Research Of Land Consolidation Technology For Heavy Metal Pollution Farmland

China is a country with a large population, leading to lack of land resources. Withthe development of economy, increase of population, industrialization andmodernization, The contradiction between human and land resource stands out. Inorder to coordinate the relationship between people and land, land consolidationtechnology emerged. Through organizing the use of farmland, rezoning landownership, make land resources to achieve efficiently and sustainable use. But thecurrent land consolidation project pay more attention to increase the quantity of land,quality of the arable land is ignored. With the rapid development of industry, a largenumber of toxic and hazardous pollutants enter the soil environment in many differentways. Without investigation and evaluation for soil environmental quality,landconsolidation project may lead to the spread of pollution, even may destroy ecologicalenvironment and endanger human health.On the basis of surveys and material, according to land use present characteristic,layout36sampling points, and collected topsoil, profile soil and plant (rice). Throughanalysis total content and available of Zn, Cu, Pb and Cd of samples, made cleardistribution characteristics and pollution condition of soil heavy metal.The main results are as follows:(1) total Zn and Cu, Pb content of topsoil lower than the secondary standardlimits in soil environmental quality standards,but total Cd content of in the topsoilsamples was significantly higher than standard.(2) Single factor index of Zn, Cu and Pb are less than1, but single-factor index ofCd are4.71~14.17has been much greater than1, indicating that topsoil was pollutedby Cd. The comprehensive pollution index of heavy metal is4.14~9.13, indicatingthat the topsoil was seriously polluted.(3) From surface to down layer, the content of heavy metals showing a overalldecreasing trend.Above50cm soil layer, heavy metal content is higher,15~20cm soil layer, heavy metal content become lower,20~50cm heavy metal content rebounded significantly,below60cm soil depth, heavy metals content reaches a minimum.(4) In rice samples, the Cd content are0.05~0.23mg/kg. According to the foodhygiene standards, maximum allowable concentration of Cd in rice is0.2mg/kg.Obviously, Cd content of6samples among total samples are exceeded standard,Exceeding rate is nearly16.7%.base on bioavailability Cd content and food hygienestandard, regression among rice Cd content, soil total Cd and bioavailability CdContent were analyzed. Through this regression analysis, the soil quality of the studyarea was defined for3levels: first level may carry on land consolidation directly,Secondary level should repair soil-pollution during land consolidation, third levelmust carry on soil reparation and land consolidation must be forbidden at the sametime. Land consolidation may go on when soil quality measure up correlativestandard.(5) Research of heavy metal pollution farmland reparation technology. WithHNO3-KMnO4system for surface modification of nano-carbon.Through cultureexperiments, the affection of the modified nano-carbon to available Cd content wasstudied.The results show that: After30days training, the treatment that add3%modifiednano-carbon made soil bioavailability Cd content lower than comparison; under threedifferent cultivation measures (flooding, alternating wet and drought&drought), thetreatment that add3%modified nano-carbon and comparison treatment made soilbioavailability Cd content decrease, former decrease was more obviously, declinepercentage of Cd to39.47%,26.31%,21.05%respectively after30days cultivation.Content of bioavailability Cd in packet application and mixed application are lowerthan comparison, but Content of bioavailability Cd in packet application seemsslightly higher than another. With the passage of time, Content of bioavailability Cdin each treatment showed a downward trend. After40days cultivation, available Cdcontent attained a minimum value.