“Ch-1菌-Cr(VI)-H2O”体系中Cr(Ⅵ)还原的电化学行为

Electrochemical behaviors of ‘Ch-1-Cr(VI)-H2O’ system were investigated by Cyclic Voltammetry. The results indicate that peak current at -0.6V vs. SCE represents the reduction reaction of Cr6+ to Cr3+and that at -0.8V is the reaction of Cr3+ which exists in the solution stably to Cr in the cyclic voltammentry curve. The electrode reaction of the system is irreversible Cr(III) will not be oxidized to Cr(VI) when scanning positively. It becomes easier for the reduction of Cr6+ because the reduction peak potential moves about 0.2V positively in the presence of bacteria Ch-1, which indicates catalysis of bacteria for electrochemical reaction takes place in the system. Potentials of hydrogen evolution, reduction of Cr(VI) to Cr(III) and reduction of Cr(III) to Cr all move positively with the addition of biomass of Ch-1 bacteria. Too high biomass mainly effects the process of reduction and precipitation of Cr(III). There is little influence of the concentration of Cr(VI) on the electrochemical behaviors of ‘Ch-1-Cr(VI)-H2O’ system. There is a remarkable effect of Ch-1 bacteria on the reduction process of Cr(VI) when initial pH value is 10. So pH of 10 is optimal for the system.