Accumulation of heavy metals in Ricinus communis L. from Mn contaminated area.

Xiangbi No. 1 and Zibi No. 7 were planted in the Mn contaminated soils to explore its potential of ecological remediation and ener-gy utilization in the areas of Mn contaminated site. The major nutrient elements and the concentrations of heavy metals(Mn, Pb, Zn, Cu and Cr) in different parts(root, branch and leaf) and topsoil samples were detected after entering into the period of reproductive growth.The results showed that the average content of Mn was as high as 7 884.96 mg·kg-1,which exceeded 6.5 times of national soil environmental quality standard(level 2).The mean level of Mn in tissues of Xiangbi No. 1 was found to be in the sequence of rootleafbranch,whereas,the mean level of Mn in different parts of Zibi No. 7 was found to be in the order of leaffruitbranchroot respectively. The average concentration of Mn in the leaf reached the peak value(765.43 mg·kg-1),which was higher than Xiangbi No.1 about 79.53%.The leaf/root ratios of Pb, Cu, Cr contents in Zibi No. 7 were higher than those of Xiangbi No. 1 samples.The accumulation and translocation in plants was affect-ed by different heavy metal elements in soils.The results demonstrated that Zibi No. 7 had a better uptake and translocation capacity of Mn,Pb,Cu and Cr, meanwhile,plants of two species had differences in accumulation and translocation ability and were proved to possess good Mn-tolerance ability for remediation of heavy metal contaminated soils.