Destratification and oxygenation efficiency of a water-lifting aerator system in a deep reservoir:Implications for optimal operation

作     者：Yang Li Tinglin Huang Xinlin Tan Zizhen Zhou Weixing Ma 

作者机构：Key Laboratory of Northwest Water ResourceEnvironment and EcologyMOEXi'an University of Architecture and Technology Shaanxi Key Laboratory of Environmental EngineeringXi'an University of Architecture and Technology 

出 版 物：《Journal of Environmental Sciences》 (环境科学学报（英文版）)

年 卷 期：2018年第30卷第11期

页      面：9-19页

核心收录：

学科分类：08[工学] 0815[工学-水利工程] 

基　　金：supported by the National Natural Science Foundation of China(Nos.51478378 and 50830303) 

主　　题：Reservoir Thermal stratification Numerical simulation Water-lifting aerator Mixing Oxygenation 

摘      要：Thermal stratification is a common phenomenon in lakes and reservoirs and has a significant influence on water quality dynamics. Heihe Reservoir is a canyon-shaped reservoir in Shaanxi Province with strong thermal stratification. Therefore, eight water-lifting aerators （WLAs） were installed in this reservoir, which could overcome thermal stratification and increase oxygenation with gas flows between 20 and 50 m3/hr, and oxygenate the hypolimnion with gas flows less than 20 m3/hr. To examine the destratification efficiency of the WLA system, we used a three- dimensional hydrodynamic module based on MIKE 3 to simulate the thermal structure of Heihe Reservoir and compared the simulations with measured data. Results showed that operation of the WLA system promoted water mixing and effectively oxygenated the hypolimnion. Through the established energy utilization assessment method, the energy utilization efficiency of the WLA system was between 5.36% and 7.30%, indicating the capability of the technique for destratification in such a large reservoir. When the surface water temperature dropped to the theoretical mixed water temperature calculated by the energy utilization assessment method, reducing gas flow could save energy. This would prevent anaerobic conditions from occurring in the bottom water and maintain good water quality in Heihe Reservoir.