Effects Of Urbanization Process On Polycyclic Aromatic Hydrocarbons Residues In Soil And River Water In Shen Fu Section Of Hun River

With the acceleration of urbanization,nitrogen,phosphorus,heavy metals,POPs and other pollutants in the soil,river and other media began to accumulate,and brought some threat to the local residents.Especially,PAHs were commonly found in environment such as water,and soils.Because difficulty degradation and volatility,PAHs caused widespread concern.In this study,the surface soils of Shenyang,Fushun and Shenfu New City in different urbanization process and the river water in Shenfu section of Hunhe River Basin were studied,148 soil samples and 22 river samples were collected.The residual characteristics of PAHs in surface soil and river water were analyzed.Effects of different urbanization factors,land use and seasonal changes on the distribution of PAHs were analyzed.The sources and risk of PAHs in soil and river water were analyzed and evaluated by various methods.The influence of urbanization on the PAHs concentrations in soil and river water was revealed.The main conclusions were as follows:1.The total concentrations of ?21PAHs in different urbanization areas in soil is as follows:Background<ShenFu<FuShun<ShenYang.The concentrations of ?21PAHs and?7PAHs(carcinogenicity PAHs)were increases with the urban construction age,which indicating that the urbanization level was positively correlated with the concentrations of PAHs in the soil.The concentrations of ?21PAHs in the topsoil of Shenfu New City in dry and wet seasons were 151.47-18276.42 ?g/kg and 27.35-46576.28 ?g/kg,respectively.The high rings PAHs were dominant,?21PAHs and ?7PAHs were all had highest concentrations in urban land use and the lowest concentrations in forest land.And the concentrations of ?21PAHs in river in dry and wet seasons were 59.10-1302.85 ng/L and 57.79-737.53 ng/L,respectively.Among them,the highest point of PAHs in wet and dry season appeared in the Peace Bridge and Dahuofang Reservoir outlet,respectively.The concentrations of PAHs were gradually increased along the flow direction of Hun-He river,and the low rings PAHs were dominantly exist.2.The diagnostic ratios and principal component analysis showed that PAHs in river water in dry season are mainly from coal combustion,motor vehicle emissions and oil input,and the atmospheric source occurs in the wet season.The PAHs in wet and dry season of Shenfu New City,Shenyang and Fushun in wet season are mainly from coal combustion,motor vehicle emissions,oil inputs and atmospheric emissions,while the sources in Background in wet season are coal burning,motor vehicle emissions and oil inputs.The main sources of PAHs in river in dry and wet seasons are motor vehicle emissions(52.9%)and oil,coal combustion(41.7%),respectively.And the main sources of wet and dry season of Shenfu New City,Shenyang,Fushun and Background in wet season are:oil inputs and coal combustion(43.9%),motor vehicle emissions(57.3%),motor vehicle emissions(53.5%),motor vehicle emissions(59.4%)and wood,oil combustion(44.3%),indicating that PAHs source distribution structure changes with the history of urbanization.3.The results of ecological risk assessment show that there are moderate ecological risks in wet and dry season of Hunhe River.And the topsoil in the study area is in the middle and low ecological risk level except for the high ecological risk of individual samples.The health risk assessment model shows that the river water is at a low level of cancer risk and the risk of dry season is higher than that of wet season,which is same as the results of ecological risk assessment.In the topsoil,the Background in wet season is at a safe value,the wet and dry season of Shenfu New City is basically in the lower Risk level,while there are potential healthy risks in Shenyang and Fushun in wet season.This shows that the risk level increases with the growth of urbanization history,and soil digest and soil dermal could bring higher healthy risk.As a result,the risk level of healthy risk is as follows:soil ingest,children>adolescents>adult,soil dermal,adolescents>children>adults,soil PAHs have higher health risks for children and adolescents,which require more attention.