生态环境学报2012，Vol.21Issue(2)：314-320,7.
海泡石和磷酸盐对镉铅污染稻田土壤的钝化修复效应与机理研究
Effect and mechanism of immobilization of paddy soil contaminated by cadmium and lead using sepiolite and phosphate
摘要
Abstract
The effect of sepiolite, acid-modified sepiolite and their compound treatments with phosphate on immobilization of cadmium and lead in contaminated paddy soil was investigated using a pot-culture experiment, and the immobilization mechanism of these amendments was clarified through incubation experiment and analysis of heavy metal fractions. The sepiolite treatments could markedly increase pH values of soils, while the treatments with phosphate and acid-modified sepiolite could not significantly affect pH values. The immobilization treatments could significantly reduce concentrations of toxicity characteristic leaching procedure (TCLP) extractable Cd and Pb, with maximal reductions of 23.3% and 47.2%, respectively. The compound immobilization treatments appeared more efficient than the single treatments in reducing TCLP extractable Cd and Pb. Through increasing soil pH values, physicochemical adsorption, and the formation of mineral precipitation, sepiolite and phosphate could promote transformation of exchangeable Cd and Pb into residual fraction, resulting in significant reduction of heavy metals bioavailability and mobility. Addition of these amendments markedly increased biomass of rice plant parts, with maximal increase of 34.3% in grain and 26.6% in straw, respectively. The compound immobilization treatments appeared more effective than the single treatments in increasing biomass of rice. The immobilization treatments markedly decreased Cd and Pb concentrations in rice plant parts, with maximal reduction of 35.8% and 40.9% in polished rice, respectively, and the compound immobilization treatments appeared more effective than the single treatments in reducing Cd and Pb uptake of rice. The Cd and Pb concentrations in polished rice under the combined treatment of sepiolite and phosphate were lower than the maximum levels permitted by Chinese standard for cadmium and lead in foods (GB 15201-94, GB 14935-94). In summary, the combined treatment of sepiolite and phosphate was the most effective treatment for immobilization of Cd and Pb in contaminated paddy soil.关键词
钝化修复/海泡石/磷酸盐/镉/铅/水稻Key words
immobilization/ sepiolite/ phosphate/ cadmium/ lead/ rice分类
资源环境引用本文复制引用
王林,徐应明,孙国红,梁学峰,孙约兵,孙扬,秦旭,戴晓华..海泡石和磷酸盐对镉铅污染稻田土壤的钝化修复效应与机理研究[J].生态环境学报,2012,21(2):314-320,7.基金项目
国家自然科学基金项目(40901154 （）
21177068 （）
21107056) （）
天津市自然科学基金项目(10JCYBJC06300) （10JCYBJC06300）
农业部农业科研杰出人才及其创新团队资金项目 （）
中央级公益性科研院所基本科研业务费专项资金项目(农业部环境保护科研监测所) （农业部环境保护科研监测所）
