Pollution Characteristics Analysis And Source Apportionment Of Polycyclic Aromatic Hydrocarbon Of Rainfall Runoff In Wuhan

The rapid development of urbanization was bound to be accompanied by the increasingly serious environmental problems.Water environmental pollution was an inevitable environmental problem in the development process.In addition to the conventional pollutants such as nitrogen and phosphorus nutrients,suspended particulates,polycyclic aromatic hydrocarbons and other persistent organic pollutants have absorbed widely attention because of their high toxicity.In this paper,the Qingshan District and Hongshan District of Wuhan were selected as the sampling areas.Conventional pollutants and ?15PAHs were selected as the research objects.The pollution characteristics of pollutants and sources apportionment of ?15PAHs were analyzed.For conventional pollutants in rainfall runoff,the two urban areas showed consistency,but slightly differed.For the contrast of different underlying surfaces,pH was basically weak alkaline,the concentration of SS and the conductivity in road runoff were significantly higher than in the roof runoff.The carbon and nitrogen elements had the highest concentration in the runoff of the linoleum roof and the asphalt roof,followed by road runoff.The lowest concentration was in the runoff of tile roof and cement roof.The result of comparison with "surface water environmental quality standard" showed that almost all of the underlying surface runoff were of grade ? or inferior ? water.The pollution was serious.For ?15PAHs in rainfall runoff,the order from large to small of the EMC concentration of ?15PAHs in different underlying surfaces was cement roof> cement pavement > asphalt pavement > tile roof / glazed tile roof > square > parking lot > linoleum roof > asphalt roof.Low-ring components accounted for a higher proportion,more than 80% in average.The concentration of medium and high-ring components was low.The concentrations of 4 rings were in the order of PYR > BaA > FLA > CHR.The concentration of IcdP was the highest in 5-6 ring components.The concentrations of medium and high ring components from large to small in roof runoff were: linoleum roofing / asphalt roofing> glazed tile roof > tile roof > cement roof,in the road runoff were: cement pavement > asphalt pavement > parking lot / square.The first flush effect was common in every underlying surface.Rainfall characteristics,underlying surface material and service life,the surrounding conditions of underlying surface,traffic conditions,the accumulation of pollutants and air pollution conditions had great impact on the concentration of pollutants and the first flush effect.Using the characteristic ratio method,the sources of PAHs in rainfall runoff of two urban areas were preliminary determined.The source was a mixed source of incomplete combustion source and oil leakage source.PCA/MLR and PMF were used to quantitatively analyze the sources of PAHs in rainfall runoff.The results obtained by the two models were close to each other.The combustion of fossil fuels,motor vehicle emissions and oil spill and volatilization were the main sources of PAHs in rainfall runoff and the contribution rate of each source was calculated.