Water quality improvement measures at the Yagang cross-section in the Pearl River Delta based on the calculation of excessive pollutant fluxes

Abstract

The aim of this study was to quantify the sources of pollution in the Yagang River Basin. A 1-D hydrodynamic model and a 1-D water quality model were combined with the excessive pollutant flux analysis method to calculate pollution data of the Yagang area. The results showed that upstream pollution was the primary cause of water quality degradation for the Yagang Basin, exceeding the water quality standards. In addition, the pollution problem ranking of the entire basin was as follows: the Yagang area (30.4%) > the Foshan area (23.2%) > the Baini River Basin (13.1%) > the Liuxi River Basin (0.6%). In addition, the rainy season had the greatest influence on pollution concentrations. It was also concluded that if the boundary water quality could meet the inspection requirements (class IV water), and the internal research area sewage collection rate reached 60%, the ammonia-nitrogen (NH3-N) in the river discharge would reach 35.7%. This would allow the water quality at the Yagang cross-section to reach standard class IV.