岩土工程学报2025，Vol.47Issue(1)：38-47,10.DOI:10.11779/CJGE20231051
pH值对MICP固化修复镉污染尾矿的影响研究
Effects of pH on MICP curing of cadmium-contaminated tailings
摘要
Abstract
The microbial induced calcium carbonate precipitation(MICP)method is regarded as an environmentally sustainable approach for the solidification and remediation of contaminated soils.However,there are limited researches dedicated to understanding the impact of pH on the MICP treatment of heavy metals.In this study,the MICP remediation experiments involving cadmium(Cd)solution and Cd-contaminated tailings using Sporosarcina pasteurii ATCC 11859 at varying pH levels of 5,7,9,and 11 are conducted.The results indicate that in the aqueous solution tests,the effective immobilization of Cd2+occurs across the pH range of 5 to 11.The optimal immobilization of Cd2+is observed at a pH of 9.In contrast,during the consolidation and remediation tests on tailings,the introduction of acidic drenching solutions expedites the leaching of Cd2+from the tailings.In this context,the MICP primarily transforms the acid-soluble fraction of Cd within the tailings into reducible and residual states.Importantly,the effectiveness of this passivation process exhibits a positive correlation with the rate of carbonate generation.The analytical characterization through FTIR,XRD,XPS and SEM-EDS of biomineralization precipitation offers insights into the mechanisms underlying the fixation of heavy metals by the MICP and the solidification of tailings.The MICP accomplishes the immobilization of heavy metal ions through a combination of biosorption and calcium carbonate adsorption,ion exchange and co-precipitation processes.Furthermore,the MICP enhances the friction angle of soil particles and promotes cohesion among them through coating,bonding and bridging effects.关键词
微生物诱导碳酸钙沉淀/pH值/固化修复污染土/镉/微观机理Key words
microbial-induced calcite precipitation/pH/solidification and remediation of contaminated soil/Cd/micro-mechanism分类
建筑与水利引用本文复制引用
江昭明,陈永贵,文子豪,付俊,周罕..pH值对MICP固化修复镉污染尾矿的影响研究[J].岩土工程学报,2025,47(1):38-47,10.基金项目
国家自然科学基金项目(42125701) （42125701）
上海市科技创新行动计划项目(22DZ2201200) （22DZ2201200）
云南省万人计划产业技术领军人才科技项目(云发改人事[2019]274号) （云发改人事[2019]274号）
中铝国际重点科研项目(CJ2021JS-06) （CJ2021JS-06）
