SOURCE APPORTIONMENT OF POLYCYCLIC AROMATIC HYDROCARBONS IN AGRICULTURAL SOIL IN TYPICAL INDUSTRIAL ZONE IN NANJING CITY

Polycyclic aromatic hydrocarbons(PAHs),a kind of environmental hormones,are harmful to environment and the healthy of human being.Therefore,PAHs have attracted much attention from researchers.In the paper,PAHs in soils around a steel mill in Nanjing were investigated and examined.Based on the analysis of residue of PAHs,the paper discussed the sources of PAHs pollution in order to deal with the pollution problems and serve for environment planning and management.Results showed that PAHs residue in this area ranged between 312.2 and 27 580.9 ng/g.The PAHs with more than 4 rings were the main pollutants.The individual pollutants were mainly Phe,Phe,Fla,Pyr,Baa,Chr,Bkf,Bap,Bgp and I1p.The contents were closely related with direction of the prevailing winds of the year.It could be predicted that the discharge of the gas pollutant was the main source of PAHs in the soil within the research area.The descending of the atmosphere probably resulted in PAHs pollution in the research area.Besides,the outflow of surface water,the discharge of solid wastes and the burning of coal all might lead to the higher residues of PAHs in soil in some of samples.The results also showed that the total content of high-ringed PAHs in soil samples was decreased with the distance of the main pollution sources,while the degree of pollution decreased when samples in the south district were further analyzed.Based on the characteristics of source profile of PAHs,sources of PAHs in different parts of soil samples were compared and deeply discussed by use of all kinds of parameters,such as molecular weight dominance,relative abundance of rings,characteristics index,and so on.It was inferred that PAHs pollution was caused by fossil burning at different degree.Coking plant inside the steel mill was one of the most important sources in the area.