设计总说明：本课题是生活污水氧化沟处理工艺设计，针对我国生活污水处理现状的研究，选择恰当的工艺流程，设置种类与实际需求相符合的处理构筑物，对其数量进行合理安排，通过设计计算、可行性研究来完善该污水处理厂的构筑物平面布置、管路型号与铺设情况等，要求对污水厂处理流程详细明了，符合实际生产要求，可以得到较高的污水脱氮率。现采用氧化沟工艺，对任务书中所给定的生活污水进行处理工艺设计。

根据生活污水的特征水质指标数据，来查阅相关出水的排放标准和出水数据，进行生活污水氧化沟处理工艺的设计和相关构筑物的计算，每天处理生活污水水量40000吨。则设计平均水量为Q=40000m³/d ，即设计最大水量Qmax=52000 m³/d。方案对比了三个氧化沟：Orbal氧化沟、立体循环氧化沟、改良型Carrousel氧化沟。

通过对常见废水处理工艺特点的讨论，拟定以下方案：改良型Carrousel氧化沟工艺。本设计拟采用两道粗细格栅对原污水进行过滤，两座初沉池进行沉淀，通过提升泵站等设施提升水头使原污水顺利进入后续构筑物。采用改良卡鲁塞尔氧化沟工艺，设置缺氧区和厌氧区，具有更高的脱氮除磷效率。液氯消毒作为补充手段。该工艺脱氮的主要影响因素是氧化沟中的溶解氧浓度，为保持较好的处理效率，曝气设备选用新型高效大功率倒伞表面曝气机。

工艺流程中设置了粗细两道格栅，进水经过格栅过滤后进入初沉池，进行沉淀处理。SS降低后的初沉池出水进入氧化沟进行生化反应，去除大部分BOD、COD后进入二沉池再次沉淀。这样的出水进入接触消毒池，进行最后的消毒处理，达标之后排放。

该水厂总占地面积共67500平方米，绿化面积12500平方米。主要构筑物包括：格栅、初沉池、氧化沟、二沉池、接触消毒池等。

经过上述处理，进水中的BOD可以去除96%，COD可去除91%，总悬浮物可去除90%以上，总氮和氨氮去除率可达90%，总磷去除率可达95%，处理效果良好。

该水厂建设总投资为2387.5万元，每年运行费用575.116万元，折合每处理1立方米污水费用0.39元，具有好的性价比。

关键词：生活污水；卡鲁塞尔氧化沟；液氯消毒池

Domestic sewage treatment process

design of oxidation ditch

General description of the design: This project is a wastewater treatment oxidation ditch treatment process design. According to the research on the current status of domestic sewage treatment in China, select the appropriate process flow, set the type of treatment structure that meets the actual demand, and arrange the quantity in a reasonable way. Calculations and feasibility studies have been carried out to improve the layout of the structures of the WWTPs, the piping types and laying conditions, etc. It is required that the treatment process of the WWTPs be detailed and in line with the actual production requirements, and a higher rate of denitrification of the sewage can be obtained.  Oxidation ditch technology is now used to process treatment processes for the domestic sewage specified in the mission book.

According to the characteristic water quality index data of domestic sewage, the relevant effluent discharge standards and effluent data are consulted, and the design of the domestic wastewater oxidation ditch treatment process and the calculation of related structures are performed. Daily domestic sewage water volume is 40,000 tons. The designed average water quantity is Q=40000m3/d, which means the designed maximum water quantity Qmax=52000 m3/d. The program compares three oxidation ditches: the Orbal oxidation ditch, the three-dimensional cyclic oxidation ditch, and the modified Carrousel oxidation ditch.