摘 要

本次毕业设计的题目为湖南省沅江市西部排水工程设计。主要任务是完成湖南省沅江市西部排水工程设计，包括污水管网工程、雨水管网工程与污水处理厂工程。

收纳水体石矶湖位于设计区域南部，通过石矶湖排入资江分河，常水位高程29.6m，洪水位37.10m。

排水管网采用完全分流制系统，设计5根由北向南的干管，收集各街区汇集的污水，并汇入一根又西向东的主干管排入位于沅江市西部城区东南方向的污水厂进行污水处理，经深度处理后污水排入石矶湖。雨水根据就近排放的原则，将整个市区分为三个部分，设置独立的雨水排出系统，在雨水管线末端设置初雨调蓄池，将初期雨水截留，并将其送到污水处理厂雨水调蓄池中，经粗格栅、细格栅、曝气沉砂池、处理后排入石矶湖，未截留雨水直接排入石矶湖中。

根据河流流向、城区坡度以及全年主导风向，将污水处理厂定址于沅江市西部城区的东南方向，近期污水处理规模为1.1万m3/d，远期污水处理规模为2.2万m3/d。根据处理水特点和受纳水体水质要求，采用一级A处理要求。因为污水处理厂设计流量较小，核心生物处理工艺选择CASS工艺，主要工艺流程为进水→粗格栅→进水泵房→细格栅→旋流沉砂池→CASS池→高密度沉淀池→消毒池→巴氏计量槽→出水。

关键词：湖南省沅江市西部排水工程、分流制排水系统、CASS工艺、初期雨水处理

Abstract

The topic of this graduation project is the design of the western drainage project in Yuanjiang City, Hunan Province. The main task is to complete the design of the western drainage project in Yuanjiang City, Hunan Province, including the sewage pipe network project, rainwater pipe network project and sewage treatment plant project.

Yuanjiang City is located in the northeast of Hunan Province and on the lakeside of Dongting Lake. Yuanjiang City has a high terrain in the west and a low terrain in the east. It is surrounded by lakes and hills in the southwest. The hills fluctuate gently with an altitude of 35-115.7 meters. The north is a plain formed by river and lake sediments. Low, flat and open, with mixed ditches, about 30 meters above sea level. Engineering geology is good. The rivers in the territory include Baisha River and Zijiang River. The lakes include Shangqiong Lake, Xiaqiong Lake, Haojianghu Lake, Liaoye Lake and Shiji Lake.

Yuanjiang city has a subtropical humid monsoon climate. Has the lake district climate characteristic. There is plenty of light and heat and moderate precipitation. The average temperature is 16.9℃. The average temperature in January is 4.3℃, and the average temperature in July is 29.1℃. The annual average rainfall is 1322 mm. Mostly in April to June. Frost-free period 276 days. In summer, the prevailing wind direction is southeasterly, in winter, northerly, and throughout the year, northerly.

Shiji Lake, which houses the water body, is located in the south of the design area and discharges into the Zijiang River by Shiji Lake. The normal water level is 29.6m and the flood level is 37.10m m.

The drainage pipe network adopts a complete diversion system. Five main pipes from north to south are designed to collect the sewage collected in each block, and then they flow into one main pipe from west to east to be discharged into a sewage plant located in the southeast of the western urban area of Yuanjiang City for sewage treatment. After advanced treatment, the sewage is discharged into Shiji Lake. Rainwater is divided into three parts according to the principle of nearby drainage. An independent rainwater drainage system is set up. An initial rainwater storage tank is set up at the end of the rainwater pipeline to intercept the initial rainwater and send it to the rainwater storage tank of the sewage treatment plant. After coarse grid, fine grid, aerated grit chamber and treatment, the rainwater is discharged into Shiji Lake, and the untreated rainwater is directly discharged into Shiji Lake.

According to the river flow direction, urban slope and the prevailing wind direction throughout the year, the sewage treatment plant will be located in the southeast of the western urban area of Yuanjiang City, with a recent sewage treatment scale of 11,000 m3/d and a long-term sewage treatment scale of 22,000 m3/d. According to the characteristics of the treated water and the water quality requirements of the receiving water body, the first-class A treatment requirements are adopted. Because the designed flow rate of sewage treatment plant is small, CASS process is selected as the core biological treatment process, and the main process flow is intake water → coarse grid → intake pump room → fine grid → cyclone grit chamber →CASS tank → advanced treatment lift pump room → high density sedimentation tank → disinfection tank → pasteurization tank → effluent.

According to the original data provided, I completed the design and calculation of the drainage pipeline system and sewage treatment plant in the southern urban area of Dongbao District in this design, drawing 8 drawings (A1, including a Zhang Mo diagram and a pencil diagram), and completing one design specification and one design calculation.

Key words: Drainage project in the southern urban area of yuanjiang City, Hubei Province, Shunt drainage system, CASS process, Initial Rain Water treatment

目录

摘 要 3

Abstract 4

Key words: 5

第一章 绪论 10

1.1研究背景 10

1.2目的和意义 10

1.3.1国外研究现状 10

第二章 设计说明书 12

2.1设计原始资料 12

2.1.1城市概况 12

2.1.2自然条件 12

2.1.3设计任务计进度安排 12

2.1.4设计采用的主要规范和标准 14

2.2排水方案设计 14

2.2.1 排水体制的选择 14

2.2.2 厂址位置选择 15

2.2.3 污水管网设计 15

2.2.4 雨水管网设计 17

2.3污水处理工艺设计 20

2.3.1 污水处理工艺的选择 20

2.3.2 工艺流程的确定 22

2.4污水厂附属构筑物 24

2.4.1面积规划 24

2.4.2水厂定员 24

2.4.3附属构筑物 25

2.5污水处理厂平面布置 26

2.5.1布置原则 26

2.5.2污水厂平面布置 27

2.6污水处理厂高程布置 27

2.6.1布置原则 27

2.6.2污水厂高程布置 28

第三章 设计计算书 28

3.1水量计算 28

3.2污水处理工艺设计计算 30

3.2.1泵前粗格栅 30

3.2.2污水提升泵房的设计计算 33

3.2.3泵后细格栅 34

3.2.4旋流沉砂池 36

3.2.5 CASS工艺设计 37

3.2.6高密度沉淀池 43

3.2.7二氧化氯消毒 49

3.2.8巴氏计量槽 50

3.2.11 配水井 52

3.4初雨处理 53

3.3.1雨水调蓄池 53

3.3.2粗格栅 54

3.3.3细格栅 55

3.3.4曝气沉砂池 56

3.4污泥处理工艺设计计算 57

3.4.1储泥池 57