Review Paper on Treatment of Food Industry Wastewater by Sequencing Batch Reactor

Food industries have an important place in the Indian economic development. However, the wastewater generated from these industries bear a high degree of pollution load. A membrane separation process was coupled to a sequencing batch reactor (SBR) for biological nutrient removal (BNR) processes and a combined system was named a membrane sequencing batch reactor (MSBR). MSBR was used for the treatment of dairy industry wastewater and optimized to increase the treatment efficiency. Since a diffuser-attached module design, subcritical flux operation, and intermittent suction method were adapted to the system, long-term operation was possible, i. e. the system could be operated for more than 110 days with only one membrane washing. BOD removal was high (9798 %) and stable. SS (suspended solid) -free effluent was obtained by membrane separation. Since nitrogen was mainly consumed as nutrient for synthesis of new cells due to the low influent concentration, the removal rate reached 96 %. Phosphorus removal was relatively low because of the limit of the biological process, i. e. removal efficiency ultimately depends on the amount of excess sludge wasting. A removal rate of 80 % was reached after system optimization.