Improved reduction of cod, bod, tss and oil & grease from sugarcane industry effluent by ferric chloride and polyaluminum chloride coupled with polyvinyl alcohol

Abstract

Rapid industrialization and urbanization severely affect our environment and water resources. Disposal of un-treated wastewater to environment is a great threat to water bodies and environment. Sugarcane industry is an important industrial sector; globally it is also largest source of pollution of surface water and groundwater resources. It comprises a huge amount of chemicals and inorganic pollutants. Many treatment methods have been employed for the treatment of the sugarcane industry wastewater, such as chemical treatment, physical treatment, ion exchange, electrocoagulation and biological treatment. It is a fact that not a single treatment technique is effective for industrial effluent treatment. In this study, the physicochemical technique was used to remove the major pollutants as per Sindh Environmental Protection Agency (SEPA) effluent standards that include Chemical Oxygen Demand (COD), Biological Oxygen Demand (BOD), Total Suspended Solid (TSS) and Oil & Grease content. In these techniques e.g. chemical coagulation ferric chloride (FC) and poly aluminum chloride (PAC) coupled with polyvinyl alcohol (PVA), with different doses were used for achieving the opti-mum results. The best results were observed for COD, BOD, TSS and Oil & Grease reduction by FC and PAC dosing 180 mg/300 ml coupled with 45 mg/300 ml PVA. Further, it was also observed that the FC removal efficiency in slightly acidic to neutral medium (pH = 6–7) for COD (97.5%) and BOD (97.5%) is higher than PAC. However, PAC does perform well in slightly neutral to basic medium (pH = 7.5–8) than FC for the removal of Oil & Grease (95.3%) and TSS (97.4%) from the sugarcane effluent.