Speciation and bioaccessibility of lead and cadmium in soil treated with metal-enriched Indian mustard leaves

作     者：Yanshan Cui Jin Fu Xiaochen Chen 

作者机构：College of Resources and Environment Graduate University of Chinese Academy of Sciences Beijing 100049 China. 

出 版 物：《Journal of Environmental Sciences》 (环境科学学报（英文版）)

年 卷 期：2011年第23卷第4期

页      面：624-632页

核心收录：

学科分类：0830[工学-环境科学与工程（可授工学、理学、农学学位）] 082803[工学-农业生物环境与能源工程] 08[工学] 0828[工学-农业工程] 09[农学] 0903[农学-农业资源与环境] 

基　　金：supported by the National High Technology Research and Development Program(863)of China(No.2008AA06Z336) the National Natural Science Foundation of China(No.20607028,20977110). 

主　　题：lead cadmium speciation bioaccessibility decomposition 

摘      要：Indian mustard （Brassica juncea （L.） Czern.） has shown good potential for the phytoremediation of soil contaminated with heavy metals. However, there is little information about the speciation and bioaccessibility of heavy metals in soil during the decomposition of metal-rich Indian mustard leaves. Incubation experiments （1-, 3-, and 6-month） were carried out in Beijing and Hunan soil with metal-rich Indian mustard leaves addition （1% and 3%） and the effects of mustard leaves addition on the speciation and bioaccessibility of heavy metals were studied. The results showed that the addition of mustard leaves led to significant increases in pH and DOC in the Hunan soil. Both 1% and 3% of mustard leaf amendment caused the percentage of the exchangeable （F1）, precipitated with carbonates （F2）, bound to Fe/Mn oxides （F3） and bound to organic matter （F4） fractions of Pb and Cd to increase dramatically, while the percentage of the residual fraction （F5） of Cd and Pb significantly dropped in both Beijing and Hunan soils. Mustard leaf addition caused the bioaccessibility of Pb to decrease in the gastric phase, whereas the values increased in the small intestinal phase. The Cd bioaccessibility increased with mustard leaf addition in both the gastric and small intestinal phases. In conclusion, the metal-enriched mustard leaves addition induces Pb and Cd concentrations and their mobility increasing in the Beijing and Hunan soils. Therefore, heavy metal risk in metal-enriched plant leaves should be considered in phytoremediation system in which heavy metal might be brought back to soil and changed over time.