Effect of Influent Concentration on Perchlorate Removal from Drinking Water in an Ion Exchange Membrane Bioreactor

Removal of perchlorate from drinking water in an ion exchange membrane bioreactor (IEMB) was investigated at different influent ClO4- concentrations when the hydraulic retention time was 5h. Except the 49th day and the 51st day, the effluent ClO4- concentrations met standard of the U.S. Environmental Protection Agency (USEPA) required 18µg/L. In the initial stages of the influent ClO4- concentration increase, the ClO4- concentration in the anaerobic bioreactor, the effluent Cl- concentration and the effluent electrical conductivity increased suddenly. As the operating time increased, the ClO4- concentration in the sludge supernatant kept below 10µg/L after steady operation; the effluent Cl- concentration declined slowly and finally stabilized at about 90 mg/L; the effluent electrical conductivity decreased gradually and finally stabilized at about 279µs/cm.