REDUCTION OF CR, MO, SE AND U BY DESULFOVIBRIO-DESULFURICANS IMMOBILIZED IN POLYACRYLAMIDE GELS

Intact cells of Desulfovibrio desulfuricans, immobilized in polyacryla mide gel, removed Cr, Mo, Se and U from solution by enzymatic-mediated reduction reactions, Lactate or H-2 served as the electron donor and the oxidized Cr(VI), Mo(VI), Se(VI) and U(VI) served as electron accep ters, Reduction of the oxidized metal species resulted in the precipit ation of solid phases of the metals, Metal removal efficiencies of 86- 96% were achieved for initial concentrations of 1 mM Mo, Se, and U and 0.5 mM Cr, Insoluble metal phases accumulated on both the surface and the interior of the polyacrylamide gel, In column tests conducted for U removal, effluent concentrations less than 20 mu g L-1 were achieve d with initial concentrations of 5 mg L-1 and 20 mg L-1 U and residenc e times from 25-37 h, The enzymatic reduction of Cr, Mo, Se, and U by immobilized cells of D. desulfuricans may be a practical method for re moving these metals from solution in a biological reactor.