Developments in sustainable chemical processing of textiles

Abstract

Chemical processing adds value to the textiles by improving aesthetics and imparting functional properties. It is usually carried out in the aqueous medium and thus requires a large amount of water. A number of chemicals and auxiliaries are employed in the process many of which are not biodegradable. Unused chemicals are discharged along with the process water as effluent which has to be treated at huge costs to make it comply with environmental regulations. Textile processing is energy intensive also as many treatments are carried out at elevated temperatures. Requirement of these inputs depends upon the nature of the fibre and machine used. As discharge and treatment of the aqueous effluent and unavailability of soft water required by the textile industry is the biggest challenge towards ensuring sustainability of the textile-processing industry, most of the developments in this field have tried to address these issues in various ways. This chapter analyses the key issues in the textile wet processing with special emphasis on the usage of dyes, chemicals, water, energy, carbon footprints, and problems associated with disposal of harmful chemicals to the environment. Research and development in sustainable processing using enzymes and natural products with better biodegradability have been discussed. Waterless technologies for textile processing with special citations of supercritical and plasma technology have been reviewed. Developments in dyes and dyeing for higher sustainability were critically analysed and alternatives for the source reduction at various processing stages have been explored. Social responsibility of different stakeholders for sustainable textile wet processing has also been discussed.