Pollutant of Runoff from Urban Highway and Impact Assessment on Environment

Highway runoff often contains many kinds of pollutants with high concentration and is toxic.Three monitoring sites were selected to evaluate the quality of the runoff from urban highway in the city of Guangzhou. The results indicated that suspended solids,chemical oxygen demand and oil and grease were high,but the contents of nutritive salt were low.The concentration of the pollutants in the runoff was in significant variations at three sites, which is believed to be attributed to variability in storm duration,rainfall intensity,antecedent dry period,average daily traffic flow,land use and so on.Compared several key quality of constituents with the ClassⅢstandard limitations in the Environmental quality standards for surface water,the levels of oil and grease,chemical oxygen demand, five-day biochemical oxygen demand,total nitrogen,total phosphorus,lead and zinc in the runoff exceeded the limited concentrations.Therefore,untreated discharge of the runoff from urban highway in Guangzhou could seriously deteriorate the water quality of receiving waters.The surface layer of soil in along highway had a change in nature and was polluted by heavy mental as a result of highway runoff discharge.