Author(s): Kui Xu; Jijian Lian; Ye Yao; Xiaozhong Sun; Jie Mu; Chao Ma
Keywords: Urban water body; Water quality improvement; New water transfer measure; Hydrodynamic performance
Abstract: To improve water quality and alleviate eutrophication in a lake or a river of a city, the freshwater is usually transferred to divert pollutants out of the water body. Specifically, the transfer of polluted water using uniform inflow and outflow has a widely application. This is a usual measure to dilute pollutants, but may have a poor efficiency as the limitation of the complex boundary of water body. A new method, a periodic transfer with different inflow and outflow synchronously (PRDIOS), is therefore proposed to improve the transfer efficiency by enhancing the velocity and mixing of the water. The case study is employed to elaborate the PRDIOS method. Four comparative scenarios are presented to investigate the effect and cost of water transfer by using the PRDIOS method and the traditional method. The total volume of inflow water is as the index to measure the water transfer cost. The dilute concentration of pollutant simulated by a two- dimensional hydrodynamic and transport modeling is used to demonstrate the transfer effect. Results show that the PRDIOS method is more efficient and economic than the current water transfer measure. The key factors to influence the effect and cost of water transfer are also investigated based on the comparative analysis of the simulation result of each scenario. It is concluded that the difference of inflow and outflow of transfer water is the key influencing factor on water transfer efficiency in water transfer project. Moreover, the pollutant could be transferred out better even though less water is used.