www.fibre2fashion.com Green Solutions and Sustainability in Textile Industry By: Harshita Chaudhary 1 www.fibre2fashion.com Green Solutions and Sustainability in Textile Industry By: Harshita Chaudhary Carbon emissions contribute significantly to climate change which is being increasingly recognized as a major challenge. It is widely accepted that the greenhouse gas (GHG) emissions caused by humans are having a negative impact on the environment. A way to track one’s greenhouse gas emissions is to be aware of your carbon footprint. Carbon footprint is a measure of the impact human activities have on the environment in terms of the amount of carbon dioxide and greenhouse gases produced, expressed as CO2 equivalent, measured in kilograms (kg) or tonnes. The textile industry is considered as the most ecologically harmful industry in the world. The clothing and textile industry is huge. Environmental impacts occur at every stage of the life cycle of a product. The garment industry has contributed to the global warming from the stage of growing of the fibres, yarn fabrication, fabric manufacture, wet processing and manufacturing of the garment, its distribution and transportation to stores and customers, its use by the consumers and finally the disposal of the product. STAGE I: Raw Materials (Fibers) Contributors to carbon footprint Cotton cultivation requires large amount of pesticides, fertilisers and water. Although the cotton crop is grown in less than 3% of the world’s farmed land, it consumes approximately 25% of the pesticides. Green Solution • Organic cotton is the most easily available “green” fabric, even though organic cotton accounts for only 0.03 percent of all the cotton produced. It is grown following the strict principles of organic agriculture where synthetic chemical pesticides, fertilizers and Genetically Modified Organisms (GMO) are not used. Organic fertilizers (such as manure) and plant-based pest management products (such as neem or garlic extract) are used. Organic cotton plant 2 www.fibre2fashion.com • Substitute cotton for other natural materials.Hemp, wool, organic cotton, soy silk, bamboo fabrics, jute, corn fiber etc are considered as eco-friendly fabrics due to their availability from nature with out any harmful effects of chemical or toxics. Moreover, as compared to other synthetic fibers they are available in a cheaper rate. Hemp is four times stronger than cotton, twice as resistant to abrasion, and more resistant to mildew, soiling, shrinkage and fading in the sun. In addition, hemp plants need little irrigation and significantly less pesticide or other chemicals. ‘Bio-fibres’, which include bamboo, soy, algae, maize, agricultural waste, can also be used. • Synthetic fabrics, such as polyesters, are easy care and more durable alternative to natural fabrics. Although they are more energy intensive in production, one of the core advantages of these fibres is that they need to be washed at lower temperatures thus saving a lot of energy throughout their life cycle. But limitation with polyester fabrics is that they are generally made from non-renewable by-products of the oil industry which take a long time to degrade and are therefore difficult to dispose off. • Cellulose based fibres like viscose can be used. There are now developments of new man- made fibres of natural origin like Tencel® (Lyocell) made from wood and Ingeo® (poly lactic acid) obtained from corn. Stage II: Yarn fabrication and Fabric Manufacture Contributor to carbon footprint There are many stages required to process cotton from fibres to fabrics. The fibres are cleaned, carded (combed), spun into yarn, coated with starches or chemicals, woven or knitted into fabric. In the sizing function, starch is used in sticky paste form, and is applied to the yarn to enhance its strength and abrasion resistance. The starch paste consists of preservatives in order to protect it from the attack of microorganisms. Oil stains get formed on the fabric surface, while it is being woven due to parts of the machine which are being lubricated Processes involved Contributors to carbon footprint Fiber preparation Fiber waste and packaging waste, electricity (machinery) Yarn spinning Packaging wastes, sized yarn, fiber waste, cleaning and processing waste, electricity (machinery) Slashing/sizing Fiber lint, yarn waste, packaging waste, unused starch-based sizes, water with high level of BOD and COD , electricity (machinery) Weaving Packaging waste, yarn and fabric scraps, used oil, electricity (machinery) Knitting Packaging waste, yarn and fabric scraps, electricity (machinery) 3 www.fibre2fashion.com Green solutions • Some preservatives like pentachlorophenol, that are obtained from phenolic or chlorinated compound, possess a toxic effect on human skin. Hence, such preservatives should be avoided. Utilizing a synthetic starch decreases the use of such preservations, thereby decreasing the health hazards which likely to occur because of phenolic or chlorinated preservative. • Proper measures should be taken during the weaving operations, so that oil stains do not get formed. Before textile chemical processing, these oil stains are removed by applying stain remover. Hence, measures can be taken to lessen oil stains in the cloth and probably the application of carbon tetra chloride based products should be avoided in stain removal and other textile products. Stage III: Textile Processing Textile processing industry is requires not only large volume of water for running various operations at the unit but also a variety of chemicals for various processes such as desizing, scouring, mercerization, dyeing, printing and finishing. Thus each and every stage requires large amounts of inputs in terms of water, chemical & energy and generate wastes at each stage. The other feature of this industry, which is a backbone of fashion garments is large variation in demand of type, pattern and color combination of fabric resulting into significant fluctuation in waste generation volume and load. Textile processing generates many waste streams, including liquid, gaseous and solid wastes, some of which may be hazardous. Effluent discharge Of all the steps involved in textiles processing, wet processing creates the highest volume of wastewater. The nature of the waste generated depends on the type of textile facility, the processes and technologies being operated, and the types of fibers and chemicals used. Textile finishing represents the most variable area in the production process. A wide and ever growing range of finishes are now available that either improve the properties, handle or texture of the fabric. 4 www.fibre2fashion.com Contributors to carbon footprint Use of chemicals like potassium dichromate, sodium hypochlorite or peroxide and sodium hypochlorite in the preparation process of desizing, scouring and bleaching with their related wash-off stages, produces heavy Biological Oxygen Demands (BOD) in the effluents. Chlorine used in bleaching creates halogenated organic substances, of which some are suspected to be carcinogenic, e.g., chloroform, thus is not preffered. Use of banned amines and toxic dyes. Banned amines are the chemicals which are released from some of the azo dyes on reductive cleavage. These are suspected to be carcinogenic and are being banned. Apart from Germany, Netherlands has also banned the presence of these amines and this is applicable to clothing, bed linen and footwear. List of banned amines is as follows: 1. 4-Aminodiphenyl /xenylamine/Biphenyl-4-ylamine 2. 2-Amino-1-nitrotoluene 3. Benzidine 4. 4-Chloro-o-toluidine 5. 2-Naphthylamine 6. O-Aminoazotoluene 7. p-Chloraniline 8. 2, 4’-Diaminoanisole /4-methoxy-m-phenylenediamine 9. 4, 4’-Diaminodiphenylmethane /4,4-methylenedianiline 10. 3, 3’-Dichlorobenzidine /3,3’dichlorobiphenyl-4,4’-ylenediamine 11. 3, 3’-Dimethoxy-benzidine /o-dianisidine 12. 3, 3’-Dimethylbenzidine /4,4’-bi-o-Toluidine 13. 3, 3’-Dimethyl-4, 4’-diaminodiphenylmethane 4,4’-methylenedi-o-toluidine 14. p-cresidin (2-Methoxy 5-methylaniline) 15. 4, 4’-Methylene-bis-(2-chloraniline) 16. 4, 4’-Oxydianiline 17. 4, 4’-Thiodianiline 18. 0-Toluidine /2-aminotoluene 19. 2, 4-Toluyendiamine /4-methyl-m-phenylenediamine 20. 2, 4, 5-Trimethylaniline 21. p-Amino-azobenzene 22. 2-Methoxyaniline / o-anisidine Carriers and solvents may be emitted during dyeing operations (depending on the types of dyeing processes used). Carriers used in batch dyeing of disperse dyes may lead to volatilization of aqueous chemical emulsions during heat setting, drying, or curing stages, thus creating harmful volatile organic compounds. Acetic acid and formaldehyde are two major emissions of concern in textiles Textile mills usually generate nitrogen and sulphur oxides from boilers Other significant sources of air emissions in textile operations include resin finishing and drying operations, printing, dyeing, fabric preparation, and wastewater treatment plants. Hydrocarbons are emitted from drying ovens and from mineral oils in high-temperature drying/curing. These processes can emit formaldehyde, acids, softeners, and other volatile compounds. Residues from fiber preparation sometimes emit pollutants during heat setting processes. 5 www.fibre2fashion.com Wool industry uses chlorine based compounds for anti-shrinking dealing, and such practice also generates toxic effluent. For removing rust stains in bleaching, before bleaching the cloth is treated with oxalic acid. The oxalic acid is lethal to aquatic organisms and it increases COD and