Accessment And Remediation On Cu And Cd Pollution In Farmland Around The Smelting Plant

Metal mining and smelting is one of the important sources of soil heavy metal pollution,the production generated in the process of dust,tailings and waste water,through atmospheric deposition,waste leakage and wastewater irrigation channels into the soil,will have varying degrees of pollution on the surrounding soil.The Guixi Smelter surrounding farmland soil as the research object,based on literature,data and field survey on farmland acquisition and repair plant after repair and restoration of farmland soil a year before,using the geoaccumulation pollution index method,single factor Nemerow comprehensive pollution dyeing index method,potential ecological risk index method to evaluate smelter surrounding farmland soil heavy metals pollution status before repair;at the same time to soil pH,the morphology of Cu/Cd,effective state and repair plant as the index to evaluate the repair effect.To prevent pollution of farmland soil again and evaluate the effect of pollution in the area has been repaired farmland provide a theoretical basis.The main findings are as follows:1.Smelter surrounding farmland soil Cu content range for 78.71 to 1120.53 mg /kg,the coefficient of variation was 85.4%;Cd content is 0.160 to 1.556 mg/kg,the coefficient of variation was 54.0%,are higher than the Jiangxi Province soil element background values,including Cu/Cd content in the highest were more than the national secondary standard of soil environment quality and 22.4 times and 5.2 times.The available contents of Cu ranged from 3.44 to 154.23mg/kg in the farmland around the smelter,the variation coefficient was1.16%,the available content of the Cd was 0.019 to 0.922mg/kg,the variation coefficient was 62.4%.Soil Cu/Cd total and effective state content was similar to the distribution,a distribution of radiation pattern;between the contents and the effective state is significantly positive correlation,positive correlation between pH and effective state of repair,repair was negative correlation.2.Geological index accumulate showed: Cu smelter surrounding farmland soil pollution level is strong,Cd pollution level is moderate to strong.Single factor-Nemerow pollution index showed: Soil surrounding the smelter comprehensive pollution index was 5.7,heavily polluted;the villages pollution index in the range of 1.6 to 14.7,the degree of contamination of mild-to-severe,specific performance JN> QQ> SM> YS> SQ> SJ>WJF> ZS> LJ> JJ> ZJ.Potential Ecological Risk Index showed: Soil surrounding the smelter hazard index was 303.6,the degree of risk is strong;the villages hazard index inthe range of 89.0 ~ 485.5,overall risk rating of slight-a strong,specific performance of JN> QQ> SQ> WJF> ZS> YS> SM> LJ> JJ> SJ> ZJ.3.Smelter surrounding farmland soil pH increased significantly after repair;Cu/Cd form in soil by plants can use state to the potential use of transition;soil Cu/Cd effective state decreased as were in more than 50%,which decline range of Cu was 54.5%-85.0%,decline range of Cd was 50.0% ~ 64.1%;soil Cu/Cd biological validity coefficients were decreased,Cu reduces the scope for 5.3% to 19.6%,Cd reduces the scope for 19.2% to 41.4%.For giant JUNCAO,JiuNiu Gang of Cu/Cd transfer maximum amount respectively 454.2 g/mu and9.54 g/mu;Vetiveria zizanioides on Cu/Cd transfer amount were 162.5 g/mu and 1.55 g/mu;e.splendens Cu/Cd transfer amount of 378.8 g/mu and 3.36 g/mu respectively;Sedum plumbizincicola on Cu/Cd transfer amount of 29.4 g/mu and 1.48 g/mu respectively.4.Has been involved in the repair project of smelter surrounding residents survey showed that residents of the village pollution of the environment is very understanding,but the awareness of environmental pollution general;when the implementation of the project,90% of the population to the forum,a letter leaflet,workmanship and other forms,in which80% of the population to work in the form of;at the same time 80% of the population think village environment quality changed for the better,that the governance of environmental pollution has been recognition of local residents and the field soil remediation projects for local villages ecological environment has improved the actual effect.