Identifying potential environmental impacts of waste ...

Environ Monit Assess (2016) 188:445 DOI 10.1007/s10661-016-5443-8

Identifying potential environmental impacts of waste handling strategies in textile industry Dalia M. M. Yacout & M. S. Hassouna

Received: 2 June 2015 / Accepted: 21 June 2016 # Springer International Publishing Switzerland 2016

Abstract Waste management is a successful instrument to minimize generated waste and improve environmental conditions. In spite of the large share of developing countries in the textile industry, limited information is available concerning the waste management strategies implemented for textiles on those countries and their environmental impacts. In the current study, two waste management approaches for hazardous solid waste treatment of acrylic fibers (landfill and incineration) were investigated. The main research questions were: What are the different impacts of each waste management strategy? Which waste management strategy is more ecofriendly? Life cycle assessment was employed in order to model the environmental impacts of each waste streaming approach separately then compare them together. Results revealed that incineration was the more ecofriendly approach. Highest impacts of both approaches were on ecotoxicity and carcinogenic potentials due to release of metals from pigment wastes. Landfill had an impact of 46.8 % on human health as compared to 28 % by incineration. Incineration impact on ecosystem quality was higher than landfill impact (68.4 and 51.3 %, respectively). As for resources category, incineration had a higher impact than landfill (3.5 and 2.0 %, respectively). Those impacts could be mitigated if state-of-the-art landfill or incinerator were used D. M. M. Yacout (*) : M. S. Hassouna Environmental Studies Department, Institute of Graduate Studies & Research, Alexandria University, 163 Al-Horiastreet, El-Shatby 21526, Alexandria 832, Egypt e-mail: [email protected]

and could be reduced by applying waste to energy approaches for both management systems In conclusion, shifting waste treatment from landfill to incineration would decrease the overall environmental impacts and allow energy recovery. The potential of waste to energy approach by incineration with heat recovery could be considered in further studies. Future research is needed in order to assess the implementation of waste management systems and the preferable waste management strategies in the textile industry on developing countries. Keywords Waste handling . Incineration . Impact assessment . Landfill . Textile . Acrylic fiber

Introduction Potential environmental impacts of textile waste Textile production is a worldwide industry with a production volume of more than 88.5 million tons per year. Recently, developing countries share reached 58.6 % of the global textile market; this share is expected to rise in order to meet the upscaling demand (Research and Markets 2011; UNCTAD 2015). The textile industry emits large quantities of pollutants in the form of liquid discharge, solid wastes, and air emissions to the environment. The industry has been always regarded as a water-intensive sector; the main environmental concern is the large amount of effluent discharged containing chemicals. Energy consumption and air emissions are

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another two important issues as well (IPPC 2001). The industry requires as many as 2000 different chemicals from dyes to transfer agents, which are used at various steps of the process. Large amounts of water are used to convey these chemicals and wash them out; the output of these processes is expelled wastewaters full of chemicals which sink into the environment (HSRC 2006). Textile mills discharge millions of gallons of effluent each year. The effluent contains natural impurities extracted from the fibers and a mixture of process chemicals such as inorganic salts, dyes, and heavy metals. The effluent is usually high in both temperature and pH because it is saturated with dyes and many chemicals used during the process. It is highly-colored and high in BOD and COD as well; it has a high conductivity and is alkaline in nature. This effluent represents a threat to the aquatic life if it is not properly treated before disposal (Lawrence 1996; Badania et al. 2005; HSRC 2006). Chemicals that evaporate into the air become air pollutants. Some of them may be breathed or absorbed through the skin. Others are carcinogenic; they may cause harm to children or may trigger allergic reactions in some people. These air pollutants can fall out to become surface water or groundwater pollutants, and water pollutants can infiltrate into the ground or volatilize into the air (Woodard 2001; HSRC 2006; Lo et al. 2012). Hazardous solid wastes from the industry and disposed in the ground can influence the quality of groundwater and surface waters as leachate may enter the groundwater and travel with it through the ground (Woodard 2001; Lo et al. 2012). Waste treatment processes can also transfer substances from one of the three waste categories to one or both of the others. Waste treatment or disposal systems themselves can directly impact the quality of the air, water, or ground. The total spectrum of industrial wastes must be managed as substances resulting from a system of interrelated activities (Woodard 2001). Waste from the textile industry raises many environmental concerns (Briga-Sá et al. 2013). Several studies were conducted in order to determine the environmental impacts of the industry and reduce its negative impacts. Ren (2000) developed environmental performance indicators for the textile process and product. Pollution prevention and waste minimization techniques in the textile industry were illustrated by Lawrence (1996) and Barclay and Buckley (2000). Environmental management systems (EMS) are implemented in order to

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reduce redundant production procedures, packaging, raw materials needed, energy and water consumption, and toxics release to the environment. EMS adopted by firms monitor waste and pollution levels, and take corrective actions to reduce them. Effective implementation of EMS enhances the utilization of raw materials, water, and energy. Additionally, it leads to cost reduction, improvement in textile quality, and waste minimization (Vandevivere et al. 1998; European Commission for Environment 2003 and Melnyk et al. 2003; Brito et al. 2008). Lo et al. (2012) studied the impact of EMS in textile industries and stated that the dyeing process in textiles processing could produce a huge amount of toxic emissions that impacts on the environment which will lead to high restoration costs. Briga-Sá et al. (2013) investigated the potential of reusing textile wastes. They illustrated that in the European Union around 5.8 million tons per year of textiles are discarded; only 1.5 million tons (25 %) of these textiles are recycled. The remaining 4.3 million tons goes to landfill or to municipal waste incinerators. Additionally, there is also the textile waste from the textile industry which represents a large amount of unused raw material (Briga-Sá et al. 2013). Beton et al. (2014) suggested to reduce textiles’ impact on the environment by minimizing the generated waste in the first place by waste recovery during production. They also suggested to develop new technologies for textile recovery. Recently, Yacout et al. (2016) recommended the development of ecofriendly technologies to minimize the negative impacts of this industry. In spite of that, the environmental issue in the textile industry has received little attention from both academics and practitioners. Most environmental researches are technology-oriented. Waste management LCA in the textile industry Nakamura and Kondo (2002) studied the different models of waste management assessment; they illustrated that the main concerns of waste management LCA are the economic and environmental impacts that result from the introduction of alternative waste-recycling and waste treatment methods. Ekvall et al. (2007) investigated the importance of LCA on waste management assessments. They declared that in assessments of the environmental impacts of waste management, LCA helps expand the perspective beyond the waste management system. LCA makes it possible to consider the environmental benefits that can be obtained through

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different waste management processes; for example, materials from recycling processes can replace production of virgin material. Udo de Haes and Heijungs (2007) also studied LCA applications regarding waste hierarchy and integrated waste management. They stated that a fixed order for waste management starts from most to least preferable options: product reuse, materials recycling, incineration, and finally landfill. A step down on this ladder is only to be taken if the higher step appears to be impossible. Cherubini et al. (2009) illustrated that there is an increasing interest in resources and waste management in order to design proper strategies for sustainable resource and waste management policies. LCA methodologies can be used in this context as an input to decisionmaking regarding the choice of strategic decisions for resource use and waste management approaches. Several studies in different areas considered incineration as a potential waste management approach. The studies covered the possibility of using incineration for waste management of municipal solid wastes at city level or waste management approach for industrial manufacturing production (Denison 1996; Finnveden and Ekvall 1998; Hassan et al. 1999; Finnveden et al. 2000; Arena et al. 2003; Mendes et al. 2004; Chaya and Gheewala 2007; Cherubini et al. 2009; Assamoi and Lawryshyn 2012). Some of these studies compared the environmental impacts of incineration vs. landfill through various scenarios (Denison 1996; Hassan et al. 1999; Arena et al. 2003; Mendes et al. 2004; Chaya and Gheewala 2007; Cherubini et al. 2009). Incineration approaches had better environmental performance than landfill in a large number of these cases. Furthermore, it was noted that in case of incineration scenarios higher emissions of CO2, N2O, and NO2 were presented than in landfill ones. On the other hand, landfill scenarios emitted higher CH4 emissions. It was reported that few studies considered the disposal or end of life phase of textiles; moreover, limited LCA data is available regarding the environmental impacts of different end of life options for textiles (Michaud et al. 2010). At the same time, it was indicated previously by White et al. (1999) that due to the geographic differences, there is no optimal system for waste management. Waste characteristics, energy sources, disposal options, and market size of the products cause the variation of waste management strategy for each country/region. In order to identify the best waste management strategy, it has to be determined locally. Previous

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LCA studies for waste management systems covered several geographical areas in Europe and North America; however, very few studies considered the potentials and impacts of using such waste management approaches for the textile industry in developing countries. Furthermore, to date, to the author’s knowledge, no similar studies were done for countries in the North African and Middle East region (MENA). In the current study, LCA methodology was used to determine the different impacts of two waste management strategies (landfill and incineration) in one of the leading countries for the textile industry in the MENA region. Comparison between the environmental impacts of the two waste streaming approaches was done next. The aim of the study was to identify which approach is more environmentally friendly. The obtained results will assist decision makers in providing sustainable waste management practices for better environmental conditions in developing countries in Africa and MENA regions.

Analysis of waste management system Egypt is famous for its textiles; it is one of the largest textile producers in MENA. It produces approximately one million tons of textiles per year (CAPMAS 2015). In the current study, data was collected from one of the largest plants for acrylic fiber production in the MENA (Middle East and North Africa) region, located at Alexandria, Egypt. The plant was established with a designed production capacity of 18,000 t per year. An inventory of generated waste was done: air emissions, liquid discharge, and solid wastes were included. Two sources of air emissions were found: water vapors and chemical vapors. Both emissions were absorbed and recycled back to the process. As for liquid discharge, the total raw effluent generated is 3600 m3/day. Two major streams are generated from process plant areas and inflow generated from utilities (El-Raey 2007). Liquid waste sources and generated amount are presented in Table 1. Both steams are treated through an effluent treatment plant; Table 2 shows the water quality parameters of process effluent to the effluent treatment plant. Effluent samples are taken every shift (three shifts/day) in order to analyze the different parameters (COD, BOD, monomers of acrylic fiber, and sodium thiocyanate). pH and temperature of the effluent were constantly monitored by on-site meters. COD ranged from 50 to

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100 ppm and BOD values were around 60 ppm. It was noticed from the analysis records that before discharge to the environment, the treated effluent was within acceptable environmental limitations according to the Egyptian standards concerning wastewater discharge to non-fresh water drains (EEAA 1994). As for solid wastes, different sources of solid waste are shown in Table 3. The filter pads and wastewater treatment sludge are being disposed of by governmentrecognized sites for toxic material. Wet and dry fiber waste from the production line were recovered and utilized again as dope solution. The fiber with the lowest grade was liquefied in the gel dissolving unit using sodium thiocyanate (Yacout et al. 2015).

carcinogens potential (CP), ecotoxicity potential (ETP), respiratory inorganic formation potential (RIFP), respiratory organic formation potential (ROFP), radiation potential (RP), ozone layer depletion (OLD), minerals depletion (MD), land use (LU), and fossil fuels depletion (FFD). These impact categories are grouped into three groups: impact on human health, impact on ecosystem quality, and impact on resources. Cumulative energy demand (CED) was also used as a single indicator for fossil fuels depletion. The life cycle assessment was realized by the software SimaPro7.

Inventory analysis Data collection and uncertainty

Goal and scope definition of LCA The investigation compared the environmental impacts of two waste streaming approaches: landfill and incineration of the generated hazardous waste from 1000 kg production of acrylic fiber. The aim was to analyze and evaluate their environmental impacts based on the current case study plant and find out which approach has less negative impact on the environment. The used method in the current study was BEco-indicator 99.^ Twelve impact categories were taken into consideration: global warming potential (GWP), acidification potential (AP), eutrophication potential (EP), Table 1 Liquid waste sources and generated amount Sr.

Source

Generated waste flow (m3/day)

1

Process waste effluent

1560a

1.1

Washing of polymer cake

1440

1.2

Stretching machine

1080

1.3

Solvent recovery area

72

2

Effluent from utilities

2040b

2.1

Cooling towers blow down

300

2.2

DW water regeneration

80

2.3

RO reject

920

2.4

Filter back wash

600

2.5

Horticulture irrigation and sanitation

140

Total a

3600c

Sum value of different process wast effluent

b

Sum value of different effluent from utilities

c

Sum value of process wast effluent plus effluent from utilities

Data were obtained from the case study facility; they were collected from the process manuals, utility manuals, data sheets, and daily reports of 2012 (Table 1). The validity period for the LCA results of the current study will be till 2017 as the acceptable time coverage of used data for LCA studies should be within the last 5 years (European Environment Agency 1997). Results of this inventory are presented in a list of consumed resources and emissions following the system of Goedkoop and Spriensma (2000). All input/output data used in the study are presented in Table 4 (Yacout et al. 2016). Impacts on human health and ecosystem were estimated and generated using the software modeling program SimaPro (Table 5). Regarding data uncertainty, several uncertainties are present in the used data. First of all, due to the difference in the geographical/regional location of the case study, the available data in the LCA database used does not always represents the product being studied (Baker and Lepech 2009). There is no available database, to date, that represents the regional location in Egypt or the Middle East, and few data on the current databases represents Africa (Yacout et al. 2016). Basic materials data used in the study is considered for the European region (Eco-Invent v2 database). These data should represent the case study only if all the used raw materials are imported from Europe. Electricity and steam generation data may vary as well based on the used database. The electrical data used in this case study was the generated electricity in Africa (IDEMAT 2001database). This data represents the average fuel use and emissions for total energy generation for the whole continent. As for steam, average data for

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Table 2 Water quality parameters of process effluent to the effluent treatment plant Parameters

No.

Concentration (ppm)

Load (kg/h)

1

pH

5–9

–

2

BOD

200–300

19.5

550–750

49.0

3

COD

4

Monomers of acrylic fiber

15–20

1.3

5

Sodium thiocyanate

20–30

2.0

generated on-site steam was used (Industry data 2.0 database), which represents the current source of steam in the case study as it purchased from a nearby generator (Yacout et al. 2016). The treatment of hazardous

and non-hazardous materials in the textile industry, in this case the chosen waste streams, is another uncertainty (Van der Velden et al. 2014). The waste management approaches and waste handling

Table 3 Solid waste description and generated amount from plant Department Production

Material preparation

Waste description

1.0

Noa

Dye empty tot

1.0

Noa

Acid empty drums

1.0

Noa

Dye empty drums

4.0

Noa

NSO empty bags

1.0

Noa

Finish empty drums

1.0

Noa

Anti-foam empty drums

1.0

Noa

Pigment waste

60.0

Kg

Waste gelled dope

60.0

Kg

Dye waste

30.0

Kg

TiO2 waste

60.0

Kg

Sodium thiocyanate waste

60.0

Kg

Unusable fiber waste

5.0

Kg

Cotton waste

2.5

Kg

Spillage polymer

0.1

Totsb

Methyl acrylate bags

2.0

Bagsc

30.0

Bagsc

Acid drums

1.0

Drumsd

Carbon

0.1

Tots**

Silica bags

0.5

Bags***

Flocculants empty bags

0.1

Noa

Filter aid polymer empty tots

0.1

Noa

Chemical empty plastic cans

2.0

Noa

50.0

Kg

3.0

Noa

Chemical sludge Cartridge filter candles a

Unit

TiO2 empty bags

Sodium thiocyanate bags

Utility

Quantity per day

No: quantity in numbers

b

Tot: plastic container that holds up to 100 kg of solid waste

c

Bag: Paper container that holds up to 10 kg of solid waste

d

Drum: plastic container that holds up to 100 kg of liquid waste

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Table 4 Input/output data for acrylic fiber production (1000 kg production) Inputs Inputs from materials Name

Amount

Unit

Acrylonitrile

910.0

Kg

Vinyl acetate

92.5

Kg

Sodium chlorate

6.0

Kg

Sodium metabisulfite

18.0

Kg

Sulphuric acid

0.3

Kg

Sodium hydroxide (50 %)

19.0

Kg

Titanium dioxide

4.2

Kg

Sodium sulfate

0.7

Kg

Nitric acid

2.4

Kg

Demineralized water

144.0

m3

Remarks

Treated water for production process

Inputs from electricity/heat Electricity

1320.0

kWh

Steam

9.8

Ton

Used mainly in dryers and material preparation area

Outputs Product Acrylic fiber

1.0

Ton

Main product

Waste and emissions Waste effluent

69.2

m3

Collected from all areas

Hazardous waste from process

1.0

Kg

Pigment waste, chemical bags, and cans

Chemical sludge

1.2

Kg

From water treatment plant

Reused mixed plastics containers

1.0

Kg

Non-hazardous solids (containers)

Recycled textiles

4.0

Kg

Filter cloth and waste fiber

Excess solvents (sulfuric acid and sodium hydroxide) are recovered and recycled. Input/output data was obtained from the case study company from process production manuals, utility manuals, data sheets, and reports (Yacout et al. 2016)

Table 5 Impact assessment of waste streaming approaches

strategies may be diverse according to the used practice in the case study area.

End-point category

Background data and waste approaches

Human health

Mid-point indicator

Climate change Respiratory inorganic/ respiratory organic formation potential

Landfill Incineration (%) (%) 46.8

28.0

51.3

68.4

2.0

3.5

Ozone layer depletion Carcinogens potential Radiation potential Ecosystem quality

Land use Acidification/ eutrophication Ecotoxicity

Resources

Fossil fuel depletion Minerals depletion

Data calculated by Sima Pro 7.1 simulation software program

LCA was applied on two waste streaming scenarios: the first scenario was based on 100 % hazardous solid waste incineration and the second scenario was 100 % hazardous solid waste landfill. The generated wastes were from 1000 kg production of acrylic fiber. Background data was created utilizing ecoprofiles from the Eco-Invent database for all the necessary input materials and processes. In compliance with ISO14044:2006 Section 4.2.3.3., a cut-off criteria of 0.1 % was chosen. The Eco-indicator 99 methodology was used for LCA single score and weighting of the 11 impact categories taken into consideration (Goedkoop and Spriensma 2000) and (Frischkneckt et al. 2007). The used LCA

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simulation model considered the impacts of Bworse-case scenario^ in both landfilling and incineration. For landfill, short-term leaching to wastewater treatment plant was considered and long-term leaching to groundwater in case of base lining failure. Regarding incineration, short-term emissions to rivers was assumed as well as long-term emissions to groundwater from slag bottom.

Page 7 of 13 445 Table 6 Life cycle inventory of landfill approach of waste Unit

Amount (kg)

Impact indicator

Emission to air Major elements

Results of life cycle assessment

CO2

g

0.0143

CH4a

g

0.0155

GWP

NO2

mg

0.088

EP, RIFP

N2Oa

mg

0.0032

GWP

GWP, RIFP

Minor elements

Results in Tables 5, 6, and 7 and Figs. 1 and 2 present the overall environmental impacts of the waste streaming approaches: landfill and incineration. In the worsecase scenario, leachate takes place in landfill, accordingly as assessed by the model; high ecotoxicity and carcinogenic potential were detected due to the release of cadmium and arsenic. In order to avoid/minimize the environmental impacts, a landfill needs to be constantly monitored (Cherubini et al. 2009). As for incineration, if the incinerator does not control the emissions properly as assumed, various impacts could be detected as presented in Figs. 1 and 2. In accordance with previous results reported by Arena et al. (2003), Mendes et al. (2004), Finnveden et al. (2005), Cherubini et al. (2009), Assamoi and Lawryshyn (2012), and Lettieri et al. (2014), Fig. 2 indicates that incineration is more environmentally friendly; shifting waste treatment from landfilling to incineration would decrease the overall environmental impacts and will allow energy recovery.

Discussion of life cycle assessment Table 5 shows that the highest impact of both approaches on ecosystem quality due to their ecotoxicity potential from emissions of copper, zinc, and nickel. The overall impact of incineration on ecosystem quality is higher than overall impact of landfill, reaching 68.4 and 51.3 %, respectively. At the same time, due to the high potential of cadmium release into the effluent, the human health indicator is the second highest impact. Landfill has an overall impact of 46.8 % on human health as compared to 28 % by incineration. As for resources, it is evident that the impact of incineration approach is higher than the impact of landfill with, 3.5 and 2.0 %, respectively. The amount of fossil fuels (coal and natural gas) used by incineration is higher than that used in a landfill. Fossil fuels are mainly consumed during

Particulates,