POTENTIAL FOR STAINLESS-STEEL MICROFILTRATION PROCESSING TO REDUCE EFFLUENT FROM A FLUID MILK AND ICE-CREAM PROCESSING PLANT

The use of a porous stainless steel micromembrane system was investiga ted as a means of chemical recovery and effluent pretreatment for the dairy industry. With a volume recovery of 89%, the chemical solutions recovered from the permeate stream, such as caustic, chlorinated alkal ine, and acidic solutions, retained their strengths. Because of the re duction in suspended solids, protein, and fat, the chemical solutions could be reused. The system also effectively removed suspended solids, fat, and protein from dairy products and from combined dairy effluent s, corresponding to a 74 to 76% removal of chemical oxygen demand from combined dairy effluents. The use of coagulation and flocculation or UF prior to or after the system did not provide additional benefits in chemical oxygen demand or solids removal.