In accordance with the established process, the design selects the process parameters of structures (including the grating, aerated grit chamber, anaerobic- anoxic-oxic bioreactor, secondary sedimentation tank, UV disinfection and sludge thickening tank) and calculates the main size, the hydraulic loss, and finished of introduction of design process, process flow diagram, factory layout and main monomer structure map.

After upgrading waste water one times by the pump, the design finished the sewage whole treatment process by gravity flow to avoid repeating sewage upgrade in order to reduce losing power, decrease the cost of wastewater treatment and manage the operation easily.

The design is technically feasible and economically reasonable results. The project cost 20.1253 million yuan, investment, operating costs 8.468million yuan / year. Equivalent to the sewage treatment costs 0.58 yuan / m3.The whole process designed can effectively save the project investments, reduce processing costs, reduce the space with a total investment of less stable, to ensure that emissions from waste-water reach the standard and it is a simple process.

The treated wastewater is expected to achieve the B level of " pollutant discharge standards of urban sewage treatment plant " (GB8978-2002), that is: CODcr ≤ 60 mg / L; BOD5 ≤ 20mg / L; SS ≤ 20mg / L ; NH3-N ≤ 8mg / L; TN ≤20mg/L；TP ≤ 1.5mg / L, reducing emissions to the environment each year for the 4380 tons COD.  So that contaminated water can be greatly improved, to achieve the aim of elimination of pollution, protection of the environment and the purpose of the benefit of human being.

Keywords: wastewater treatment; A2/O Process; biological method; Nitrogen and phosphorus removal

目  录

1绪论 1

1.1 设计背景 1

1.2 设计依据与原则 1

1.2.1 设计依据 1

1.2.2 设计原则 2

1.3 设计规模和目标 2

2污水处理工艺的选择 3

2.1 城市生活污水处理的方法 3

2.1.1 按废水处理的程度来分类 3

2.1.2 按污染物的性质分类 3

2.2 废水生物法处理工艺方案论证 3

2.2.1 传统活性污泥法处理工艺 3

2.2.2 氧化沟法处理工艺 4

2.2.3 A/O法处理工艺 5

2.2.4 A2/O法处理工艺 6

2.3 各工艺间的比较 7

2.4 设计方案的确定 7

2.5 预计处理效果 8

3设计说明 9

3.1 工艺说明 9

3.1.1 粗格栅及进水泵房 9

3.1.2 细格栅及曝气沉砂池 9

3.1.3 A2/O生物反应池 10

3.1.4 二沉池 10

3.1.5 回流及剩余污泥泵房 11

3.1.6 污泥处理处置构筑物 11

3.1.7 紫外线消毒池 11

3.1.8 污泥浓缩池 11

4总体布置 12

4.1 平面布置