Speciation and bioaccessibility of lead and cadmium in soil treated with metal-enriched Indian mustard leaves.
Speciation and bioaccessibility of lead and cadmium in soil treated with metal-enriched Indian mustard leaves.
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DOI：
10.1016/s1001-0742(10)60456-1
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发表时间：
2011-04
影响因子：
6.9
通讯作者：
Yanshan Cui;Jinyi Fu;Xiaochen Chen
中科院分区：
文献类型：
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作者：
Yanshan Cui;Jinyi Fu;Xiaochen Chen
印度芥菜（Brassica juncea（L.）Czern.）在重金属污染土壤的植物修复中显示出良好的潜力。然而，有很少的信息，在土壤中的重金属的形态和生物可及性的分解过程中富含金属的印度芥菜叶。在北京和湖南土壤中分别添加1%和3%的印度芥菜叶，进行1个月、3个月和6个月的培养试验，研究芥菜叶对重金属形态和生物可利用性的影响。结果表明，芥菜叶的添加显著提高了湖南土壤的pH值和溶解有机碳（DOC）。施用1%和3%的芥菜叶后，北京和湖南土壤中Pb和Cd的可交换态（F1）、碳酸盐沉淀态（F2）、铁锰氧化物结合态（F3）和有机质结合态（F4）的比例显著增加，而残留态（F5）的比例显著降低。芥菜叶除了导致铅的生物可利用性降低，在胃阶段，而在小肠阶段的值增加。镉的生物可利用性增加芥菜除了在胃和小肠阶段。总之，添加富金属芥菜可提高北京和湖南土壤中Pb和Cd的含量和迁移率。因此，在重金属可能被带回土壤并随时间发生变化的植物修复系统中，应考虑富集金属植物叶片的重金属风险。
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.