Wang Bi-ling, Xie Zheng-miao, Li Jing, Wu Wei-hong, Jiang Jun-tao
College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310029, China.
Huan Jing Ke Xue. 2008 Jun;29(6):1724-8.
Effect of chlorine on in situ lead immobilization using phosphorus in a soil contaminated by lead and zinc mining tailings was evaluated. The results showed that water soluble and exchangeable Pb were reduced by 92.0%-95.1% in the soil after P application. It was also suggested that application dosage of phosphorus at the P/Pb molar ratio of 0.6, was enough to remediate Pb toxicity in the soil. Compared to without Cl treatment at the level of molar ratio of 0.6 P/Ph, water soluble and exchangeable Pb in the soil treated with Cl was reduced markedly. It was concluded that the effects chlorine addition on in situ lead (Pb) immobilization using phosphate were improved. Visual MINTEQ model was employed to figure out Pb and P species distribution and saturation indices for minerals in the soils treated by P and Cl. The results showed that Pb activity was controlled by lead phosphate in the soil, especially pyromorphite [Pb5(PO4)3Cl], which would be the reason for Pb bioactivity reduction in the soil after application of Cl and P. The effective Pb bioactivity reduction indicated that addition of Cl was necessary to to improve in situ lead immobilization using phosphorous in the lead-contaminated soil.
评估了氯对铅锌矿尾矿污染土壤中利用磷进行原位铅固定的影响。结果表明，施磷后土壤中水溶性和可交换态铅减少了92.0% - 95.1%。研究还表明，磷与铅摩尔比为0.6时的磷施用量足以修复土壤中的铅毒性。与磷/铅摩尔比为0.6时不进行氯处理相比，经氯处理的土壤中水溶性和可交换态铅显著减少。得出的结论是，添加氯可改善利用磷酸盐进行原位铅固定的效果。采用Visual MINTEQ模型来确定经磷和氯处理的土壤中铅和磷的形态分布以及矿物的饱和指数。结果表明，土壤中铅的活性受磷酸铅控制，尤其是氯磷灰石[Pb5(PO4)3Cl]，这可能是施用氯和磷后土壤中铅生物活性降低的原因。有效的铅生物活性降低表明，在铅污染土壤中添加氯对于改善利用磷进行原位铅固定是必要的。
