摘要：
水资源是经济可持续发展的基本保证，污水的任意排放或处理不彻底的排放，都会给水资源环境带来严重的污染问题。盐山县排水系统很不完善，大量的城市污水、工业废水无法及时处理，使水体受到严重的污染，当地自然环境正受到严重的威胁，并且已经影响到经济的发展和人民正常生活。建设污水处理厂已成为迫在眉睫的大事。
该污水处理厂原污水中各项指标为：BOD浓度为200mg/L，COD浓度为400mg/L，SS浓度为200mg/L，NH3–N浓度为35mg/L ，TN浓度为50mg/L，P浓度为1mg/L经处理后水质要求达到如下排放标准：BOD≤20mg/L，COD≤60mg/L，SS≤20mg/L，NH3–N≤15mg/L，TN≤20mg/L，P≤1mg/L。本设计对污水处理厂一级、 以及以 A/O 法为主体的二级处理工艺流程的选择给予说明，对具体污水及污泥构筑物结构进行了详细计算。
A/O工艺是缺氧-好氧生物脱氮工艺的简称，一般适用于要求脱氮的大中型城市污水厂。A/O工艺具有流程简单、投资低、沉淀效果好等优点。
污水厂设计方案为：
污水处理流程：粗格栅 → 污水提升泵房 → 细格栅 → 曝沉砂池 →A/O反应池→ 消毒接触池 → 计量槽 → 排放；
污泥处理流程：剩余污泥 → 浓缩池 → 贮泥池→ 污泥脱水机房 → 泥饼外运。
污水处理厂处理规模： 15万m3/d。
关键词: 城市污水处理厂 A/O工艺 污水 污泥
The initial design of the wastewater
treatment plant of YanSan
Abstract：Water resources ensure the sustaining development of economy. Sewage discharged at random or half treated can expose serious pollution to the water resources
．The waster water discharge system of Yan San is not good enough
．Great amount of domestic and industrial waster water is discharged without proper treatment
，which pollutes the river badly. The damaged environment is endangering the development of economic and people’s life. The building of water drainage system is a must
．
Various indexs in the raw wastewater of the wastewater treatment are：the concentration of BOD is 300mg/L， the concentration of COD is 700mg/L， the concentration of SS is 100mg/L，the concentration of NH3–N is 35mg/L，the concentration of TN is 50mg/L，the concentration of P is 1mg/L，and after treatment the water quality must reach the discharge standard，i.e. BOD≤20mg/L，COD≤60mg/L， SS≤20mg/L，NH3–N≤15mg/L，TN≤20mg/L，P≤1mg/L．
The design reasons the choice of primary and secondary treatment process— A/O process，the calculation of constructing process．
A/O is short for Anoxic-Oxic，which is one of many biological nitrogen processes．It is adaptative in some large and medium-sized sewage treatment plants．I found that the A/O has the following advantages：simple process，low investment and good sedimentation，so I choose A/O for the treatment of wastewater．
The process of the wastewater plant that the wasterwater treatment plant adopted is as following:
Wastewater treatment process: middle bar screen → pump station → fin bar screen → aeration desilting tank → A/O process →secondary sedimentation tank→ disinfection of contact pool→measurement groove → drain;
Sludge handling and disposal process: excess activated sludge → concentrated pool → sludge tank → machine dewatering → disposal of sludge cake.
The disposal ability of the wastewater treatment plant is 15×104m3/d.
Key words: sewage treatment plant; Anoxic-Oxic process; sewage; sludge
