Keywords: textile effluent, physico-chemical treatment, conventional coagulants, polyelectrolytes, COD removal, chemical oxygen demand, wastewater treatment, flocculation, alum, polyaluminium chloride, PAC, acrylamide copolymers, textile dyes
Performance of four polyelectrolytes as flocculation aids in the primary treatment of textile effluents
Samples of textile effluents were subjected to physico-chemical treatment using alum, Polyaluminium Chloride (PAC), and different anionic and cationic acrylamide copolymers. Except for alum, all chemicals were tested individually. Combinations of alum and PAC with different anionic and cationic polyelectrolytes were also tested. Results indicated the anionic polyelectrolyte to be the best polymer when used in combination with inorganic coagulants. 30-40 mg/L PAC and 0.75 mg/L of anionic polymer resulted in the best removals of Chemical Oxygen Demand (COD), Total Suspended Solids (TSS) and Turbidity of 32.0-38.2%, 80.0-85.0% and 25.3-47.0%, respectively. This study indicated that dye-loaded textile wastewater could be treated with blends of inorganic?organic coagulants to reduce the organic load. However, the colour of the wastewater could not be removed.