氯和磷对土壤中水溶-可交换态铅的影响  

Effect of Chlorine and Phosphorus on Water Soluble and Exchangeable Lead in a Soil Contaminated by Lead and Zinc Mining Tailings

作　　者：王碧玲[1] 谢正苗[1] 李静[2] 吴卫红[2] 姜军涛[1] 

机构地区：[1]浙江大学环境与资源学院,杭州310029 [2]杭州电子科技大学环境科学与工程系,杭州310018

出　　处：《环境科学》2008年第6期1724-1728,共5页Environmental Science

基　　金：国家自然科学基金项目(40771100);国家自然科学基金重点项目(40432004)

摘　　要：在实验室培养条件下研究了氯离子（Cl^-）对含磷物质KH2PO4降低污染土壤中铅毒作用的影响.结果表明,在铅锌矿污染土壤中添加KH2PO4显著降低了土壤中铅（Pb）的水溶-可交换态含量,降低幅度为92.0%-95.1%,显著降低了铅的生物有效性.数据统计分析表明,KH2PO4用量在P/Pb摩尔比为0.6时已足够修复土壤的铅毒,并且在此磷添加量水平时,加氯与不加氯比较,显著降低了土壤中Pb的水溶-可交换态含量,说明了添加氯对含磷物质降低铅毒有促进作用.运用Visual MINTEQ模型模拟计算的结果表明,添加磷和氯处理土壤后,土壤中Pb的活度主要受P的控制,尤其是磷氯铅矿[pyromorphite,Pb5（PO4）3Cl]沉淀.在使用含磷物质修复铅污染土壤技术时,添加适量的氯,以达到最佳修复效果.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/Pb,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.

关 键 词：磷 铅 氯 Visual MINTEQ 土壤修复 

分 类 号：X53[环境科学与工程—环境工程]