期刊
ENVIRONMENTAL SCIENCE & TECHNOLOGY
卷 48, 期 19, 页码 11337-11342出版社
AMER CHEMICAL SOC
DOI: 10.1021/es5031849
关键词
-
资金
- BANDD consortium (Biogeochemical Applications in Nuclear Decommissioning and Waste Disposal - EPSRC) [Ep/G063699/1]
- Office of Science, Office of Basic Energy Sciences, of the U.S. Department of Energy [DE-AC02-05CH11231]
- Engineering and Physical Sciences Research Council [EP/G063699/1] Funding Source: researchfish
- EPSRC [EP/G063699/1] Funding Source: UKRI
Contamination of the environment with Cr as chromate (Cr(VI)) from industrial activities is of significant concern as Cr(VI) is a known carcinogen, and is mobile in the subsurface. The capacity of Fe(II)-containing phyllosilicates including biotite and chlorite to alter the speciation, and thus the mobility, of redox-sensitive contaminants including Cr(VI) is of great interest since these minerals are common in soils and sediments. Here, the capacity of bacteria, ubiquitous in the surface and near-surface environment, to reduce Fe(III) in phyllosilicate minerals and, thus, alter their redox reactivity was investigated in two-step anaerobic batch experiments. The model Fe(III)-reducing bacterium Geobacter sulfurreducens was used to reduce Fe(III) in the minerals, leading to a significant transformation of structural Fe(III) to Fe(II) of 0.16 mmol/g (similar to 40%) in biotite and 0.15 mmol/g (similar to 20%) in chlorite. The unaltered minerals could not remove Cr(VI) from solution despite containing a larger excess of Fe(II) than would be required to reduce all the added Cr(VI), unless they were supplied in a very high concentration (a 1:10 solid to solution ratio). By contrast, even at very low concentrations, the addition of bioreduced biotite and chlorite caused removal of Cr(VI) from solution, and surface and near surface X-ray absorption spectroscopy confirmed that this immobilization was through reductive transformation to Cr(III). We provide empirical evidence that the amount of Fe(II) generated by microbial Fe(III) reduction is sufficient to reduce the Cr(VI) removed and, in the absence of reduction by the unaltered minerals, suggest that only the microbially reduced fraction of the iron in the minerals is redox-active against the Cr(VI).
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据