CROSS-FLOW MICROFILTRATION WITH DYNAMIC MEMBRANES

The effect of dynamic membrane formation on the performance of crossfl ow microfiltration in treating domestic wastewater was investigated. T he dynamic membrane was formed on top of a woven polyester primary mem brane by circulating a precipitate of MnO2. The dynamic membrane forma tion was investigated at different conditions of pH values and KMnO4 c oncentrations. Secondary effluent from a domestic wastewater treatment plant was used thoughout the study. The MnO2 dynamic membrane was fou nd to improve the performance of crossflow microfiltration by producin g higher flux values, extending the running time, and increasing rejec tion of solids. The optimum permeate flux values were obtained when th e dynamic membrane was formed at a pH of 10 and using 100 mg/l of KMnO 4. At optimum conditions, the permeate turbidity was found to stabiliz e at values of less than 0.2 NTU. Cleaning the membrane was achieved e asily and efficiently by brushing the outside surface of the primary m embrane. (C) 1997 Elsevier Science Ltd.