摘要：为该地区设计的污水处理构筑物，主要是用于处理该城市生活污水。该城市经济状况较为发达，由于该城市生活污水成分复杂并且水质变化很大，根据给定的设计参数分析，该区的水质可生化性性质较好，所以用生物处理法处理废水是最佳的选择，由于污水中有机物负荷较高，污水相应的处理要求也比较高，例如BOD5的处理效果要达到92%，根据这样的特征，为了确保能达到预期的处理效果，所以需要对污水有一个必要的操作是要进行较好的预处理过程，最终综合选择下来，选定的处理工艺为氧化沟工艺，氧化沟工艺相比于其他工艺来说有一个明显的优势，就是工艺流程简单，操作起来方便和便于管理，不需要初沉池即可有良好的处理效果，甚至污泥消化池也不需要。氧化沟工艺能够运行稳定，在污水有机物处理方面表现良好，据以往经验，氧化沟工艺有良好的治理效果和良好的运行效果。经过氧化沟工艺处理的BOD5指标处理平均水平能达到惊人的95%左右，氧化沟工艺的水力停留时间较长,污泥龄较长,有较大的循环稀释水量，所以纵使较大载荷的水量冲击也能够承受，同时对高浓度的工业废水，氧化沟工艺也有较强的适应能力，由于氧化沟污泥在氧槽内性质稳定，污泥产量少，所以污泥管理起来简单方便,运行费用低和治理成本低廉，基础设施投资也不需要很高。

处理原始的条件及数据：某城市污水处理要求生活污水流量：150000m³/d，进水水质为：BOD5=250mg/L, COD=550mg/L, SS=260mg/L。经过调研论证，处理后达到的水质标准为：BOD5=20mg/L, COD=80mg/L， SS=20mg/L。

本设计中污水BOD5浓度为250 mg/L, COD浓度为550 mg/L，SS浓度为260 mg/L，属于可生化性较好的水质。本设计采用的工艺流程是“从污水入水 → 到粗格栅初步过滤 → 经过集水井及提升泵房提升 → 再到细格栅处理 → 然后曝气沉砂池曝气  → 到三沟式氧化沟循环曝气 → 到二沉池沉淀 → 再到接触消毒池消毒处理 → 最后出水”的工艺。通过以上流程处理，出水水质本设计中所要求的标准。

关键字：污水处理厂工程工艺设计，氧化沟，生活污水，有机物负荷

Engineering of wastewater treatment process design

Abstract：Designed to build sewage treatment plants in the region, mainly used for urban sewage processing. City economy is developed, due to the complexity of composition of sewage and water quality change is very big, according to the design parameters of a given analysis, water quality in the area, can better biochemical nature, know better with biological treatment method and treatment of waste water, sewage, water quality high organic load its corresponding processing requirement is high also, such as the processing effect of BOD5 to achieve 92%, according to such a feature, in order to ensure that can achieve the desired effect, so you need to, to the operation of the sewage is a necessary for a better pretreatment, finally selected treatment process for the oxidation ditch process, compared to other technology, oxidation ditch technology has an obvious advantage, is the technological process is simple, convenient to operate and easy to manage, do not need early pond, good treatment effect, namely sludge digester and even don't need. Oxidation ditch process can run stability, organic matter in wastewater treatment performance is good, has the good governance effect and good operation effect. According to previous studies, treated with oxidation ditch process of BOD5 index average around 95%, oxidation ditch technology of hydraulic retention time is longer, sludge age longer, have bigger circulation of dilution water, a larger impact load of water also can withstand, the industrial wastewater of high concentration, oxidation ditch technology also has the strong ability to adapt, because of the oxidation ditch sewage sludge properties in slot on oxygen stability, less sludge production, so the simple convenient to management and operation cost and low cost, and investment in infrastructure.