| With the exploitation and utilization of manganese mines, vast tailings produced and contaminated the surrounding soil, destruction of the ecological environment in mining areas. Therefore ecological restoration mine tailings contaminated soil has become an urgent and important issue. By Xiangtan manganese tailings soil physical and chemical analysis and determination of heavy metal content, combined with the indoor cultivation of plants induced chelation testing the toxicity of tailings contaminated soil were evaluated, and to deal with different chelation compound tailings contaminated soil physiology of ramie biochemical characteristics were studied and patience, and the impact of research tailings contaminated soil composite restorative effects of ramie different chelation agent treatment for Xiangtan manganese mines and similar soils provide a theoretical basis and technical measures to restore. The main research results are as follows:(1) Compared with Yuelushan soil, the physical and chemical properties of manganese mines tailings soils are poor, nutrient deficiency,and the tailings soils are not conducive to plant growth and vegetation recovery.5kinds of heavy metals in soil (Mn, Cd, Cu, Pb, Zn) were higher than background values in soil in Hunan and national background values, where high levels of Cd, Pb, and more polluting, Zn over pollution alert value, integrated to see belong mild heavy metals contamination, soil contamination of heavy metals suitable for use this feature phytoremediation.(2) For the results from the pot experiment, for ramie shoot dry weight, the natural chelation citric acid to produce a stimulating effect on the growth of ramie, other synthetic chelator EDTA, EGTA, EDDS, NT A will inhibit its growth has a certain effect. Ramie leaf chlorophyll content of different chelation treatment reduced (except citric acid outside), photosynthesis affected; malondialdehyde (MDA) content increased, leading to cell membrane peroxidation, membrane system stability decreased, plant roots and leaves of ascorbic acid peroxidase (APX) activity has a significant impact, ramie roots and leaves APX activity increased, causing the plant’s own defense mechanisms to protect themselves against poison reaction. Affected by various chelation agents handling the growth of ramie have some toxic effects.(3) Different chelator treatment ramie soil repair have different efficiency and applying chelation treated soil water, extractable Cd, Cu, Mn, Pb and Zn were increased compared with the control group, a part of that increased significantly. Ramie aerial parts of the heavy metal content were increased compared with control subjects (except the NTA, citric acid, Cd, Cu of citric acid, zinc).For Cd, Cu transfer capability is best EGTA (transfer coefficient BTC=3.007,1.429), for Mn, Pb transfer capability is best EDTA (BTC=4.517,2.022), for Zn transfer capability is best EDDS (BTC=4.346). Cd, Cu transfer capability is best EGTA, for Mn, Pb transfer capability is best EDTA, Zn transfer capability for the best is EDDS. Ramie EGTA treatment enrichment capability Cd, Mn ability (enrichment factor BAC=2.402,2.393), ramie NTA enrichment process Cu, Zn (BAC=1.575,2.414) ability, EDTA treatment Pb Accumulation ramie (BAC=0.321) compared to other chelation group for the best. |
PDF Full Text Request