Investigation And Evaluation Of Heavy Metal Pollution In Soil Of E-waste Dismantling Area In Longtang Town,Shijiao Town,Qingyuan County

In this paper,40 soil samples and 10 sediment samples were collected from the soil surrounding the Shijiao Town,Longtang Town,Qingyuan City,Guangdong Province,and the E-waste dismantling area.The nine heavy metals Cd in the sample were collected.The total amount of Cr,Cu,Ni,Sb,Zn,Pb,AS and Mn were analyzed and tested to study their spatial distribution characteristics,discuss possible sources of pollution,and conduct ecological risk assessment of heavy metals.This paper uses soil environmental quality assessment methods and geostatistics methods to make heavy metal spatial distribution maps,pollution assessment maps and ecological risk assessment maps,making it more intuitive to show its spatial characteristics.The results of the study are as follows:(1)Statistical characteristics of soil heavy metal contents: In addition to As,Cr,Mn,and Ni,the average values of the other five heavy metals were higher than the background values of the Pearl River Delta,and the spatial variability was larger,indicating Cu in the soil within the study area.The contents of Cd,Zn,Pb,and Sb have been affected by varying degrees of human activities.The contents of As,Cr,Mn,and Ni can also reflect the influence of natural factors to some extent.(2)Statistical characteristics of heavy metal content in river sediments: Except for As,Cr,Mn,and Ni,the average values of the other five heavy metals were higher than the background values of the Pearl River Delta.The variation coefficient of variation was small,and certain dispersion also explained.The river area is affected by certain human activities.(3)Evaluation results of heavy metal pollution in soil: the three results of comprehensive pollution index evaluation,potential ecological hazard assessment andenvironmental capacity assessment have similarity.The results show that most of the study areas are clean,and the heavily polluted areas are distributed in a distributed pattern.Concentrated in Banchong Village,Xinji Village,Huangbu Village,the maximum value of comprehensive pollution index reached 90.70,64.08,57.33,the maximum value of potential ecological hazard index reached 5562.90,4751.26,3099.14,and the minimum value of environmental capacity index was-19.79,-21.75,-18.60 respectively.(4)The result of heavy metal pollution evaluation in river sediment: the result of pollution index evaluation showed that the five heavy metal elements,were all polluted by humans to varying degrees.The results of potential ecological hazard evaluation showed that Cd was in a very strong harm state and Sb was in a strong harm state,while the other seven heavy metals,such as Cr,Cu,Ni,Zn,Pb,As and Mn,were in a relatively slight harm state.The results of the environmental volumetric method show that the Zn content of the Cd,Cu,Sb,Pb,Zn is in an overloaded state.