The Research On Pavement Sediment Of Gas Station And Runoff Pollution Characteristic In Nanchang City

With the development of automobile industry,the amount of gas stations increase constantly.As a special part of the city,its increasing hazard to the ecological environment can't be ignored.The gas stations in Nanchang city are taken as the research object in the paper, pavement sediments and rain runoff samples of the gas stations are analyzed,and the characteristics of pavement sediments and rain runoff are dissected.The conclusions in the research are as follows:(1)The physicochemical properties of the pavement sediments are essential trait of particulate matter.The oil environment of the gas stations presents acid,average pH value of pavement sediments is 7.87,compared to pH value of road pavement sediments in Nanchang,it presents obvious weak alkaline,the disparities of different points are small.The size distributions of pavement sediments are between 0.125mm and 0.5mm,and 50%of the pavement sediments can enter atmosphere by external force,and become suspended particles.The average value of organic matter contents of pavement sediments is 4.45%,the disparities of different areas are small,and the contents are lower than the organic matter contents in the road.(2)Petroleum type substances are comprised in pavement sediments of gas stations,the average value of petroleum contents is 0.149mg/g.The management level,size distributions,organic matter contents exert influence on the petroleum pollutant contents.(3)Heavy metal pollution can be found in the pavement sediments of gas stations, the total level of contents is low,and approximates to soil background value,except Hg and Zn.It has disparity compared to the situation of the road pavement sediments. The pH value,size distribution and organic matter in the sediments exert influence on the heavy metal contents.(4)The oil concentration in rain runoff of gas stations is high,which is the main pollutant in rain runoff of gas stations.The rain's oil concentration in initial stage exceeds the discharge standard,so the rain in initial stage should be collected and disposed before discharge.The oil concentration of rain runoff of gas stations is related to car flow,oiling condition,and has direct proportion with oil contents in the pavement sediments of gas stations.(5)Some organic pollutants can be found in the rain runoff of gas stations,the concentrations of COD are between 50mg/L and 250mg/L,the concentration in initial stage is highest.Car flow and management level exert influence on the COD concentration of rain runoff of gas stations.(6)The concentrations of rain runoff are related to pavement sediments of gas stations,the pollution trait of sediments makes impact on the pollution trait of gas stations,especially for oil pollutants.