Effects Of Bentonite In Copper Contaminated Soil On Cu Form Of Soil And Rape Growth

It is an important research to soil science and environmental science about heavy metal pollution in Soil. and it is an important part of ensureing the quality of agricultural environment and the production of safe agricultural products about Studying heavy metals morphology changes in soil and control repair technology. A pot experiment was conducted to study the effects of bentonite on copper contaminated soil repair, discussion of bentonite on copper contaminated soil about the form of Cu transformation and enzyme activity in soil, rape growth and the content of Cu in the rape. The result showed that:1.The content of Cu forms in soil increased as the concentration of copper contaminated increased. copper is0mg/kg, the proportion is in the form of copper of soil:residual Cu> Fe-Mn oxidation Cu> carbonate bound Cu> organic Cu> exchangeable Cu. Copper contaminated in soil carbonate bound Cu and Fe-Mn oxidation Cu increased, the residual Cu is decreased, it had no obvious change of the exchangeable Cu and the organic Cu. Carbonate bound Cu> Fe-Mn oxidation Cu> residual Cu> organic Cu> exchangeable Cu. Bentonite in high concentrations of copper contaminated soil, the exchangeable and Carbonate bound Cu in soil was significantly reduced, and the content of Fe-Mn oxidation, organic and residual Cu increased significantly. By biological effective state into invalid state, the content of effective Cu of soil increased as the concentration of copper contaminated increased. bentonite can effectively reduce the content of effective Cu in soil.2.The urease activity, catalase activity and invertase activity in Soil decreased as the concentration of copper contaminated increased. Bentonite could significantly increase the catalase and invertase activity of soil in copper contaminated, and decreased as the concentration of copper contaminated increased. Bentonite could increase significantly the urease activity of soil. Show the effect of repairing continuously at high concentrations of copper contaminated; Bentonite could increase significantly the invertase activity of soil, especially the growth is greater at high concentration copper contaminated than the low concentration of copper contaminated; The alkaline phosphatase activity and nitrate reductase activity of soil showed up the trends of increased to decreased as the concentration of copper contaminated increased, Bentonite could improve the alkaline phosphatase activity of soil significantly, Show the effect is gradually strong of repairing continuously at high concentrations of copper contaminated; Bentonite could increase the nitrate reductase activity in copper contaminated soil significantly, show the effect is greater in low concentration of copper contaminated than the high concentration copper contaminated.3.The content of malondialdehyde and proline in rape increased as the concentration of copper contaminated increased, Bentonite treatment could decrease significantly the content of malondialdehyde, proline in rape; The content of Cu on upper part and underground part of rape increased as the concentration of copper contaminated increased. Bentonite could decrease the content of Cu on upper part and underground part of rape effectively. the migration coefficient of Cu in Rape increased as the concentration of copper contaminated increased, Bentonite could inhibit copper from the root to the aboveground in rape effectively, so as to reduce the copper pollution to rape.4. The fresh weight, dry weight, chlorophyll content of rape decreased the concentration of copper contaminated increased, bentonite conducive to rape growth, and could improve the biomass and content of chlorophyll of rape significantly.