Pollution Investigation Of Heavy Metals In Guangxi Manganese Mine Area And Electrokinetic Remediation Of The Polluted Soil

In recent years,the heavy metal pollution has evolved into a global environmental problem.With the development of economy,Guaingxi province has expedited the exploition of manganese mine in the territory,caused serious heavy metal pollution of the soil.In this thesis,According to Chromium(Cr),Cadmium(Cd)and Manganese(Mn)vertical distribution features,Metal Geo-accumulation Index Method(Igeo)was used to assess the soil heavy metal pollution degree in Manganese Mine,GuangXi Province.In order to study their potential ecological risks,Cr,Cd and Mn speciation analysis in different depth were conducted.Our study showed that manganese mine are polluted by Cr lightly,polluted by Cd seriously,and partially polluted by Mn seriously.The speciation analysis results showed that most of Cr exist in residual form and does not change with soil depth.Cd in our soil samples mainly existed in non-residual form,and was vulnerable to soil environment.Mn existed in reducible form in the hotel and Manganese Mine,and existed in residual form in Slag.With the differences of depth,there were no significant changes in three heavy metal form distributions,However,based on the serious pollution,it is still necessary to take appropriate and effective strategies to carry out the remediation of heavy metal polluted soils.In Chapter III,aimed at adsorption and desorption law,a variety of different ionic strength and desorption experiments were carried out to simulate the soil of Cr,Cd,Mn expectphysical and chemical analysis test.As a results,Cr?Cd?Mn adsorption capacity order in soils: Cr>Mn>Cd.The maximum adsorption amount ofCr,Cd,Mn was same.When ionic strength was 0.1mol / L,it's the optimum desorption conditions.andpotassium oxalate had strong specificitytoCd,Mn,EDTA-Na was betterthanpotassium oxalate in desorption rate and difference.In soils.There were Competitive effect existed between Cr,Cd,Mn inadsorption and desorption.The more the heavy metal existed,the more it desorbed,Cr,Cd inhibitedMndesorption obviousily,too much Cd?Mn will inhibit themselves..The fourth chapter is to explore the electric power repair Cr,Cd,Mn feasibility simulated soil.In 0.1mol / L NaNO3 as desorption solution,repair,voltage 10 V,repair time five days to simulate soil restoration experiments.The results show that in the non-uniform field strength,electric repair Cr,Cd and Mn simulate soil to good effect,Cr,Cd,Mn total removal rates were 48.2%,66.7%,81.2%,of which Cr,Cd accumulation does not remove the most part near the cathode and anode.The longer the time to repair electric,fix it better,but the lower the degree of the effect of the increase;on the electrode polarization interference,reducing the system current,lower repair efficiency.After the repair was made acidic soil on the whole,lower soil pH,conductivity similar to the removal of heavy metals in subsoil were higher than the top,with the total removal rate decreases,the gap is more obvious.