微生物沥浸法去除底泥中的重金属  

Removal of heavy metals from sediment by bioleaching

作　　者：谢华明[1,2] 杨朝晖[1,2] 徐海音[1,2] 高万超[1,2] 黄兢[1,2] 曾光明[1,2] 李小江 唐志刚 

机构地区：[1]湖南大学环境科学与工程学院,长沙410082 [2]环境生物与控制教育部重点实验室(湖南大学),长沙410082 [3]株洲环境保护研究院,株洲412000

出　　处：《环境工程学报》2012年第4期1320-1326,共7页Chinese Journal of Environmental Engineering

基　　金：国家自然科学基金资助项目(30970105;51078131);国家水体污染控制与治理科技重大专项资助课题(2009ZX07212-001-02);长沙科技计划重点资助项目(K0802151-31)

摘　　要：以硫酸亚铁盐为底物,培养以氧化亚铁硫杆菌为主要菌种的土著沥滤微生物,采用批式方法对湘江长沙段底泥进行微生物沥浸实验。实验结果表明,底物投加量与底泥固体浓度比(Sd/Sc)为1.5时已能满足底泥的微生物沥浸要求,进一步研究发现底泥固体浓度为13%、底物投加量为19.5 g/L、沥浸时间为6 d时,底泥中超标重金属Cd、Zn和Cu的去除率可分别达到83.1%、75.3%和61.2%;沥浸后底泥中大部分重金属以残渣态存在,且含量低于农用污泥中污染物控制标准,其中硫化物有机结合态Cu浸出较Zn、Cd需更低的pH,且Cu以间接机理浸出为主;以Fe2+为底物的沥浸体系中,黄铁矾的重吸附或共沉淀是沥浸实验后期重金属浸出率下降的原因之一。The sequencing bioleaching test was used to investigate the removal efficiency of heavy metals from contaminated sediment of the Xiangjiang River in Changsha section.In this study,ferrous sulfate was selected as energy substrate to cultivate the bioleaching dominated bacterium of Thiobacillus ferrooxidans.The results demonstrated that the ratio of substrate dosage and solid concentration（Sd/Sc） was 1.5,which could meet the requirements of bioleaching.Further study showed that the removal rates of Cd,Zn and Cu in sediment were 83.1%,75.3% and 61.2%,respectively after 6 days,when the solid concentration was 13%,the substrate dosage was 19.5 g/L.The heavy metals mainly existed as residual state after bioleaching,and the concentrations of them were lower than the control standards for pollutants in sludge from agricultural use.The leaching of organic matter/sulfide-bound Cu needed lower pH compared to Zn and Cd,and the indirect leaching was its main mechanism.In the bioleaching system with Fe2＋ as substrate,the adsorption and coprecipitation of ihleite was one of the important reasons for the decrease of soluble metals in later period.

关 键 词：污染底泥 微生物沥浸 Sd/Sc 固体浓度 底物投加量 重金属形态 

分 类 号：X705[环境科学与工程—环境工程]