Comparison of coagulants and coagulation aids for treatment of meat processing wastewater by column flotation.

The physicochemical treatment of the wastewater from a meat processing industry was studied using three ferric salts as coagulants in conjunction with four different polymers as coagulation aids by batch column flotation. The effluent was characterized in terms of pH (6.5-6.7), turbidity (1000-12000 NTU), total solids (TS) (2300-7000mgl(-1)), oils and greases (OG) (820-1050mgl(-1)), and biochemical and chemical oxygen demands (BOD(5) and COD) (1200-1760 and 2800-3230mgl(-1)), respectively. The treatments achieved typical organic load reductions of oils and greases, and total solids (up to 85%), as well as biochemical and chemical oxygen demands (between 62.0-78.8% and 74.6-79.5%, respectively). The research also found that the utilization of a column flotation achieved high efficiency of organic matter removal and its operation as a primary treatment showed no significant dependence of pollutant removal and air flow rate.