Study on environmental impact of pollutant dispersion from Yangtze River to Zhoushan sea area

Abstract

The pollutants from the Yangtze River will diffuse along the coastal zones with the action of the current. However, whether they will reach Zhoushan city or not and the impact, diffusion path of the pollutants from the Yangtze River is not clear. At present, there are few studies on the large-scale diffusion of pollutants from the Yangtze River into the sea. In this study, the transport and diffusion of chemical oxygen demand (COD) from the Yangtze River to Zhoushan sea area were studied by numerical simulation. The results showed that the diffusion of pollutants from the Yangtze River could reach Zhoushan. Both Hangzhou Bay and Zhoushan Island were greatly affected, resulting in an increase of COD concentration of 0.5-0.8 mg/L in most of Zhoushan sea areas. Because of the low background concentration of COD in Zhoushan, the percentage of COD increment caused by pollution in the Yangtze Estuary was more than 50%.