滇池环湖截污干渠在输运农村农业面源径流污水时,TP浓度会沿程降低且在截污干渠末端低于水质净化厂设计进水浓度,导致水厂TP无法达标排放。为探究截污干渠主要设计参数对输运末端农村农业面源TP浓度的影响,为截污干渠设计提供技术参考,研究针对建设完善的滇池东岸截污干渠所运输的农村农业面源污水,以颗粒态磷为主要对象,利用FLUENT三维模拟软件构建了滇池东岸截污干渠流体的多相流模型并进行流动过程的模拟,分析了截面形状、粗糙度、水力直径、坡度等主要设计参数对干渠末端出口TP浓度的影响。结果表明,末端TP浓度圆形截面最低,梯形最高；末端出口TP浓度随粗糙度增大均升高；随水力直径或坡度的增大,矩形及梯形截面的末端出口TP浓度增加或降低,圆形截面则总体降低或变化不大。

When the agricultural non-point source runoff is transported to waste water treatment plant by sewage interception trunk around Dianchi Lake, the TP concentration will decrease along the way and be lower than the designed influent concentration at the end of trunk, which results in the failure of meeting the discharge standard. In order to explore the influence of main design parameters on end TP concentration and provide technical reference for the design of sewage interception trunk, the conducted research focused on the granular phosphorus in the agricultural non-point source transported by the well-constructed sewage interception trunk on the east bank of Dianchi Lake. The three-dimensional simulation software FLUENT was used to build the multiphase flow model of the fluid in sewage interception trunk and simulate the flow process. The influences of different section shape, roughness, hydraulic diameter, slope on the end TP concentration were analyzed. The simulation results show that the end TP concentration for the circular cross section is the lowest and is the highest for the trapezoidal section. With the increase of the roughness, the end TP concentration for the three section shapes increases, and there is a small variation range of the end TP concentration for rectangular section, while the largest variation range is for the circular section. With the increase of hydraulic diameter or slope, the end TP concentration for rectangular or trapezoidal section increases or decreases, while that of circular section decreases or has little change.

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重庆大学大型仪器设备开放基金项目(202303150125)