摘要
氧化亚铁硫杆菌生物淋滤修复重金属污染土壤研究报道很少,因为该菌对低分子量有机酸敏感。研究6种低分子量有机酸(甲酸、乙酸、丙酸、草酸、苹果酸和柠檬酸)对嗜酸性氧化亚铁硫杆菌R2氧化Fe2+的影响,且利用高效液相色谱法测定沈阳冶炼厂和张士灌区重金属污染土壤中低分子量有机酸的浓度。结果表明,6种有机酸对R2氧化能力均具有抑制作用,且抑制顺序为:甲酸>乙酸>丙酸>草酸>苹果酸>柠檬酸。其中R2对甲酸最敏感,甲酸浓度为0.064 mmol/L时,抑制率达到60%;浓度为0.254 mmol/L时,R2氧化Fe2+的能力完全被抑制。液相色谱分析可知,冶炼厂和张士灌区土壤中有机酸的浓度很低,其中草酸含量最高,分别为0.04和0.149 mmol/L。尽管氧化亚铁硫杆菌对低分子量有机酸很敏感,但是试验土壤中低分子量有机酸的浓度远远低于硫杆菌的耐受限度。因此,分离菌株R2有望应用于重金属污染土壤的修复。
A little work has been reported concerning bioleaching of heavy-metal contaminated soil using Acidithiobacillus ferrooxidans, since this acidophile is sensitive to low molecular weight （LMW） organic acids. Effects of LMW organic acids （formic, acetic, propionic, citric, malic and oxalic acids） on Fe2＋ oxidation by A. ferrooxidans R2 were examined, and the concentrations of LMW organic acids in soils （from Shenyang Smelt- ery and Zhangshi irrigation area） were determined by high performance liquid chromatography （HPLC）. Iron ox- idation by R2 was inhibited by a variety of LMW organic acids. Growth experiments with ferrous iron as an oxi- dant showed that the inhibition capability sequence was formic acid 〉 acetic acid 〉 propionic acid 〉 oxalic acid 〉 malic acid 〉 citric acid. Formic acid was the most toxic that the inhibition rate was up to 60% at the concentra- tion of 0. 064 mmol/L and the oxidation ability of R2 was entirely inhibited at the concentration of 0. 254 retool/ L. HPLC analyses showed that the highest concentrations of LMW organic acids in the soils were 0.04 mmol/L and 0. 149 mmol/L oxalic acid, respectively. Although R2 was sensitive to organic acids, the concentrations of LMW organic acids in the contaminated soils were rather lower than the tolerable levels. Hence, it is feasible that R2 might be used for bioleaching of heavy metal-contaminated soils.
出处
《环境工程学报》
CAS
CSCD
北大核心
2008年第9期1269-1273,共5页
Chinese Journal of Environmental Engineering
基金
国家“863”高技术研究发展计划项目(2007AA061101)
国家“973”重点基础研究发展规划项目(2004CB418506)
国家环保局“全国土壤现状研究调查及污染防治专项”资助项目
中国科学院知识创新工程重大项目(kzcx1-yw-06-03)
