【作者】 何国建；

【导师】 汪德爟；

【作者基本信息】 河海大学 ， 环境工程， 2004， 硕士

【摘要】 近年来随着生活水平的提高，城市生活污水和工业废水的排放量也逐年递增。解决城市水污染的根本出路在于建设城市污水处理厂。我国在城市污水处理厂建设方面成绩卓著，但许多己建成的污水厂由于污水处理效率不能尽如人意，迫切需要改进处理流程，如何优化主要污水处理反应容器的设计和运行已是当务之急。 本文在总结前人对平流式沉淀池的物理模拟和数学模拟成果的基础上，建立了沉淀池水流数学模型和悬浮物沉降模型，通过压力校正法求解非正交同位网格上的各项变量，最终模拟出平流式沉淀池内流速场和悬浮颗粒的浓度场分布，并经过各种工况下悬浮颗粒出水浓度的比较，得出沉淀池优化结构设计尺寸范围。 从结果分析中可以看出，沉淀池挡板的高度和沉淀池本身的高度对悬浮污染物的去除影响较大，因为挡板的高度决定了沉淀池中回流区的大小，回流区越大，污水经过的时间越短，形成短流，从而达不到预期效果；在沉淀池容积一定时，计算得出的结论同理想沉淀池一样，即沉淀池高度越小，表面积就越大，悬浮颗粒的去除率越高；当沉淀池表面积一定时，沉淀池高度的变化也会较大的影响它的运行效果，池深过小或过大均会使得沉淀池中悬浮物的去除率降低；在相同表面负荷以及其它尺寸不变的情况下，不考虑污泥斗中装有污泥的情况，进水口流速的大小对沉淀池运行效果影响不明显。更多还原

【Abstract】 With the improvement of living standard, the discharge of domestic sewage and industrial wastewater is becoming larger. The key way to solve this problem is to construct effluent plant. In our country, the construction of effluent plant has received a great success. But the efficiency of the constructed effluent plants in removing pollutant form wastewater is not very satisfied. So, it is in urge require to optimize the design and run of the main structure of the effluent plant.In this paper, based on the analysis and summarization of study results on settling tanks by predecessors, a mathematical model for predicting the velocity field and suspended solids transport in rectangular settling tanks is developed.Using SIMPLE algorithm for a colocated variable arrangement, the variables can be solved. Then, the current field and the consistency distribution are finally simulated. Compare the consistency of outlet in different size tanks, an optimization design can be concluded.The model is applied to study the effect of structural size of settling tanks on the operating efficiency of settling tanks. From the analysis of the solution, it can be seemed that the high of the reaction baffles and the high of tank itself affect the removing pollutant efficiency very much. For the high of the reaction baffles and the high of tank itself determine the circumfluence in the settling tanks, and then affect the removing pollutant efficiency. On the contrary, taking no account of the instance that the sludge full filled in mud hopper, the velocity of inlet has little influence to the removing pollutant efficiency.更多还原