Huang Chiyue, Guo Zhaohui, Peng Chi, Anaman Richmond, Zhang Pan
Institute of Environmental Engineering, School of Metallurgy and Environment, Central South University, Changsha 410083, China.
Institute of Environmental Engineering, School of Metallurgy and Environment, Central South University, Changsha 410083, China.
Sci Total Environ. 2023 May 15;873:162306. doi: 10.1016/j.scitotenv.2023.162306. Epub 2023 Feb 18.
Microorganisms are widely used in large-scale pollution remediation due to their rapid reproduction and low cost. In this study, bioremediation batch experiments and characterization methods were adopted to investigate the mechanism of FeMn oxidizing bacteria on the immobilization of Cd in mining soil. The results showed that the FeMn oxidizing bacteria successfully reduced 36.84 % of the extractable Cd in the soil. The exchangeable forms, carbonate-bound forms, and organic-bound forms of Cd in the soil decreased by 11.4 %, 8 %, and 7.4 %, respectively, due to the addition of FeMn oxidizing bacteria, while FeMn oxides-bound and residual forms of Cd increased by 19.3 % and 7.5 %, as compared to the control treatments. The bacteria promotes the formation of amorphous FeMn precipitates such as lepidocrocite and goethite, which have high adsorption capacity on soil Cd. The oxidation rates of Fe and Mn in the soil treated with the oxidizing bacteria reached 70.32 % and 63.15 %, respectively. Meanwhile, the FeMn oxidizing bacteria increased soil pH and decreased soil organic matter content, further decreasing the extractable Cd in the soil. The FeMn oxidizing bacteria have the potential to be used in large mining areas to assist in the immobilization of heavy metals.
微生物因其繁殖迅速且成本低廉而被广泛应用于大规模污染修复。本研究采用生物修复批次实验和表征方法，探究铁锰氧化细菌对矿区土壤中镉固定的作用机制。结果表明，铁锰氧化细菌成功降低了土壤中36.84%的可提取镉。由于添加了铁锰氧化细菌，土壤中镉的交换态、碳酸盐结合态和有机结合态分别减少了11.4%、8%和7.4%，而与对照处理相比，铁锰氧化物结合态和残留态的镉分别增加了19.3%和7.5%。该细菌促进了诸如纤铁矿和针铁矿等无定形铁锰沉淀物的形成，这些沉淀物对土壤中的镉具有高吸附能力。用氧化细菌处理的土壤中铁和锰的氧化率分别达到70.32%和63.15%。同时，铁锰氧化细菌提高了土壤pH值并降低了土壤有机质含量，进一步减少了土壤中可提取的镉。铁锰氧化细菌有潜力应用于大型矿区以协助固定重金属。
