期刊名称：IOP Conference Series: Earth and Environmental Science
印刷版ISSN：1755-1307
电子版ISSN：1755-1315
出版年度：2019
卷号：242
期号：5
页码：1-7
DOI：10.1088/1755-1315/242/5/052020
出版社：IOP Publishing
摘要：Heavy metal pollution of soils has become increasingly serious, and chemical immobilization is usually used to remediate heavy metal contaminated soil. With changing environmental conditions, the immobilization heavy metal may be released again, which is a risk to ecological environment and human health. In the study, sepiolite is applied to the heavy metal contaminated soil (0.5%, 2%, 5%), training for 60 days, adding 2mmol/Kg, 10mmol/Kg and 20mmol/Kg citric acid into the contaminated soil. This research adopted characteristic leaching procedure (TCLP) to evaluate the remedition effect and BCR to analysis the change of heavy metal species of soil. The results show that, no adding citric acid, the content of TCLP-Cd decreased with the increase of sepiolite addition ratio. When the sepiolite addition ratio was 5%, TCLP-Cd is lower than its of TCLP international standards. It shows that sepiolite can effectively remediate heavy metals in soil. When the proportion of sepiolite is constant, low concentration of citric acid is helpful to remedition, while high concentration of citric acid is not conducive to remediation of heavy metals. BCR method showed that the exchangeable content increased with the increase of citric acid concentration, but the oxidizable content decreased, indicating that citric acid could increase the bioavailability of heavy metals.
