Study On The Pollution Of Heavy Metals In Chemical Mixed Soil To Surrounding Soil And Groundwater

With the development of economy and industry,chemical plants are playing an increasingly important role,and these companies produce a large amount of waste residues and waste water and other chemical wastes in the production process.These chemical wastes are stacked in violation of laws and regulations.It has caused extremely serious pollution to the soil and groundwater,and has a huge impact on the environment.This study is aimed at a chemical company’s chemical miscellaneous fill buried near a village.Through data collection and a large number of on-site sampling,the current distribution of eight heavy metal elements in the chemical miscellaneous fill and its surrounding farmland and groundwater was analyzed,and they were analyzed separately.The single-factor pollution index method,Nemero pollution index method and potential ecological risk index method were used to evaluate the current status of soil and groundwater pollution in the region,and the pollution characteristics of the miscellaneous fill to farmland and groundwater were determined,and the chemical miscellaneous fill was clarified.The impact on the surrounding environment provides technical support and theoretical basis for the later restoration of the plot.1.1.As,Hg,Cu,Zn and Cd in the chemical miscellaneous fill stacking area are all polluted.According to the single factor index and Nemero index,the main pollutants are Zn and Cd,and among the samples contaminated by Cd,there are More than 50% of the points are rated as severe pollution.The main pollution points are 0.5～2.5m depth of A4 and A5 and 0.5m depth of A6.The remaining points are basically light pollution;according to the potential ecological hazard index method,Only the two elements Hg and Cd reach the level of medium ecological hazard and above.The points above the medium ecological hazard in the study area are mainly concentrated in two points A4 and A5.2.The miscellaneous fill has a significant impact on the heavy metal content of the farmland area with a width of 200 m.The main factors are As,Hg,Cu,Zn,and Cd.The test found that some points have pollution.According to the single factor index and Nemero According to the index,most of the pollution is slight pollution,Cd pollution is the heaviest,and points B5 and B6 have moderate pollution;the main pollution points are concentrated in B4,B5 and B6,and B5 has the highest pollution degree,which is severe pollution;according to the potential ecology According to the hazard index method,only Hg and Cd have reached the level of medium ecological hazard and above,and only B5 is above the medium ecological risk.3.The groundwater in the study area is also significantly affected by the miscellaneous fill.The groundwater sampling points DX1～DX6 are in the heavily polluted area of the miscellaneous fill,and their Pb concentration exceeds the groundwater class III standard,and the Zn in the points DX2,DX3,DX4 and DX6 The concentration exceeds the groundwater level III standard;the groundwater is evaluated by the internal Merrow comprehensive index method of the groundwater,and the points DX1～DX6 in the miscellaneous fill area are poor water quality,and the main contributing elements are As,Hg,Zn and Cd.The groundwater at points DX7～9 in the farmland area of the miscellaneous fill area is of good water quality.4.Comparing the pollution spatial distribution map of chemical miscellaneous fill soil and surrounding farmland and the pollutant migration change map in three different directions,it can be concluded that miscellaneous fill soil and farmland pollution are closely related,and the polluted area of farmland is next to the miscellaneous fill soil.Seriously polluted areas,and farmland soils far away from the polluted area have normal heavy metal content.The farther away from the miscellaneous fill,the lower the heavy metal pollution;the closer to the miscellaneous fill,the higher the heavy metal pollution.Miscellaneous fill pollutes farmland in three categories.The order of pollution degree in the three directions from high to low is E>ES>EN,which is significantly related to the wind direction in the study area and the activities of nearby villagers.The groundwater in the miscellaneous fill area is of poor water quality,while the groundwater in the farmland area is of good water quality.It can be seen that the heavy metal pollution of the chemical miscellaneous fill has a great impact on the surrounding environment.5.Since the main soil pollutants are heavy metals,and the main pollution points are concentrated,the amount of pollution is not large.According to the analysis of research data,it is recommended that the 0～2.5m soil of A4 and A5 and the 0～0.5m soil of A6 in the miscellaneous fill area,0～0.2m soil of farmland area B4～B6 is landfilled and repaired,and the contaminated soil is excavated and transported to the landfill.