农业环境科学学报2016，Vol.35Issue(12)：2334-2344,11.DOI:10.11654/jaes.2016-0873
螯合剂和鼠李糖脂联合淋洗污染土壤中Cd
Leaching characteristics of Cd in the contaminated soils with chelates and rhamnolipid
摘要
Abstract
The simulated pollution soils with three Cd concentration levels were prepared, the leaching characteristics of Cd from the soils were studied with chelates and rhamnolipid, and the speciation variations of Cd in soil during the joint leaching process with EDTA and rhamnolipid was also discussed. When the eluent concentration was 0.025 mol·L-1 and the initial pH was 7, the leaching process reached e-quilibrium at 220, 140 and 60 min with EDTA, ethylenediamine disuccinic acid(EDDS)and citric acid, respectively. The best leaching re-sults could be obtained with EDTA, and the maximal leaching percentages were 93.16%, 93.62%and 94.09%for 0.38, 0.69 and 0.93 mg· kg-1 Cd contaminated soils, respectively. The leaching process with EDTA could be described by pseudo two-order kinetic model, and the leaching rate constant showed a decreasing order of 0.38 mg·kg-1 Cd contaminated soil, 0.69 mg·kg-1 Cd contaminated soil and 0.93 mg·kg-1 Cd contaminated soil. When the volume ratio of EDTA and rhamnolipid(0.025 mol·L-1)was 1.5:1, the leaching percentages reached 85.45%, 89.25%and 93.88%for the three contaminated soils, respectively, and the leaching equilibrium time decreased to 50 min. Joint leaching can effectively release the exchangeable, carbonate bound and organic bound Cd in the contaminated soils, and the possible mecha-nism is the synergistic effect of EDTA chelation and the micellar solubilization of rhamnolipid.关键词
镉/污染土壤/螯合剂/鼠李糖脂/淋洗特征Key words
cadmium/contaminated soil/chelates/rhamnolipid/leaching characteristics分类
资源环境引用本文复制引用
陈冬月,施秋伶,张进忠,刘江,钱盛..螯合剂和鼠李糖脂联合淋洗污染土壤中Cd[J].农业环境科学学报,2016,35(12):2334-2344,11.基金项目
国家高技术研究发展计划（863）项目 （）
