Characteristics of Soil-plant Heavy Metal Migration in Pb-Zn Mine Tailings Pond under Different Ecological Restoration models
Taking alfalfa,dogroot and white grass as the research objects,the content of heavy metals in plants and their enrichment and migration characteristics were analyzed,and different ecological restoration modes of the tailings pond of a Pb-Zn mine were analyzed by TOPSIS comprehensive evaluation method.The results showed that:① The contents of Pb,Zn,Cu and Cd were different in different parts of different herbs,but the content of Pb was the highest,followed by Zn and Cu,and the content of Cd was the lowest.② The content of Pb in the root of alfalfa,the root of radix canthus and the white grass was signif-icantly higher than that in the stem and leaves(P<0.05),but there was no significant difference in the stem and leaves of the three herbs(P>0.05).③ The contents of 4 elements in different parts of different herbs were also different.The contents of 4 elements in alfalfa and dog's root were root>stem>leaf,indicating that the 4 elements were mainly concentrated in the root of alfalfa and dog's root.The enrichment degree of the 4 elements was different in different parts of the white grass.The enrich-ment ability of the 4 elements was Pb>Cu>Zn>Cd,and the enrichment coefficient was less than 1.④ The degree of migration of heavy metal absorbed by the roots of the three herbaceous plants to the stems and leaves was different,and the migration co-efficients of Pb of the three herbaceous plants was less than 1,indicating that the three herbaceous plants had weak absorption and migration ability of heavy metal Pb.For Zn and Cd,the migration coefficients of white grass were 2.67 and 1.86 respec-tively,which were significantly higher than those of alfalfa and dogroot.For Cu,the migration coefficients of the three herba-ceous plants were as follows:dogroot>alfalfa>white grass,and the differences among the three herbaceous plants were signifi-cant(P<0.05).⑤ The three herbaceous plants migrated to the leaves with less heavy metals absorbed by the roots,and the white grass had a strong tolerance to heavy metals.TOPSIS comprehensive evaluation method was used to evaluate the ecologi-cal restoration model,which showed that the combination of alfalfa,dogtooth root and white grass was the best ecological resto-ration model.
ecological restorationPb-Zn mineheavy metalstailings pondenrichment and migrationvegetation restora-tionTOPSIS
NETL
NSTL
万方数据
