Biological Treatment of Textile Effluents: Best adoptable option results in cost & environment savings with outstanding treatment efficiency
Textile wet processes generate effluents of extremely variable composition and constitute an environmental risk specially water pollution of major concern. By rapid disposal of untreated wastewater deteriorate the ecosystem and damage the aquatic life. To combat ecological degradation it is mandatory for a textile dyeing industry to install an effective effluent treatment plant (ETP). This study, focused on investigating the best possible solution to install the most economic and effective effluent treatment plant analyzing physico-chemical, biological, chlorination and other combined wastewater treatment techniques practiced in composite textile industries at present times in Bangladesh. It is found that biological wastewater treatment possesses high degree of efficiency with minimum running cost (5 to 6 times less) compared to other methods. Average reduction efficiency of BOD, COD, TSS and TDS is found 84%, 59.1%, 81.7% and 54.8% respectively by biological treatment. None of the methods except biological method can satisfy discharge standard. Combined physico-chemical and biological method is considered as the most efficient method. But real situation is different. High running cost (20-28 tk/m3) due to high chemical consumption, huge amount of highly toxic sludge (2-5 kg/m3) disposal problem do not encourage the owners to run the plant effectively. Treatment with chlorine is very cheap but high probability of producing dangerous disinfection byproducts (DBPs) restricts its application.
The author is student of Final year in Department of Wet Processing Technology at Bangladesh University of Textiles.