Reduction remediation of hexavalent chromium by bacterial flora in Cr(VI) aqueous solution.
Chromium(VI) is a priority pollutant in soils and wastewaters and reduction of Cr(VI) to Cr(III) is a solution to this problem. In this study a low-cost method was proposed to adapt indigenous bacteria and use them to reduce Cr(VI) in solutions. The experiment results show that Cr(VI) could be efficiently reduced by indigenous bacteria under anaerobic and pH-unadjusted conditions. After about 24 h the concentration of Cr(VI) could be reduced from 21.74 mg/L to below 0.5 mg/L. The observed Cr(VI) reduction rates were affected by temperature and pH. Cr(VI) in aqueous solutions could be reduced to Cr(III) completely and partly be incepted by the organisms. Cr(VI) reduction was enzyme-mediated. It was not an energy-conserving process but a detoxification reaction. This method could be used in an anaerobic reactor to treat low-concentration wastewater or industrial water as the last step.
Wang
Qian
Q
Department of Environmental Engineering, Zhejiang University, Zheda Road 38#, Hangzhou 310027, China. ivywangqian@zju.edu.cn
Xu
Xinhua
X
Zhao
Fanglin
F
Liu
Zhihao
Z
Xu
Jinan
J
D001419:Bacteria / Q000378:metabolism*; D001673:Biodegradation, Environmental; D002857:Chromium / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D010084:Oxidation-Reduction; D013696:Temperature; D014874:Water Pollutants, Chemical / Q000378:metabolism*
D014874:Water Pollutants, Chemical; D002857:Chromium; C074702:chromium hexavalent ion