设计总说明：水是人类生产、生活中不可缺少的组成部分,在各个领域内发挥着重要的作用。但水是不可再生资源,随着人类文明的进步、社会的发展、工农业生产水平的提高,人类对水资源的污染、破坏确日益严重,水危机威胁着地球,水污染的防治已进入人类的日程安排。对污水进行排放前的处理,即是控制污染源,以达到从根本上防止水体污染的目的。地球虽然有70.8％的面积为水所覆盖，但淡水资源却极其有限，人类真正能够利用的是江河湖泊以及地下水中的一部分，仅占地球总水量的0.26%，而且分布不均。 20世纪50年代以后，全球人口急剧增长，工业发展迅速。全球水资源状况迅速恶化，“水危机”日趋严重。一方面，人类对水资源的需求以惊人的速度扩大；另一方面，日益严重的水污染蚕食大量可供消费的水资源。全世界每天约有200吨垃圾倒进河流、湖泊和小溪，每升废水会污染8升淡水；所有流经亚洲城市的河流均被污染；美国40％的水资源流域被加工食品废料、金属、肥料和杀虫剂污染；欧洲55条河流中仅有5条水质差强人意。20世纪，世界人口增加了两倍，而人类用水增加了5倍。世界上许多国家正面临水资源危机：12亿人用水短缺，30亿人缺乏用水卫生设施。20244
近年来，为了遏制水环境受到的严重污染，国家对城市污水处理项目的投入持续增加，相继在大、中城市兴建了多座城市污水处理厂，城市污水处理事业得到了很大发展。目前城市污水处理厂的建设已开始从大、中城市向县级城镇普及，城市污水处理厂的数量将会大幅度增加。
目前处理城镇生活污水常用的方法为活性污泥法。活性污泥法是以活性污泥为主体的污水处理技术。活性污泥主要是由大量繁殖的微生物群体所构成，它易于沉淀与水分离，并能使污水得到净化、澄清。
本次毕业设计的题目为500立方米/天生活污水处理厂的工艺设计。主要任务是工艺流程选择及构筑物设计和计算。其中初步设计要完成设计说明书一份、污水处理厂流程图一张，曝气沉砂池图一张，氧化沟图一张，二沉池图一张，该污水处理厂工程，总规模达到500吨/日。该污水厂的污水处理流程为：从泵房到沉砂池，进入氧化沟，二沉池，最后出水；污泥的流程为：从二沉池排出的剩余污泥首先进入浓缩池，进行污泥浓缩，然后进入污泥脱水车间进一步脱水后，运至垃圾填埋场。设计结果表明：污水处理厂处理后的出水达到《城镇污水处理厂污染物排放标准》（GB18918-2002）中的一级B标准。
关键词： 卡鲁塞尔氧化沟工艺；生活污水处理；脱氮；
 Oxidation ditch sewage treatment process design
The total designed: Water is an integral part of human production, play an important role in various fields. But water is non-renewable resources, with the progress of human civilization, the development of the society and the improvement of industrial and agricultural production, human pollution, destruction of water resources is increasingly serious, water crisis threatens the earth, the water pollution prevention and control has entered human's schedule. Before the sewage discharge processing, namely is to control the pollution sources, in order to fundamentally prevent water pollution. Earth although 70.8% of the area is covered with water, but fresh water resources is extremely limited, the human really able to use is part of the rivers and lakes, and groundwater, accounts for only 0.26% of the earth's total water, and distribution. Increased sharply since the 1950 s, the world's population, industrial development is rapid. Global water situation to deteriorate rapidly, "water crisis" has become increasingly serious. On the one hand, human demand for water resources expanding at an alarming rate; On the other hand, the increasingly serious water pollution, eating into a large number of water resources available for consumption. Every day all over the world, about 200 tons of rubbish into the rivers, lakes and streams, each will waste water pollution 8 litres water; All rivers flowing through the Asian cities are polluted; The 40% of the water resource is processed food waste, metals, fertilizer and pesticide pollution; Article 55 river in Europe only five poor water quality. In the 20th century, the world's population has doubled, while human water increased five times. Many countries in the world is facing a water crisis: 1.2 billion people water, 3 billion people lack water sanitation. 小区生活污水氧化沟处理工艺设计:http://www.751com.cn/huaxue/lunwen_11953.html