Laboratory of Environmental Pollution and Bioremediation, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi, Xinjiang 830011, China.
J Hazard Mater. 2012 Jan 30;201-202:178-84. doi: 10.1016/j.jhazmat.2011.11.067. Epub 2011 Nov 28.
Arsenic is a highly toxic metalloid and has posed high risk to the environment. As(III) is highly mobile in soil and leached easily into groundwater. The current remediation techniques are not sufficient to immobilize this toxic element. In the present study, an As(III) tolerant bacterium Sporosarcina ginsengisoli CR5 was isolated from As contaminated soil of Urumqi, China. We investigated the role of microbial calcite precipitated by this bacterium to remediate soil contaminated with As(III). The bacterium was able to grow at high As(III) concentration of 50mM. In order to obtain arsenic distribution pattern, five stage soil sequential extraction was carried out. Arsenic mobility was found to significantly decrease in the exchangeable fraction of soil and subsequently the arsenic concentration was markedly increased in carbonated fraction after bioremediation. Microbially induced calcite precipitation (MICP) process in bioremediation was further confirmed by ATR-FTIR and XRD analyses. XRD spectra showed presence of various biomineralization products such as calcite, gwihabaite, aragonite and vaterite in bioremediated soil samples. The results from this study have implications that MICP based bioremediation by S. ginsengisoli is a viable, environmental friendly technology for remediation of the arsenic contaminated sites.
砷是一种剧毒的类金属，对环境构成了高风险。三价砷在土壤中具有高迁移性，很容易浸滤到地下水中。目前的修复技术不足以固定这种有毒元素。本研究从中国乌鲁木齐砷污染土壤中分离出一株耐砷菌 Sporosarcina ginsengisoli CR5。我们研究了该菌微生物碳酸钙沉淀对修复砷（III）污染土壤的作用。该菌能够在 50mM 的高砷（III）浓度下生长。为了获得砷的分布模式，进行了五阶段土壤连续提取。生物修复后，土壤中可交换态的砷迁移性显著降低，随后碳酸化态的砷浓度明显增加。ATR-FTIR 和 XRD 分析进一步证实了微生物诱导碳酸钙沉淀（MICP）过程在生物修复中的作用。XRD 图谱显示，生物修复土壤样品中存在各种生物矿化产物，如方解石、Gwihabaite、文石和球霰石。本研究的结果表明，S. ginsengisoli 基于 MICP 的生物修复是一种可行的、环保的技术，可用于修复砷污染场地。
