Treatment of textile wastewater using microbes’ inoculated free-floating aquatic plants based wetlands

Textile wastewater is a big source of aquatic and environmental pollution. Currently, various physicochemical textile effluent treatments are practiced in the textile industry, but they have challenges with respect to cost, maintenance, labour management, chemicals usage and production of additional sludge. The present study was carried out to develop a less expensive, chemicalfree, green and sustainable plant based floating treatment wetlands (FTWs) system augmented with bacteria to remedy the effluents from textile finishing unit. Two free-floating aquatic plants, Eichhornia crassipes and Pistia stratiotes, were vegetated to develop FTWs system and its efficacy was studied with and without inoculating two plant growth-promoting and pollutant- degrading bacteria, Bacillus cereus and Bacillus subtilis. The worth of this system was analyzed by screening physicochemical parameters like potential hydrogen (pH), electric conductivity (EC), total dissolved solids (TDS), total suspended solids (TSS), biological oxygen demand (BOD) and chemical oxygen demand (COD) of wastewater for hydraulic retention periods of 0, 24, 48 and 72 hours. The pH of the treated wastewaters was changed from acidic to neutral/alkaline side while a significant reduction was found in all other physiochemical parameters as per set limits of industrial and municipal wastewater standards as specified by the National Environmental Quality Standards (NEQS) of Pak istan and Zero Discharge of Hazardous Chemicals (ZDHC) program.