Study On The Complex Pollution Of Soil By Heavy Metals Near The Representative Lead-zinc Smelt Mills

Today, complex pollution by heavy metals, which was caused by the exploitation of mine resources, has become one of focuses and problems in modern environmental issues. It is necessary to study the features of soil polluted by heavy metals near the smelt mills and the absorbance of some metals in the plants, which is significant for guiding safely ecological using of soils and plants recovery.In this research, an investigation about the heavy metal pollution in the representative smelt mills of lead-zinc mine was given. It was found that the contents of heavy metal pollution in the soil and the characters of it near the mills had some relationship. It illustrated that in this area the content of pollution by Cd had reach a level of strong to extreme, Pb and Zn as a level of meddle pollution , Hg, Cu, Cr, As as slight to meddle pollution, and there was a complex relationship of different metals. We collected a large amount of vegetable samples in the area of mills where it had been polluted by heavy metals seriously, the content analysis of the heavy metals in the vegetables suggest that: (1) In the soil the different heavy metal element was absorbed respectively, and an bigger difference existed . The difficulty degree of heavy metal absorbed by the vegetables is Cr < Zn < Pb < Cu < Ni < Cd, this is related to in vivo absorption of the heavy metal element in crops and transportation mechanism and biochemistry process; (2) The different type vegetables had different ability to absorb heavy metal elements in the soil. The onion garlic class, the rhizome class have strong ability to absorb heavy metal elements, the egg plant fruit class and the melon class have little ability to absorb heavy metal elements; (3) The ability of concentrating heavy metal for identical kind of vegetables differentiate in different areas. The identical type vegetables in different vegetables variety also have the different ability of absorbing heavy metals, big difference existed, the onion, the fragrant-flowered garlic have a strong ability to absorb the heavy metal pollutant, the corn, the cowpea and so on is weak.The leaf mustard and the rape have been chosen as the experiment marriage partner. The orthogonal uniform design was used in this experiment. The cropping experiment was carried out by simulating Cd-Zn-Pb compound contaminating the environment soil. Results indicated that the leaf mustard and the rape have strong ability to survival and concentration in the heavy metal contaminated oil. The rape and the leaf mustard concentrate the Cd to 96.021mg/kg&17.917mg/kg respectively on average, which also have good effect to concentrate Pb, Zn. So, the leaf mustard and the rape have the potential to do phytoremediation in the heavy metal compound contaminated area.