| The present subject was aimed at dealing with the chemical process of the heavy metal pollution and its migration between soil and plant, and with the ecological effect of soil heavy metal pollution on the distribution and structure of soil animal community.(一)The heavy metal pollution and its migration between soil and plant A field investigation and indoor analysis were carried out to evaluate contamination of soil by heavy metals at some sites in Huainan including two typical coal mining and Luohe power plant and near its coal ash area.The results indicated that As,Pb,Cd,Cr,Zn,Cu were major polluting elements and the level of pollution around coal ash area was higher than the other sites. In soil-plant system, the content of heavy metals leached out from coal-waste rocks and coal ash was detected. It was shown that the concentration of the heavy metal elements Pb and Zn mainly accumulated in wheat seeds while Cd and As mostly in wheat roots .The rate of transportation of Zn,Cd and Pb was higher than that of other elements. The difference of the adsorption of Zn and Cu for four grains was significant. Adsorption of fine coal ash was the highest, while tiny sand was the lowest. The adsorption of fine coal ash under different pH value was most at pH 5 and was lowest at pH 3. Compared with the newly coal-waste rocks, the old coal-waste rocks had a longer leaching and accumulating time and the content of polluting elements was higher in near soil. The content of heavy metal between exchangeable element in soil and wheat root was detected. It was proved that the content of exchangeable heavy metal directly influences the bio-availability of heavy metal. The kinds of plant and environment factors in soil also affected migration and transportation between soil and plant. The distribution of lead in roots and leaves of wheat and corn was studied by using graded centrifugation and the themical form of lead and using sequential extraction. Not only was the content of lead in wheat roots more than that in com roots and that both more than 91% lead in roots and more than 71% in leaves, but also the lead mainly was located in cell wall and residual state (Fj) ,and over 70% lead in the roots and leaves could be extracted by acetic and HC1 and NaCl.(二) The influence of soil heavy metal pollution on the structure of soil animal community By the means of ecology, the paper made a analysis of heavy metal pollution on the structure of soil animal in Huainan. The result showed that the heavy metal contamination did harm to the soil animal. Through investigation, 26 kinds of soil animal were collected , which could be classified into 9 classes belonging to 4 phyla. The dominent group taxa of among them were Nematoda, Collembola and Acarina. The rest of 23 genera belong to common species or rare species. As pollution degree went up, the kinds and numbers of soil animals decreased. The density of soil animals also had much to do with the level of heavy metal contamination in soil. The soil animals had not an obvious character of surface aggregation in the contaminated soil, even surface aggregation was disappear. Some important indexes of community structure such as H, E, DG, C showed that the higher the pollution was, the smaller the community indexes were, but C index increased in initial stage and then decreased in coal ash site. H index was positively related with the E index, but negatively with the C index. In addition, the number of individuals of soil animal community did not relate positively with the amount of organic matter. Similarity index showed that there was a high value between the coal mining sites and coal ash sites because of similarity source of heavy metal.
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