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设计总说明：此次毕业设计的题目为污水脱氮处理工艺设计，主要任务是分析生活污水处理技术和处理工艺等，从而确定污水处理厂脱氮工艺流程和处理构筑物的类型与数量，对构筑物及设备的工艺进行设计计算以及对污水厂各个构筑物和各类管渠等进行总体布置，让整个污水脱氮处理工艺流程合理可用，从而得到较高的污水脱氮率。同时绘制相关工艺流程图，设计出水满足相关标准的参数要求并且计算。我所选择的污水处理流程如下：
- 上一篇：取代苯异腈与脂肪胺的加成反应
- 下一篇：环保型镀锌电解液中添加剂性能的比较
通过整个工艺流程可以较好得降低污水中CODcr 、BOD5、SS、NH3-N，从而符合《城镇污水处理厂污染物排放标准》（GB18918-2002）一级B排放标准排放的要求。
此次设计选择的主要工艺为氧化沟工艺，因为它具有以下几个特点：
第一，工艺流程和装置构造都相对简单，易于工艺的运行以及文护管理。
第二，整个工艺运行相对稳定，污水处理效果较好， BOD5的处理效果较高，一般处理水平可达95%左右，同时脱氮效率也比较高，一般处理水平可达80%以上；相对于其他工艺而言，氧化沟工艺水力停留时间长、泥龄长，因此能够更好地承受水质水量的冲击负荷并且对浓度较高的污水具有较强的适应能力。
第三， 能够在同一个沟渠中实现有机物和总氮的去除，从而降低成本；电耗较小，运行费用较低；另外，在污水处理规模较小的情况下，氧化沟工艺的建设投资成本比传统活性污泥法更节省。
由于本设计的污水处理厂的总规模为8万吨／天，因此我选择卡罗塞尔氧化沟工艺。卡鲁塞尔氧化沟工艺采用垂直安装的低俗表面曝气器，每组沟渠内安装一个，均安装在统一端，从而形成了曝气器上游以及外环的缺氧区和靠近曝气器下游的富氧区，不但有利于生物凝聚，而且有利于活性污泥的沉淀。BOD5去除率可高达95%～99%，脱氮率可达90%。卡鲁塞尔氧化沟将厌氧、缺氧、好氧过程集中在一个池内完成，各部分用隔墙分开自成体系，但彼此又有联系，达到充分利用污水在氧化沟内循环流动的目的，把好氧区和缺氧区有机结合起来，实现无动力回流，节省了能量的消耗。
关键词：生活污水；脱氮；氧化沟Nitrogen removal wastewater treatment process design
General description of the design： The graduation design topic for nitrogen removal from wastewater treatment process design, the main task is to analyze the sewage treatment technology and process, so as to determine the type and amount of nitrogen removal process and the construction of sewage treatment plant, the design process of structures and equipment as well as the sewage plant construction and various types of pipe canal, overall layout, let the sewage treatment process reasonably available nitrogen, so as to get a higher sewage denitrification rate. At the same time to draw the process flow diagram, design parameters of effluent meet the related standards and calculation. The process of sewage treatment I selected as follows:
Better reduce the wastewater CODcr, BOD5, SS, NH3-N through the entire process, to meet the "urban sewage treatment plant pollutant discharge standard" (GB18918-2002) level B emission standard emission requirements.
The main process of my choice for oxidation ditch process, because it has the following characteristics:
First, the process and the device structure is relatively simple, easy process operation and maintenance management. Second, the whole process of relatively stable operation, good sewage treatment effect, high treatment effect of BOD5, the general processing level of up to about 95%, while the nitrogen removal efficiency is high, the above general level of up to 80%; compared with other processes, the oxidation ditch process long hydraulic retention time, sludge age long, so the impact load can be better under water and the high concentration wastewater with a strong ability to adapt. Third , to achieve the removal of organic matter and total nitrogen in the same ditch, thereby reducing the cost; the power consumption is small, low operation cost; in addition, the sewage treatment of smaller, oxidation ditch process construction investment more cost savings than traditional activated sludge process.