化学和微生物复合还原六价铬污染土壤研究  

Research on the Remediation of Soil Contaminated with Hexavalent Chromium by Chemical and Microbial Reduction

作　　者：陈窈君 黄沈婷 CHEN Yaojun;HUANG Shenting(Shanghai Academy of Environmental Sciences,Shanghai 200233,China;State Environmental Protection Engineering Center for Urban Soil Contamination Control and Remediation,Shanghai 200233,China)

机构地区：[1]上海市环境科学研究院,上海200233 [2]国家环境保护城市土壤污染控制与修复工程技术中心,上海200233

出　　处：《环境科学与技术》2024年第S2期19-25,共7页Environmental Science & Technology

基　　金：上海市环境科学研究院青年创新基金项目(CX2021140325);上海市土壤污染状况调查、风险管控和修复全过程监管技术规程与管理制度研究项目(2023HJCG-ZB05)

摘　　要：该文章以处理土壤中的高浓度Cr(Ⅵ)为目的,提出了化学和微生物法联合处理土壤Cr(Ⅵ),先加入多硫化钙还原高浓度Cr(Ⅵ),再加入生物刺激剂,通过微生物作用还原稳定土壤中剩余的Cr(Ⅵ),探究不同反应条件下Cr(Ⅵ)的处理效果及其修复机理。结果表明:多硫化钙添加量为2.5%时,土壤中Cr(Ⅵ)含量为187 mg/kg,去除率达92.34%。再添加4%的乳糖生物刺激剂反应60 d,Cr(Ⅵ)的含量为6.2 mg/kg,Cr(Ⅵ)毒性浸出质量浓度为2.82 mg/L。将还原稳定化后的土壤用高锰酸钾溶液氧化,其浸出浓度与单一化学还原后的土壤相比显著降低,微生物可以有效避免Cr(Ⅲ)的再次氧化。稳定化后的土壤进行灭菌后土壤中的Cr(Ⅵ)含量和浸出浓度与灭菌前相比均无显著差异,微生物对Cr(Ⅵ)的还原效果较稳定。A combined chemical and microbial approach was proposed to treat high concentrations of Cr(Ⅵ)in soil.The process involved the addition of calcium polysulfide to chemically reduce the high concentrations of Cr(Ⅵ)followed by the introduction of a microbial stimulant to further reduce the remaining Cr(Ⅵ)in the stabilized soil.The study aimed to investigate the treatment effectiveness and remediation mechanism of Cr(Ⅵ)under different reaction conditions.The results showed that the addition of 2.5%calcium polysulfide resulted in a removal efficiency of 92.34%,reducing the Cr(Ⅵ)content in the soil to 187 mg/kg.After adding 4%lactose bio-stimulant and reacting for 60 days,the Cr(Ⅵ)content was 6.2 mg/kg,the toxic leaching concentration of Cr(Ⅵ)was 2.82 mg/L.Oxidation of the stabilized soil using potassium permanganate solution resulted in significantly lower leaching concentrations compared to soil treated with only chemical reduction,indicating the microbial action effectively prevented re-oxidation of Cr(Ⅲ).The content and leaching concentration of Cr(Ⅵ)in the stabilized soil showed no significant difference before and after sterilization,demonstrating the stability of microbial reduction of Cr(Ⅵ)in the treated soil.

关 键 词：土壤 六价铬 多硫化钙 微生物 复合还原 

分 类 号：X53[环境科学与工程—环境工程]