EVALUATION OF INDUSTRIAL DYEING WASTEWATER TREATMENT WITH COAGULANTS AND POLYELECTROLYTE AS A COAGULANT AID

Textile industry is the major source of water consumption and wastewater pollution. there are varioustreatment techniques to remove textile wastewater pollution. coagulation-flocculation is a widely usedprocess to remove pollution due to suspended particles, in this research, different coagulants like alum,lime, feci3, fes0 4 and mgclz were applied to select the suitab le ones with optimum remova l efficiency.settling characteristics of floes formed in the coagulation process were studied in a laboratory scalesettling column unit. parameters such as color, cod, tss, turbidity and settled sludge volume have beenevaluated. the optimum coagulant dose and ph value were determined by comparing the effectiveness ofthese coag ulants. results showed other coagulants excep t lime could eliminate color and codsuccessfully. in this case, fes04 was chosen as an optimum coagu lant for color removal because of thelowest required coagulant dose, minimum settled sludge volume and maximum decolorization.