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Journal of Cleaner Production 15 (2007) 950e957 www.elsevier.com/locate/jclepro

Integrated water resource management model for process industry in Lithuania Jolanta Dvarioniene*, Zaneta Stasiskiene The Institute of Environmental Engineering, Kaunas University of Technology, K. Donelaicio Street 20, LT-44239 Kaunas, Lithuania Received 14 July 2005; accepted 23 January 2006 Available online 31 March 2006

Abstract Water resource management has become an important operational and environmental issue. The increasing costs of dependable water supplies and wastewater disposal have increased the economic incentive for implementing technologies that are more environmentally friendly, and that can ensure efficient use of natural resources. A structured ‘‘integrated water resources management,’’ (IWRM) model for water management is presented as a useful tool for research into complex water using production systems in industrial companies. The step-by-step procedure and the consistent relationships between the diagram types allow straightforward implementation of water saving projects. By performing various case studies, it became clear that the IWRM model is applicable to various types of water using industrial companies. Therefore, wastewater reclamation and reuse are effective procedures for more sustainable industrial development programs. Ó 2006 Elsevier Ltd. All rights reserved. Keywords: System analysis; Flow diagram; Process integration; Sustainable water consumption; Water reclamation

1. Introduction The demand for water resources is increasing daily in the world [1]. In the past water was a cheap and abundant resource; the wastewater could be discharged to surface water or to the sewer system without excessive costs and restrictions. However, the rising costs of dependable water supplies and wastewater disposal have increased the economic incentive for implementing technologies that are more environment friendly, and can ensure efficient use of natural resources [2]. The key European Directive 61/96 ‘‘Integrated Pollution Prevention and Control’’ (IPPC) is going to be implemented in all European Union countries. The implementation of the Directive will be determinant in sustaining and encouraging water reuse and recycling application. The purpose of the Directive is to achieve integrated prevention and control of

* Corresponding author. Tel.: þ370 37 300763; fax: þ370 37 209372. E-mail addresses: [email protected] (J. Dvarioniene), zaneta. [email protected] (Z. Stasiskiene). 0959-6526/$ - see front matter Ó 2006 Elsevier Ltd. All rights reserved. doi:10.1016/j.jclepro.2006.01.009

pollution arising from the large number of activities listed in its Annex I, leading to a high level of protection of the environment as a whole [3]. The best available techniques (BAT) will be defined for several industrial processes with a view to eliminate or reduce emissions. As far as the process industries are concerned, some of the BATs are likely to lead to implementation of closed-loop options for industrial water usage. Implementation of the IPPC will contribute to more sustainable water management. The process will encourage water reuse and recycling applications in Lithuania. Appropriate wastewater treatment and recycling are ways to reduce the negative impact of human activities on the environment. With the regulations becoming more stringent, the increase in water consumption efficiency is relevant to today’s problems not only in Lithuania but also in the EU and other countries of the world. Lithuania, as all the other countries of the previous Soviet block, inherited economies with very ineffective use of water and other natural resources [4]. To produce one unit of GDP the Lithuanian economy consumes several times more natural resources than the EU15 average.

J. Dvarioniene, Z. Stasiskiene / Journal of Cleaner Production 15 (2007) 950e957

Until recently, Lithuanian enterprises were achieving the necessary minimal pollution level by diluting wastewater at the end of the pipe. It was the only way to avoid huge fines imposed by environmental specialists. Today this practice is no longer rational, and also causes huge economic damage to the company. On the other hand, wastewater treatment is costly, and Lithuanian enterprises are facing a great need of starting the recycling of wastewater and introducing various types of systems for water reuse. Several industrial branches have been analysed, the basic water consumption indicators in different Lithuanian industrial companies are compared with those in foreign countries. For example, water consumption in different companies of the yarn industry in Lithuania (see Fig. 1) is much higher compared to water consumption using Best Available Techniques (BAT). Compared to the companies and enterprises of developed European countries (see Fig. 2), the tendencies for water consumption and the problems of the effective use of wastewater are common for most of the industries in the country (textile, pulp and paper, food, chemistry, electronics, etc.). As the costs of water and wastewater treatment increase (see Fig. 3), Lithuanian companies are compelled to look for new ways to improve economic effectiveness. After analysis of the world practice and methods of pollution prevention cleaner production and environmental management projects implemented in Lithuanian companies, the following conclusions used for further investigations were made: 1) There is a huge potential for water reuse, water recycling and closed water cycles in most of the companies of different industrial branches. 2) Textile, pulp and paper, chemical, food and metal processing, and power generation industries have the greatest possibilities of minimizing water consumption and wastewater generation. 3) Compared to water usage known in foreign practice, many Lithuanian companies exceed water consumption several times, in some cases even more than 10 times.

160

Water supply, EUR/m3

Denmark United Kingdom Finland France Germany Netherlands Sweden Belgium Lithuania

0,56 1,21 1,05 1,34 1,43 1,19 1,1 1,8 0,26

Wastewater discharge, EUR/m3 2,00 1,42 1,28 1,29 2,19 1,48 1,36 0,63 0,45

Total, EUR/m3 2,56 2,63 2,33 2,63 3,62 2,67 2,46 2,43 0,71

Fig. 2. The comparison of costs for water supply and wastewater discharge.

2. Water resource management and environmental protection Wastewater reclamation and reuse are effective tools for sustainable industrial development programs. Appropriate wastewater treatment and recycling are ways to help reduce the negative impacts of human activities on the environment. The international experiences provide insight into the potential to increase water consumption efficiency using preventive technologies. The increase in water resource consumption efficiency is understood as the decrease in quantity of water used per unit of production (GDP) while fulfilling environmental requirements. Several methodologies for systematic evaluation and minimization of water consumption are discussed in the literature [5e8]. An evaluation of the needs, possibilities and possible effectiveness of such worldwide approaches such as ‘‘water pinch analysis’’ was made. Water pinch analysis provides a systematic approach for minimizing the use of water and for the discharge of effluent while also addressing the costs. It is a valuable and strategic tool for water management in industry. The fundamental theoretical formulations for the application of the pinch concept to wastewater problems were pioneered by El-Halwagi and Manousiouthakis [9], and Smith et al. [10]. The design methodologies and approaches cover a variety of techniques ranging from the graphically based water pinch analyses and the source-sink graphical methodology to mathematical optimization- based approaches [11e 14]. All these methodologies have a number of benefits and drawbacks but the major challenge encountered is the expertise required for the practicing engineer to apply these techniques successfully [15]. Various technologies for

120 100

Water costs, Lt/m3

Water consumption, m3/t

140

Country

951

80 60 40 20 0 Lithuanian company

Lithuanian company

Lithuanian company

A

B

C

BAT

Fig. 1. Water consumption in yarn producing companies.

5 4,5 4 3,5 3 2,5 2 1,5 1 0,5 0

1993

1994

1995

1996

1997

1998

1999

Year Fig. 3. Costs for water supply and wastewater discharge in Lithuania (1993e 1999).

952


wastewater treatment and regeneration were presented by many researchers. Currently, membrane technologies are known as the most suitable approach for industrial wastewater reclamation. Membrane technologies have emerged as reliable and applicable technologies for the treatment of various industrial process effluent streams [16]. Membrane systems have several advantages. They are compact and modular. In addition to high selectivity of the membrane systems they can provide substance concentrations as low as parts per billion and have low energy consumption. Therefore, membrane units can relatively easily be implemented on existing production sites. Furthermore, modern membranes present high resistance to heat, to acid and alkaline conditions, to a number of other aggressive chemicals and to micro-organisms [17]. Membrane technology (or membrane filtration) covers four different membrane groups: microfiltration, ultrafiltration, nanofiltration and reverse osmosis depending on the rejection capability of the membrane [18]. The membrane filtration can bring savings in water, chemicals and production time, and also can give large energy savings. 3. Methodology The research work on water saving in various industrial companies was done in several stages such as: 1) Theoretical analyses of the research were performed in situ. At the beginning of the research, the efficiency of water consumption in different Lithuanian companies was analysed and compared to good practice examples from the EU developed countries and worldwide. 2) The water saving potential in process industry companies in Lithuania was then determined. 3) The detailed analysis of ‘‘Water Pinch’’ method and experiments of process integration in a Lithuanian company were performed. 4) The experiments with membrane filtration were done and the possibilities of reclaimed water reuse were evaluated. 5) The IWRM model methodology for estimating economic benefits was applied in a Lithuanian company.

3.1. Process integration methodologies for water network optimization Process integration is an important branch of process engineering. It refers to the system-oriented, thermodynamicsbased, integrated approaches to the analysis, synthesis and retrofit of a process in an industrial plant. The main goals of process integration (PI) are to integrate the use of materials and to minimize the generation of wastes [19]. A recent development in pinch technology that deals with pollution prevention, resource recovery, and waste reduction is mass-exchange integration. In identifying water reuse and recycling opportunities, a systematic technology called the water pinch diagram that employs a graphical tool for analysing water networks was introduced

by Wang and Smith [11]. The water pinch diagram is used to identify key design targets such as the minimum amount of freshwater required by the studied system, the amount of water recycling and achievable reuse, and the water quality concentration bottleneck [20]. In order to maximize the possibility of water reuse from processes, the highest possible inlet concentration should be specified. The changing of the inlet concentration of water used in a process results in a change of outlet concentration. The maximum permissible effluent concentration should be determined and compared to the resulting one when increasing the influent concentration [12]. 3.2. Criteria of efficient water usage The main driver for improved efficiency of water use Ww is the increasing costs of water for companies. Ww /min

ð1Þ

At the same time, it is important to keep a high productivity and to meet the environmental requirements of EU standards. N ¼ constant;

ð2Þ

Q Qmin ;

ð3Þ

where Ww is the quantity of water used; N is the production quantity; and Q and Qmin are the production quality indicator and its minimal value, respectively. Two theoretical criteria were selected for further estimation: 1) the decrease in water consumption per unit of production; and 2) minimization of water costs.

3.2.1. The decrease in water consumption per unit of production In the process industry expenditure of water resources (Ew) for a unit of product is the main criterion (indicator) of efficient water consumption Ww ð4Þ N This criterion has to be followed by every enterprise, which uses water in its processes and seeks to minimize water consumption

Ew ¼

Ew /min;

ð5Þ

3.2.2. Minimizing water costs This criterion can be used in every enterprise’s calculations of water and wastewater treatment expenditures, regardless of the type of industry or the technological process used in the company


K¼

X

tWw þ rWww þ Wother ;

ð6Þ

where K is the cost of water in the company; Ww is the amount of water consumed; Www is the amount of wastewater discharged; Wother is other costs related with water resources; t is the tariff of water resources; and r is the tariff of the discharged wastewater. In this case the objective is to decrease the costs of water under conditions (2) and (3) ð7Þ

K/min:

3.3. Wastewater regeneration by membrane technologies The membrane filtration experiments on rinse water after reactive dyeing of cotton were made at a textile company [21]. Experiments were performed with pilot scale membrane filtration equipment. This system operates over the pressure range of 1e70 bars and a maximum of 0.7 m2 of total membrane area. The process performance was controlled by measuring the permeate flow and the pressure at the inlet and outlet of the module during experiments.

The permeate samples were examined after the membrane tests were collected for water quality and washing test. Colour was measured by a Vis/UV spectrophotometer (Perkin Elmer Lambda 7). COD was estimated by WTW Photometer MPM 3000, pH was measured with an ion analyzer Merck QpH 70, and WTW LF318/SET instrument was used to measure conductivity. Washing tests were done on AHIBA Texomat equipment. For wet rub fastness evaluation ATLAS-Textile Testing Products, CM-5, AATCC Crockmeter was used. 4. Integrated water resources management (IWRM) model A structured model was developed for water resource management which is a useful tool for research into complex water using production systems (Fig. 4). The IWRM model enables researchers to analyse the process water system in a static domain, given by a certain time frame, and in a dynamic domain, where time dependent changes can be monitored. The step-by-step procedure and the consistent relationships between the input and output diagram types allow a straightforward performance of water saving projects.

Setting goals for use of IWRM model

Static analysis Water resource flow diagram of technological process Water balance Input-Output diagram

Designing the Flow Chart of the whole enterprise Composition

Water costs flow diagram of technological process Specification of water costs

Dynamic analysis Process integration using „Water Pinch“analysis The diagram of chosen technological process

Scenario for sustainable water resources’ management Optimizing and modelling According to selected criteria

Operation

Input variables

Output variables

Estimation

System

Disturbances

953

Side effects

Objective function

-Ew, Kw

Fig. 4. The structure of a model for integrated water resources management (IWRM) in industry.


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The Static diagram evaluation reveals the structure of the system i.e. flows and processes. A system optimization is possibly based on water quantities and costs that are calculated and balanced by freshwater and wastewater in order to identify possible savings. The diagrams are hierarchically structured in several levels of detail allowing an in-depth analysis of complex systems with numerous sub-systems. The detailed water network analysis enables researchers to determine the best water recycling solutions using wastewater regeneration technologies. Membrane technology was chosen as an approach for the process reuse experiments. Membrane technology has been proven to be a commercially viable alternative to discharge of effluents to the drain. It is not a panacea for effluent treatment problems and it is still important to seek expert advice, and to perform extensive trials, in order to ensure that the technology will be compatible with the application. 4.1. Application of the IWRM model There are two main areas for applying the IWRM model: (1) a technological process in appropriate equipment, which uses water (a simple object) and (2) a technological chain consisting of several technological processes or equipment using water (a complex object). Assessment of technological object relations between these parameters is stipulated. This process is demonstrated in Fig. 5. Usually, technological processes are affected by various factors (variables), such as: a) Input variables x1, x2, . xn e They are described by quantitative and qualitative parameters of water consumption. This can be water from different sources of water such as from the municipal supplier, from the company’s own wells, and also with information on the concentration of separate components present in the water, its temperature, etc. b) Output variables y1, y2, . yn e These pertain to wastewater flows from different technological processes and

tn

Technological object

y1 y2 yn

xn

Output variables

Input variables

x1 x2

t2

4.2. Principle of the IWRM model operation The IWRM model is based on the optimal solution approach [22]. The optimum control is a feedback strategy using a combination of the costs of control and system costs as objective functions, and using the system model as a linear constraint. An objective function is understood as water resource usage rates per unit of production Ew or minimization of wastewater treatment costs K. The IWRM model is employed for optimization of the objective function with regard to quality and environmental requirements (Fig. 6). This model makes it possible to keep the system in balance by integrating the preventive measures for waste minimization. When applying the model in a selected enterprise, all possible ways of water use reduction should be systematically assessed, i.e.: a. implementation of direct water recycle; b. water collection and reuse in technological processes; c. application of regenerative technologies for wastewater treatment; and d. development of closed water cycles for separate production lines or for different technological processes. The IWRM model (Fig. 4) consists of two separate parts: 1) Static analysis e diagrams for separate production processes, water flows and costs balances. 2) Dynamic analysis for development of sustainable water use scenarios in an enterprise by evaluation and assessment of pollution quantities in different technological processes; for systematic measurement of water reuse

Disturbances t1

pollutant concentrations as well as temperature. These values determine the process mode and describe the state of a technological process. c) Disturbances t1, t2, . tn e Effects regarding the changes of water quality, resource limits, and changes in legislative requirements. d) Control parameters u1, u2, . un e Changing regimes of technological processes and the compensation of existing interferences.

u2

un

Estimation

System

Disturban ces u1

Output variables

Input variables

Side effects

Objective function -

E. w, Kw

Control parameters

Fig. 5. Structural scheme of technological object.

Fig. 6. Principal operational scheme of the IWRM model.


and for increasing water reuse and closed water cycles; for modelling of water flow integration and optimization with regard to the production program (depending on time, e.g. week or month). The model allows systematic evaluation of possible scenarios for minimization of water usage and for their comparative effectiveness. If the calculated values are not in line with the sought ones, then it is possible to revise the input and output variables and to re-evaluate the incidental impacts in order to correct the production technology management. The IWRM model complies with all basic stages of the enterprise management e planning, assessment, performance analysis, implementation, monitoring and improvement. One of the most important elements of this model is continuous improvement. The single analysis of the possibility to save water and to minimize wastewater production can be economically effective, but it does not provide any guarantee of success with such measures. Only continuous monitoring of primary water source balance and continuous updating of the data from water flows, water and wastewater costs and the analysis of financial accounting indicators are the only conditions guaranteeing the minimization of the enterprise’s water usage costs. 5. Application of the IWRM model The application of the IWRM model in practice has been applied to saving water and minimizing wastewater in different industrial companies. The applications have mostly been made in textile companies. Why have the textile companies been chosen for the experimental work? The textile industry wastewater is a significant source of pollution, containing high concentrations of inorganic and organic chemicals and is strongly coloured by residual dyestuffs. The generated effluents contain a wide range of contaminants, such as salts, dyes, surfactants, oil and grease, oxidizing and reducing agents. In environmental terms these contaminants are suspended solids, COD, BOD, as well as high pH and very strong colour. The fabrics are usually washed too long and too intensively and in order to achieve the best rubbing and wash fastness wastewater is drained directly into the wastewater treatment plant without any recycling or cleaning. To apply the IWRM model the following steps have been used: identification of the machine groups with the largest annual water consumption; investigation of machine groups with regard to possible direct water reuse, theoretically and in practice; evaluation of direct water reuse solutions; estimation of the value of direct water reuse initiatives; selection of relevant technologies capable of working with the process water from rinsing after cotton dyeing; estimation of the reduction in polluting substances in the reclaimed process water after membrane filtration; determination of the applicability of this permeate for reuse as rinse water in the dyehouse; and

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evaluation of economic efficiency of water reclamation by membrane filtration and reuse in processes. First, the water consumption analysis was conducted. Then, the theoretical water reuse target was estimated. The water consumption analysis confirmed that washing and rinsing are two of the most common operations in the textile industry and optimization of washing efficiency can conserve significant amounts of water. In overflow rinsing, clean water is fed into the machine and drained through an overflow weir usually set near the normal running level. This technique is useful for removing the surface scum resulting from poor quality water or chemicals or from inefficient pre-treatment. In terms of water consumption, it is inefficient especially with a high liquor ratio. Furthermore, the analysis clearly revealed that the washing machines consume a lot of water. Determination of a well founded estimate of the possible maximum reuse of water at textile and leather companies assuming that the available sources of water could be combined with the available sinks in an optimal way while ignoring any practical obstacles. 6. Application of the IWRM model in the textile company The production of studied SME Textile Company covers numerous processes from weaving to final finishing of lining textiles. Washing and rinsing are two of the most common operations in the textile processing. Optimization of washing efficiency can save significant amounts of water as well as energy. Before investigations and application of the IWRM model, water consumption for the production of 6 million meters of textiles was approximately 94,600 m3. After analysis of all recipes, identification of the machine groups with the largest annual water consumption, and evaluation of direct water reuse solutions for rinsing using Process Integration tools were made. The water evaluation criteria selected for evaluation were conductivity, pH and temperature. They were used to determine wastewater reuse possibilities using three different equalisation tanks. According to these criteria, wastewater streams were grouped into three different streams with different wastewater parameters. After analysis it was estimated that 61,164 m3 of wastewater could be reused in technological processes of the company, mainly in the washing processes. Using the IWRM model in the test textile company, 62% freshwater savings were achieved. The overall economic potential for freshwater savings at this company was approximately 55,000 EUR/year. 6.1. Wastewater regeneration by membrane technologies Biological treatment, chemical precipitation, membrane technology, activated carbon adsorption and evaporation are the common wastewater treatment techniques of textile industry effluents. Low salinity rinse water can be treated with all the four techniques. However, membrane filtration is technically advantageous compared to these other techniques. Process water membrane filtration in the textile industry has


been reported as a favourable answer for water reuse. Membrane filtration experiments were done in cooperation with scientists from the Danish Technical University and a textile company. Six membranes were selected for testing at the factory. Nanofiltration membranes were supplied by Osmonics (Desal DK and Desal DL) and by DSS (NFT 50). Reverse osmosis membranes were supplied by Film Tec (BW30), by DSS (HR98), and by Osmonics (Desal SG). 6.2. Characteristics of permeate and washing results Nanofiltration and reverse osmosis membranes were evaluated at a dyehouse for their ability to separate colour, COD and conductivity of the process water coming from the washing machine. As an example, the results of the permeate quality at different concentration degrees (CD) are presented (Fig. 7). The permeates from NF membranes are not colourless at CD5, while permeates from the RO membranes are always colourless or nearly colourless. Almost complete colour removal was achieved with reverse osmosis membrane filtration. The feed COD value was between 920 and 966 mg/l. COD retention of the NF membranes was approximately 95% for the RO membranes, the COD retention was approximately 97%. In some examples, the COD was lower than 10 mg/l. The rinsing (washing out) tests were performed on an AHIBA Texomat apparatus at the laboratory at ITC in Denkendorf. Tests were performed by rinsing of cotton textiles dyed at the dyehouse. The rinse water, after being passed through the different membranes did not differ from freshwater (Fig. 8). In the future the main challenge for water professionals will be to provide new engineering solutions such as membrane technologies for better management and for closing the water cycle in both small and large industrial companies. Appropriate wastewater treatment and recycling are the ways to reduce the negative impacts of human activities on the environment. When performing the case studies, it was found that the IWRM model is applicable to various types of water using production systems, especially to those consuming large quantities of water. For example, using the IWRM model in the evaluated textile companies 52e62% freshwater savings CD 2 COD, mg/l

CD 5 COD mg/l

1200

COD, mg/l

1000

2NFT50 Fresh water 2HR98

2BW30 2DK 2DL 2SG

0,9 0,8

Extinction (470 nm)

956

0,7 0,6 0,5 0,4 0,3 0,2 0,1 0 0

200

400

600

800

1000

1200

1400

1600

1800

2000

Time (sec) Fig. 8. Rinsing test.

were achieved, and a correctly applied membrane filtration system makes it possible to create a closed water loop for a textile rinsing process. Integration of ‘‘Water Pinch’’ and wastewater regeneration technologies can ensure process optimization and provide financial savings conserve natural resources and help to meet present and future environmental legislation requirements. 7. Conclusions and considerations The comparative analysis of water usage in industry has revealed that Lithuanian enterprises use 3e5 (in some cases 10) times more water per unit of production compared to the best examples from other parts of the world. This is especially true in the textile, pulp and paper, metal processing, chemistry and food industries. The IWRM model is useful to assess and systematically evaluate ways of reducing freshwater usage and opportunities for wastewater reuse. By applying this model to the enterprise there are possibilities to create various scenarios for optimal management of water resources within single production processes or within the entire multi-process system of the entire company. Analysis of the effectiveness of the IWRM revealed that in the case of a large enterprise in the textile industry, it was effective in helping to identify opportunities for realizing water savings of 52% per ton of product. In the case of a small textile enterprise, water savings of 62% were calculated. By applying the IWRM model under free market conditions, the industrial company gains by: a) optimization of freshwater usage in technological processes; b) improving the choice of optimal production modes; and c) forecasting freshwater rates and wastewater quantities.

800 600 400 200

References

0 FEED

BW30

DK

DL

Membrane type Fig. 7. COD retention.

SG

NFT50

HR98

[1] Gleick PH. The worlds water 2000e2001, The biennial report on freshwater resources. Washington, USA: Island Press; 2001. [2] Anderson J. The environmental benefits of water recycling and reuse. Water Science and Technology: Water Supply 2003;3(4):1e10.

J. Dvarioniene, Z. Stasiskiene / Journal of Cleaner Production 15 (2007) 950e957 [3] Directive 96/61/EC. The European Parliament and of the Council of 24 September 1996 concerning integrated pollution prevention and control. Official Journal of the European Communities 1996. L 257 of 10. [4] Dvarioniene J, Stasiskien_e Z. Water resource saving in Lithuanian industry: possibility analysis. Environmental Research, Engineering and Management 2002;1(19):34e42. [5] Asano T. Reclaimed wastewater as a water resource. Asian Water 1998; 14:16e98. [6] Byers W, Doerr W, Krishnan R, Peters D. How to implement industrial water reuse: a systematic approach. New York: Center for Waste Reduction Technologies (CWRT), American Institute of Chemical Engineers (AIChE); 1995. [7] Smith R, Petela EA. Waste minimisation in the process industry. The Chemical Engineer 1994;506:21. [8] Dhole VR, Tainsh RA, Wasilewski M, Ramchandami N. Make your process water pay for itself. Chemical Engineering 1996;103. [9] El-Halwagi MM, Manousiouthakis V. Simultaneous synthesis of mass exchange and regeneration networks. AIChE 1990;24:633e54. [10] Smith R, Petela E, Wang YP. Water, water everywhere. The Chemical Engineer 1994;565:21e4. [11] Wang YP, Smith R. Wastewater minimisation. Chemical Engineering Science 1994;49(7):981e1006. [12] Wang YP, Smith R. Wastewater minimisation with flow rate constraints. Chemical Engineering Science 1995;49(7):889e904. [13] Wang YP, Smith R. Effluent treatment system design. Chemical Engineering Science 1997;52(23):4273e90. [14] Linnhoff B. Pinch analysis e state-of-the-art overview. Trans IChemE 1993;71(Part A). [15] Wenzel H, Dunn RF. Process integration design methods for water conservation and wastewater reduction in industry. Part 3: experience of industrial application. Journal of Clean Products and Processes 2002;5:217e29.

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[16] Scott K. Handbook of industrial membranes. Elsevier Advanced Technology; 1998. [17] Jarusutthirak C, Amy G. Membrane filtration of wastewater effluents for reuse: effluent organic matter rejection and fouling. Water Science Technology 2001;43(10). [18] Judd S, Jefferson B. Membranes for industrial wastewater recovery and reuse. Elsevier Ltd; 2003. p. 14e45. [19] El-Halwagi MM. Pollution prevention through process integration, Systematic design tools. USA: Academic Press; 1997. p. 262e74. [20] Bedard M, Sorin M. The global pinch point in water reuse networks. Trans IcehmE 1999;77(Part B). [21] Dvarioniene J, Stasiskien_e Z, Knudsen HH. Pilot scale membrane filtration study on water reuse after reactive cotton dyeing. Environmental Research, Engineering and Management 2003;3(25):3e10. [22] Staniskis JK, Stasiskien_e Z, Kliopova I. Cleaner production: system approach. Monograph. Kaunas; 2002. Dr. Jolanta Dvarioniene, researcher at the Institute of Environmental Engineering Kaunas University of Technology. Main research areas: Pollution prevention/waste minimization/cleaner production in Lithuanian industry, sustainable consumption, water resources management and minimization. ˇ aneta Stasiskiene, senior researcher, project department Assoc. Prof. Dr. Z manager at the Institute of Environmental Engineering, Kaunas University of Technology. Main research areas: Pollution prevention/waste minimization/cleaner production in Lithuanian industry; cleaner production investments, environmental management accounting.