农业环境科学学报Issue(12)：2335-2342,8.DOI:10.11654/jaes.2014.12.009
有机酸和FeCl3复合浸提修复Cd、Pb污染农田土壤的研究
Remediation of Cadmium and Lead Contaminated Farmland Soil by Washing with Combined Organic Acids and FeCl3
摘要
Abstract
Soil washing is one option to remediate heavy metal contaminated soils. The present study examined the removal efficiency of cad-mium(Cd)and lead(Pb)from a farmland soil by batch extraction with mixture of organic acid(citric acid or tartaric acid)and FeCl3. Metal fractions before and after soil washing were also determined. The Cd and Pb removal efficiency from the soil was up to 40.7%and 20.9%for mixture of citric acid(100 mmol·L-1)and FeCl3(20 mmol·L-1), and up to 42.6%and 16.5%for mixture of tartaric acid(100 mmol·L-1) and FeCl3(20 mmol·L-1), respectively. The metal removal efficiency was higher for mixed reagents than single reagent. Increasing pH of washing solution decreased the removal efficiency of heavy metals. The optimum washing conditions were liquid to solid ratio of 5∶1, washing time of 24 h and washing cycles of 3. Metal fractionation showed that the removed Cd by organic acids combined with FeCl3 was mainly from exchangeable(77.3%~79.8%decline)and Fe-Mn oxides forms(86.7%~87.0%reduction), while the organic matter bound metals were al-most unchanged. The removed Pb came from Fe-Mn oxides(70.0%~70.8%decrease)and organic matter form(58.8%~66.0%drop). After soil washing, however, the exchangeable Pb significantly increased to 24.2%~24.5%, but Cd and Pb in carbonates almost disappeared with residual metal form unchanged. The removal efficiency of Pb in soil could be significantly increased by repeated washing, and up to 47.0%~48.2%of Pb could be extracted after 3 washing cycles.关键词
有机酸/FeCl3/重金属/污染土壤/复合浸提Key words
organic acid/FeCl3, heavy metal/contaminated soil/soil washing分类
资源环境引用本文复制引用
李玉姣,温雅,郭倩楠,祝媛,董长勋,胡鹏杰..有机酸和FeCl3复合浸提修复Cd、Pb污染农田土壤的研究[J].农业环境科学学报,2014,(12):2335-2342,8.基金项目
江苏省科技支撑项目 （）
国家大学生创业训练项目 （）
