Textile industry is the huge sector where a large amount of waste streams or effluents are produced. The effluent which is produced in different sector of textile industry is dangerous for the environment. Mainly effluent is produced from desizing, scouring, bleaching, mercerizing, dyeing, printing, finishing, washing and others process. This type of waste water contains harmful chemicals for the environment, for this reason it needs to purify before discharge to the environment. Effluent treatment plant is used for treated the effluent which is come from the textile or other chemical industry.
Characteristics of Process Waste Streams of Textile Industry: Now, I will show you the process unit of textile industry from where effluent is produced, possible pollutant contain in water and nature of waste water. It must help us to get the general concept about the effluent of the textile industry and we can set up ETP for treated the effluent.
Desizing: We know that, size materials are apply on the yarn surface in weaving sector. The removing process of size materials from the fabric is called desizing. Possible pollutant in water is Starch, Glucose, CMC, PVC, Resins, Fats, and Oils etc. The nature of the waste water is high BOD (35-50%) of total.
Scouring: Scouring is the process by which impurities of the textile materials are removed. Possible pollutant in water is NaOH, Na2CO3, Waxes, Grease, Fragments of cotton etc. Nature of waste water is strongly alkaline, dark color, high BOD (30%) of total.
Bleaching: Natural color of the textile materials are removed by the bleaching process. Possible pollutant in water is Na(0Ocl)Cl, NaOH, Cl2, H2O2, Na2O2, acids etc. Nature of waste water is alkaline, BOD (5%) of the total.
Mercerizing: It is an additional process to improve the physical properties of the fiber. Possible pollutant in water is NaOH, H2SO4, Na2CO3 etc. Nature of waste water is strongly alkaline, BOD (less than 1%).
Dyeing: Dyeing unit is the main production house of waste water. Waste water which is produced in yarn dyeing, woven dyeing or knit dyeing unit is highly polluted. Possible pollutant in water is various Dyes, Salts, Acids, Alkalis, Soap, and Detergent etc. Nature of waste water is strongly colored, fair BOD (6%) of the total.
Printing: Various type of decorous design is formed by the printing process. Possible pollutant in water is Colors, Pigments, Gums, Oils, Acids, different salt and other auxiliaries. Nature of waste water is highly colored, oily appearance, BOD (6 to 10%) of the total.
Finishing: Different types of finishing are applied in the finishing section. Possible pollutant in water is Traces of Starch, Resins, Softeners, and Stiffeners etc. Nature of waste water is low BOD (2 to 4%) of the total.
To protect the environment from the harmful effect of the effluent of the textile industry, the owner of the industry should set up an Effluent Treatment Plant (ETP).