磷矿粉稳定铅污染土的溶出特性研究

采用磷矿粉作为稳定剂对铅污染土进行修复处理。通过毒性浸出试验（TCLP）,研究磷矿粉稳定铅污染土的溶出特性,探讨了不同磷矿粉掺量和养护龄期对铅、钙溶出量的影响,分析不同初始铅浓度作用下铅、钙的溶出规律。结果表明：铅溶出量随磷矿粉掺量和养护龄期的增加而减小,钙溶出规律与之相反,钙溶出量与铅溶出量存在线性负相关性；稳定污染土和浸出液的pH值受初始铅浓度影响显著,并随着磷矿粉掺量增加而逐渐增大。

Leaching characteristics of lead-contaminated clay stabilized by phosphate rock

An investigation of leaching characteristics of phosphate rock (PR) stabilized Pb-contaminated clay is presented under different initial Pb concentrations and phosphate rock contents via a series of toxicity characteristic leaching procedure (TCLP) at curing time of 1, 3, 7, 1, and 28 days. The designed initial Pb concentrations are 500, 1000, 5000, and 10000 mg/kg (dry soil weight basis), and phosphate rock contents are 5%, 8%, 12%, 15%, 20% and 30%. The results show that Pb concentrations of leachate decrease with the increase of the phosphate rock content and curing time. Furthermore, the variation between the Ca and Pb concentrations of leachate is negatively correlated. The pH values of specimen and leachate are influenced by the initial Pb concentration and increase with the phosphate rock content and curing time. It is found that the variation between Pb and Ca concentrations of leachate is mainly influenced by the initial Pb concentration. A proposed fitting equation based on the value of the initial Pb concentration is adopted to evaluate the variation between the Pb and Ca concentrations of leachate.