耐镉硫酸盐还原菌对镉污染土壤的修复  

Remediation of Cadmium-contaminated Soil by Cadmium-resistant Sulfate-reducing Bacteria

作　　者：王鹤 吴明林 秦永丽[1] 郑婉盈 蒋永荣[1] 李学军[1] WANG He;WU Minglin;QIN Yongli;ZHENG Wanying;JIANG Yongrong;LI Xuejun(College of Life and Environmental Sciences,Guilin University of Electronic Technology,Guilin 541004,Guangxi,China)

机构地区：[1]桂林电子科技大学生命与环境科学学院,广西桂林541004

出　　处：《矿产综合利用》2025年第1期86-94,共9页Multipurpose Utilization of Mineral Resources

基　　金：国家自然科学基金(52060004);广西高校中青年教师科研基础能力提升项目(2021KY0204);广西区大学生创新创业训练计划项目(201810595169、201810595170、202010595164、202110595063)。

摘　　要：为探究耐镉硫酸盐还原菌(SRB)对镉污染土壤的修复效果,以耐镉硫酸盐还原污泥为种泥筛选分离出耐镉SRB,并将其投加于不同镉污染程度(轻度、中度、重度)的土壤中,考查SRB作用下土壤镉的赋存形态、硫酸盐还原活性及微生物群落结构的变化特征。结果表明,经耐镉SRB修复53 d后,不同镉污染程度土壤的总镉含量未发生明显变化,不稳定态镉(可交换态、碳酸盐结合态)的占比由修复前的45%~68%降至26%~40%,稳定态镉(铁锰氧化态、有机结合态、残渣态)占比由最初的30%~50%大幅增加至60%~75%,实现了不同重金属镉污染程度土壤中镉的有效钝化;修复过程中,不同镉污染程度土壤的硫酸盐含量均呈现先逐步降低后增加的趋势,硫酸盐还原活性则逐步降低,体系存在硫酸盐的再生;耐镉SRB修复过程中各污染土壤细菌门类的变化趋势大致相同,Proteobacteria和Bacteroidetes为主要门类,Desulfosporosinus和Desulfobacca为主要的SRB菌属,修复过程中其丰度逐步降低,硫氧化菌则有增高的趋势。由此可见耐镉SRB可降低镉污染土壤中不稳定态镉含量,降低了镉的迁移性,但修复过程中优化修复参数强化硫酸盐还原及抑制硫氧化是有必要的。In order to investigate the cadmium reduction effect of cadmium-tolerant sulfate-reducing bacteria(SRB)on cadmium-contaminated soil,cadmium-tolerant SRB was screened and isolated using cadmium-tolerant sulfate-reducing sludge as seed sludge,and was injected into soils with different degrees of cadmium contamination(mild,moderate,and severe)to investigate the fugitive morphology of soil cadmium,the changes in sulfate reduction activity and microbial community structure.The results showed that after 53 d of Cd-tolerant SRB remediation,the total Cd content of soils with different Cd contamination levels did not change significantly,the proportion of unstable Cd(exchangeable state,carbonate-bound state)decreased from the initial 45%~68%to 26%~40%,and the proportion of stable Cd(Fe-Mn oxidation state,organic-bound state,residue state)increased significantly from the initial 30%~50%to 60%~75%.The effective passivation of cadmium in soils with different degrees of heavy metal cadmium pollution was achieved.The sulfate content of soils with different degrees of cadmium pollution showed a trend of gradually decreasing and then increasing during the remediation process,while the sulfate reduction activity gradually decreased,and there was regeneration of sulfate in the system.The change trend of each contaminated soil bacterial phylum during the remediation of cadmium-tolerant SRB was more or less the same,with Proteobacteria and Bacteroidetes as the main phylum,Desulfosporosinus and Desulfobacca as the main SRB genera,and their abundance gradually decreased during the remediation process,while sulfur-oxidizing bacteria had a tendency to increase.This shows that cadmium-tolerant SRB can reduce the content of unstable cadmium in cadmium-contaminated soil,and reduce the mobility of cadmium,but it is necessary to optimize the remediation parameters to enhance sulfate reduction and inhibit sulfur oxidation in the remediation process.

关 键 词：重金属镉 硫酸盐还原菌 土壤修复 镉形态分布 群落结构 

分 类 号：X53[环境科学与工程—环境工程]