Soil heavy metal pollution and its prevention and control strategies based on risk management approach
Taking the farmland around a mining area in Zhengzhou,Henan Province as an example,soil heavy metal pollution was studied based on the risk control idea.The results showed that the content order of five heavy metals Zn,Cr,Pb,Cu,and Cd in each soil layer was:Zn>Cr>Pb>Cu>Cd,which decreased with the increase of soil depth.In the 0-15cm soil layer,the contents of Cu,Cr,Zn,and Pb were significantly higher than those in the lower soil layer.As the depth of the soil layer increases and decreases,its sources may mainly be factory emissions of smoke and dust,atmospheric dust,car exhaust,etc.The migration of heavy metals to the lower layer was not significant,and they mainly accumulate in the surface layer.The risk of heavy metals entering the food chain from the soil increases.In the 0-15cm soil layer of the study area,the average contents of Cu,Cd,and Pb were 20.30%,93.10%,and 57.47%higher than the background values of the study area,respectively.There was a significant positive correlation between heavy metals in soil,with Zn and Cu having the highest correlation,while Cr,Cd,and Pb had weaker correlation.The variability of Cd is large in the first principal component,and the high value area is mainly distributed near the cement factory,and the man-made activities such as"three wastes",farmland fertilization and transportation are identified as the first principal component.The countermeasures of soil heavy metal pollution for priority protection and safe utilization were put forward.
risk management and controlheavy metalspollutionprevention and control strategiessoil
万方数据
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