Pollution Discharge Feature of Stormwater Runoff on Two Urban Underlying Surfaces and Treatment in Beijing

In this paper, stormwater runoff from an urban traffic road and building located in Beijing, China, was characterized to measure the stormwater runoff discharge rates and pollutant concentrations. Based on monitoring, the runoff water quality on two underlying surface conditions was analyzed. The temporal dynamics of chemical oxygen demand (COD), NH_3-N, NO₃-N and total phosphorus (TP) were similar and the concentration dropped quickly in the first half hour. The initial concentration of COD, NH₃-N, NO₃-N and TP are worse than the fifth category of national surface water standard, some of them were even beyond the standard of the third category of emission discharge standard. In the urban water resource conservation, reuse of stormrain is a good potential. So, a simple combination of treatment methods with Quartz sand and activated carbon was proposed to reduce the pollution concentration. The COD and TP concentration decreased significantly after the treatment, and the removal rate is sensitive to the hydrological loading of inlet water. The activated carbon did not have impact on NH₃-Nand NO₃-N and the removal rate is stable on three kinds of hydrological scenarios. The study demonstrates the discharge characteristics of urban sotrmrain runoff and provides the results of simple and cheap treatment equipment.