城市5万吨水处理厂工艺设计.doc

摘 要 随着我国国民经济的高速发展和改革开放的不断深入，城市生产力不断增大，与此同时，城市人口数也不断增加。城市速发展每天都会产生的大量污水，若不及时进行收集处理，将严重影响人们的正常的生活。而且我国又是一个严重缺水的国家，水资源分布不平衡，因此大规模建设污水处理厂，将污染物水平降低到符合国家排水的相关规定，有效防止河流被污染，有效的缓解我国水资源紧缺的现状十分重要。 此次任务对北方某城市5.0万m3/d污水处理厂进行工艺设计，由水质分析可知，该城市污水水量大，污染物水平高。因此主体工艺选择UASB+氧化沟工艺，UASB工艺的优点是污泥床内生物量多，容积负荷率高，废水在反应器内的水力停留时间较短，适合处理污染物浓度高的水质。经UASB池处理后的污水，其污染物浓度降到一定水平，但还不能达标排放，在其后再加上氧化沟工艺，便可达到目标排放要求。氧化沟工艺流程简单、污泥产生量少、管理维护简单等，去除COD、BOD5等主要污染物效率极高，而且适合处理大规模水量。由于污水中动植物油浓度很高，因此在主体处理工艺前设计了隔油池和气浮池等。在二级处理工艺后又设了一个超级膜工艺，用于对部分污水作进一步处理。二级三级出水均达到目标要求。 关键词：城市污水；UASB；DE氧化沟；深度处理；工艺设计 Abstract With the development of our national economy and the deepening of the reform and opening，urban productivity is Increasing constantly, the population is increasing at the same time. Large amounts of sewage will be produced everyday in the city, without collection and processing timely, this sewage will affect peoples normal life seriously. China is also a serious water shortage country, and is unbalanced of water resources, so building large-scale sewage treatment plants for reducing the level of pollutants to meet the relevant provisions of the national drainage，Preventing the rivers be polluted and easing of current situation of Chinas water shortage effectively is very important. It is suitable for handling large-scale water. The mission is to design a process of sewage treatment plant for the northern city of 50,000 m3 per day. By the analysis of the water quality, we can see that the amount of urban sewage is large and the concentration of pollutants is high. So we choose UASB and oxidation ditch to be our main process. The advantage of UASB is the amount of biomass in the sludge bed is large, and the burden rate of volumetric is high, and the time of its HRT is short. It is suitable deal with high concentrations of pollutants. After the process of UASB, the concentrations of pollutants is reduced to a certain level, but it is also can not meet the discharge standards. This can be solved to add a oxidation ditch aft