含磷材料在铅污染土壤修复中的应用

铅不是生物体必需的元素,具有很强的生物毒性,低剂量铅就会对人体健康产生严重威胁.铅的生物有效性与其生物毒性密切相关,降低土壤铅生物有效性是铅污染土壤修复的重要手段之一.含磷材料可作为铅的稳定修复剂的特性被广泛地接受.含磷材料通过吸附、沉淀、离子交换等作用与铅离子形成稳定的磷氯铅矿类物质[Pb5(PO4)3X;X=F,Cl,Br or OH].通过概述国内外关于含磷材料原位钝化修复铅污染土壤的分子机理,列举了几种应用较为广泛的含磷材料(如磷酸、磷酸盐、羟基磷灰石、磷矿石等)的最新研究进展,总结了温度、pH值、磷铅摩尔分子比等影响因子及其修复效果方面的研究进展,并讨论含磷材料原位修复铅污染土壤的工程适用性及其长期稳定性.

Application of phosphorus materials in remediation of lead-contaminated soil

As a scattered toxic metal and not a essential elements of organisms in the world, low concentration of lead is insidious with negative health effects on individuals, particularly pre-school aged children. Lead phytotoxicity is closely related to lead bioavailability. How to reduce lead bioavailability is an important key of lead-contaminated soil remediation. The use of phosphate as a stabilizing agent that is widely accepted and capable of lead-contaminated soil remediation. The principal mechanism of Pb stabilization by different types of phosphorus materials through adsorption, precipitation, ion exchange action with Pb2+ to form highly insoluble mineral pyromorphite [Pb5(PO4)3X; X =F, Cl, Br or OH]. Phosphorus materials are present: calcium dihydrogen phosphate (Ca(H2PO4)2·H2O), calcium hydrogen phosphate (CaHPO4), sodium phosphate (Na3PO4), hydroxyl apatite (hydroxyapatite), orthophosphate (orthophosphate), phosphate rock (phosphate rock), superphosphate (single-superphosphate) and a mixture of hydroxyapatite and calcium phosphate. This review article comprehensively discusses the background, concepts and the phosphorus materials molecular mechanism of lead-contaminated soil, effects on impact factors of the remediation and outlines the future trends in application of phosphorus materials in remediation of lead-contaminated soil.