management, Kozhikode, India, Natural Science 2012, Vol.4, No.4, 245-251. [17] V. Krishna Veni and K. Ravindhranath. 2012. Removal of chromium (VI) from polluted waters using powders of leaves or their ashes of some herbal plants, Journal of Experimental Sciences 2012, 3(4): 01-09. ICICE-2013


An Experimental Study on Duckweed For Improving Pond Water Quality S.Vanitha, NVN.Nampoothiri, C.Sivapragasam, Anitha Menon.M Abstract— This paper deals with the laboratory experiments on the case studies prepared using pond water, ‘Duckweed’ and a toxic herbicide ‘Glyphosate’. The water used in this study was collected from ‘Mariyan Oorini’ pond, ‘Sattur’, ‘Virudhunagar’ district of Tamilnadu. The experiments were performed on five cases for 10 days and the various physiochemical parameters such as DO (dissolved oxygen), temperature, Nitrate, Ammonia, Phosphate, Turbidity, pH were analysed. These results were very much useful in understanding the removal efficiency of pollutants from the water sample by Duckweed. This study is also helpful to understand the effect of Glyphosate dosage on Duckweed growth. Index Terms — Ammonia, Duckweed, Glyphosate, Nitrate, Phosphate, Pond water, Removal efficiency.

—————————— ——————————

1. INTRODUCTION

P

onds and lakes are meant for storing rain water in order to fulfill the basic human demands such as domestic and irrigation needs. In olden days ponds were maintained by the respective village people but nowadays, ponds are considered as a dumping site for solid wastes & drainage water. Most of the ponds are polluted due to human intervention and lack of public awareness. Unfortunately, ponds have got transformed as a sink for spreading harmful diseases and to create a polluted unhealthy living environment. Due to this, incident of water borne diseases such as Chikungunya, Dengue, Malaria, etc. has increased considerably over the recent years.

Since these types of ponds contain less amount of water as compared to a river or stream, affording a treatment unit in every nook and corner of the town is not practically possible due to economic constraints. Sangeeta Dhote [15], stated that several water treatment technologies are available currently which consume large economic resources and are also highly power consuming as well as non eco friendly. Here, the phytoremediation has a major role in tackling the problem. Phytoremediation is one of the serious efforts towards sustainability. According to Anima Priya [1], the macrophyte based water treatment systems have several potential advantages compared with conventional treatment systems. Nayyef M. Azeez [10] conducted studies using Duckweed on waste water from ‘Basrah Oil Refinary’ and proved that Duckweed plant can be successfully used for waste water pollutant removal. J.M Dalu [8] concluded that significant reduction of parameters to within permissible limit was obtained except for COD, BOD and turbidity 60% of reduction were observed with the addition of Duckweed in stabilization ponds. ————————————————

• Mrs.S.Vanitha is currently working as Assistant Professor-II in Department of Civil Engineering, Kalasalingam University, India, PH-09442947299. E-mail: [email protected]. • Dr.NVN.Nampoothiri is currently working as Associate Professor in Department of Civil Engineering, Kalasalingam University, India, PH- 09842335165. E-mail: [email protected] • Dr. C.Sivapragasam is currently working as Senior Professorand Head, Department of Civil Engineering, Kalasalingam University, India, PH-09003613130. E-mail: [email protected]. • Ms.Anitha Menon. M is currently pursuing masters degree program in environmental engineering in Kalasalingam University, India, PH-9496456322. E-mail: [email protected]. ICICE-2013

Olah.V et al. [12], conducted studies on two species of Duckweed and observed that the physiological responses of the different species to same ambient concentration of a toxic chemical (hexavalent Cr VI) is in different manner. Anong Phewnil et al. [3], concluded that the growth rate of Lemna Perpusilla Torr. reduced when atrazine concentration were present in the range of 250 -32000 μg/l within 24 hours. InHwa Chang et al. [6], studies concluded that Duckweed uses different adaptive mechanism in order to counter balance high doses of a particular toxicant like NaCl. John. R et al. [7], conducted experiments on Duckweed and found that Duckweed growth rate increased at a concentration of 1, 10 and 20 mg/l of Cd and Pb while a reduced growth rate was observed in 30 and 40 mg/l concentration. Harini Santhanam [5] concluded that the Fuzzy quality index is better than Carlson’s trophic state index for trophic status analysis. R. Sooknah [13] concluded that pollutant removal in water hyacinth system depends on the nutrient assimilative capacity of plant and the biochemical / physiochemical process taking place within the system. Thongchai Kanabkaew [16] concluded that as the HRT increases, the removal of BOD is increased. According to Nihan Ozengin [11], the maximum removal of the Total Phosphate, nitrate and COD by Duckweed (Lemna minor.L) occurs at 360minutes and the maximum removal of Total nitrate was observed at 1440 minutes for industrial and municipal waste water. M.D.Ansal [9] found that a dividing system of fish and Duckweed is more efficient than combined systems. Reeta D. Sooknah [14] in this paper, the potential of 3 floating aquatic macrophyte on anaerobically flushed dairy manure waste water was studied. The growth of water hyacinth was robust followed by polyculture and further followed by the other two monocultures. Bhupinder [4] in this paper, Salvinia exhibit for removing contaminants such as heavy metals, inorganic nutrients from waste water. In salvinia, physical process is fast (adsorption, ionic exchange and chelation) while biological process such as intercellular uptake is comparatively slow for removing heavy metals. In this paper, the phytoremediation of the pond water from ‘Mariyan Oorini’, located near NH-7, ‘Sattur’ (taluk) of ‘Virudhunagar’ District of Tamilnadu was performed. This 13


water sample was taken to form different experimental case studies using Duckweed and a toxic herbicide ‘Glyphosate’. In this study, the work has been divided into 2 phases Phase1: Efficiency of Duckweed on pond water quality. Phase2: Effect of toxicant Glyphosate on the Duckweed plant growth. The physiological parameters like DO, pH, CO2, Ammonia, Nitrate, Phosphate, Temperature and Turbidity in all samples were analysed for 10 days using the standard procedures and % reduction in the parameters was found out to understand the maximum removal of pollutants by Duckweed.

2. MATERIALS AND METHODOLOGY In this study, five artificial ecosystems has been studied using pond water taken from “MARIYAN OORINI”, Sattur, Virudhunagar district, Tamilnadu. An aquatic plant macrophyte (Duckweed) belonging to lemnacea family is used for this experimental study. A toxic herbicide (Glyphosate) is also used to test the toxicity effects on the artificial ecosystem. Mariyan Oorini is a part of Sattur town and is situated at 9º27´ North latitude and 77º46´ East latitude. Fig. 1 and Fig. 2, show the image of Mariyan Oorini taken using digital camera as well as downloaded from Google Earth.

Following different experimental ponds are prepared in this study. Case 1 - Study of original pond water sample (control). Case 2 - Study of pond water sample with introduction of a macrophyte Duckweed (15 gm wet weight). Case 3 - Study of pond water sample after introduction of Duckweed (15 gm wet weight) along with a toxic herbicide Glyphosate with concentration of 0.125mg/l. Case 4 - Study of pond water sample after introduction of Duckweed (15 gm wet weight) along with a toxic herbicide Glyphosate with concentration of 0.250mg/l. Case 5 - Study of pond water sample after introduction of Duckweed (15 gm wet weight) along with a toxic herbicide Glyphosate with concentration of 0.500mg/l. The functioning of these five artificial ponds was surveyed for a period of 10 days. Each artificial pond was initially filled with 14.8 litres of pond water.

2.1 EXPERIMENTAL PROGRAM For all the above case studies, daily analysis of pH, temperature, Nitrate, Ammonia, Phosphate, Dissolved oxygen and Turbidity were performed using standard procedures. The Dissolved oxygen is measured using ‘Winkler’s method’. Electrode method was used to analyse pH, temperature using thermometer, Nitrate using Brucine sulphate method, Ammonia by titrimetric method, Phosphate using ammonium molybdate method and turbidity by Nephlometric turbidity metric methods respectively for 10 days i.e. from 11/10/2012 to 22/10/2012. Fig. 3 shows the laboratory setup of Duckweed ecosystem. The initial condition of the pond water analysed is shown in Table.1

Fig. 1. Photo View of Mariyan Oorini

Fig. 3.laboratory set up of Duckweed ecosystems

Fig. 2.Digital image of Mariyan Oorini

The pond water is formed by the collection of the wastewater from the surrounding areas of Sattur town thus making it unfit for domestic purpose. Further, there is a high risk of this waste water to affect the quality of the underground water through seepage as well as subsurface water flow. The depth of the pond water is very shallow and visibly green colour is due to the presence of algae. 14

Table. 1. Initial Condition of Pond water. Initial condition of pond water Parameter unit value Temperature ºC 22 Nitrate mg/l 45 Phosphate mg/l 1.6 Ammonia mg/l 1.703 Turbidity NTU 167 pH nil 8.74 DO mg/l 6.72 ICICE-2013

INTERNATIONAL CONFERENCE ON INNOVATIONS IN CIVIL ENGINEERING 9th and 10th of May 2013 Table. 6. Percentage Reduction in Case 5

3. RESULT AND DISCUSSIONS The physiochemical parameters obtained and percentage reduction for different case studies are shown in Table 2 to6.

No 1

Initial Final conce- Percentage concentration ntration reduction

Temperature

ºC

22

22

-

CASE:1

Nitrate

mg/l

45

15.505

65.54

3

Phosphate

mg/l

1.6

1

37.5

4

Ammonia

mg/l

1.703

0.425

75.04

5

Turbidity

NTU

167

190.5

-14.07

6

pH

nil

8.74

8.38

-

7

DO

mg/l

6.72

2.43

-

Parameters

Initial Final conce- Percentage Unit concentration ntration reduction ºC

22

20

-

mg/l

45

15.505

65.5

3

Phosphate

mg/l

1.6

0.8

50

4

Ammonia

mg/l

1.703

0.425

75.04

5

Turbidity

NTU

167

105.5

36.8

6

pH

nil

8.74

8

-

7

DO

mg/l

6.72

2.08

-

Table. 3. Percentage Reduction in Case 2. CASE:2 Parameters

Unit


1

Temperature

ºC

22

20

-

2

Nitrate

mg/l

45

17.72

60.62

3

Phosphate

mg/l

1.6

0.4

75

4

Ammonia

mg/l

1.703

0.425

75.04

5

Turbidity

NTU

167

135.5

18.86

6

pH

nil

8.74

7.8

-

7

DO

mg/l

6.72

3.04

-


1

Temperature

2

Unit


ºC

22

21

-

Nitrate

mg/l

45

19.335

57.03

3

Phosphate

mg/l

1.6

1

37.5

4

Ammonia

mg/l

1.703

0.425

75.04

5

Turbidity

NTU

167

195.5

-17.06

6

pH

nil

8.74

8.23

-

7

DO

mg/l

6.72

2.9

-


1

Temperature

2

Unit


ºC

22

20

-

Nitrate

mg/l

45

17.72

60.62

3

Phosphate

mg/l

1.6

1

37.5

4

Ammonia

mg/l

1.703

0.425

75.04

5

Turbidity

NTU

167

198.5

-18.86

6

pH

nil

8.74

7.56

-

7

DO

mg/l

6.72

2.8

ICICE-2013

Unit

2

Nitrate

No

Parameters

1

2

No

No

Table. 2. Percentage Reduction in Case 1.

Temperature

No

CASE:5

I- Efficiency of Duckweed on pond water quality. The phosphate removal in original pond water and in the presence of Duckweed after 10 days was measured as 50 % and 75% respectively. The phosphate removal is more with the presence of Duckweed than original pond water due to the following reason (1) this may be due to phosphate uptake by Duckweed plant and assimilation into plant protein. (2) Adsorption on plant leaves, (3) Chemical precipitation and (4) Microbial uptake. The phosphate removal in control may be due to the uptake by micro organism and other biological activities taking place according to Anima Priya [1]. The turbidity removal in original pond water and in presence of Duckweed after 10 days was measured as 36.8 % and 18.86 % respectively. The turbidity removal is less with the presence of Duckweed than original pond water. The reason for this may be due to presence of some dead leaves of Duckweed. The pH value is decreased from 8.74 to 7.8 in the presence of Duckweed. This may be due to respiration by Duckweed plants. The ammonia removal in original pond water and with the presence of Duckweed was both 75.04 %. i.e., for ammonia removal, there is no difference between original pond water and pond water with Duckweed. Hence, Duckweed plant does not efficiently remove ammonia nitrogen. The nitrate nitrogen removal in the pond water and with the presence of Duckweed is namely 65.5 % and 60.62 % respectively. For nitrate removal, there is no considerable difference between original pond water and pond water with Duckweed. Hence, Duckweed plant is not effective in nitrate nitrogen removal as compared to phosphate removal. In the original pond water the dissolved oxygen (DO) level initially decreased from 6.72 mg/l to 1.6 mg/l and then increased to 2.08 mg/l. But in the presence of Duckweed, the DO initially decreased from 6.72 mg/l to 1.92 mg/l and then increased to 3.04 mg/l respectively. The reduction of DO may be due to the decomposition of organic matter by aerobic bacteria. Later, the DO starts to increase. When compared to the original pond water, the DO level is more in the presence of Duckweed at the end of the experiment. This may be due to (1) Supply of oxygen by Duckweed plants. (2) Atmospheric diffusion. When compared to original pond water sample, the DO level is more in the 3rd, 4th and 5th case at the end of the experiment. This may be caused by the presence of Duckweed in the latter case. II - Effect of toxicant Glyphosate on the Duckweed plant growth. In the presence of Duckweed, without adding toxicant, the phosphate removal is 75 %. The phosphate removal is 15


decreased from 75% to 37.5 % (almost half) when Glyphosate is added in the dosages namely 0.125 mg/l, 0.250 mg/l and 0.500 mg/l. From this observation, phosphate removal is reduced after adding Glyphosate toxicant. This may be due to the reason that plant growth is affected by Glyphosate toxicant.

Fig. 4 Dry weight of Duckweed determined The dry weight of Duckweed biomass in Case2 (without toxicant) is 4.243 g/m2 (dry). The dryweight of Duckweed biomass after adding 0.125, 0.250 and 0.500 dosages of toxicant are 2.066 g/m2 (dry), 1.983 g/m2 (dry) and 1.841 g/ m2 (dry) respectively. With the increase of toxicant dosages, the dry biomass weight of the Duckweed plant decreases. From this observation, we can conclude that there is a negative effect of toxicant Glyphosate on plant growth. But several toxicant dosages are needed for complete analyses of growth of Duckweed plant. Interestingly, in 3rd, 4th and 5th cases, the turbidity increased at the end of the experiments when compared to the initial values. This is due to suspended impurities caused by dead plants.

4. CONCLUSION From the experimental studies conducted, it was understood that the Duckweed plant efficiently removes 75% phosphate from pond water. Comparatively, the Duckweed growth rate enhancement is seen more in the pond water without toxicant Glyphosate. According to Anong Phewnil et al. [3], there is no current set of standard in toxicity of Atrazine in surface water. In particular, the toxicity to the aquatic plants which are primary producers will cause an imbalance of the aquatic ecosystem. Similarly Glyphosate is being used in large quantities in India causing contamination of surface water. The result obtained in this study may be used to develop Glyphosate application standards for the surface waters of India.

5. ACKNOWLEDGEMENT This study was supported by Dr. Thillai Arasu, HOD, Department of Chemistry, Kalasalingam University, Dr. Sundar, HOD, Department of Biotechnology, Kalasalingam University and Dr. Palanivelu, Principal, Arulmigu Kalasalingam College of Pharmacy. Special thanks tribute to B.Tech students G. Magara Jothi, K. Lakshmi Devi and R. Gajalakshmi, for their assistance in collecting Duckweed and conducting chemical analyses.

6. REFERENCES [1]

16

Anima Priya, Kirti Avishek and Gopal Pathak, “Assessing the potentials of lemna minor in the treatment of domestic wastewater at pilot scale”, Environmental monitoring assessment, Springer Journal, Vol.184, pp. 4301-4307, 2012.

[2]

Anitha Menon.M, NVN.Nampoothiri, C. Sivapragasam and S.Vanitha, “Study on effectiveness of Duckweed plant for the improvement of pond water quality”, International Conference on Futuristic innovations & Developments in Civil engineering (ICFiDCe ‘13), Mepco Schlenk Engineering College, Sivakasi, Tamilnadu, 2013. (Selected for publication in International Conference Proceedings)

[3]

Anong Phewnil, Nipon Tungkananurak, Supamard Panichsakpatana, and Bongotrat Pitiyont, “Phytotoxicity of atrazine herbicide to fresh water macrophyte Duckweed (lemna perpusilla torr.) in Thailand”, Environment and Natural Resources Journal, Vol.10, no.1, pp. 16-27, 2012.

[4]

Bhupinder and Dhir, ‘Salvinia, “An aquatic term with potential use in phytoremediation”, Environment and we, An international Journal of Science and Technology, Vol. 4, pp. 23-27, 2009.

[5]

Harini Santhanam, Raj.S and Thanashekaran.K, “Comparision of the performance of two indices of trophic status for depicting the status of pulicat lagoon ecosystem,” Journal of Environmental Science & Engineering, National Environmental Engineering Research Institute, Nagpur, India, Vol. 53 no. 4, pp 413-422, 2011.

[6]

In-Hwa Chang, Kai-Teng Cheng, Po-Chuan Huang, Yen-Yu Lin, Lee-Ju Cheng and Tai-Sheng Cheng, “Oxidative stress in greater Duckweed (Spirodela polyrhiza) caused by long-term NaCl exposure”, Acta Physiol Plant, Vol.34, pp.1165-1176, 2012.

[7]

John.R, Ahamed.P, Gadgil.K and Sharma.S, “Effect of cadmium and lead on growth, biochemical parameters and uptake in lemna polyrrhiza l.,” Plant soil environ., Council for Scietific and Industrial Research, New Delhi, India, Vol.54 no. 6, pp– 262270, 2008.

[8]

J.M Dalu and J.Ndamba, “Duckweed based waste water stabilization ponds for waste water treatment [a low cost technique for small urban areas in Zimbabwe],” Vol. 28, issue 20-27, pp.1147-1160, 2003.

[9]

M.D Ansal, A. Dhawan and V.I Kaur, “Duckweed based bioremediation of village ponds: An ecologically and economically viable integrated approach for rural development through aquaculture”, Journal of Livestock research for rural development, Vol. 22 no.7, 2010.

[10] Nayyef M. Azeez and Amal A. Sabbar, “Efficiency of Duckweed (Lemna Minor L.) in Phytotreatment of wastewater pollutants from Basrah oil refinery”, Journal of Applied Phytotechnology in Environmental Sanitation, ISSN 2088-6586, Vol.1, no. 4, pp.163-172, 2012. [11] Nihan ozengin and Ayse Elmaci, “Performance of Duckweed (Lemna minor.L) on different types of waste water treatment”, Journal of environmental Biology, Vol. 28 no. 2, pp.307-314, 2007. [12] Olah.V, Lakatos.G, Bertok.C, Kanalas.P, Szollosi.E, Kis.J and I.Meszaros, “Short-term chromium (VI) stress induces different photosynthetic responses in two Duckweed species, lemna gibba l. and lemna minor l.”, Photosynthetica, Vol.48 no. 4, pp. 513520, 2010. [13] R.Sooknah, “A review of the mechanisms of pollutant removal in water hyacinth system”, Journal of Science and Technology, Vol.6, 2000. [14] Reeta D.Sooknah and Ann.C.Wilkie, “Nutrient removal by floating aqua tic macrophytes cultured in an aerobically digested flushed dairy manure wastewater”, Journal of Ecological Engineering, Vol. 22, pp.27-42, 2004. [15] Sangeetha Dhote and Savita Dixit, “Water quality improvement through macrophytes – a review,” Environmental Monitoring Assessment, Springer journal, Vol.152, pp. 149-153, 2009. [16] Thongchai Kanabkaew and Udomphon Puetpaiboon, “Aquatic plants for domestic waste water treatment Lotus and Hydrilla,” Journal of Science and Technology, Vol.26 no. 5, pp. 749-756, 2004. ICICE-2013


Reduction of COD of Pulp and paper mill effluent using Sequencing batch reactor Afzal Husain Khan, Iqbal Khan, Nadeem Ahmad khan, Misbahul Islam, Arshad Husain Abstract —Paper mills generate varieties of pollutants depending upon the type of the pulping process. The wastewaters discharged from these mills have high chemical oxygen demand (COD) and colour, which indicating high concentrations of recalcitrant organics. This study was conducted using a Sequencing Batch Biofilm Reactor of 3.3 L working volume, operated in an aerobic condition and packed with .For the two months, they can be set at 24 hours and later it was adjusted to 12 hours in order to evaluate the performance of the system. The treated wastewater samples for these studies were taken from a recycled pulp and paper mill factory in Moradabad, India with different batch characteristics. The results also indicated that the Biofilm attached can substantially remove these recalcitrant organics in the wastewater, within the range of 10 – 100% COD removal. COD reduction can see easily and the use combination with SBR is one of the best methods for the COD reduction. Thus, COD reduction can observed about 60-80%. Index Terms— Biofilm, Chemical oxygen demand (COD), COD reduction, Effluent, Paper mill effluent, Recalcitrant organics, Sequencing batch reactor.

—————————— ——————————

1 INTRODUCTION

T

he pulp and paper industry is one of India’s oldest and core industrial sector. The socioeconomic importance of paper has its own value to the country’s development as it is directly related to the industrial and economic growth of the country. Although paper has many uses, its most important contribution to modern civilization is its use as a medium to record knowledge. The main steps in pulp and paper manufacturing are raw material preparation, such as wood debarking and chip making; pulp manufacturing; pulp bleaching; paper manufacturing; and fibre recycling. Pulp mills and paper mills may exist separately or as integrated operations. Manufactured pulp is used as a source of cellulose for fibre manufacture and for conversion into paper or cardboard. Pulp manufacturing starts with raw material preparation, which includes debarking (when wood is used as raw material), chipping, and other processes such as depithing (for example, when bagasse is used as the raw material). Cellulosic pulp is manufactured from the raw materials, using chemical and mechanical means. The manufacture of pulp for paper and cardboard employs mechanical (including thermo mechanical), chemimechanical, and chemical methods. Mechanical pulping [1],[2] separates fibres by such methods as disk abrasion and billeting. Chemimechanical processes involve mechanical abrasion and the use of chemicals. Thermo ———————————————— • • • • •

Afzal Husain Khan, Assistant Professor Integral University, Lucknow (India), Mob-+91-9557142342. E-mail: [email protected] Iqbal Khan, Assistant Professor Integral University, Lucknow (India), E-mail: [email protected] Nadeem Ahmad Khan, Assistant Professor, Department of Civil Engineering Mewat Engineering Collage, NUH, Haryana., Email: [email protected], Misbahul Islam, Assistant Professor, Department of Civil Engineering Mewat Engineering Collage, NUH, Haryana.Email: [email protected] Arshad Husain, Associate Professor, Civil Engg. Section, F/O Engg. & Technology, AMU, Aligarh (U.P.) India). Email: [email protected]

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mechanical pulps, which are used for making products such as newsprint, are manufactured from raw materials by the application of heat, in addition to mechanical operations [3],[4],[5]. Chemimechanical pulping and chemithermomechanical pulping (CTMP) [6] are similar but use less mechanical energy, softening the pulp with sodium sulphite, carbonate, or hydroxide. Chemical pulps are made by cooking (digesting) the raw materials, using the Kraft (sulphate) and sulphite processes. Kraft processes produce a variety of pulps used mainly for packaging and high strength papers and board. Wood chips are cooked with caustic soda to produce brownstock, which is then washed with water to remove cooking (black) liquor for the recovery of chemicals and energy [7]. Pulp is also manufactured from recycled paper. Mechanical pulp can be used without bleaching to make printing papers for applications in which low brightness is acceptable primarily, newsprint. However, for most printing, for copying, and for some packaging grades, the pulp has to be bleached. For mechanical pulps, most of the original lignin in the raw pulp is retained but is bleached with peroxides and hydrosulphides [8]. In the case of chemical pulps (Kraft and sulphite), the objective of bleaching is to remove the small fraction of the lignin remaining after cooking. Oxygen, hydrogen peroxide, ozone, peracetic acid, sodium hypochlorite, chlorine dioxide, chlorine, and other chemicals are used to transform lignin into an alkali soluble form.

2 WASTE CHARACTERISTICS The significant environmental impacts of the manufacture of pulp and paper result from the Pulping and bleaching processes. In some processes, sulfur compounds and nitrogen oxides are emitted to the air, and chlorinated and organic compounds, nutrients, and metals are discharged to the wastewaters.

2.1 Air Emissions In the Kraft pulping process, highly malodorous emissions of reduced sulfur compounds [9], measured as total reduced sulfur (TRS) and including hydrogen sulfide, methyl mercaptan, dimethyl sulfide, and dimethyl disulfide, are 17


emitted, typically at a rate of 0.3–3 kilograms per metric ton (kg/t) of air dried pulp (ADP- Airdried pulp is defined as 90% bone-dry fiber and 10% water) [10]. Other typical generation rates are: particulate matter, 75–150 kg/t; sulfur oxides, 0.5–30 kg/t; nitrogen oxides, 1–3 kg/t; and volatile organic compounds (VOCs), 15 kg/t from black liquor oxidation. In the sulfite pulping process, sulfur oxides are emitted at rates ranging from 15 kg/t to over 30 kg/t. Other pulping processes, such as the mechanical and thermo mechanical methods, generate significantly lower quantities of air emissions. Steam and electricity generating units using coal or fuel oil emit fly ash, sulfur oxides, and nitrogen oxides. Coal burning can emit fly ash at the rate of 100 kg/ t of ADP.

product. Afterwards, the mixture is dewatered, leaving the fibrous constituents and pulp additives on a wire or wiremesh conveyor. Additional additives may be applied after the sheet making step. The fibers bond together as they are carried through a series of presses and heated rollers. The final paper product is usually spooled on large rolls for storage.

2.2 Liquid Effluents

4.2 Inoculums

Wastewaters are discharged at a rate of 20–250 cubic meters per metric ton (m3/t) of ADP. They are high in biochemical oxygen demand (BOD), at 10–40 kg/t of ADP; total suspended solids, 10– 50 kg/t of ADP; chemical oxygen demand (COD), 20–200 kg/t of ADP; and chlorinated organic compounds, which may include dioxins, furans, and other absorbable organic halides, AOX, at 0–4 kg/t of ADP. Wastewater from chemical pulping contains 12–20 kg of BOD/t of ADP, with values of up to 350 kg/t. The corresponding values for Mechanical pulping wastewaters are 15–25 kg BOD/t of ADP. For chemimechanical pulping, BOD discharges are 3 to 10 times higher than those for mechanical pulping. Pollution loads for some processes, such as those using nonwood raw materials, could be significantly different. Phosphorus and nitrogen are also released into wastewaters [11]. The main source of nutrients, nitrogen, and phosphorus compounds is raw material such as wood. The use of peroxide, ozone, and other chemicals in bleaching makes it necessary to use a complexion agent for heavy metals such as manganese.

The inoculums used in this experiment were collected from oxidation pond and procured from a batch anaerobic reactor located in the laboratory, which has been maintained at ambient temperature condition.

3 MANUFACTURING PROCESS In general, paper is manufactured by applying a liquid suspension of cellulose fibers to a screen, which allows the water to drain, and leaves the fibrous particles behind in a sheet. The liquid fibrous substrate formed into paper sheets is called pulp. Processes in the manufacture of paper and paperboard can, in general terms, be split into three steps: pulp making, pulp processing, and paper/paperboard production. Paperboard sheets are thicker than paper sheets; paperboard is normally thicker than 0.3 mm. Generally speaking, however, paper and paperboard production processes are identical [12]. First, a stock pulp mixture is produced by digesting a material into its fibrous constituents via chemical, mechanical, or a combination of both. In the case of wood, the most common pulping material, chemical pulping actions release cellulose fibers by selectively destroying the chemical bonds in the gluelike substance (lignin) that binds the fibers together. After the fibers are separated and impurities have been removed, the pulp may be bleached to improve brightness and processed to a form suitable for papermaking equipment. Currently, onefifth of all pulp and paper mills practice bleaching [13]. At the papermaking stage, the pulp can be combined with dyes, strength building resins, or texture adding filler materials, depending on its intended end 18

4 MATERIALS AND METHODS 4.1 Sample collection The effluent samples (bleached) were collected from a pulp and paper mill effluent and were stored in plastic containers, kept at 4 °C and transported to our laboratory. The remaining effluent sample was kept in the cold room for later use.

4.3 SBBR A reactor with 3 L working volume was used in this study. It was operated at room temperature.The reactor was earlier operated at hydraulic retention time (HRT) of 36 hours can of the six months and later can adjusted to HRT of 24 hours in order to make the performance comparison of the Biofilm between both the HRTs. The samples were analyzed for COD, AOXs and the amount of biomass washout before being fed into the reactor.

5 EXPERIMENTAL METHOD The overall methodology of this study is as illustrated the SBBR system was initiated with the characterization of the influent and effluent samples and these were followed by the kinetic studies of the microorganism growth and the optimization of reactor operating parameters [14], [15] ,[16]. The COD and biomass parameters were analyzed using the standard methods with the respective instruments as listed in Table 2. The Adsorbable organic halides were extracted using the solid phase extraction (SPE) .

6 RESULTS AND DISCUSSION The characteristics of batches of samples from recycled paper mill factory were determined. That the maximum influent concentrations obtained for COD on all samples were 7860 mg/L while the COD values on the effluent were below 300 mgL/1. The removal ranges for COD 24 hours were 50– 80% and 50–66%, respectively. As was previously observed by the study of Barr et al. (1996), the removal of COD was found to decrease with the decreasing of the HRT. It was also observed that at the initial stage of the study (approximately within the first 20 days), the COD removal was higher even though the biomass concentration was below 2000 mgL1. This was most probably due to the adsorption of the COD onto the freshly introduced .The concentrations of the compounds as identified in the paper mill effluent with their percentage removals were as shown in the concentrations of phenol were found to be very low and could hardly be detected. The efficiency of a system is also very dependent on the characteristics of the microbe population in the reactor. ICICE-2013


.Analysis of the growth kinetic parameters in SBBR had deduced that the system is capable to operate a long biomass retention time under anoxic condition (or less oxygen).Anderson et al. (1996) has reported that the consumption of nonbiodegradable substrate would lower the specific growth rate. Wastewater from pulp and paper industry is one of the serious problems due to the high concentration in COD and color substances.Several treatment systems have been introduced for treating this kind of wastewater on the basis of its high removal efficiency and low operating cost. NAINI pulp and paper Industries Co., Ltd, one of the biggest companies to produce pulp and paper products in India, was used for checking the wastewater quality. The wastewater from this factory had high concentration of COD, BOD5 and color substances as 1255 mg/l, 449 mg/l and 697 Pt- Co units, respectively. The COD: BOD ratio was 2.8:1. This means that the pulp and paper industry wastewater contains large amounts of organic compounds that are difficult to biodegrade and inorganic reducing substances. However, most of the pulp and paper industry factory still uses the biological treatment system such as the oxidation pond, aerated lagoon or activated sludge. Many factories have problems with the fluctuation in the quality of the effluent, stability of the system and, operating and investment cost. The SBR system has been introduced into several kinds of industries such as seafood and meat processing industries for reduction of investment and operating costs. In this study, we have tried to introduce the SBR system to treat pulp and paper industry wastewater. The results show that the microorganisms in SBR system can remove both organic matters (COD and BOD5) and color substances from the wastewater. The effluent qualities, except color intensity passed the standard permission .The removal efficiencies of SBR system improved with the increase of HRT, except for color removal efficiency. The COD removal efficiencies of the SBR system were increased from 73.26% to 89.80% while the color removal efficiency was reduced from 56.96%to 48.92% when HRT of the system was increased from 1 day to 3 days. It means that when the HRT was increased, the organic loading was decreased then; the removal efficiency was increase.

Table 2. The AOXs were extracted using the solid phase extraction (SPE) Technique and later analyzed using the HPLC instrument. PARAMETER

INSTRUMENTS

Chemical Oxygen Demand (COD)

HACH DR 5000 Spectrophotometer

Absorba(HPLC) ble organo- with UV

METHOD

REFERENCE

Digestion Method

EPA

Zorbax-SB C18 Column logies (150mm×4.6mm ×5μm) Mobile phase: 20% Aceton Nitril (ACN)/80%0.01MH3 PO4 to 45%CAN in 7.5 minwith gradient of 80% ACN in 2min and UV detection at 254 nm

Agilent techno(2002)

halides (AOX)

detector (Agilent series 1100)

Biomass

Filtration unit Mass liquid Suspended solids

APHA (1992)

Kinetic growth

-

Monod (1949)

Monod Equation

7 Conclusion The study can show that selection of suitable processes effect the COD removal. The results of this initial study thus reaffirm the fact that SBBR system treatment of recycled pulp and paper mill effluents could be considered as an alternative option not only for energy cogeneration but also as a means of significantly reducing some of the more important, albeit organic recalcitrant, objectionable parameters. COD reduction can see easily and the use of with combination with SBR is one of the best methods for the COD reduction. The reduction were observed about 6080% and rest of the parameters analysied as shown in the graph below from fig.1 to fig.5

Table 1: Different values for batch process Date 18 June,2010

MLSS Conc. At starting stage

4340Kg/m3

Date 18 June,2010

VSS Conc. At starting stage

1520mg/l

Date 28 June,2010

MLSS Conc.

3840 Kg/m3

Date 28 June,2010

VSS Conc.

1540 mg/l

Date 12 July,2010

MLSS Conc.

5220 Kg/m3

Date 12July,2010

VSS Conc.

2520 mg/l Fig. 1: COD characteristics of influent and effluent observed.

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19


References

Fig 2: Time Vs COD concentration and their %age removal

Fig 3: Time Vs Influent & Effluent TSS Concentrations.

Fig 4: D.O Vs MLVSS/MLSS Concentration

[1]

Karnis. A, The mechanism of fibre developmentin mechanical pumping. J. Pulp paper science, vol. 20, no. 10.1994, pp J280,-J288

[2]

Salmen, L. Lucander, M. Harkonen, E. and Suldholm, J.,Fundamental of mechanical pulping.Mechanical pulping (Paermaking science and technology, Book-5) Jan Sundholm, Fapet Oy Finland, 2000. Pp.35-61.

[3]

Hill, J., Sabourin, M., Johansson,L., et al., Int. Mech. Pulping Conf., Proc., SPCI, Stockholm, 2009, p. 36.

[4]

Muhic´, D., Sundström,L., Nilsson,L., et al., Int. Mech. Pulping Conf., Proc., SPCI, Stockholm, 2009, p. 344.

[5]

Mokvist, A., Russell, G., and Lauritzen, J., Int. Mech. Pulping Conf., Proc., Oslo, 2005, Conf. CD

[6]

Meadow, D. G. 1998. “Improvements add CTMP line to Enso’s Imatra mill” Tappi Journal 81(1).

[7]

Panesar, P.S., S.S. Marwaha and R. Rai: Methanogenesis of black liquor of pulp and paper industry using UASB reactor in biphasic system. J. Indus. Pollut. Cont., 15(2), 157-163 (1999)

[8]

Buisman, C.J., Witt, B. & Lettinga, G. (1988). A new biotechnological process for sulphide removal with sulphur production. In: Fifth International Symposium on Anaerobic Digestion.Bologna, Italy, pp. 1922

[9]

Wegener, G. (1992). Pulping innovations in Germany. Ind. Crops Prod., 1(2-4):113-117

[10]

M. Benjamin, et al., “A General Description of Commercial Wood Pulping And Bleaching Processes”, Journal Of The Air Pollution Control Association, 19(3):155-161, March 1969

[11]

Manning J F and Irvine R L. The biological removal of phosphorus in a sequencing batch reactor [J]. J. War. Pollut. Control Fed., 1985, 57: 87-94.

[12]

Dellinger, R.W. (1980). Development document for effluent limitations guidelines and standards for the pulp, paper and paperboard and the builders’ paper and board mills.US Environmental Protection Agency Report EPA440/025b, Washington DC, USA.

[13]

Kham, L., Bigot, Y.L., Mlayah, B.B., and Delmas, M. (2005b). Bleaching of solvent delignified wheat straw pulp. Appita J., 58(2):135–137.

[14]

Chozick R and Irvine R L. Preliminary studies on the granular activated carbon-sequencing batch biofilm reactor [J]. Environ. Prog., 1991:282.

[15]

Wilderer P A, Roske I, Ueberschar A and Davids L. Continuous flow and sequenced batch operation of biofilm reactors: a comparative study of shock loading responses[J]. Biofouling, 1993, 6: 295-304.

[16]

Wilderer P A. Technology of membrane biofilm reactors operated under periodically changing process conditions [J]. War. Sci. Tech., 1995, 31: 173- 183.

Fig 5: Time Vs pH & Alkalinity profile 20

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Suitability of Sludge as a Building Material Krishna Priya Nair, Vivek J M, Prof.Shibu K Abstract— Different industries produce sludge of different quality and in different quantities. Common method adopted for disposing the sludge is land filling. Landfill disposal of the sludge has drawbacks like high cost of transportation, difficulty in getting suitable sites for land filling, heavy metal contamination of the land, emission of foul gases etc. Thus the disposal of sludge has become a major issue.The objective of this study is to identify the possibilities of using the sludge obtained from effluent treatment plant in Hindustan Latex Limited,Trivandrum as a brick material. The different engineering properties were also studied by conducting tests on brick specimens of various mix proportions prepared.It was seen that when percentage of sludge was increased beyond 60%, water requirement as well as water absorption of the bricks increased by 18%. But at the same time, compressive strength of the brick deccreased by 10.85% . But on addition of cement, flyash and sisal fibres, the compressive strength increased by 30% and thre properties of the bricks improved.Further it can be added that other alternatives like coir fibres,charcoal husk ,lime whose addition shall enhance the properties which can be considered as the scope for future research. Index Terms— Brick,Cement,Compressive strength,Effluent,Flyash,HLL Lifecare Limited,Moisture,Property,Sisal fibres,Water absorption

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1 INTRODUCTION

A

large quantity of sludge is generated each year from various industries. The quantity of the sludge produced depends upon the amount of wastewater and the type of treatment adopted for treating the wastewater. Common method adopted for disposing the sludge is land filling. Landfill disposal of the sludge has drawbacks like high cost of transportation, difficulty in getting suitable sites for land filling, heavy metal contamination of the land, emission of foul gases etc. So, disposal of sludge has become a major issue. The use of sludge in construction industry is considered to be the most economic and environmentally sound option.This study focuses on the possibility of using sludge as a brick material[1]. The sludge for this study was collected from HLL Lifecare Limited; Peroorkada,Trivandrum. The main raw material used in this industry is Latex (colloidal suspension of very small polymer particles in water). The bricks were subjected to compressive strength test and water absorption test and thus their suitability for construction purpose was examined[2].

1.1HLL (formerly Hindustan Latex Ltd.)Lifecare Limited Hindustan Latex Limited or HLL Lifecare Limited is a Government of India undertaking, under the Ministry of Health and Family Welfare, Government of India, which started as a corporate entity in March 1966. Their product ranges from contraceptive aids and healthcare aids to social marketing products.HLL gives emphasis on ————————————————

•

Krishna Priya Nair is currently pursuing Bachelor degree program in Civil Engineering in College of Engineering ,Trivandrum,Kerala, India, PH-08547186572. E-mail: [email protected]

•

Vivek J M is currently pursuing Bachelor degree program in Civil Engineering in College of Engineering ,Trivandrum,Kerala, India, PH-09400452755. E-mail: [email protected]

•

Shibu k is currently working as an Assistant professor in Civil Engineering department ,College of Engineering Trivandrum,Kerala, India, PH-09446066302. E-mail: [email protected]

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effective quality control at every manufacturing stage right from the raw material to the final product, during its various production stages.

1.2 Literature Review A study was conducted on the use of recycled paper processing residues in making porous brick with reduced thermal conductivity by Mucahit Sutcu et.al.(2009)[3]. In this study mixtures containing brick raw materials and the paper waste were prepared at different proportions (upto 30% by weight). The results obtained showed that the use of paper processing residues decreased the fired density of bricks down to 1.25 g/cc. Compressive strengths of the brick samples obtained in this study were higher than that required for standards. Another study conducted by Chih-Huang Weng et.al (2003) investigated [4]the influence of sludge proportion and the firing temperature in determining the brick quality. Results showed that the brick weight loss in ignition was mainly attributed to the organic matter content in the sludge being burnt out during the firing process. With upto 20% sludge added to the bricks, the strength measured at temperatures 960 °C and 1000°C met the requirements of the Chinese National Standards. Toxic Characteristic Leaching Procedure (TCLP) tests of bricks also showed that there is low metal leaching. The study conducted by Chihpin et al. (2001) investigated [5]the use of sludge as partial substitute for clay in brick manufacturing. In this study, four different series of sludge and clay proportioning ratios were studied, which exclusively involved the addition of sludge with ratios 50%, 60%, 70% and 80% of the total weight of sludge-clay mixture. Each series involved the firing of bricks at 950°C, 1000°C, 1050°C and 1100°C, giving 16 different brick types. The physical properties of the manufactured bricks were then determined and evaluated according to Egyptian Standard Specifications and British standards. From the results, it was concluded that by operating at the temperature commonly practiced in the brick kiln, 50% was the optimum sludge addition to produce brick from sludge-clay mixture. 21


2 OBJECTIVE OF THE STUDY

3.7.Treated effluent water collection tank

The objective of this study is to identify the possibilities of using sludge obtained from effluent treatment plant [6] in HLL Lifecare Limited ; Peroorkada, Trivandrum as a brick material. The different engineering properties were also studied. The sewage sludge is having a typical composition leading to a preliminary property analysis[7].The bricks thus manufactured were subjected to compressive strength test and water absorption test and thus their suitability for construction purpose was examined.

Overflow from sand filter is fed to final effluent water collection tank through a cascade. The overflow from the final treated water is discharged through the final outlet. pH of treated water is maintained at the range of 6-8 and recycled on hourly basis. The flow rate through final outlet is noted using V notch and calculated using the following relation:

3 NATURE OF THE EFFLUENT TREATMENT PLANT The Effluent Treatment Plant (ETP) in HLL was installed for clear water discharge from production line since 1969. Present ETP can handle up to l000 kL/day of wastewater.The following are the components of the said plant:

3.1.Collection Tank/ Equalization tank The function of the equalization tank is to collect effluent from the different streams and to keep uniform characteristics for the effluent stream. Effluents from various sections of the plant, which includes latex, filtrate from Nutsche filter, wash water and canteen effluent are collected in this tank. Four such collection tanks are installed to collect wastewaters from the three plants A, B and C.

3.2.Lime Mixing Channel pH of the raw effluent ranges from 9-10. Hydrated lime, i.e., 1% solution of lime is therefore added to the effluent in order to make the pH 12. This enhances floe formation. Lime is allowed to flow into the channel under gravity.

3.3.FeCl3 Mixing Channel FeCl3 reagent stored in Sintex tank is next transferred under gravity and is added to the effluent at the rate of 150-1000 mL/min. This neutralizes the pH and brings the pH level to 6-8.

3.4.Sludge Recirculation Sump Sludge from secondary settling tank is to be fed to sludge recirculation sump by gravity. Sludge will be partially recycled back to the aeration tank. Balance portion will be send to sludge drying bed. It is cleaned once in a month.

3.5.Chemoxidation Tank Overflow from secondary settling tank is fed to Chemoxidation tank. Diluted sodium hypochlorite solution is dosed for 24 hours (20 litre NaHOCl in 180 litre of water). General flow rate is maintained as 140-200 mL/min. Addition of NaHOCl oxidizes residual biodegradable organics. pH after dosing is maintained at 7-8.

3.6.Pressure Sand Filter The clear overflow from the chemoxidation tank is pumped through two Pressure Sand Filters operated in parallel for removing any precipitated solids during Chemoxidation. Filter feed pumps are used for feeding the effluent to the pressure sand filter. The filter is backwashed every 20 minutes. 22

Q=H5/2x 1.4x 60x 60x24

(1) 3

where,Q- Discharge through the V notch in m /s H- Height of the water flow through V notch in cm While calculating the discharge using (1), height of water flow through V notch is maintained in the range of 6.5-12.5 cm.

3.8.Recycling of treated effluent water 40% of treated water [8] is used for gardening, toilet flushing, floor cleaning, ETP cleaning works etc. In addition to the above, treated water is supplied in tankers for gardening at Golf Club, Trivandrum.

3.9.Sludge Drying Beds Solid cake from the filter press is transferred to sludge drying beds. Sludge from the other tanks during cleaning operation is also transferred to sludge drying beds. There are 6 cells in sludge drying beds. After filling each cell, sludge is taken to the next cells. This process is separated till the sludge covers the entire cells in drying cells. Filtrate from the bed is allowed to enter aeration tank for further treatment.

4 STUDY SPECIMENS-BRICKS Brick is one of the oldest building materials and it is extensively used even at present because of its durability, strength, reliability, low cost, easy availability etc. Bricks are obtained by moulding clay in rectangular blocks of uniform size then by drying and burning these blocks in brick kilns .The use of typical sludge is the focal point of this study[10].The study conducted at water treatment plants had shown that the percentage of sludge in brick manufacture can be progressively increased to desired strength with addition of special additives[10,11,12].Use of flyash is being studied here.

5 MATERIALS AND METHODS USED The sludge subjected to drying for a period of two weeks was collected from the effluent treatment plant of HLLLifecare Limited, Peroorkada.The different engineering properties studied are as follows: 5.1.Materials •

Sludge( 14% B/t d” 33

As/At> 13% B/t d” 30 2.2 Hardening Index, (HI) The main advantages of CFST is the enhanced ductility because such columns are prefered in high-rise buildings and/or high seismic activity zones. It is also commonly ICICE-2013

Fig. 7. Effect of wall width to wall thickness on hardening index parameter 109


3 CONCLUSIONS A total of twenty two finite element CFST columns have been simulated to investigate the optimum ratio of area of steel in the composite section of such columns.A threedimensional non-linear finite element model has been used for conducting a parametric studt to investigate the effect of controlled increase in area of steel tube in the composite section on the load carrying capacity and ductility of CFST. It is concluded that the area of steel should be at least 13 % of the total area of composite section with cross-section to thickness ratio (B/t ) d”30 to enhance the load carrying capacity and ductility of CFST. No significance enhancement in load carrying capacity was observed for columns having area of steel lower than 13% or B/t higher than 30. Further, to achieve an Elastic-Perfectly-Plastic or strain hardening characteristics as it is desired for design purposes and sustain ductility, the area of steel should be at least 14 % of the total area of composite section.This ratio is also be governed by the parameter B/t which should be less than 33. Strain softening behaviour was observed for columns having unsaftisfied limit for this purpose. Eventually, using superposition principle, it is recommended to use such composite columns with minimum area of steel 14% of total area of cross-section and maximum B/t ratio as 30 to efficiently utilize the distinct composite features of CFST columns. 4 REFERENCES [1] M. Shams and M.A. Saadeghvaziri, “State of the Art of Concrete-Filled Steel Tubular Columns,” ACI Structural Journal, pp. Title No. 94-S51, 558-569, 1997. [2] J. Gardner and R. Jacobson, “Structural behavior of concrete filled steel tubes,” ACI Journal, pp. Title No. 64-38, 404-413, 1967. [3] Robert B. Knowles and Robert Park, “Strength of concrete filled steel tubular columns,” Journal of the structural division, Proceedings of the American Society of Civil Engineering, vol. 95, no. (ST12), pp. 2565-2587, 1969.

110

[4] S.P. Schneider, “Axially Loaded Concrete-Filled Steel Tubes,” Journal of Structural Engineeing, ASCE, pp. Vol. 124, No. 10, 1125-1138, 1998. [5] D Liu , “Behaviour of high strength rectangular concrete-filled steel hollow section under eccentric loading,” Thin Walled Structures, vol. 42, no. 12, pp. 1631-1644, 2004. [6] Toshiaki Fujimoto, Akiyoshi Mukai, Isao Nishiyama, and Kenji Sakino, “Behaviour of eccentrically loaded concrete-filled steel tubular columns,” Journal of Structural Engineering,ASCE, vol. 130, no. 2, pp. 203212, 2004. [7] B. Lakshmi and N. E. Shanmugam, “Nonlinear analysis of in-filled steel-concrete composite columns,” Journal of Structural Engineering,ASCE, vol. 128, no. 7, pp. 922-933, 2002. [8] Qing Quan Liang, Brian Uy, and J.Y. Richard Liew, “Strength of concrete-filled steel box columns with local buckling effects,” in Australian Structural Engineering Conference, Newcastle, Australia, 2005, pp. 1-10. [9] Hsuan-Teh HU, Chiung-Shiann Huang, and Zhi-Liang Chen, “Finite element analysis of CFT columns subjected to an axial compressive force and bending moment in combination,” Journal of Constructional Steel Research, vol. 61, pp. 1692-1712, 2005. [10] P. K Gupta, Ziyad A. Khaudhair, and A. K. Ahuja, “A study on load carrying capacity and behaviour of concrete filled steel tubular members subjected to axial compression,” in the 11th International Conference on Concrete Engineering and Technology 2012, Putrajaya, Malaysia, 2012, pp. 337-342. [11] P. K. Gupta, Ziyad A. Khaudhair, and A. K. Ahuja, “3D Numerical simulation of concrete filled steel tubular columns using ANSYS,” in Innovations in Concrete Constructions, Jalandhar, India, 2013, Accepted for Publishing. [12] M. Johansson, “The efficiency of passive confinement in CFT columns,” Steel and Composite Structures, vol. 2, No. 5, , 2002, pp. 379-369.

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Effect of Corrosion on Load Deflection Behaviour of OPC concrete in NBS Beam Akshatha Shetty, Katta Venkataramana, Babu Narayan K. S Abstract— Problems of corrosion have always been a matter of serious concern for structural engineers. The problems of corrosion are widespread all over the globe. Expansive corrosion products provoke cracks along the reinforcement, and subsequently, spalling of the concrete cover occurs. loss of bond-strength may lead to reduction in load bearing capacity.This paper aims to quantify the experimental investigation on load carrying capacity and center deflection behavior under different degree of corrosion levels on Ordinary Portland Cement (OPC) in NBS beam specimen. Index Terms—Bond Strength, Corrosion, Deflection, Flexural Behavior, Load, OPC, Reinforcement Bar.

—————————— —————————— 1

INTRODUCTION

F

lexural strength is a measure of resistance against failure in bending. Although the probability of structures being flexure deficient is low, one of the factors by which failure can occur due to reduction or total loss of rebar area causing the corrosion in service environ-ments. Quality concrete is an utmost environment for embedded rebars, but the increased use of chlorides and carbon dioxide are result into corrosion of rebar. Corrosion is one of the important factors that reduces the cross-sectional area of the steel, thereby reducing the load carrying capacity, bond strength and spalling of concrete and induces brittle failure of structure without prior warning. Hence, these effects of corrosion need to be studied for better performance of structures. When steel corrosion develops, the corrosion products first accumulate at the bar surface and try to fill the closest voids. Then they spread throughout the material and mix with the hydrated products of cement [1], [2], [3]. Once the threshold value of chloride content at the reinforcement reaches, then accumulates in the concrete –steel interfacial zone, generate unrestrained pressure on the surrounding concrete, and cause crack initiation and propagation [4]. Longitudinal cracks may affect the load bearing capacity of the structural elements presenting this distress, and in consequence may shorten their service life, in addition to opening a path for a quicker arrival of aggressive elements to the environment [5].

1.1 Time-Dependent States of Reinforcement Corrosion The status of corrosion of steel in concrete may be predictable to change as a function of time. Corrosion process has three distinct stages, namely; depassivation, propagation, and final state, as shown in Fig. 1. Depassivation is the loss of thin film passive layer over the rebar, which is initially formed due to the high alkalinity of concrete. The process of depassivation takes an initiation period, tp, ———————————————— •

•

Ms. Akshatha Shetty is currently pursuing her PhD program in Department of Civil Engineerimg NITK, Surathkal. E-mail: [email protected] Co-Authors: Katta Venkataramana and Babu Narayan K.S. are professors in the Department of Civil engineering NITK Surathkal. Srinivasnagar- 575025

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which is the time from construction to the time of initiation of corrosion (depassivation). It had been noted that the initiation and propagation of corrosion in the specimens depend on many factors; the important among them are given below [6]: i. Permeability of the concrete matrix; ii. Cover thickness; iii. The electric current applied; iv. Density of the solution used; v. The environmental temperature.

Fig. 1: Typical deterioration levels for a steel reinforced concrete structure suffering from corrosion [7]. The propagation phase starts from the time of depassivation, tp, to the final state, is reached at a critical time, tcr, at which corrosion would produce spalling of concrete cover or cracking through the whole of concrete cover. During the propagation period, i.e. corrosion period, tcor, which begins at the moment of depassivation, the rebar corrosion is usually assumed to be in a steady state, as indicated by a straight line in Fig. 1. The critical time, tcr, as defined above can be expressed as:

t cr = t p + t cor

(1)

For reinforced concrete, it has been assumed reasonable to equate the unacceptable corrosion damage to the onset of 111


spalling of concrete cover. Therefore, the service life can be equated to the critical time, as given by equation (1). The depassivation time, tp, can be assumed to be zero when the quantity of free chloride ions, introduced in concrete at the time of construction itself by any means, is found to be more than the rebar corrosion threshold value. The corrosion of rebar in concrete is generally considered as an electrochemical process [8], [9], [10], [11]. With attention of researchers focusing towards the prediction of the residual life of reinforced concrete structures affected by reinforcement corrosion, the use of electrochemical techniques for the determination of relevant parameters in this regard becomes a major area of durability study. Therefore nowadays the electrochemical techniques are widely used for the study of rebar corrosion in laboratories together with their application to real life structures [12].

Specimens were immersed in a 5% NaC1 solution for 8 days. Current required to achieve different corrosion levels can be obtained using Faraday’s law. The amount of current to be applied to obtain required corrosion levels of 2.5%, 5% and 7.5% and 10% are respectively 2.5A, 5A, 7.5A and 10A. For each trial, three specimens were considered. A photo of accelerated corrosion of beam specimen is shown in Fig. 3. After completion of accelerated corrosion the corrosion rate is monitored with applied corrosion monitoring instrument as in Fig. 4, based on Linear Polarization Resistance (LPR) method.

1.2 Effects of corrosion on the structural behavior It has been already accentuate that corrosion of reinforcing bars produces effects on the structural behavior of RC members. This phenomenon involves due to the reduction in the bond strength of two composite materials i.e. steel and concrete. The effects of steel corrosion are mainly distinguishing between the “local” effects, i.e. at the RC member level, and the “global” effects, i.e. at the RC structure level. It is worth noting that, among the global consequences of corrosion on the structural performance, together with the decline of load carrying capacity and ductility, also the shift of the failure mechanism and detrimental torsion effects may occur [13].

Fig. 2: Reinforcement details of beam specimen (NBS beam)

2 EXPERIMENTAL PROCEDURES 2.1 Preparation of NBS Specimens National bureau of Standard (NBS) beam specimens of size 2.15mx0.457mx0.203m were designed as an under reinforced section as per IS 456-2000 [14] for the present study. A total fifteen number of specimens were cast and a mass concreting was adopted for the huge specimens. TMT rebar of 25mm diameter bar was placed at a cover depth of 50mm from bottom and 12mm hanger rebar was provided at top and Side bars of 12mm with a stirrups of 8mm diameter as in Fig. 2. Concrete mix for M30 Grade was prepared using Ordinary Portland cement concrete (OPC), fine sand and aggregate (20 & 12.5mm) as per IS 10262:2009 [15]. Mix proportion of 1: 1.77: 2.87 was used for the present study. Water cement ratio of 0.45, with an addition of 2ml/kg of a commercially available chemical admixture was used to get desired. Slump obtained was 58mm. Specimens were kept in water for 28 days of curing. Compressive strength of 34.44N/mm 2 achieved at the end of 28days.

2.2 Accelerated Corrosion Technique The electrochemical corrosion technique was used to accelerate the corrosion of steel bars embedded in the beam specimens. Electrical wires were connected to the rebar at both the ends and it was left outside to impress current, at one end and monitoring of specimen at the other end. 112

Fig. 3: A Photo of accelerated corrosion of beam specimen The corrosion current density was calculated by using the Stern-Geary formula. (1) where,

icorr = corrosion current density (ìA/cm2)

Rp

= polarization resistance (kÙ cm2).

B = 26 mV (for steel in active condition this value is normally used). Using Faraday’s law, the corrosion rate in mm/year obtained from gravimetric measurement was converted to corrosion current density (μA/cm2) by assuming uniform corrosion over the rebar surface by the following equation [16], [17], [18]: ICICE-2013

INTERNATIONAL CONFERENCE ON INNOVATIONS IN CIVIL ENGINEERING 9th and 10th of May 2013 rate ( mm / year ) =

Corrosion

0 . 0327 × a × i corr n× D

(2)

where, a =atomic weight of iron, i.e. 55.84 amu n = no. of electrons exchanged in corrosion reaction, i.e. 2 for iron and

=density of rebar (7.85g/cm3).

Fig. 6: Position of Dial gauges at centre and load points

Fig. 4: Monitoring of Test Specimen

3 Test Setup

D

The beam specimens were tested under four point bending to determine load and deflection measurements. Dial gauges were fixed at the top side (two at load points and one at centre) to measure the deflection at each load increment. Proving ring of 50 tonnes capacity was used to note the applied load (Fig. 5 and Fig. 6). Pump of the hydraulic jack (50 tonne capacity) was operated by a hand lever. In the present paper only central deflection behaviour with increase in the load for different degree of corrosion levels is calculated. Effect of corrosion on load -deflection curve is shown in Fig. 7.

Fig.7: Effect of corrosion on load with central deflection curve

4 CONCLUSIONS Beam specimens of different degree of corrosion levels such as 2.5%, 5% 7.5% and 10% beam respectively failed at 0.94, 0.92, 0.88 and 0.85 times than that of the control specimens. It is observed that as the corrosion level increases load carrying capacity decreases as well as the deflection increases. The explanation for this may be that, as steel reinforcement yielded, bond between reinforcement steel and concrete failed, and the deflection increased with higher corrosion percentage.

5. ACKNOWLEDGMENT This research has been funded by the Board of Research in Nuclear Science (BRNS), Government of India.

REFERENCES [1]

A. Raman, A .Razvan, B. Kuban, K.A. Clement and E. Gravesw, “ Characteristics of the rust from weathering steels in Louisiana bridge spans,” Corrosion NACE, Vol. 42, No. 8, pp. 447-455, 1986.

[2]

K.K. Sagoe- Crentsil, and F.P. Glasser, “Analysis of the steel concrete interface,” 3rd Symp. Corrosion of reinforcement in Concrete, Edt. C.L.Page et al. pp. 74-96, (Elsevier Applied Sci-

Fig. 5: Test set up of NBS beam Specimen

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113

INTERNATIONAL CONFERENCE ON INNOVATIONS IN CIVIL ENGINEERING 9th and 10th of May 2013 ence), 1990. [3]

[4]

[5]

A.G. Constantinou, K.L. Scrivener, C. Alonso, and C. Andrade, “The corrosion of steel in concrete subjected to chloride and carbon dioxide environment”, Conf. on cement and Concrete Science, Oxford, Sept, 1992. Dong Chen, and Sankaran Mahadevan, “Chloride induced reinforcement corrosion and concrete cracking simulation,” Cement and Concrete Composites, Vol. 30, pp. 227-238, April 2007. C.Alonso, C. Andrade, J. Rodriguez, and J.M. Diez. “Factors controlling cracking of concrete affected by reinforcement corrosion,” Materials and structures, Vo.31, August/September 1998, pp. 435-441.

[6]

S. Ahmad, “Reinforcement Corrosion in Concrete Structures, Its Monitoring and Service Life Prediction––A Review,” Cement & Concrete Composites, Vol. 25, pp. 459–471.

[7]

Fib (International Federation of Structural Concrete) Bulletin, “Model Code for Service Life Design,” ISBN 978-2-88394-0741, Vol. 34, 2006.

[8]

T. Maheswaran, J. G. Sajavan, “A semi-closed form solution for chloride diffusion in concrete with time varying parameters,” Journal of Material Concrete Research, Vol. 56, pp. 359-366, 2004.

[9]

[10]

114

B. Elsener, “Macrocell corrosion of steel in concrete implications for corrosion monitoring.” Journal of Cement concrete Composites. Vol. 24, pp. 65-72, 2002. M.A. EI-Gelany, “Short-term corrosion rate measurement of OPC and HPC reinforced concrete specimens by electrochemical techniques”. Journal of Material Structures, Vol. 34, pp. 426-432, 2001.

\[11] T. Liu. R.W. Weyers, “Modelling the dynamic corrosion process in chloride contaminated concrete structures,” Journal of Cement Concrete research, Vol. 28, pp. 365-379 1998. [12]

C. Andrade and C. Alonso. “Corrosion rate monitoring in the laboratory and on site,” Journal of Construction building materials, Vol. 10, pp. 315-328, 1996.

[13]

P. Simioni, “Seismic response of reinforced concrete structures affected by reinforcement corrosion,” Thesis of Civil engineering and environmental Sciences university, Braunschweig and Florence, 2009.

[14]

IS 456:2000, Indian Standards, “Plane and reinforced concrete “– code of practice, Bureau of Indian Standards, New Delhi, 2000.

[15]

IS 10262-2009, Indian Standards, “Concrete mix proportioning guidelines,” Bureau of Indian Standards, New Delhi, 2009.

[16]

D. Trejo and P.J. Monteiro, “Corrosion performance of conventional (ASTM A615) and low-alloy (ASTM A706) reinforcing bars embedded in concrete and exposed to chloride environments,” Cement and Concrete Research, Vol. 35, No. 3, pp. 562 -71, May 2005.

[17]

B. Pradhan, and B. Bhattacharjee, “Performance evaluation of rebar in chloride contaminated concrete by corrosion rate,” Construction and Building Materials, Vol. 23, No. 6, pp. 2346-2356, June 2009.

[18]

C. Andrade and C. Alonso, C. Gonzalez, J.A. and J. Rodriguez “Remaining service life of corroded structures”, Proceedings of [ABSE Symposium on Durability of structures, Lisbon, pp. 359363, September 1989.

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Assessment of First Order Computational Model for Free Vibration Analysis of FGM Plates K. Swaminathan, D. T. Naveenkumar Abstract— This paper presents the complete theoretical formulation and the analytical solutions for the free vibration analysis of functionally graded material (FGM) plates using First-order Shear Deformation Theory (FSDT). The material properties are assumed to be isotropic along the plane of the plate and vary through the thickness according to the power law function. The equations of motion are obtained using Hamilton’s principle. The analytical solutions are obtained in closed-form using Navier’s solution technique and by solving the eigenvalue equation. Index Terms— Analytical solution, Functionally graded Material plates, First-order model, Hamilton’s principle, Navier’s method, Power law function, Shear deformation.

—————————— ——————————

1 INTRODUCTION

T

he concept of Functionally Graded Materials (FGMs) was proposed in 1984 by materials scientists as a means of preparing thermal barrier materials. FGMs are the heterogeneous composite materials in which the material properties are gradually varied along certain directions in a predetermined manner. Thus, mitigating the problems induced due to sudden change of thermomechanical properties as in the case of laminated composites. FGMs have a great potential of becoming an advanced structural material in various engineering and industrial applications. Therefore, to use them efficiently a good understanding of their structural and dynamical behavior and also an accurate knowledge of the deformation charecteristics, stress distribution, natural frequencies and buckling loads under various load conditions are needed. Several analytical and numerical approaches have been proposed by various authers for the analysis of FGM plates. Hamilton’s principle and assumed mode technique were used to study the parametric resonance of FGM rectangular plates based on classical plate theory under harmonic in-plane loading [1]. A meshfree radial point interpolation method was employed for static and dynamic analyses of FGM plates based on First-order Shear Deformation Theory (FSDT) [2]. First five natural frequencies of an FGM plate were maximized using FSDT along with FEM [3]. The CPT was employed to show that FGM plates can be idealized as homogeneous plates by properly selecting the reference surface so that no special tool is required to analyse their behavior [4]. A Levi type solution was employed for free vibration analysis of FGM plates based on FSDT, where two opposite edges are simply supported and other two edges under various boundary conditions [5]. ————————————————

•

K. Swaminathan, Professor Department of Civil Engineering, NITK Surathkal, India, PH-09448477825. E-mail: [email protected]

•

D. T. Naveenkumar, Research scholar, Department of Civil Engineering, NITK Surathkal, India, PH-09632553840. E-mail: [email protected]

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In this paper, an attempt has been made to compare and assess quantitatively the accuracy of the results obtained using Firstorder computational model for predicating free vibration response of simply supported FGM plates.

2 DISPLACEMENT MODEL Based on the FSDT the displacement field at a point in an FGM plate is expressed as [7],

u ( x, y , z ) = u0 ( x, y ) + z θ x ( x, y ), v ( x, y , z ) = v0 ( x, y ) + z θ y ( x, y ),

(1)

w( x, y , z ) = w0 ( x, y ). Where the terms u, v and w are the displacements of a general point (x, y, z) in x, y and z directions respectively. Where the terms u0, v0 are the in-plane displacements and the term w0 is the transverse displacement of a general point (x, y) on the middle plane. The functions è x, è y are rotations of the normal to the middle plane about y and x axes respectively. The strain is assumed to be linear through the thickness of the FGM plate (2)

(3)

2.1 Constitutive Relationship Assuming through the thickness gradation of material properties, the volume fraction composition is defined using power law function as, (4)

115


Where, Em = Young’s modulus of metal, Ec = Young’s modulus of ceramic, p=Parameter that dictates the variation of material profile through the thickness, ν=Poisson’s ratio, h=Thickness of the plate. The stress-strain relationship accounting for the transverse shear deformation is given by,

{σ} = [Q]{ε}. Where,

(5)

{σ} = Stress vector,

=

Q 22 =

Q 44

=

Q 55

=

E(z)

( ) 1-ν

Q 66

2

,

Q12 E(z)

=

2(1+ν)

=

Q 21

=

νQ11 ,

.

2.3 Govering equations The governing equations of motion are derived using Hamilton’s principle. The equations of motion associated with the present firstorder computational model are,

∂N x

δ uo : δ vo : δθ x : δθ y :

∂x ∂N y ∂y ∂M x ∂x ∂M y

δ w0 :

∂y ∂Qx ∂x

∂N xy

+

= I1&& v 0 + I 2&& θy,

∂x

+ + +

∂M xy ∂y ∂x ∂y

h/2

(6)

∂M xy ∂Q y

− Qx = I3&& θ x + I 2 && u0 ,

⎡ Q44

[B] = ∫ ⎢ Q −h/2

− Q y = I 3&& θ y + I 2 v&&0 ,

(10)

Where the matrices [A], [A ′], [B], [B′], [D], [D′], [E], [E ′] are the matrices of plate stiffness whose elements are defined as,

h/2

∂N xy

+

(9)

⎧ θy ⎫ ⎧ θx ⎫ ⎧⎪Qy ⎫⎪ ⎪ ⎪ ⎪ ⎪ ⎨ * ⎬ = [E] ⎨∂w0 ⎬ + [E ′] ⎨∂w ⎬. ⎪ ⎪ ⎪ 0⎪ ⎩⎪Qy ⎪⎭ ⎩ ∂x ⎭ ⎩ ∂y ⎭

⎡ Q11 Q12 Q11 z ⎢Q Q22 Q12 z [A] = ∫ ⎢ 12 ⎢Q11 z Q12 z Q11 z 2 −h/2 ⎢ 2 ⎣Q12 z Q22 z Q12 z

u 0 + I 2&& θx , = I1&&

∂y

(8)

⎧ θy ⎫ ⎧ θx ⎫ ⎧⎪Qx ⎫⎪ ⎪ ⎪ ⎪ ⎪ ⎨ * ⎬ = [D] ⎨∂w ⎬ + [D′] ⎨∂w0 ⎬, ⎪ 0⎪ ⎪ ⎪ ⎩⎪Qx ⎭⎪ ⎩ ∂x ⎭ ⎩ ∂y ⎭

[Q ] = Transformed elastic stiffness matrix,

{ε} = Strain vector. Q11

⎧ ∂u0 ⎫ ⎧ ∂u0 ⎫ ⎪ ∂x ⎪ ⎪ ∂y ⎪ ⎪ ⎪ ⎪ ⎪ ⎪ ∂v0 ⎪ ⎪ ∂v ⎪ ⎪ ⎪ ⎪ 0⎪ y ∂ ⎧⎪N xy ⎫⎪ ⎪ ⎪ ⎪ ∂x ⎪ ' ⎨ ⎬ = ⎡⎣B ⎤⎦ ⎨ ⎬ + [B′] ⎨ ⎬' ⎪⎩M xy ⎪⎭ ⎪∂θ x ⎪ ⎪∂θ x ⎪ ⎪ ∂x ⎪ ⎪ ∂y ⎪ ⎪ ⎪ ⎪ ⎪ ⎪∂θ y ⎪ ⎪∂θ ⎪ ⎪ ⎪ ⎪ y⎪ ⎩ ∂y ⎭ ⎩ ∂x ⎭

⎣

44

h/2

[D] = ∫ [Q

z

Q44 Q44 z

66

Q66 ] dz ,

55

Q55 ] dz ,

Q44 z Q44 z

2

Q12 z ⎤

Q22 z ⎥

⎥ dz , ⎥ 2⎥ Q22 z ⎦ Q12 z

2

Q44 z ⎤

dz , 2 Q44 z ⎥⎦

−h/2

+

&& 0 . + Pz = I1 w

h/2

[E] = ∫ [Q −h/2

Here (Nx, Ny, Nxy), (Mx, My, Mxy) and (Qx, Qy) respectively denotes in-plane, bending and shear stress resultants, which can be defined as,

⎧ ∂u0 ⎫

⎧ ∂u0 ⎫

⎪ ∂x ⎪ ⎪ ∂y ⎪ ⎪ ⎪ ⎪ ⎪ ⎧Nx ⎫ ⎪ ∂v0 ⎪ ⎪ ∂v0 ⎪ ⎪N ⎪ ⎪ ⎪ ⎪⎪ ∂x ⎪⎪ y ∂ ⎪ y⎪ ⎪ ⎪ ⎨ ⎬ = [A] ⎨ ⎬ + [A′] ⎨ ⎬' ⎪M x ⎪ ⎪∂θ x ⎪ ⎪∂θ x ⎪ ⎪⎩M y ⎪⎭ ⎪ ∂x ⎪ ⎪ ∂y ⎪ ⎪∂θ ⎪ ⎪ ⎪ ⎪ y⎪ ⎪∂θ y ⎪ ⎩⎪ ∂y ⎭⎪ ⎩⎪ ∂x ⎭⎪

116

[ A′] = [ B′] = [C ′] = [ D′] = 0. 2.4 The Navier Solutions The following boundary conditions are imposed for a simply supported rectangular FGM plate having thickness h with sides a and b. At edges x=0 and x=a;

v0 = 0; w0 = 0; θ y = 0; (7)

M x = 0; N x = 0;

(11)

At edges y= 0 and y = b

u0 = 0; w0 = 0; θ x = 0; M y = 0; N y = 0;

(12)

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X 44 = A33α + B23 β + D11 , 2

∞

∞

∑∑ u

u0 =

m =1 n =1 ∞

2

0 mn

m =1 n =1 ∞

w0 =

sin α x cos β y e

∞

∑∑ w m =1 n =1 ∞

0 mn

-iωt

sin α x sin β y e

∞

θ x = ∑ ∑ θ x cos α x sin β y e

X ij = X ji ,

-iωt

(13)

-iωt

mn

m =1 n =1 ∞

X 45 = A34αβ + B24αβ ,

-iωt

X 55 = A44 β + B24α + E11 ,

∞

∑∑v

v0 =

cos α x sin β y e

0 mn

2

∞

θ y = ∑ ∑ θ y sin α x cos β y e

-iωt

mn

m =1 n =1

Where,

α= Where,

α=

mπ a mπ a

and β =

and β =

nπ

.

b

Substituting eqn. (11)-(13) in in eqn. (6) and collecting the coefficients, one obtain

⎧u 0 ⎫ ⎪ ⎪ ⎪v0 ⎪ ⎪ ⎪ ([ X ]5 X 5 − λ [ M ]5 X 5 ) ⎪⎨ w0 ⎪⎬ = 0, ⎪ ⎪ ⎪θ x ⎪ ⎪ ⎪ ⎪⎩θ y ⎪⎭5×1

X 11 = A11α + B11 β , 2

X 12 = A12αβ + B12αβ , X 13 = 0, X 14 = A13α + B13 β , 2

2

X 15 = A14αβ + B14αβ , X 22 = A22 β + B12α , 2

2

X 23 = 0, X 24 = A23αβ + B13αβ , X 25 = A24 β + B14α , 2

2

X 33 = D12α + E12 β , 2

X 34 = D11α , X 35 = E11 β ,

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2

For any fixed values of m and n. The elements of mass matrix [M] are given as,

M1,1 =I1

M1,2 = 0

M1,3 = 0

M1,4 =I 2

M1,5 = 0

M 2,2 =I1

M 2,3 = 0

M 2,4 = 0

M 2,5 =I 2

M 3,3 =I1

M 3,4 = 0

M 3,5 = 0

M 4,4 =I3

M 4,5 = 0

M 5,5 =I3

In this section, the numerical examples solved are described and discussed. A shear correction factor of 5/6 is used in the present model for computing results. For all the problems, a simply supported rectangular FGM plate with SS-1 boundary conditions is considered for the analysis. The following sets of data are used in obtaining numerical results, Material set 1 [7].

E m = 70GPa,

ν = 0.3,

ρ = 2702kg / m

3

,

E c = 200GPa,

ν = 0.3,

ρ = 5700kg / m

3

,

E m = 70GPa,

ν = 0.3,

ρ = 2702kg / m ,

E c = 380GPa,

ν = 0.3,

p = 1.

Where λ=ω

2

.

(1)

For any fixed values of m and n. The elements of coefficient matrix [X] are given as, 2

i , j = 1 to 5.

3 NUMERICAL RESULTS AND DISCUSSION

.

b nπ

2

Material set 2 [8]. 3

ρ = 3800kg / m , 3

p = Open. Results are reported using the following non-dimensional form,

⎛ a 2 ⎞ ρm ⎟ ⎝ h ⎠ Em

ωmn = ωmn ⎜

Example 1: A simply supported FGM square plate is considered for the analysis. Material set 1 is used. The nondimensionalized values of natural frequency for various side-to-thickness ratio (a/h) are given in Table 1. The non-dimensionalized values of natural frequency are found to increase with increase in the side-to-thickness ratio. It is found that at lower thickness modes, the present results are in good agreement with the exact three-dimensional elasticity solution [7] where as significant difference between the ptesent results and exact solution exists at higher thickness modes. Example 2: A simply supported FGM plate with side-to-thickness ratio equal to 5 is considered for the analysis. Material set 2 is used. The nondimensionalized values of natural frequency for various aspect ratio (a/b) and power law function are given in Table 2. For any given a/b ratio, the non-dimensionalized natural frequency decreases as the power law function p increases and for any given power law

117


function value p as the a/b value increases, the natural frequency increases.

4

CONCLUSION

[4]

Analytical formulations and solutions to study the free vibration response of simply supported FGM rectangular plates using a firstorder computation model are presented. The accuracy of the solution is first established by comparing the results with exact threedimensional elasticity solution available in the literature. After establishing the accuracy of prediction, new results for the FGM plates with varying side-to-thickness ratio, aspect ratio, and power law function are presented. TABLE 1 NON-DIMENSIIONALIZED NATURAL FREQUENCY

Thickness mode 1 2 3 4 5 1 2 3 4 5 1 2 3 4 5

a/h

5

10

10

[3]

3D exact solution [7] 5.4806 14.558 24.381 53.366 57.620 5.9609 29.123 49.013 207.50 212.22 6.1076 58.250 98.145 823.92 828.78

[5]

[6]

[7]

Present FSDT 5.6908 15.341 25.925 57.812 62.691 6.1864 30.686 51.866 225.25 230.60 6.3372 61.374 103.74 894.88 900.37

[8]

R.C. Batra, and J.Jin, “Natural frequencies of a functionally graded anisotropic rectangular plate,” Journal of Sound and Vibration, vol. 282, no. 12, pp. 509–516, 2005, doi: 10.1016/j.jsv.2004.03.068. S. Abrate, “Functionally graded plates behave like homogeneous plates,” Composites part B: engineering, vol. 39, no. 1, pp. 151–158, 2008, doi: 10.1016/j.compositesb.2007.02.026. S. Hosseini-Hashemi, M. Fadaee, and , S.R. Atashipour, "A new exact analytical approach for free vibration of Reissner–Mindlin functionally graded rectangular plates " , International Journal of Mechanical Sciences, vol. 53, no. 1, pp. 11–22, 2011, doi: 10.1016/j.ijmecsci.2010.10.002. J.M. Whitney and N.J. Pagano, “Shear deformation in heterogeneous anisotropic plates,” Computer Methods in Applied Mechanics and Engineering, vol. 37, pp. 1031-1036, 1970, doi: doi: 10.1115/1.3408654. S.S. Vel and R.C. Batra, “Three-dimensional exact solution for the vibration of functionally graded rectangular plates,” Journal of Sound and Vibration, vol. 272, no. 3-5, pp. 703–730, 2004, doi: 10.1016/S0022460X(03)00412-7. A.M. Zenkour, “A comprehensive analysis of functionally graded sandwich plates: Part 2—Buckling and free vibration,” International Journal of Solids and Structures, vol. 42, no. 18-19, pp. 5224–5242, 2005, doi: 10.1016/j.ijsolstr.2005.02.015.

TABLE 2 NON-DIMENSIIONALIZED NATURAL FREQUENCY

p 0 0.5 1 5 10

1.0 10.374 8.8650 8.0107 6.7767 6.5019

1.5 15.857 13.602 12.306 10.330 9.8731

a/b 2.0 22.683 19.536 17.700 14.739 14.029

2.5 30.414 26.298 23.861 19.720 18.695

3.0 38.732 33.614 30.542 25.073 23.681

REFERENCES [1]

[2]

T. Ng, K. Lam, and K Liew, “Effects of FGM materials on the parametric resonance of plate structures,” Computer Methods in Applied Mechanics and Engineering, vol. 190, no. 8-10, pp. 953–962, 2000, doi: 10.1016/S0045-7825(99)00455-7. K.Y. Dai, G.R. Liu, K.M. Lim, X. Han and , S.Y. Du, “A meshfree radial point interpolation method for analysis of functionally graded material (FGM) plates,” Computational Mechanics, vol. 34, no. 3, pp. 213–223, 2004, doi: 10.1007/s00466-004-0566-0.

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Higher order computational model for the thermo-elastic analysis of cross-ply laminated composite plates K. Swaminathan, Reginald Fernandes Abstract— Analytical formulations and solutions for the stress analysis of simply supported cross-ply laminated composite plates subjected to thermal load based on higher order refined theory are presented. In addition, another higher order theory and the first-order theory developed by other investigators and already available in the literature are also considered for the evaluation. The equation of equilibrium is obtained using Principal of Minimum Potential Energy (PMPE). Solutions are obtained in closed form using Navier’s technique by solving the boundary value problem. The transverse stresses are obtained by integrating equilibrium equations. Plates with different aspect ratio are studied. Numerical results are presented for the displacments and the stresses. Index Terms— Analytical solution, Composite plates, Higher-order theory, Navier’s solution, Stress analysis, Thermo-elastic, Thermal load .

—————————— ——————————

1 INTRODUCTION

M

ulti-layered plates made up of composite materials are widely used in aerospace, aeronautical, automobiles and other hi-tech industries. Mathematical modeling and behavior of these structural components subjected to severe thermal loading has attracted considerable attention. Delamination of layers and longitudinal cracks in the matrix are predominant cause of failure of composite plates subjected to severe thermal loading, therefore developing very accurate and efficient theoretical model for thermo-elastic analysis of composite plates have constantly been an important area of research. The thermal-membrane coupling effect was found to be very significant in the thermo-elastic analysis of antisymmetric cross ply and angle ply laminates [1]. The finite element formulations and solutions using first order shear deformation theory (FSDT) and penalty finite element was presented for the thermal analysis of multi-layered plates [2]. A generalized Levy type solution in combination with state-space method is used to analyses the thermal bending of cross-ply laminated plates [3]. To get complete insight in to this area, researchers may refer to the review article on the various computational models used for the thermo-elastic analysis of multi-layered plates [4], [5]. A discrete-layer shear deformation laminated plate theory is used to analyses steadystate thermal stresses in laminated plates [6]. A displacement centered higher order theory which employs realistic displacement variations through the thickness is presented in [7]. In-order to overcome the limitation of classical and first order shear deformation theory, globahigher-order based on power series for the evaluation of inter-laminar stresses subjected to thermal loading have been devel

oped by [8]. A global-local higher order theory combined with finite element method is been used to capture the response details of laminate subjected to thermal loading [9]. In this paper, an attempt has been made to compare and assess quantitatively the accuracy of the results obtained using the various higher order models in predicating the thermal stresses of simply supported cross-ply laminated composite plates subjected to thermal loading.

2 DISPLACEMENT MODELS The following two higher order and the first order shear deformation models are considered. PRESENT [10] ∗

∗

u ( x, y , z ) = u0 ( x, y ) + z θ x ( x, y ) + z u0 ( x, y ) + z θ x ( x, y ) 2

∗

3

∗

v ( x, y , z ) = v0 ( x, y ) + z θ y ( x, y ) + z v0 ( x, y ) + z θ y ( x, y ) 2

3

w( x, y , z ) = w0 ( x, y ) HSDT5 [11]

⎡

u ( x, y, z ) = u 0 ( x, y ) + z ⎢θx ( x, y ) −

4⎛ z⎞

2

{

⎜ ⎟ θx ( x, y ) + 3⎝h⎠

∂w0

}⎤⎥⎦

∂x ⎣ 2 4⎛ z⎞ ⎧ ∂ w ⎫⎤ ⎡ v( x , y , z ) = v0 (x , y ) + z ⎢θ y ( x , y ) − ⎜ ⎟ ⎨θ y ( x, y ) + 0 ⎬⎥ 3⎝h⎠ ⎩ ∂ y ⎭⎦ ⎣ w ( x, y, z ) = w0 ( x , y )

FSDT [12]

————————————————

•

K. Swaminathan, Professor, Department of Civil Engineering, NITK Surathkal, India, PH-09448477825. Email: [email protected]

•

Reginald Fernandes, Research scholar, Department of Civil Engineering, NITK Surathkal, India, PH-09880536130. E-mail: [email protected]

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The parameters u0 , v0 are the in-plane displacements and w0 is the transverse displacement of a point (x, y) on the middle plane (z=0). The functions θ x , θ y are the rotations of the normal to the middle ∗ ∗ ∗ plane about y- and x- axes, respectively. The parameters u0 , v0 , θ x , ∗ θ y are the higher-order terms in the Taylor’s series expansion and they represent higher-order transverse cross-sectional deformation modes. The stress-strain relationship accounting for the transverse shear deformation and thermal effects is given by

{σ } = [Q ]{ε } − [Q ]{α } ΔT

In-plane normal stress (σ x ) : ( a / 2, b / 2, + h / 2) (σ y ) : ( a / 2, b / 2, − h / 2) In-plane normal stress In-plane shear stress (τ xy ) : (0, 0, − h / 2) Transverse shear stress (τ xz ) : (0, b / 2, ± h / 6) Transverse shear stress (τ yz ) : ( a / 2, 0, ± h / 6) Example: A steady-state thermo-elastic bending of a simply supported three layer cross-ply (0/90/0) square laminated plate (a=b) is analyzed.

(4)

TABLE 1 IN-PLANE AND TRANSVERSE DISPLACEMENTS FOR THERMAL LOADING

Where, {σ } = Stress vector

a/h

elastic coefficients = [Q ]Transformed

{ε } = Strain vector

4

{α } =Thermal expansion coefficient vector ΔT = Temperature rise in the laminate

10

The equations of equilibrium are obtained using principal of Minimum Potential Energy (PMPE). Solutions are obtained in closed form using Navier’s technique by solving the boundary value problem. The in-plane stresses are computed using the constitutive relationship and the transverse stresses are obtained by integrating the 3D elasticity equilibrium equations.

20

3 NUMERICAL RESULTS AND DISCUSSION

50

In this section, the numerical example solved is described and discussed. A steady state thermo-elastic bending of a simply supported cross-ply laminated plate is considered for analysis. The material properties and the thickness of each layer are uniform. The material constants considered are as follows [7]:

MODEL

u

v

w

PRESENT

14.58 14.45 9.17 18.11 15.85 15.58 14.30 16.61 15.96 15.88 15.53 16.17 15.99 15.97 15.92 16.02

71.88 62.52 71.14 81.83 29.49 27.87 29.70 31.95 19.66 19.24 19.71 20.34 16.59 16.52 16.60 16.71

25.67 25.78 22.75 42.69 14.17 14.11 13.30 17.39 11.27 11.25 11.03 12.12 10.36 10.36 10.32 10.50

HSDT5

FSDT EXACT [7] PRESENT HSDT5



FSDT EXACT [7]

TABLE 2 IN-PLANE AND TRANSVERSE STRESSES FOR THERMAL LOADING

E1 / E2 = 25,

E2 = E3 = 1,

ν 12 = ν 13 = ν 23 = 0.25,

G12 = G13 = 0.5,

G23 = 0.2

a/h

α 2 / α1 = 1125

Results reported are using the following non-dimensional form:

w=

w hα1 T0 S

σx =

τ xz

=

2

σx E2 α1 T0

τ xz E2 α1 T0

u =

σy =

τ yz

=

u hα1 T0 S

σy E2 α1 T0

τ yz

Where,

E2 α1 T0

v =

τ xy

=

4

v hα1 T0 S 10

τ xy E2 α1 T0 S=

a

20

h

Unless otherwise specified within the table the location (i.e. x,y and z coordinates) for values of displacements and stresses for present evaluation are as follows: In-plane displacements (u ) : (0, b / 2, − h / 2) In-plane displacements (v ) : ( a / 2, 0, − h / 2) Transverse displacement ( w) : ( a / 2, b / 2, ± h / 2)

50

MODEL

σx

σy

τ xy

τ xz

τ yz

PRESENT

898 880.1 471.0 1183 964 942 842 1026 965 958 931 982 964.9 963.7 959.3 967.5

890.2 919.8 896.8 856.1 1023 1028 1023 1014 1054 1055 1054 1051 1063 1063 1063 1063

135.8 120.9 126.2 157.0 71.23 68.26 69.10 76.29 55.95 55.16 55.36 57.35 51.17 51.05 51.08 51.41

94.5 95.6 104.2 84.81 62.16 62.52 63.60 60.54 34.23 34.29 34.44 33.98 14.09 14.10 14.11 14.07

-135.74 -137.78 -134.50 -121.87 -66.65 -66.82 -66.61 -66.01 -34.86 -34.88 -34.85 -34.76 -14.13 -14.13 -14.13 -14.13

HSDT5




FSDT EXACT [7]

CC

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Fig. 1. Through thickness variation of In-plane displacement ratio of a/h=10

Fig. 2. Through thickness variation of In-plane normal for ratio of a/h=10

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σx

u

for

stress

Fig. 3. Through thickness variation of Transverse shear stress τ xz for ratio of a/h=10

Fig. 4. Through thickness variation of Transverse shear stress for ratio of a/h=10

121

τ yz


The plates are loaded through a temperature distribution of the form:

ΔT ( x , y , z ) =

2T0 h

⎛ π x ⎞sin ⎛ π y ⎞ ⎟ ⎜ ⎟ ⎝ a ⎠ ⎝ b ⎠

z sin ⎜

The non-dimensional values of in-plane and transverse displacements and the stresses for various values of a/h ratio are given in Table 1 and Table 2. It is found that the results generated using the three models are in good agreement with the exact threedimensional elasticity solution for thick to relatively thin plates, whereas considerable difference in numerical values exists in the case of very thick plates (i.e. a/h=4). This is attributed to the fact that these models do not represent the higher-order transverse cross sectional deformation modes, which is very significant in thick plates. Fig. 1 represents through the thickness variation of in-plane displacement. The through the thickness variation of in-plane and transverse stresses are shown in Fig. 2, Fig. 3 and Fig. 4. It is found that the variation of all the three models are in close agreement with each other.

Wise Theories for Computing Inter-Laminar Stresses of Laminated Composite Plates Subjected to Thermal Loadings," Composite Structures, vol. 64, no. 2, pp. 161-177, 2004, doi: 10.1016/j.compstruct.2003.08.001. [9] W. Zhen, and C. Wanji, "An Efficient Higher-Order Theory and Finite Element for Laminated Plates Subjected to Thermal Loading," Composite Structures, vol. 73, no. 1, pp. 99-109, 2006, doi: 10.1016/j.compstruct.2005.01.034. [10] B.N. Pandya, and T. Kant, "Finite Element Stress Analysis of Laminated Composites Using Higher Order Displacement Mode," Composites Science and Technology, vol. 32, no. 2, pp. 137–155, 1988, doi:10.1016/0266-3538(88)90003-6. [11] J.N. Reddy, "A Simple Higher-Order Theory for Laminated Composite Plates," Journal of Applied Mechanics, vol. 51, no. 4, pp. 745–752, 1984, doi: 10.1115/1.3167719. [12] J.M. Whitney, and N.J. Pagano, "Shear Deformation in Heterogeneous Anisotropic Plates," Journal of Applied Mechanics, vol. 73, no. 1, pp. 1031–1036, 1970, doi: 10.1115/1.3408654.

4 CONCLUSION Analytical formulations and solutions for the thermal stress analysis of simply supported cross-ply laminated composite plates using higher- order shear deformation theory is presented. The maximum and through the thickness variation of displacements and stresses with varying side-to-thickness ratio are discussed. The accuracy of each model in prediciting the displacments and stresses are established by comparing the results with the three-dimensional elasticity solutions. The bench mark numerical results presented herein will provide a good reference for researchers working in the area of thermo-elastic analysis of composite plates.

References [1]

[2]

[3]

[4]

[5]

[6]

[7]

[8]

C.H. Wu and T.R. Tauchert, "Thermo-Elastic Analysis of Laminated Plates. 2: Antisymmetric Cross-Ply and Angle-Ply Laminates," Journal of Thermal Stresses, vol. 3, no. 3, pp. 365-378, 1980, doi:10.1080/01495738008926975. J.N. Reddy and Y.S. Hsu, "Effects on Shear Deformation and Anisotropy on Thermal Bending of Layered Composite Plates," Journal of Thermal Stresses, vol. 3, no. 4, pp. 475-493, 1980, doi:10.1080/01495738008926984. A.A. Khdeir and J.N. Reddy, "Thermal Stresses and Deflections of CrossPly Laminated Plates Using Refined Plate Theories," Journal of Thermal Stresses, vol. 14, no. 4, pp. 419-438, 1991, doi: 10.1080/01495739108927077. T.R. Tauchert, "Thermally Induced Flexure, Buckling and Vibration of Plates," Applied Mechanics Review, vol. 44, no. 8, pp. 347-360, 1991, doi: 10.1115/1.3119508. A.K. Noor, and W.S. Burton, "Computational Models for High-Temperature Multi-Layered Composite Plates and Shells," Applied Mechanics Review, vol. 45, no. 10, pp. 419-446, 1992, doi: 10.1115/1.3119742. Ji-Fan He, "Thermoelastic Analysis of Laminated Plates Including Transverse Shear Deformation Effects," Composite Structures, vol. 30, no. 1, pp. 51-59, 1995, doi: 10.1016/0263-8223(94)00026-3. J.S.M. Ali, K. Bhaskar, and T.K. Varadan, "A New Theory for Accurate Thermal/Mechanical Flexural Analysis of Symmetric Laminated Plates," Composite Structures, vol. 45, no. 3, pp. 227-232, 1999, doi: 10.1016/S0263-8223(99)00028-8. H. Matsunaga, "A Comparison Between 2D Single Layer and 3D LayerCC

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Ductility Behavior of reinforced high volume flyash concrete beams R.Preetha, Joanna.P.S, Jessy Rooby,C.Sivathanu Pillai Abstract— Ductility behavior of reinforced high volume flyash beams in comparison with reinforced ordinary Portland cement beams were studied experimentally. The ductility factors obtained experimentally are also compared with theoretical values . Index Terms—Beam, Curvature ,Ductility, Displacement, Flyash Concrete, Rotation, Strain.

—————————— ——————————

1

INTRODUCTION

Ordinary Portland cement (OPC) is one of the main ingredients used for the production of concrete. The utilization of industrial waste like fly ash in eco-friendly way along with cement, helps in preserving resources and also improves durability of concrete as it densifies the matrix. The enhanced durability of fly concrete is well documented; hence an attempt is made to study the structural behavior of reinforced flyash concrete beams in comparison with ordinary concrete beams. Beams are the structural elements in which large amount of seismic energy dissipation takes place, through stable flexural yield mechanism. In this paper ductility of reinforced flyash concrete beams is compared with reinforced ordinary Portland cement concrete beams. Ductility is the capacity to undergo inelastic deformation and absorb energy. These include curvature, displacement and rotational ductility.

3 BEAM DETAILS & TEST SETUP The beam span was 2500 mm and cross section 150mm x 250mm. The specimens were designed as per IS 456:2000 (Table 1). Out of the twelve specimens tested, four specimens were cast without fly ash and the other eight specimens were cast with 40%&50% fly ash. Six specimens were tested at 28th day and six specimens were tested at 56th day from the date of casting.

Table 1 Test beams details

2 MATERIAL & MIX DESIGN The materials used in the mix were Ordinary Portland Cement (OPC), river sand, Fly Ash (F grade) and potable water. Beams are of M30 grade concrete(fig.1). Water-binder ratio of 0.45 and 0.75% conplast superplasticizer was used for OPC reinforced concrete beams(1:1.8:2.7). Water-binder ratio of 0.45 and 1.3% conplast superplasticizer was used for fly ash concrete beams(1:1.7:2.5). Fe 500 grade steel was used for longitudinal reinforcement and for stirrups.

Fig.1 Compressive strength at 28 and 56 days ————————————————

• • • •

R.Preetha,Scientific officer,IGCAR,Kalpakkam,India. E-mail: [email protected] P.S .Joanna,Professor,Civil engineering department,Hindustan university,Chennai,India E-mail: [email protected] Jessy Rooby,,HOD,,Civil engineering department,Hindustan university,Chennai,India E-mail: [email protected] C.SivathanuPillai,Associate Director,CEG,IGCAR, Kalpakkam, India. Email: [email protected]

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The testing was carried out in a loading frame of 400 kN capacity. TML strain gauge was fixed at the mid span of the tension bar and then protected using coating tape to avoid accidental damage during pouring of concrete[1]. Strain gauges were also attached to the concrete surface in the central region of the beam to measure the strain at different depths. The top surface of the beam was instrumented with strain gauge to measure the concrete compressive strains in the pure bending region. LVDTs were used for measuring deflections at several locations one at mid span, two directly below the loading points and two near the end supports .Strain gauges and LVDTs were connected to a data logger from which the readings were captured by a computer at every load intervals until failure of the beam occurred . The test was carried using a 400 kN hydraulic actuator and the beams were subjected to two-point loads under a load control mode (fig.2). 123


5.1 Curvature ductility Theoretical curvature ductility was arrived using the following equations and compared with the experimental values[4,5] .

ϕy =

………………….. [1]

E s (1 − k )d

⎧ ⎛ ⎛ d '⎞⎞ ⎫ 2 2 …… [2] ⎨ (ρ + ρ ' ) n + 2 ⎜⎜ ρ + ⎜ ρ ' ⎟ ⎟⎟ n ⎬ − n (ρ + ρ ' ) ⎝ d ⎠⎠ ⎭ ⎝ ⎩

k =

ϕu =

ε c β1

…………………… [3]

a

AS f y − A' s f y

a=

…………………… [4]

0.85 f c b

ϴϬ ϳϬ ϲϬ ϱϬ

ϬйϭͲϱϲ

ϰϬ

ϬйϮͲϱϲ

DŽŵĞŶƚ;ŬE͘ŵͿ

Fig 2. Test set-up 4 OBSERVATIONS Vertical flexural cracks were observed in the constant-moment region and final failure occurred due to crushing of the compression concrete with significant amount of ultimate deflection[2]. When maximum load was reached, the concrete cover on the compression zone started to fall for both beams with and without fly ash. Crack formations were marked on the beam at every load interval at the tension steel level. It was noticed that the first crack always appeared close to the mid span of the beam. The cracks formed on the surface of the beams were mostly vertical, suggesting flexural failure in beams(fig.3).

fy

ϰϬйϭͲϱϲ

ϯϬ

ϰϬйϮͲϱϲ

ϮϬ ϭϬ Ϭ Ϭ

ϮϬ

ϰϬ

ϲϬ ƵƌǀĂƚƵƌĞ ϴϬ

ϭϬϬ

ϭϮϬ

ϭϰϬ

ϴϬ ϳϬ


ϲϬ ϱϬ

ϬйϭͲϮϴ

ϰϬ

ϬйϮͲϮϴ

ϯϬ

ϰϬйϭͲϮϴ ϰϬйϮͲϮϴ

ϮϬ ϭϬ Ϭ Ϭ

ϮϬ

ϰϬ

ϲϬ ϴϬ ϭϬϬ ƵƌǀĂƚƵƌĞ;yϭϬͲϲͿ

ϭϮϬ

ϭϰϬ

ϭϲϬ

Fig 3. Crack formations

5 DUCTILITY Ductility is the capacity to undergo inelastic deformation and absorb energy. Several forms of ductility are often considered. These include curvature, displacement and rotational ductility. Displacement ductility(μΔ) is the ratio of ultimate (Δu) to first yield deflection (Δy). Based on idealized moment curvature (M-φ) behavior, curvature ductility(μφ) is defined as the ratio of maximum curvature (φu) to curvature at first yield (φy). Similarly, rotational ductility(μθ) is the ratio of ultimate rotation (θu) to yield rotation (θy)[3].

Fig.4 Moment curvature theorectical

124

Fig.5 Moment curvature experimental

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Moment-Curvature diagrams were generated for all the beams based on the concrete strain and steel strain(fig.5). The experimental results

Theoretical rotational ductility was arrived from equation shown in fig.6 and compared with the experimental values.

showed 80-95% of theoretical curvature ductility. 5.2 Displacement ductility

ϴϬ

Theoretical displacement ductility was arrived using the following equations and compared with the experimental values[3]. DŽŵĞŶƚ;ŬE͘ŵͿ

ϳϬ

z z ⎞ ⎛ + ϕ y z 2 ⎜ z1 + 2 ⎟ 3 2⎠ ⎝ L p = 0.08 z1 + 0.022d b f y

Δu = ϕ y

ϱϬ

ϬйͲϭϮϴ

ϰϬ

ϬйͲϮϮϴ

ϯϬ

ϰϬйͲϭϮϴ

ϮϬ

ϰϬйͲϮϮϴ

ϭϬ Ϭ

………………… [5]

Ϭ

Ϭ͘ϱ

ϭ

ϭ͘ϱ

Ϯ

Ϯ͘ϱ

ϯ

ŶĚZŽƚĂƚŝŽŶ;ĞŐƌĞĞͿ

………………… [6]

Lp ⎞ ⎛ z z ⎞ ⎛ ⎟ + ϕ u z 2 ⎜ z1 + 2 ⎟ + (ϕ u − ϕ y )L p ⎜⎜ z1 − 3 2⎠ 2 ⎟⎠ ⎝ ⎝ 2 1

…………………. [7] Table 2. Performance details of fly ash concrete beams and OPC concrete beams.

ϴϬ ϳϬ


Δy = ϕy

2 1

ϲϬ

ϲϬ ϱϬ

ϬйͲϭϱϲ

ϰϬ

ϬйͲϮϱϲ

ϯϬ

ϰϬйͲϭϱϲ

ϮϬ

ϰϬйͲϮϱϲ

ϭϬ Ϭ

BeamID /testing day

Deflection at yield (mm)

Max. deflection (mm)

Displacement ductility

CB0% -28

4.8

20.0

4.17 5.09

CB0% -28

5.4

27.5

CB40% -28

5.0

20.6

4.12

CB40%-28

5.8

25.2

4.35

CB0% -56

4.6

24.6

5.34

CB0%-56

3.5

22.0

6.28

CB40% -56

6.2

28.6

4.61

CB40% -56 CB50% -28

4.9 5.0

21.7 19.3

4.43 3.86

CB50% -28

5.0

22.2

4.44

CB50% -56

5.0

21.6

4.32

CB50% -56

4.0

20.5

5.13

CB50% -75

4.3

27.0

6.30

Ϭ

Ϭ͘ϱ

ϭ

ϭ͘ϱ

Ϯ

Ϯ͘ϱ

ŶĚZŽƚĂƚŝŽŶ;ĞŐƌĞĞͿ

The experimental results showed 80-100% of theoretical displacement ductility. 5.3 Rotation ductility Fig.7 Moment rotation experimental

The experimental results showed 70-90% of theoretical rotational ductility. 5.4 Comparison of different types of experimental ductility factors

Fig.6 Yield & Ultimate rotation theoretical

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Comparison of different measures of ductility was made with the experimental results. It is seen from fig.8 that the behaviour of beams with and without flyash are similar and within -10% to +10% range of each other. Curvature ductility is the measure of the cross section ,hence it is seen as significant than other two measures of ductility. In general

125


•

The reinforced concrete beams cast with high volume flyash as designed in the experiment are capable of under going large deflections prior to failure .Thus indicating that the flyash concrete reinforced beams can be considered for structural members subjected to large displacement such as sudden forces caused by earthquake.

REFERENCES μφ

[1]

μΔ μθ

CB50% 56

CB40% 56

CB0% 56

CB50% 28

[2] CB40% 28

7.0 6.0 5.0 4.0 3.0 2.0 1.0 0.0

CB0% 28

Ductility factor

high ductility ratios indicate that a structural member is capable of undergoing large deflections prior to failure.

[3]

Mix designations

Fig.8 Comparison of different ductilities

[4] [5]

Effect of Replacement of Cement with FA on the Strength and Durability Characteristics of HPC, Indian Concrete Journal,2011, p. 335-341. Gopalakrishnan S, Rajamane NP, Neelamegam M, Annie Peter J, Dattatrya JK. Assessment of High-Volume Replacement Fly Ash Concrete-Concept of Performance Index, Construction and Building Materials, 2012. Obada Kayali, Sharfuddin Ahmed M. Ductility of High Strength Concrete Heavily Steel Reinforced Members, A.A. Maghsoudi1 and Y. Shari, Transaction A: Civil Engineering Vol. 16, No. 4, pp. 297{307c Sharif University of Technology, August 2009. Reinfoced concrete design ,S.Unnikrishna Pillai,Devdas Menon. Earthqauke resistant structures,Andreas Kappos,G.G.Peneles.

6 CONCLUSION Total of twelve reinforced beams specimens were tested under two point loading and following inferences were made. • Vertical flexural cracks were observed in the constantmoment region and final failure occurred due to crushing of the compression concrete with significant amount of ultimate deflection. • The cracks formed on the surface of the beams were mostly vertical, suggesting flexural failure in beams • The ductility factors ie. Curvature,displacement and rotational of beams with and without flyash are similar and within -10% to +10% range of each other. • The experimental and theoretical ductility factors are very close to each other.

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Investigations on Elastic Behaviour of Corrugated Plates Lathi Karthi, C.G.Nandakumar Abstract— The high inherent stiffness of corrugated profile along with high, strength to weight ratio, makes the corrugated plates a versatile construction material in marine structures, girders, decking, sheet piling, roofing, wall cladding and even as blast walls on offshore installations. Corrugated plates undergo bending due to transverse loading and buckling due to inplane compressive loads. Very few research publications are available in the strength prediction of corrugated plates under different load combinations and various boundary conditions. In many of the studies, the corrugated plates are approximated as orthotropic plates of uniform thickness but differ in the elastic properties along the two perpendicular directions. A parametric study on the strength of corrugated plates with varyinyg parameters viz., thickness, angle of corrugation and aspect ratio for various boundary conditions have been carried out using linear elastic analyses. Equations for maximum principal stress and maximum deflection for corrugated sheets subjected to various loadings with simply supported boundary condition are made available in non dimensional parameters based on the multivariable regression method. Index Terms— Angle of corrugation, aspect ratio, corrugated plates, lateral loading, linear elastic analyses, maximum principal stress, parametric study.

—————————— —————————— 1 INTRODUCTION

2 ORTHOTROPIC PLATE MODEL

C

Corrugated plates have different flexural characteristics along the two perpendicular directions. The theoretical analysis of corrugated plate is based on the assumption that it can be analysed as an equivalent thin orthotropic plate of uniform thickness. The governing differential equation[13] for orthotropic plates of thickness ‘h’ with E, G and õ as the Young’s modulus, shear modulus and Poisson’s ratio respectively, is

orrugated plates are used in the field of civil engineering, architecture, marine transportation, container body, sheet piling, web plates in bridge girders etc. They are found in decking, roofing and sandwich plate structures.These are light, easy to form and can provide higher load carrying capacity than flat plates. They are shaped into alternate ridges and grooves. Corrugated plates are plates with inbuilt stiffness. Their higher depth due to the corrugations attribute to higher structural rigidity. The structural orthotropy of corrugated plates is due to their geometric configuration unlike the sandwich plate where it is due to the material. Corrugated plates have higher stiffness to weight ratio and high strength to weight ratio. For a high performance structure, corrugated plates can be recommended because of the above special structural features and/properties and low fabrication cost. This paper presents the the parametric investigation into the linear elastic ehavior of corrugated plates with trapezoidal profile under variations in thickness, depth of corrugation and angle of corrugation,when they are subjected to various loadings with different boundary conditions. The stress analyses are done with the help of the software ANSYS, a finite element software, used extensively for linear and nonlinear analysis in the field of research. The validation of the analysis for corrugated plates using the software ANSYS was done with the results published in the research paper of Liew et al6].

———————————————— •

Lathi Karthi, Research Scholar, Department of Ship Technology, Cochin University of Science and Technology, Kochi682022, India. E-mail: [email protected]

•

C.G. Nanadakumar, Associate Professor, Department of Ship Technology, Cochin University of Science and Technology, Kochi,682022, India. E-mail: [email protected]

ICICE-2013

(1) Where,

The number of elements and calculation time can be reduced by modeling the corrugated plate as two dimensional orthotropic plates. Samanta and Mukhopadhyay [10], Brassoulis [2], and Liew et al [6] have analytically derived extensional and flexural rigidities of corrugated plates.

Classical Equations In corrugated plate analysis, Seydel’s formula available with[1], [4] is considered to be classical expressions. Briassoulis[2], Easley[3], and Lau[4] have later modified these formulae after comparing the computation results from the expressions and precise analysis. Samanta [10], Briassoulis[2] derived new and more precise expressions for the extensional rigidity of trapezoidally corrugated plates. Many of the past studies reveal that the effect of transverse shear causes errors in the results. Various equations involved in the analysis of trapezoidally corrugated plates subjected to different kinds of loads are given elsewhere [5],[7],[8],[9]. 127


3 LINEAR ELASTIC ANALYSIS

3.3 Modeling and Meshing

3.1 Selection of Model

Three dimensional static linear analysis for the corrugated plate is performed using ANSYS. ANSYS is a general purpose finite element program for static, dynamic as well as multiphysics analyses and includes a number of shell elements with corner nodes only and with corner and midside nodes. An 8-node rectangular SHELL93 element[14] with six degrees of freedom at each node, i.e., translation in x, y and z directions and rotations about x, y and z axes as shown in fig 2, is employed for the analysis. The deformation shapes are quadratic in both in-plane directions. Shell 93 has the advantage that it can follow a curved surface.

The profile of the model selected for the study is trapezoidal and the dimensions are adopted from commercially available plates. The geometry of the corrugated plate is given in fig. 1. The variations in the parameters adopted for the numerical analysis are tabulated in Table 1.

L

length of plate parallel to corrugation

W

breadth of the plate (a) Plan

Fig. 2. Details of a 8 nodded shell 93 element[14]

a, c width of flange and web, s width of unit corrugation

Linear elastic analyses for deflection and maximum principal stress are done for 256 models as per the numerical values given in table 1.

h, t

3.4 Analyses

height and thickness, l length of unit corrugation (b) Details of Corrugation Fig. 1. Profile of the corrugated plate TABLE 1 VARIATIONS IN THE PARAMETERS

Length (L)

1219 mm

Thickness of Plate (t)

4 mm, 5 mm, 5.5 mm & 6 mm

Angle of Inclination (è)

45p , 50p , 55p & 60p

Height (h) (mm)

63.50 , 76.20 , 88.90 & 101.60

Flange (a) (mm)

63.50, 76.20 , 88.90 & 101.60

For the lateral loading of the trapezoidally corrugated plate, a uniformly distributed load of 0.05MPa is considered. Fig. 3 and Fig. 4 show typical model and response for the analysis done for the lateral load case. For inplane loading, the boundary condition for the corrugated edge is kept as simply supported. A uniform pressure of 500MPa is applied on the corrugated edge.

The non dimensional parameters taken for the analysis are (0.9

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