Study on Removing Hexavalent Chromium by Sulfate-Reducing Bacteria (SRIV).
Wang Pin etal. ( Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu)
A strain of sulfate- reducing bacteria capable of reducing hexavalent chromium was isolated from electroplating sludge by using Hungate anaerobic technique. The strain was a motile curved rod, possessing singly polar flagella. The cell was 0. 5-0. 8μm in length, non- sporing, non- capsules, Gram-negative. The oxidation was incomplete, leading to acetate production; and glucose, sucrose, pyruvate, H2 + CO2, alcohol, and formate were fermented in the absence of an external electron acceptor. These characteristics established the isolate as Desulfovibrio sp. Reclaiming of hexevalent chromium with the isolate has shown that it was resistant to Cr(VI) concentrations of up to 10 ×10-3mol/L at the optimum temperature 30℃ and at optimum pH 7. 0. And under such conditions, the optimun Cr(VI) concentration for its growth was 4×10-3mol/L. The removal of Cr(VI) was 99. 8 %. SRIV strain was a engineered strain in removing Cr(VI) from wastewater.