混凝深度处理城市污水厂初步设计.doc

毕 业 设 计 相 关 材 料 题 目: 院 (系)： 化工与环境工程学院 专 业： 工程 学 生： 班 级： 09-1 毕 业 设 计 相 关 材 料 清 单 序 号 材 料 名 称 份 数 1 毕业设计选题表 1 2 毕业设计开题报告 1 3 毕业设计外文资料翻译 1 4 毕业设计小组答辩记录 1 5 毕业设计成绩考核表 1 摘 要 当今，随着经济的快速发展，人民生活水平的不断提高，环境污染日趋严重，加大城市生活污水治理力度势在必行，并且城市用水日益紧缩，需要对出水进行回用。 现拟建一座城市生活污水处理厂，处理规模为200000m3/d。进水水质为CODCr ：250mg/L，BOD5 ：150mg/L，SS：200mg/L，pH=7.0~8.5,出水水质为CODCr ≤50mg/L，BOD5≤10mg/L，SS≤10mg/L，pH=6.5~9。根据进出水水质，本设计拟采用完全混合液态的生物工艺和深度混凝法工艺，经比选，确定在生物处理阶段采用周期循环曝气活性污泥（CASS）工艺。CASS工艺污水呈完全混合液态，对进水水质、水量、PH和有毒有害物质起到较好的缓冲作用，具有较强的耐冲击负荷能力，同时对丝状菌的生长起到抑制作用，可有效防止污泥膨胀。此工艺具有投资省，处理效果好，运行管理方便等优点，适用于大中型污水处理厂使用。本设计包含污水处理工艺流程的确定，工艺流程中各单元的计算，图纸的绘制等。本工程的实施将显著改善受纳水体水质，同时间接产生经济效益，促进经济可持续发展。 关键词 ：污水处理厂；CASS工艺；深度混凝 Abstract Nowadays, with the rapid development of economy, people’s living standards are rising, environmental pollution is worsening, and increasing the intensity of urban sewage treatment is imperative. What’s more, city water is decreasing and it is necessary to recycle water. Now it is proposed that a plant of city sewage treatment is built and its treating scale is 200000m3 / d. The ram water quality is CODCr, BOD5, SS, and pH keep at 250mg / L,150mg / L,200mg / L, and 7.0 ~ 8.5, respectively.The treated water quality is CODCr, BOD5, SS, and pH keep at 100mg / L, 30mg / L, 30mg / L and 6 ~ 9, respectively. According to the treated water quality, the design plans to use the completely mixed biotechnology and depth coagulation process. By comparison, it determines to use cyclic activated sludge system (CASS) process at the stage of biological treatment . Sawage of CASS process is completely mixed, which has a good buffer effect on water quality, water quantity, PH, toxic and hazardous substances. With a strong resistance to shock loading capacity, meanwhile it has an inhibitory effect on the growth of filamentous bacteria, Which can effectively prevent sludge bulking . This process has the advantage of less investment, good effect, easy operation and m