攀西矿区典型重金属污染土壤化学-微生物联合修复技术探索

Exploration of Chemical-Microbial Combined Remediation Technology for Typical Heavy Metals-Contaminated Soils in Panxi Mining Region

本研究以攀西矿区典型重金属污染土壤为研究对象,以硫酸盐还原菌为修复微生物,以低分子有机酸为络合剂,开展了化学-微生物联合修复技术探索,通过测定OD_(600)、FeS生成量、土壤理化性质、重金属形态等重要参数,综合研究了化学-微生物联合修复技术对重金属污染土壤修复效果。研究结果显示:硫酸盐还原菌对镉、铅均有良好的钝化还原效果,对Cd^(2+)、Pb^(2+)的去除率可达94.8%、93.9%;柠檬酸和苹果酸与硫酸盐还原菌更相匹配,其可作为硫酸盐还原菌的良好碳源,亦可作为重金属络合剂;化学-微生物联合修复对土壤重金属镉、铅能起到一定的钝化效果,镉的交换态占比最大降低了60.7%,铅的铁锰结合态最大降低了25.9%,同时有助于土壤肥效的提高。通过本文研究表明,化学-微生物联合修复能够降低土壤重金属活性,对土壤重金属能起到一定的稳定化效果。

Study selects the typical heavy metals-contaminated soils in Panxi region as the research object,using sulfate reducing bacteria as bioremediation microorganism andusing low molecular organic acid as complexing agent,to Multipurposely explore the effects of chemical-microbial combined remediation technology on heavy metals-contaminated soils by measuring the OD_(600),FeS,soil physical and chemical properties,heavy metal speciation and other important parameters.Results showed that sulfate reducing bacteria had effective passivation reduction on cadmium and lead with the removal rate up to 94.8%and 93.9%,respectively;Citric acid and malic acid are more compatible with sulfate reducing bacteria,which can be used as a good carbon source for sulfate reducing bacteria as well as a heavy metal complexing agent;Chemical-microbial combined remediation could passivate cadmium and lead to a certain extent,leading the exchangeable fraction of cadmium decreased by 60.7%and the iron manganese bound fraction of lead decreased by 25.9%,which was helpful to improve soil fertility.These results showed that chemicalmicrobial combined remediation can reduce the activity of heavy metals in soil and stabilize the heavy metals in soil.