Understanding Textile Manufacturing Process in the light of Textile Wastewater Types and Chemicals Used
Textile industry deploys many different process stages in its manufacturing life cycle which involves both mechanical processing and wet-treatment processes. The mechanical processes are spinning, knitting, weaving and garment production. The wet processes are sizing, desizing, scouring, bleaching, mercerizing, dyeing, printing and finishing. Table 1 lists the types of waste generated in every stage of textile production.
Table 1. Types of Textile Waste Produced by Process (Water, Solid and Emission)
A variety of chemicals are used in each and every stage of the production process of textiles. These chemicals end up as waste once their intended function is achieved in the production process. These spent up chemicals end up as effluent and need to be treated accordingly for a stricter compliance of the rules and regulations of Wastewater Management of the State. Table 2 lists down the type of chemicals used in each stage of the production process.
Table 2: Chemicals Used in Different Production Processes In Textile Manufacturing
To produce a kilogram of textiles, approximately 200 litre of water is utilized. Ntuli F, Omoregbe I, Kuipa P, Muzenda E, Belaid M (2009) have reported a concise percentage split of water used in a textile manufacturing process: “38 % of water is used during process of bleaching, 16 % in dyeing, 8% in printing, 14 % in boiler and 24 % for other uses”. The textile wastewater effluent contains high amounts of suspended and dissolved solids, biological oxygen demand (BOD), chemical oxygen demand (COD), chemicals, trace metals like Cr, As, Cu and Zn and color.
Hence it is a mandate to treat the textile wastewater with right care and technology to safeguard the environment.