类芽孢杆菌对铜陵新桥矿区土壤中Cu化学形态的影响

采用Tessier五步连续提取法和红外光谱技术,研究类芽孢杆菌对铜陵新桥矿区重金属污染土壤中Cu化学形态的影响,初步探讨了Cu形态变化的机理。结果表明,不同投入量的类芽孢杆菌接种到土壤培养一周后,土壤溶液pH值降低,土壤中可交换态、有机结合态Cu含量增加,碳酸盐结合态、铁锰氧化物结合态和残渣态Cu的含量降低。土壤中可交换态、铁锰氧化物结合态和残渣态Cu含量的变化主要受土壤溶液的pH值控制;有机结合态升高主要与类芽孢杆菌菌数及其代谢产生的低分子量有机酸有关。类芽孢杆菌可以改变矿区土壤中Cu的化学形态,影响Cu的生物有效性。

Effects of Cohnella sp. on Chemical Forms of Copper in Soils in Xinqiao Mining Area, Tongling, Anhui

The five step Tessier sequential extraction method and the infrared spectroscopy technology were used to investigate the changes of chemical forms of Cu in soils infected by Cohnella sp., meanwhile, the possible mechanism of changing forms of Cu was studied. Results showed that a week after soil was infected by different inoculation of Cohnella sp., pH values of soil solution reduced, distribution ratio of exchangeable form and organic combined form of Cu increased, and acid soluble form, oxidation form and residual form of Cu redued. The changes of the exchangeable form, oxidation form and residual form of Cu were influenced by pH values ; while, the increase of organic combined form of Cu was related to the amount of Cohnella sp. and low molecular weight organic acids produced by microbial metabolism. So, the Cohnella sp. could change the chemical forms of Cu in soils in Xinqiao Mining Area, and substantially increase bioavailability of Cu in soils.