微生物铁硫还原耦合水体中As(V)吸附行为研究

Microbe-mediated Iron-sulfur Reduction Coupled Adsorption Behavior of As(V) in Water

采用循环伏安法(CV)、铁的L边和硫的K边X射线近边吸收光谱(XANES)和电感耦合离子光谱发生仪等,研究了碱性厌氧环境中S.oneidensis介导下的铁硫还原过程与水体中As(V)的吸附行为。结果表明,核黄素能够促进S.oneidensis介导的铁硫还原,电子传递过程为乙酸盐→核黄素→底物;S.oneidensis作用24 h后,沉积物中铁硫形态逐渐被还原,Fe(Ⅱ)/Fe(Ⅲ)的比例不断增加,出现硫化矿物特征峰,表明有新的铁的硫化矿物(FeS)生成;FeS对As(V)的吸附量随着时间而增加,6 h后逐渐达到平衡,120 h时吸附量为8.35 mg,吸附效率为89%。微生物铁硫还原生成的Fe S对水体中As(V)有显著的吸附效果,有良好的应用前景。

The process of iron and sulfur reduction mediated by S. oneidensis and As（V） adsorption performance in alkaline anaerobic environment were studied by cyclic voltammetry（CV）, Fe L-and S K-edge XANES and inductively coupled plasma spectrometer（ICP）. The results showed that, riboflavin could promote process of iron and sulfur reduction mediated by S. oneidensis, and the electron transfer process was acetate→ riboflavin → substrate;elemental sulfur and jarosite were gradually reduced after 24 h of S. oneidensis reaction, the ratio of Fe（II）/Fe（III） in precipitation increased and the characteristic peak of sulfide mineral had come out, suggesting that iron sulfide minerals（Fe S） had generated; the adsorption amount of As（V） by Fe S increased with the increase of time and gradually reached balance after 6 h, the adsorption amount was 8.35 mg at 120 h and its adsorption efficiency could reach 89%. The generation of Fe S mediated by S. oneidensis had a significant adsorption ability on As（V） in the water, which would have good application prospect.