新型杂化材料钝化修复镉铅复合污染土壤的效应与机制研究

采用盆栽实验,研究了新型杂化材料及其与磷酸盐复配使用对镉铅复合污染土壤的钝化修复效果,并通过重金属形态分析、吸附平衡实验以及X射线光电子能谱(XPS)探讨了杂化材料钝化修复重金属污染土壤的机制.结果表明,杂化材料单一处理对油菜生长没有明显的促进作用,而杂化材料与磷酸盐复合处理则能显著提高油菜地上部和根部生物量,分别比对...

Effect and Mechanism of Immobilization of Cadmium and Lead Compound Contiminated Soil Using New Hybrid Material

The effect of new hybrid material and its compound treatments with phosphate on immobilization of cadmium and lead in contaminated soil was investigated using a pot-culture experiment, and the immobilization mechanism of hybrid material was clarified through analysis of heavy metal fractions, sorption equilibration experiment and X-ray photoelectron spectroscopy(XPS). The single treatments of hybrid material could not significantly promote growth of Brassica chinensis, while the compound treatments of hybrid material and phosphate markedly increased dry biomass of shoots and roots, with maximal increases of 75.53% and 151.22%, respectively. Different hybrid material treatments could significantly reduce Cd and Pb concentrations in shoots, with maximal reductions of 66.79% and 48.62%, respectively, and the compound amendment treatments appeared more efficient than the single amendment treatments in reducing Cd and Pb uptake of B. chinensis. Different hybrid material treatments could significantly decrease concentrations of toxicity characteristic leaching procedure(TCLP) extractable Cd and Pb, and the compound hybrid material treatments appeared more efficient than the single treatments in reducing TCLP extractable Cd and Pb. Through the formation of bidentate ligand between metal ions and surface sulfhydryl by complexing reaction, the hybrid material could absorb and fix mobile fractions of Cd and Pb in soil, and promote transformation of acid extractable Cd and Pb into residual fraction, resulting in significant reduction of heavy metals bioavailability and mobility and then fixing remediation of contaminated soil. In summary, the compound treatment of hybrid material and phosphate is the most effective treatment for immobilization of Cd and Pb in contaminated soils, and the hybrid material inactivates Cd and Pb in soil mainly through special chemical adsorption.