城市污水处理厂是城市市政基础设施的重要组成部分，也是城市水污染控 制的关键环节，而其建设运行耗资较大，且受多种因素的制约和影响，其中处 理工艺方案的优化是确定其运行性能发挥和降低工程造价、运行费用的关键因 素。因此有必要依据确定的水质目标和设计原则从整体优化的观念出发，结合 设计规模、水质特征以及当地实际条件和要求，参考国内外技术发展动态，选 择技术先进、切实可行、经济合理的处理工艺方案，并经过全面技术经济比较， 优选出最佳总体处理工艺方案。 天津市污水虽属一般城市污水水质、出水要求达到国家《城镇污水处理厂 污染物排放标准》（GB18918-2002）中二级标准，处理难度不高，津南新城现有 污水处理厂 1 座（环兴污水处理厂），但是随着城市经济的发展，污水厂的出水 水质及处理规模均不能满足津南新城发展的需要，为了促进城市可持续发展， 从根本上改善该区域内水域的环境质量，给该区域的经济发展创造良好的载体 环境，污水处理厂的改造扩建迫在眉睫。本工程污水处理厂应具备一定的除磷 脱氮功能。根据本工程的特点，选用垂直叶轮曝气环流氧化沟法和分点进水倒 置 A/A/O 法两个方案，综合比较两个方案的各项指标，得出分点进水倒置 A/A/O 法，在工艺上是最常规的生脱氮除磷工艺，每一组反应池为单个反应器，从空 间上进行厌氧、缺氧和好氧分区，通过进水点及泵系统调节回流量，控制脱氮 除磷效果。采用微孔曝气器，提高氧利用率，同时采用可调风量鼓风机，大幅 度减少电耗。厌氧、缺氧区采用水下搅拌机，使得在搅拌时没有空气进入，确 保搅拌效果；在设备要求上只要求大型鼓风机进口；在运行管理方面，经验丰 富，构筑较多，根据进水水质可灵活调整运行工况。从工程投资费用来说，两 个方案相当，但这个方案的处理成本及运行成本较低，占地较省。因此本工程 选用分点进水倒置 A/A/O 工艺。 污水处理厂处理工艺采用分点进水倒置 A/A/O 工艺，处理后出水外排大沽 排污河；处理过程产生栅渣垃圾和剩余生物污泥，经机械浓缩脱水后，外运垃 圾填埋场进行卫生填埋处置。工程建成后会避免城市污水对地下水的污染，保 护地下水资源，同时污水资源的可持续利用，为社会经济的可持续发展提供了 可靠保证。 关键词：A/A/O 工艺 、 氧化沟工艺、 除磷脱氮Abstract Municipal wastewater treatment plants are not only the significant components of municipal infrastructure but also the key step to control the urban water pollution. However, their construction and operation costs are large and they are restricted by various factors. To optimize the treatment craft is the key factor to ensure its operation performance and to reduce its cost. Thus, it is necessary to choose treatment craft with advanced technology, feasibility and reasonable costs according to the defined quality target and the design concept about integrative optimization. What’s more, the design scale, water quality characteristics and local physical condition and requirements should also be taken into account. After a general technical and economical consideration, the best treatment craft can be selected. The municipal wastewater in Tianjin is belong to common municipal wastewater and the requirements to the outlet water should attain the second class of ‘Discharge standard of pollutants for municipal wastewater treatment plant’ (GB18918-2002); it is not very difficult to deal with, and there is also a treatment plant in Jinnan new district (Huanxin sewage wastewater treatment plant), but as the development of the city’s economics, the outlet water quality of the plant can’t meet the requirements of development of Jinnan new district. To promote sustainability of the city and ameliorate the water environment quality in the district, and to build a good atmosphere for the economic development, it is urgent to reconstruct the wastewater treatment plant. The craft in this plant has the function to remove nitrogen and phosphorus. Based on the characteristics of the project, the two crafts of circulation oxidation ditch with vertical impeller aeration and inverted AAO with inletting water in different points. After comparing these two plans comprehensively, the inverted AAO is one of the most common craft to remove nitrogen and phosphorus and each reaction group is a reactor, and to divide it into anaerobic zone, anoxic zone and aerobic zone, the reflux quantity should be adjusted by adjusting water inlet points and pump system, to control the effect of removing nitrogen and phosphorus. The fine bubble aerator can be used to improve the oxygen utilization. In order to save the electric energy in a large scale, the adjustable aerator should be adopted. In anaerobic and anoxic zone, the agitator under water can be used to ensure the performance. In the operation management, it has been used widely and many experiences could bestudied. Its work condition also can be regulated according to the inlet water quality easily. To the investment, two crafts are just as the same, but AAO plan spends much less cost to treatment and operation, and its floor space is smaller. Thus, the project chooses inverted AAO plan. The treatment plant adopts the craft of inverted AAO with inlet wastewater in different points, and discharges the water into Dagu River after treated. After mechanical thickening and dehydration, the rubbishes and surplus biological sludge in the process will be transported to landfill to dispose. The project will prevent municipal wastewater to pollute the underground water and protect the groundwater resources. At the same time, it is the sustainable utilization to wastewater resources that supply ensure to the social economic sustainable development. Key word: AAO crafts, oxidation ditch craft, remove nitrogen and phosphorus目 录 第一章 绪 论 .................................................... 1 第二章 项目概况 ................................................... 3 2.1 项目背景 ......................................................3 2.2 项目建设必要性和治理目标 ......................................3 2.2.1 项目实施的意义和必要性 ....................................3 2.2.2 治理目标 ..................................................4 2.3 设计原则 ......................................................4 2.4 采用规范和执行标准 ............................................5 2.5 国内外城市污水处理 ............................................5 第三章 建设规模与工程目标 ......................................... 7 3.1 城市污水量预测与建设规模 ..................................7 3.1.1 用水量预测 ................................................7 3.1.2 区域污水量 ................................................7 3.1.3 处理规模 ..................................................8 3.2 处理程度与工程 .............................................8 3.2.1 城市污水水质现状 ..........................................8 3.2.2 进水水质预测 ..............................................9 3.2.3 设计水质确定 .............................................10 第四章 污水处理工艺方案选择论证 .................................. 12 4.1 污水处理工艺方案比选原则 .....................................12 4.1.1 工艺方案选择确定的原则 ...................................12 4.1.2 污水中主要的污染物去除方式 ...............................12 4.1.3 处理工艺方案选择 .........................................13 4.2 污水处理工艺方案比选确定 .....................................14 4.2.1 氧化沟 ...................................................14 4.2.2 A/A/O 工艺 ..............................................174.2.3 处理工艺方案比较与推荐工艺方案的确定 .....................18 4.3 污泥处理工艺与处置、利用 .....................................24 4.3.1 污泥处理工艺与处置、利用 .................................24 4.4 排水消毒方案比选确定 .........................................25 4.4.1 消毒技术的选择 ...........................................25 4.4.2 紫外线消毒技术的原理 .....................................26 4.4.3 二氧化氯消毒技术的原理 ...................................26 4.4.4 紫外线消毒与二氧化氯消毒的综合比较 .......................27 4.5 方案论证小结 .................................................27 第五章 污水处理厂设计 ............................................ 29 5.1 工程设计基础数据 .............................................29 5.1.1 设计污水量及污泥量 .......................................29 5.1.2 进出水水质及处理效率 .....................................29 5.2 污水处理厂工艺流程 ...........................................29 5.2.1 污水处理流程 .............................................29 5.2.2 污泥处理流程 .............................................30 5.3 污水处理厂平面布置及排放口 ...................................30 5.3.1 平面布置 .................................................30 5.3.2 尾水排放管及污水排放口 ...................................31 5.4 污水处理厂高程布置 ...........................................31 5.5 主要处理构筑物工艺设计 .......................................31 5.5.1 老厂区部分主要污水处理构筑物工艺设计 .....................31 5.5.2 新厂区部分主要处理构筑物工艺设计 .........................34 第六章 结 论..................................................... 38