某居民小区生活污水处理系统设计
设计总说明：
我国水资源人均占有量仅为世界人均的1／4，水资源严重短缺。我国经济正处于快速增长期，工业用水大幅度增长，水资源供需矛盾将更加突出，水资源不足已成为制约国民经济和社会发展的重要因素。随着城镇经济快速发展，人口迅速增加，城镇生活污水排放量逐年增多，而大多数城镇污水处理设施不够完善，生活污水未经处理直接排放，严重污染了环境。国家对城镇生活污水处理问题高度重视，明确要求到2010年全国设市城市和建制镇污水平均处理率不低于50%。当前，各地都在加快城市污水处理厂的建设，在此其中，小区污水处理的建设占据了很重要的地位。因此建设小区污水处理厂是一个污水处理的一个重要趋势。
我的毕业设计是关于日处理1万吨的某生活小区污水处理厂的设计。该城市居民生活小区位于市郊，污水排放量为10000吨/日，主要来源于小区居民的日常生活排放的卫生间粪便冲洗水、淋浴水、厨房废水以及日常清洗废水。
这个设计采用以下标准，(1)该厂的进出水水质水量资料；(2)《中华人民共和国污水综合排放标准》；(3)《给水排水快速设计手册》。我综合考虑了该小区的污水的特点，结合个方面因素，设计一个工艺流程合理，布局合适的污水处理厂。
我根据小区废水的特点进行了综合分析，采用了传统活性污泥法，其工艺流程是：污水→格栅→初次沉淀池→曝气池→二沉池→出水。活性污泥法是处理城市生活污水最广泛使用的方法,它能从污水中去除溶解的和胶体的可生物降解的有机物以及能被活性污泥吸附的悬浮固体和其它一些物质.它既适用于大流量的污水处理,也适用于小流量的污水处理.运行方式灵活,日常运行费用较低,但管理要求较高.活性污泥法本质上与天然水体的自净过程相似,二者都为好氧生物过程,只是它的净化强度大,因而活性污泥法是天然水体自净作用的人工化和强化. 活性污泥法由曝气池,沉淀池,污泥回流系统和剩余污泥排除系统所组成,各级处理效果与总处理效果比较好,出水水质达标.
其工艺原理是：a． 曝气池为推流式，废水与回流污泥从同一端进入，有机物与污泥充分接触，且沿操作方向下降。b． 污泥经理了以对数期→平衡期，甚至到衰老期，完成了吸附和代谢的过程。主要优点为：a.处理效果好：BOD5的去除率可达90-95%；b.对废水的处理程度比较灵活，可根据要求进行调节。传统活性污泥法的设计参数：
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BOD5—SS负荷(kgBOD5/kgMLSS.d) 0.2～0.4 ；容积负荷(kgBOD5/m3.d) 0.3～0.6 污泥龄(d) 5～15；MLSS(mg/l) 1500～3000； MLVSS(mg/l) 1200～2400 ；回流比(%) 25～50；曝气时间HRT(h) 4～8；BOD5去除率(%) 85～95。
关键词：生活污水 活性污泥 悬浮填料
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Resident plot sanitary sewage processing system design
General Design Introduction:
Per capita water in our is just1/4 of world, the water resources is hard up.The speed of growth of our economy is fast, and water used for industry grows significantly, the short of water become factors of restricting country economy and society development. with the development of economy, population increases quickly, dirty water also increase year by year. But facilities of dirty water is not enough perfect, dirty water is exhausted without disposal, so it pollute environment seriously. The nation think much of processing problem, stipulate the processing rate lower than 50% till 2010.At present, constructing the small area dirty water processing factory is an important trend .
My graduation project is about the processing factory design of certain residence zone. The residence zone of city locate in suburb, exhausting dirty water 10000 tons per day, which is mainly coming from daily life using water, such as using for flushing\\ kitchen
\\cleaning\\shower. This design uses the following standard 1.The data of water in and out of factory.2.National comprehensive exhaustion standard（GB8978-1996）3.The design handbook of exhausting and draining water. Considering characteristics of the dirty water of the residence zone, we design this processing factory whose all facets our synthesizing to craft is reasonable and layout is suitable
I acted according to the plot waste water the characteristic to carry on the generalized analysis, has used the traditional active sludge law，Its technical process is: waste water→bar screen→horizontal flow settling tank→aeration tank→upward flow settling tank→water leakage .The active sludge law was processes the city life sewage most widespread use the method, it could remove from the sewage dissolves and the colloid may the biodegradation organic matter as well as can by the active sludge adsorption suspended solid and other materials. It is already suitable for the great current capacity sewage treatment, is also suitable for the small current capacity sewage treatment. The movement way is flexible, the daily operating cost is low, but the management request is high. The active sludge law essentially and the natural water body's automatic depuration process is similar, the two for the good
oxygen biology process, are only its purification intensity are big, thus the active sludge law is natural water body automatic depuration function artificializing and the strengthening. The active sludge law by the aeration tank, the sedimentation pond, the sludge recalculating system and the excess sludge elimination system is composed, all levels of processing effect with always processes the effect to be quite good, water leakage water quality standards.
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Its craft principle is: a. The aeration tank is the drift type, the waste water and the returned sludge enters from the identical end, the organic matter and the sludge contact fully, and drops along the operation direction. b. Sludge manager by logarithmic phase -> balanced time, even arrives at the senescence phase, has completed the adsorption and metabolism process. The principal advantage is: a. the processing effect is good: The BOD5 elimination rate may reach 90-95%; b. the degree of processing is quite nimble to the waste water, may act according to requests to carry on the adjustment.
Traditional active sludge method design variable: BOD5-SS load (kgBOD5/kgMLSS.d) 0.2~0.4; Volume load (kgBOD5/m3.d) 0.3~0.6 sludge age (d) 5~15; MLSS(mg/l) 1500~3000; MLVSS(mg/l) 1200~2400; Reflux ratio (%) 25~50; Aeration time HRT(h) 4~8; BOD5 elimination rate (%) 85~95.
Key words: wastewater；activated sludge；fill material
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1.文献综述
1.1选题背景
我国水资源人均占有量仅为世界人均的1／4，水资源严重短缺。我国经济正处于快速增长期，工业用水大幅度增长，水资源供需矛盾将更加突出，水资源不足已成为制约国民经济和社会发展的重要因素。随着城镇经济快速发展，人口迅速增加，城镇生活污水排放量逐年增多，而大多数城镇污水处理设施不够完善，生活污水未经处理直接排放，严重污染了环境。国家对城镇生活污水处理问题高度重视，明确要求到2010年全国设市城市和建制镇污水平均处理率不低于50%。当前，各地都在加快城市污水处理厂的建设，在此其中，小区污水处理的建设占据了很重要的地位。因此建设小区污水处理厂是一个污水处理的一个重要趋势。
1.2 小区污水处理技术概述
目前,较为常用的处理工艺有以下几种
(1)污水→调节池→初次沉淀池→生物接触氧化池→二沉池→出水,生物接触氧化是应用最广泛的方法,主要优点是停留时间短、易挂膜,尤其适合设备化,埋地建设倍受环保公司及用户青睐, 但由于维修管理及设备防腐等方面的问题, 近年来应用受到限制。但如果建成地下钢筋混凝土形式,设置人员通道以便维修,此种地下建设方式在小区水处理中具有较大市场,但这种方式一般处理规模较小,每天排放污水量小于几百吨的小区较为理想。对上千吨的小区污水处理,推荐采用地面建设方式,生物处理部分可采用接触氧化, ,曝气方式建议采用低噪音的风机或水下曝气机[1]。
(2)污水→调节池→好氧生物处理→混凝沉淀→过滤→出水,对处理程度要求不高,且水量较小时,可采用此工艺,具有占地面积小,异味小,管理简单等优点。另外,在好氧生物处理之前加上酸化水解,有利于降低能耗, 提高系统的总去除率。生活小区通常有较大的绿地面积,如果把污水处理后回用于浇灌绿地、道路、冲洗汽车, 应在上述处理出水后加上消毒或其它补充措施[2]。
（3）序批式活性污泥法(SBR)，SBR是序批式活性污泥法的简称,它是从加入及排放反应器发展而来的,SBR 的核心是SBR反应池, 该池集均化、初沉、生物降解、二沉等功能于一体。所谓序列包括两层含义:一是不同SBR 池的运转是按顺序进行,由于污水大都是连续或半连续排放,SBR为2个池或多个池交替运行,因此,从总体上污水连续按顺序依次进入每个反应器,它们相互协调作为一个有机的整体完成污水净化功能[3]。但对每
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