Through the discussion of the characteristics of common wastewater treatment processes, the following plan was developed: Improved Carrousel oxidation ditch process. In this design, two coarse and fine grids are used to filter the raw sewage, and two primary sedimentation tanks are used for sedimentation. The lifting of the water head through such facilities as the pumping station will allow the original sewage to enter the subsequent structures smoothly. The improved Carrousel oxidation ditch process is used to set the anoxic zone and anaerobic zone, which has a higher efficiency of nitrogen and phosphorus removal. Liquid chlorine disinfection as a supplement. The main influencing factor of nitrogen removal in this process is the concentration of dissolved oxygen in the oxidation ditch.In order to maintain a good treatment efficiency, a new type of high-efficiency, high-power inverted umbrella surface aerator is selected for the aeration equipment.

In the process flow, two grids of thickness are set, and the influent water passes through the grid and enters the primary sedimentation tank for sedimentation. After the SS is reduced, the primary sedimentation tank effluent enters the oxidation ditch for biochemical reactions. After removing most of the BOD and COD, it enters the secondary sedimentation tank for re-precipitation. This effluent enters the contact disinfection tank for final disinfection and discharges after reaching the standard.

The water plant has a total area of 67,500 square meters and a green area of 12,500 square meters. The main structures include: grids, primary sedimentation tanks, oxidation ditch, secondary sedimentation tanks, contact disinfection tanks, etc.

After the above treatment, the BOD in the influent water can be removed by 96%, the COD can be removed by 91%, the total suspended matter can be removed by more than 90%, the removal rate of total nitrogen and ammonia nitrogen can reach 90%,the removal rate of total phosphorus can reach 95%,and the treatment effect is good.

The total investment in the construction of the water plant is 23.875 million yuan, and the annual operating cost is 5.7517 million yuan, equivalent to 0.39 yuan per one cubic meter of wastewater treatment, which has a good value for money.

KeyWords：Domestic sewage; Carrousel oxidation ditch; Liquid chlorine disinfection tank 

目 录

1 绪论 1

1.1 背景介绍 1

1.2 反应原理 2

1.3氧化沟工艺的发展 3

2 设计内容 5

2.1 设计原则 5

2.2 主要构筑物 5

2.3 主要内容 5

2.4 设计主要数据 5

2.5 设计任务(图纸) 6

3 设计方案 7

3.1 方案对比 7

3.2 方案选择 10

4 设计计算书 11

4.1设计主要数据 11

4.3初沉池 14

4.4卡鲁塞尔氧化沟 15

4.5二沉池 19

4.6接触消毒池 21

4.7污泥浓缩系统 23

4.8水路高程 24

5 计算整理及设备清单 27

5.1 计算数据整理 27

5.2 设备清单