Reduction of chromate by molybdenum hydrogen bronze

Abstract

Molybdenum hydrogen bronze, H0.57MoO3, is capable of removing up to 80 mequiv./g chromate from aqueous solution. The redox process is accompanied by adsorption of the reduced chromium species so that the chromium is completely removed from solution. Chromate removal was only weakly dependent on pH, being slightly favored at acidic pH. The kinetics appear to involve the rapid adsorption of chromate in an equilibrium process that is followed by reduction of the chromium(VI). The rate constant was found to be first order in chromate and the amount of suspended H0.57MoO3 with a rate constant of 1.40 L g−1 min−1.