Chai Liyuan, Huang Shunhong, Yang Zhihui, Peng Bing, Huang Yan, Chen Yuehui
School of Metallurgical Science & Engineering, Central South University, Changsha, PR China.
J Hazard Mater. 2009 Aug 15;167(1-3):516-22. doi: 10.1016/j.jhazmat.2009.01.030. Epub 2009 Jan 17.
Hexavalent chromium (Cr) is a toxic element causing serious environmental threat. Recently, more and more attention is paid to the bio-remediation of Cr (VI) in the contaminated soils. Cr (VI) remediation by indigenous bacteria in soils contaminated by chromium-containing slag at a steel-alloy factory in Hunan Province, China, was investigated in the present study. The results showed that when sufficient nutrients were amended into the contaminated soils, total Cr (VI) concentration declined from the initial value of 462.8 to 10 mg kg(-1) at 10 days and the removal rate was 97.8%. Water soluble Cr (VI) decreased from the initial concentration of 383.8 to 1.7 mg kg(-1). Exchangeable Cr (VI) and carbonates-bound Cr (VI) were removed by 92.6% and 82.4%, respectively. Meanwhile, four Cr (VI) resistant bacterial strains were isolated from the soil under the chromium-containing slag. Only one strain showed a high ability for Cr (VI) reduction in liquid culture. This strain was identified as Pannonibacter phragmitetus sp. by gene sequencing of 16S rRNA. X-ray photoelectron spectroscope (XPS) analysis indicated that Cr (VI) was reduced into trivalent chromium. The results suggest that indigenous bacterial strains have potential application for Cr (VI) remediation in the soils contaminated by chromium-containing slag.
六价铬（Cr）是一种有毒元素，会对环境造成严重威胁。近年来，受污染土壤中六价铬（Cr(VI)）的生物修复受到越来越多的关注。本研究对中国湖南省一家钢铁合金厂含铬炉渣污染土壤中土著细菌对Cr(VI)的修复情况进行了调查。结果表明，向污染土壤中添加充足养分后，总Cr(VI)浓度在10天时从初始值462.8降至10 mg kg(-1)，去除率为97.8%。水溶性Cr(VI)从初始浓度383.8降至1.7 mg kg(-1)。可交换态Cr(VI)和碳酸盐结合态Cr(VI)的去除率分别为92.6%和82.4%。同时，从含铬炉渣下的土壤中分离出4株抗Cr(VI)细菌菌株。在液体培养中只有一株菌株表现出较高的Cr(VI)还原能力。通过16S rRNA基因测序，该菌株被鉴定为芦苇泛菌（Pannonibacter phragmitetus sp.）。X射线光电子能谱（XPS）分析表明，Cr(VI)被还原为三价铬。结果表明，土著细菌菌株在含铬炉渣污染土壤中对Cr(VI)的修复具有潜在应用价值。
