碱性异化金属还原菌T.magadiensis对Cr(Ⅵ)的还原研究

Reduction of Cr(Ⅵ) by an alkaline dissimilative metal reduction bacterium of T. magadiensis

铬(Cr)作为一种环境中常见的重金属污染物,可以通过还原作用,从Cr(Ⅵ)降低价态至Cr(Ⅲ),实现减毒。该研究探讨了碱性厌氧异化金属还原菌Tindallia magadiensis对模拟含铬废水的减毒能力,分别研究了初始Cr(Ⅵ)浓度、碳源、初始p H和共存金属离子对其生长和Cr(Ⅵ)还原能力的影响。结果表明:该菌具有较好的Cr(Ⅵ)耐受能力,可在初始Cr(Ⅵ)浓度30 mg/L、pH 8、NaHCO3为碳源时,实现96.9%的Cr(Ⅵ)还原;微量Cu2+的存在还可以进一步促进对Cr(Ⅵ)的还原;T. magadiensis为碱性环境中少量Cr(Ⅵ)的微生物减毒提供了新的研究思路和菌种选择。

As a common environmental heavy metal pollutant, the toxicity attenuation of chromium(Cr) can be archived by valence state reducing from Cr(Ⅵ) to Cr(Ⅲ). In this study, the attenuation ability of an alkaline anaerobic dissimilative metalreducing bacterium of Tindallia magadiensis was investigated in the simulated chromium-containing wastewater. Effects of initial Cr(Ⅵ) concentration, carbon source, initial pH and coexisting metal ions on its growth and Cr(Ⅵ) reduction ability were studied. The experimental results indicated that the bacterium had a good Cr(Ⅵ) tolerance, and a 96.9% Cr(Ⅵ) reduction was achieved with the initial Cr(Ⅵ) concentration of 30 mg/L, pH of 8, and NaHCO_(3) as the carbon source. The presence of trace Cu^(2+) had a promotion on the reduction of Cr(Ⅵ). The reduction of Cr(Ⅵ) by T. magadiensis provided a new research idea and an alternative way for the microbial attenuation of small amount of Cr(Ⅵ) in the alkaline environment.