The Study Of Heavy Metal Capacity And Composition Of Hainan Latosols

With the growth of the population and the rapid development of social economy, make a lot of heavy metal pollutants into the soil environment, causing serious soil heavy metal pollution.This research takes the soils in Hainan tropical that have high, medium and low organic matter content as the research object. Simulation of different pollution levels of copper (Cu), lead (Pb) of the single and compound heavy metals pollution condition, research the adsorption of heavy metals in different soils, and the composition of soil heavy metal characteristics and influencing factors.The results showed that:1.Under the condition of the added exogenous Cu,high, medium and low organic matter soil were no saturated adsorption amount of Cu.Residual,bound to organic matter,exchangeable and bound to carbonates in turn became the main form in high organic matter soil.In medium organic matter soil, bound to carbonates became the main form in lower level of content.With the increasing of adding amount,exchangeable became the main form. And then bound to carbonates became the main form in lower level of content.In low organic matter soil,bound to carbonates was the main form in all level of content.With the increasing of adding amount,the influence factors was also changing.pH, organic matter, total phosphorus, cation exchange capacity, free iron oxide and clay content all will affect the Cu in the soil distribution form.2.Under the condition of the added exogenous Pb, the heavy metal adsorption amount did not reach saturation in high organic matter soil.The saturated capacity were 6.88 and 4.45mg · g-1 in medium and low organic matter soil.Residual was the main form in high organic matter soil when exogenous addition amount is less than 0.025mg · g-1. Exchangeable was the main form in high organic matter soil when exogenous addition amount is more than 0.025mg · g-1. Exchangeable was the main form in medium and low organic matter soil.pH, organic matter, total phosphorus, cation exchange capacity, free iron oxide and clay content will influence the distribution of Pb in soil.3. Under exogenous Cu and Pb compound pollution level,high, medium and low organic matter soil were no saturated adsorption amount of Cu and Pb.Residual was the main form in high organic matter soil when exogenous addition amount is less than 0.05mg · g-1 of Cu and 0.025mg · g-1 of Pb. With the increase of adding amount, the content of residual reduced and bound to carbonates became the main form.Bound to carbonates Cu and exchangeable Pb were the main form in medium organic matter soil.Bound to carbonates Cu was the main form in low organic matter soil.In low organic matter soil, exchangeable Pb became the main form when exogenous addition amount is less than 15mg · g-1. With the increasing of adding amount,bound to carbonates became the main form. Compound pollution condition,due to the interaction of Cu2+ and Pb2+, with the ion competition effect and synergistic effect,makes the content of heavy metal in different morphological change.The change of heavy metal content in different soil is not the same.