Application of cross-flow electro-microfiltration in chromium wastewater treatment

Cross-flow microfiltration (CFMF) was experimentally studied for the separation of precipitates of chromium hydroxide. Although this process enables one to obtain chromium-free filtrate, a disadvantage is that the filtration flux declines rapidly due to membrane fouling. In order to avoid this fouling problem and increase the filtration flux, an electric field was applied across the membrane as an antifouling technique (cross-flow electro-microfiltration-CFEMF). The surface charges of the precipitates were modified by adding a dispersant. The experimental results indicate that this modified process of CFEMF is highly effective in reducing the membrane fouling, which eventually leads to a remarkable filtration flux increase. The application of this antifouling technique of CFEMF is cited only for the suspensions containing charged particles and colloids. Nevertheless, the process of modification of surface charge with a dispersant permits us to use this technique with a wide variety of suspensions.