Sewage through the grid to remove large suspended solids in the first, the sewage pump room upgrade a certain height, and then through the fine screen to remove coarse screen not to remove suspended solids, and then into the grit chamber to remove sewage medium density larger inorganic particle pollution (such as mud, sand, coal cinder, etc.), and then enter the CAST reaction pool, under the coordinating role of different microorganisms of conventional organic matter is removed for denitrification and phosphorus removal at the same time, after biodegradation of the wastewater by contact disinfection pool disinfection, water reached the urban sewage treatment plant pollutant discharge standards GB8978-1996 "standard of level 1 B, can discharge. The residual activated sludge through enrichment of CAST reaction pool outbound processing after dehydration.

KEY WORDS:  urban sewage, CAST process, design

目  录

绪  论 1

1 设计依据及设计任务 2

1.1 设计题目 2

1.2 设计任务 2

1.3 设计原始资料 2

2 污水处理量设计 3

2.1 平均日污水处理量与最大日污水处理量计算 3

3 污水处理厂工艺流程的确定 4

3.1 污水处理厂的规模 4

3.2 设计水质分析 4

3.2.1 进出水水质 4

3.2.2 污水处理程度计算 4

3.2.3 进水水质分析 5

3.3 污水处理厂工艺比选 6

3.3.1 二级处理主体工艺选择 6

3.3.2 二级处理优选工艺比较 8

3.3.3 污水深度处理流程选择 8

3.3.4 污泥处理工艺流程选择 9

3.3.5 污水处理工艺流程图 9

3.4 污水处理构筑物的选择 10

3.4.1 格栅 10

3.4.2 沉砂池 10

3.4.3 CAST反应池 10

3.4.4 消毒工艺 12

3.4.5 计量设备 12

4 一级处理构筑物 13

4.1 格栅的设计计算 13

4.1.1 中格栅的计算