Abstract:
Bangladesh textile sector is the highest contributor to the national economy. Textile (dyeing) industries consumes substantial amount of chemicals in their processes which ultimately discharge a large volume of textile (dyeing) effluent treatment plant (ETP) sludge in open places, thereby leaving a huge environmental footprint and posing negative impacts. Currently, there are no published national sludge discharge standard for Bangladesh textile dyeing industries. Therefore, this thesis focusses on the management of solid wastes i.e., textile (dyeing) effluent treatment plant sludge which is a complex mixture of particles originating from organic and inorganic chemicals. Several characterization techniques were applied to define the sludge generated from textile (dyeing) for different effluent treatment techniques (physio-biological, physio-chemicalbiological, and electro-coagulation). These testing protocols reveal that the textile dyeing sludge contains heavy metals like Cu, Ti, Ru, Cl, Zn, Mn, Ni, Cr, Sr, etc. and their quantities aided the authors for carrying out the elementary risk assessment. Bio-toxic effect of dyeing sludge was realized from the life cycle analysis of Escherichia coli (E. Coli), that characterizes sludge as ecologically harmful. Extraction of the sludge solution was used with broth media at different ratios (1:10, 1:2, and 1:1) and the results of the toxicity analysis reveal that the increasing amount of sludge ratio in nutrient media causes a more toxic effect on the bacterial life cycle and inhibits bacterial growth. The study concludes that predictive approaches, along with preventive measures for the reduction of chemical consumption in dyeing processes using sustainable initiatives and practices, will make a paradigm shift from the reactive approach for sludge management to the preservation of resources. Less water and chemical consumptions will reduce the effluent load, and health risks associated with the heavy metals of textile sludge.
