Notice of Retraction: Quality Characterization and Impact Assessment of Urban Runoff in a Medium Size City of China

Abstract

Water quality of stormwater runoff from urban areas was characterized by qualitatively and quantitatively determining particle size and event mean concentration (EMC). The results show that the 5~40μm size class dominates in all the samples. Mean EMC's in mg/L were 186, 235, 6.85 and 2.16 for TSS, COD, TN, and TP. With respect to the mean values of four nutrients' EMC at the residential area, they are generally were greater than EMC at the other areas. Antecedent dry period is the main hydrographic parameters which found a positive relationship between ADP and EMC of TSS, COD, TN and TP at a significance level of 0.001. The antecedent dry period is longer, EMC of the pollutants in the initial period surface runoff increased. The antecedent dry period determined the build-up process of pollutants which is chemical medium condition affecting the change in concentration of pollutants. These findings will facilitate the recognition of characterization of contamination of stormwater runoff, especially for providing the scientific basis for non-point source pollution control and management in China.