In this study, enzyme-induced calcite precipitation (EICP)-based treatment for tropical soils contaminated with divalent heavy metals such as cadmium (Cd), nickel (Ni), and lead (Pb) were evaluated for their sorption and desorption capabilities. Heavy metals were taken in three different combinations: a single metal and a combination of two and three metals. They were mixed with locally available kaolinite and montmorillonite soils. EICP-treated soil retained the maximum quantity of Cd among all the heavy metals studied. The Cd retention exceeded Ni and Pb retention. The same was confirmed with desorption studies, relying on aggressive chelants such as ethylene diamine tetra acetic acid (EDTA) and citric acid. Before subjecting the kaolinitic soil to EICP treatment, it was found that the sorption capacity for Cd and Ni was 2.124 and 1.974 mg/g for Cd and Ni, respectively. The sorptive values increased to 3.457 and 4.418 mg/g for Cd and Ni, respectively, after EICP treatment. The retention is attributed to the formation of CdCO3 and NiCO3 in the soil matrix, which exhibits very low values of solubility product even in the presence of aggressive chelants. The study establishes that EICP treatment is a prospective method for remediation of soils laced with heavy metal ions.

在这项研究中，基于酶诱导方解石沉淀 (EICP) 的处理对被镉 (Cd)、镍 (Ni) 和铅 (Pb) 等二价重金属污染的热带土壤的吸附和解吸能力进行了评估。重金属采取三种不同的组合：一种金属和两种和三种金属的组合。它们与当地可用的高岭石和蒙脱石土壤混合。在所有研究的重金属中，EICP处理的土壤保留了最大量的Cd。Cd 保留量超过 Ni 和 Pb 保留量。解吸研究也证实了这一点，依赖于腐蚀性螯合剂，如乙二胺四乙酸 (EDTA) 和柠檬酸。在对高岭土进行 EICP 处理之前，发现其对 Cd 和 Ni 的吸附能力分别为 2.124 和 1。Cd 和 Ni 分别为 974 mg/g。在 EICP 处理后，Cd 和 Ni 的吸附值分别增加到 3.457 和 4.418 mg/g。保留归因于土壤基质中 CdCO3 和 NiCO3 的形成，即使在存在腐蚀性螯合剂的情况下，溶解度积也非常低。该研究表明，EICP 处理是修复含有重金属离子的土壤的一种前瞻性方法。