The distribution, compositions, sources and ecological risk for polycyclic aromatic hydrocarbons (PAHs) in industrial fields at a large iron and steel enterprise are discussed. Maximum ΣPAHs concentrations in soils of different workshops ranged from 17.50 to 11266.80 mg•kg-1. The ΣPAHs concentrations of the field could classify three categories due to different discharge ways and combustion condition: >1000 mg•kg-1 , 10-1000 mg•kg-1 , <10 mg•kg-1. The spatial distribution of BaP concentration in the coking topsoil was affected by fugitive emissions significantly. Peak values of PAHs occurred in silt lens in 20-30 m depth indicated that pore size radius and conductivity of unsaturated zone played a critical role in the vertical distribution. The strong linear correlation between the multiple organic contaminants indicated that benzene series worked as co-solvents and competitors in unsaturated zone to promote PAHs migration. Nap and Phe were the most abundant compounds in the coking and coal stockyard sites, while Fla, BbF, Pyr, Phe and Chry predominated in other workshops affected by different sources in which coal combustion was the primary source of PAHs. The calculated TEQ of the coking site was found highest and BaP was the most concerning pollutant of the field since the values accounted for 57.8-64.4% of total PAHs in the different workshops.

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To guarantee the river water quality reaching the surface water quality standards，this paper used a small-scale experimental equipment and optimized hydraulic retention time (HRT) and optimum temperature range of the artificial wetland sewage treatment plant effluent, and the effect of advanced treatment was studied.When the HRT of horizontal subsurface flow artificial wetland is 24h and the HRT of vertical flow artificial wetland is 16h, in summer, the COD, Nitrogen and TP removal rate of combined artificial wetland removal rates were 85.0%, 75.0% and 80% respectively. COD of effluent increased when the temperature was less than 5 ℃ in autumn and winter， whatever horizontal subsurface flow artificial wetland, vertical flow artificial wetland or combined artificial wetland was used. Using three wetland, ammonia and TP can removed to some extent. The removal rates of ammonia were 38.2%, 49.8% and 69.01%, respectively. TP removal rates were 61.0%, 66.0% and 87.0%, respectively.