摘要
Bioleaching Xiangjiang River alkaline sediment contaminated by multiple heavy metals was investigated. Multiple metals in alkaline sediment possess significant toxicity to aquatic organisms or humans and will greatly inhibit bioleaching. The bioleaching method using autotrophic bacteria mixed with heterotrophic bacteria can solve this problem successfully. The experiment results showed that bioleaching efficiencies of Zn, Mn, Cu, and Cd were 95.2 %, 94.2 %, 90.1 %, and 84.4 %, respectively. Moreover, the changes of heavy metal concentrations in different fractions in contaminated sediment before and after bioleaching were analyzed by selective sequential extraction, and it was discovered that the main fractions of Zn, Mn, Cu and Cd after bioleaching are Fe-Mn oxide, organic associated form and a residual form. Its biotoxicity decreased greatly. The bioleaching heavy metals from sediment using autotrophic bacteria combined with heterotrophic bacteria can effectively improve the bioleaching efficiency and reduce toxicity.
探讨了生物浸出法处理湘江河床多种重金属污染的碱性底泥。底泥中的多种重金属对水生生物与人类有较大的毒性以及显著抑制细菌的浸出,利用自养细菌与异养细菌协作的浸出方法可以解决这个问题。结果表明,底泥中锌、锰、铜和镉的生物浸出率分别达95.2%、94.2%、90.1%和84.4%。利用连续提取法分析了浸出前、后底泥中不同形态重金属的含量变化,发现浸出后底泥中残余重金属主要以铁锰氧化态、有机结合态和残渣态的形式存在,这些存在形态的生物毒性较低。本研究说明自养菌结合异养菌的浸出法可有效提高碱性底泥重金属的浸出率和降低生物毒性。
基金
Projects(51174239,30700008)supported by the National Natural Science Foundation of China
Projects(20090461028,201003526)supported by China Postdoctoral Science Foundation
