| The advancement of national industrialization,the industrial enterprise production activities increased,the production scale,a large number of production process of pollutants discharged into the environment medium,the seepage control measure is not perfect industrial enterprise,the soil is often suffered serious pollution,and because of the soil pollution characteristics of concealment,cumulative,hysteresis,irreversible,as well as the characteristics of difficult treatment,high cost and long cycle,pollutants continue to accumulate in the soil,if the site after the relocation of enterprises is used for human life,it will cause a long-term great risk to human health.In this paper,soil pollution sites of three different industrial enterprises in Sichuan province were selected as the research objects,including coating production site,zinc sulfate production site and coke(oil)production site.According to the raw and auxiliary materials and production process of each site,the characteristic pollutants and pollutant emission channels of different industrial enterprises were identified.Using single factor pollution index method,mei pollution index method,to accumulate within the pollution index method of coating production site,zinc sulfate production site and coke(oil)pollution evaluation on the production site,by SPSS software to each field of pollutants on qualitative analysis,and based on Arc GIS,ordinary kriging interpolation method in simulation field pollution distribution,determine the site of pollution sources,human health risk assessment model and IEUBK blood lead model were used to assess the risk of characteristic pollutants in different industrial production sites.The results show that:(1)Under the single factor and nemerow pollution index evaluation methods,the comprehensive pollution intensity is in the order of zinc sulfate production site > coke(oil)production site > paint production site.The zinc sulfate production site is mainly polluted by Cd,Pb,As and Hg,while the coke(oil)production site is mainly polluted by polycyclic aromatic hydrocarbons(PAHs).The concentration values of pollutants in coating production sites are As and Cd.The cumulative pollution index evaluation shows that Cd,Pb,As and Ni pollution in zinc sulfate production site is greatly affected by human production activities,and benzo [a] anthracene,benzo [b] fluoranthene,benzo [k] fluoranthene and chrysene pollution in coke(oil)production site is greatly affected by human production activities.(2)The degree of heavy metal pollution is in the order of zinc sulfate production site>coke(oil)production site > paint production site.The average concentration of heavy metals in zinc sulfate production site was Pb(1076.76 mg/kg)> As(108.57 mg/kg)> Cd(100.84 mg/kg)> Cu(43.88 mg/kg)> Cr(42.37 mg /kg)> Ni(32.97 mg/kg)> Hg(2.98 mg/kg),and the multiples exceeding the screening values were As(5.43)> Cd(5.04)> Pb(2.69)> Hg(0.37)> Ni(0.22)> Cu(0.022)> Cr(0.021),the variation coefficients of As,Cd,Pb,Hg and Ni were all over 100%.Organic pollution only exists in coke(oil)production sites,the average concentration of polycyclic aromatic hydrocarbons was benzo [b] fluoranthene(12.97 mg/kg)>benzo [k] fluoranthene(11.58 mg/kg)> benzo [a] anthrene(11.41 mg/kg)> chrysene(10.53mg/kg)> benzo [a] pyrene(5.27 mg/kg)> dibenzo [a,h] anthracene(1.63 mg/kg)> indeno[1,2,3-c,d] pyrene(1.47 mg/kg)> naphthalene(0.13 mg/kg),benzo [a] pyrene(9.59)> dibenzo[a,h] anthracene(2.96)> benzo [b] fluoranthene(2.36)> benzo [a] fluoranthene(2.07)> indeno[1,2,3-c,d] pyrene(0.27)> benzo [k] fluoranthene(0.21)> chrysene(0.021)> naphthalene(0.005),the variation coefficients of benzo [a] anthracene,benzo [a] pyrene,benzo [b]fluoranthene,dibenzo [a,h] were all over 100%.(3)Zinc sulfate production field characteristics of pollutants Cd,Pb,As,Hg,homology pollution,major pollution units for wastewater collection pool and temporary slag stacking area,present in wastewater collection pool in horizontal plane and the temporary slag stacking area of point source pollution spreading around,in the vertical plane from the northeast to the northwest migration trends,The pollution concentration was 0.5-1.0m > 0-0.5m > 1.0-1.5m.The characteristic pollutants of the coke(oil)production site are polycyclic aromatic hydrocarbons(PAHs),especially benzo [a] anthracene,benzo [a] pyrene,benzo [b]fluoranthene and dibenzo [a,h] anthracene.The main pollution unit is the tar tank,and the tar tank is the pollution point source and diffuses to the surrounding area on the horizontal plane.The concentration of As and Cd in the coating production site is more prominent,mainly concentrated in the northwest side of the site,and in the horizontal plane,the northwest is the pollution point source and spreads to the periphery.(4)Coating production site As,zinc sulfate production site As,Cd,Pb and coke(oil)production site benzo [a] anthracene,benzo [a] pyrene,benzo [b] fluoranthene,dibenzo [a,h]anthracene have carcinogenic risk to human body;Benzo [a] pyrene in coating production site As,zinc sulfate production site As,Cd,Pb,Hg and coke(oil)production site have certain noncarcinogenic risk to human body.The risk of heavy metals to human health was As > Cd > Hg in zinc sulfate production site > coating production site.Among the risks of polycyclic aromatic hydrocarbons(PAHs)to human health in coke(oil)production sites,benzo [a] pyrene has the highest risk and naphthalene has the lowest risk.The proportion of risk contribution rate showed that under carcinogenic effect,the main exposure routes of As were oral intake of soil particles(86.34%),inhaled soil particles(100%),and polycyclic aromatic hydrocarbons(PAHs)were oral intake of soil particles and inhalation of gaseous pollutants from surface soil in outdoor air.Under the non-carcinogenic effect,the main exposure routes of As are oral intake of soil particles(77.38%),inhalation of soil particles(48.14%)and oral intake of soil particles(46.55%),and inhalation of gaseous pollutants from surface soil in outdoor air(32.90%)and oral intake of soil particles(30.77%),polycyclic aromatic hydrocarbons(PAHs)are gaseous pollutants from surface soil that are inhaled orally from soil particles and inhaled into outdoor air.Through the study on the pollution characteristics and risk assessment of soil contaminated sites in different industrial enterprises in Sichuan province,this paper provides a basis for soil remediation and pollution risk prevention and control in different industrial enterprises.Human health risk assessment is an essential step before soil remediation,which can provide feasible and economic options for remediation work. |
