Reduction remediation of hexavalent chromium by bacterial flora in Cr(VI) aqueous solution

摘要

Chromium(VI) is a priority pollutant in soils and wastewaters and reduction of Cr(VI) to Cr(III)nis a solution to this problem. In this study a low-cost method was proposed to adapt indigenousnbacteria and use them to reduce Cr(VI) in solutions. The experiment results show that Cr(VI) couldnbe efficiently reduced by indigenous bacteria under anaerobic and pH-unadjusted conditions.nAfter about 24 h the concentration of Cr(VI) could be reduced from 21.74mg/L to below 0.5mg/L.nThe observed Cr(VI) reduction rates were affected by temperature and pH. Cr(VI) in aqueousnsolutions could be reduced to Cr(III) completely and partly be incepted by the organisms.nCr(VI) reduction was enzyme-mediated. It was not an energy-conserving processnbut a detoxification reaction. This method could be used in an anaerobic reactor to treatnlow-concentration wastewater or industrial water as the last step.