The Characteristics of Soil Heavy Metal Pollution and Source Analysis of the Key Supervision Enterprise in Qingdao's Industrial Park
Qingdao city is one of the core areas to promote ecological protection and high-quality development in the Yellow River basin.It is of great significance to study the status,sources and potential risks of heavy metal pollution in the surface soil of this region.Based on the content and pollution characteristics of 6 heavy metal elements(As,Cd,Cu,Pb,Hg,Ni)in the surface soil(0-20 cm)of an industrial park in Qingdao,the correlation analysis and positive definite matrix factorization(PMF)model were used to analyze the source of heavy metals in soil.The results showed that all heavy metal elements in surface soil did not exceed the second type of construction land screening values in GB 36600-2018 Soil Environment Quality Risk Control Standard for Soil Contamination of Development Land.However,compared with the background value in Shandong province,all heavy metal elements were enriched to different degrees,Cd and Hg were 6.38 and 4.85 times of the background value,respectively,showed obvious enrichment.The variation coefficients of Cd and Hg were greater than 100%,which belonged to strong variation,the other heavy metals showed moderate variation.The variation coefficients of As,Cu and Pb were slightly more than 50%,and the variation coefficient of Ni was the smallest(32%).The evaluation results of the local accumulation index showed that Ni,Cu and As were pollution-free(Igeo<0),Pb and Cd were mildly polluted(0≤Igeo<1),and Hg was moderately polluted(1≤Igeo<2).Source analysis results showed that the sources of heavy metals in the surface soil in the park were affected by pesticide and fertilizer production activities,industrial emissions,atmospheric subsidence and natural sources,and their contribution rates were 15.99%,37.32%,30.35%and 16.34%,respectively.