Contamination and migration characteristics of heavy metals at a typical electroplating site
Heavy metal contamination is a common issue at electroplating sites.It is important to investigate the characteristics and migration of heavy metals in the soil and groundwater for subsequent environmental management and remediation strategies.In this study,a defunct electroplating factory in Shanghai was selected as the research site.A total of 70 soil samples and 6 groundwater samples were collected from five heavily contaminated sites and one control point.The spatial distribution characteristics of heavy metals(Hg,Pb,Cd,Cr,and As)in soil at different depths and groundwater were determined and analyzed,and the influencing factors of heavy metals migration were explored in combination with soil texture.The results showed that the soil at the electroplating plant had been contaminated to varying degrees with heavy metals.The vertical distribution of Hg,Pb,Cr,and Cd in the soil exhibits a decreasing trend with increasing soil profile depth,reaching a stable state at a certain depth.Overall,the levels of heavy metal contamination were much higher in the vadose zone soil than in the saturated zone soil.While,there is no significant trend for As to increase or decrease as the soil profile depth increases.Correlation analysis results indicate that soil particle size is a critical factor affecting the vertical migration of heavy metals.Based on the calculation of migration coefficients,it is evident that the migration capacity of Cr in the saturated zone soil is stronger than in the vadose zone,indicating that the contamination of Cr in the saturated zone should not be underestimated.High levels of Cr in the soil have caused significant contamination of groundwater with Cr.Soil heavy metal content,soil particle composition and groundwater burial depth are important factors that affect the amount of heavy metal in groundwater.
electroplating siteheavy metal contaminationsoilmigration
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NSTL
万方数据
