文档介绍：目录
摘要 1
Abstract 2
1 总论 3
3
3
自然地理 3
气象水文 3
4
城市污水现状排放量 4
城igning requirement and thought of looking for novelty: the content of nitrogen is on the high side in this project water quality,so it should be dealed with,while get rid of BOD5 and SS .We adopt and use a kind of craft,which is a comparatively extensive denitrification crafts at present, namely, 3 ditch type oxidizing craft. The advantage of this comprehensive craft is extensive adaptability , totally suitable for reality originally designed's purpose. Its main structures includ gate well , grid , sewage pumping house , earate and sinking sand pool , oxidizing ditch , the second sinking pool, contacting pool , concentration tank , mud to dehydrate in the computer lab etc.
This design have adopted the denitrification craft and equipment of good performance, and the procedure is simple, management is convenient, do not need to add the first sinking pool , digestive system .reducing building and operating expenses, realizing automation totally at the same time, easy to manage, making the treated water reach sewage discharge standard , accomplish the rational utilization of water resource.
[Keywords]: Types of three ditch oxidizing ditch , Grid, Concentration pool, Pumping house ,New craft, The second sinking pool
1 总论

某城市是全国40个严重缺水城市之一，工业及生活用水以地下水为水源。随着工业化及城市化的迅速发展，该市的水环境污染问题日趋严重。流经市区的A河、B河均受到极严重的污染。由实测资料可以看出，/L(2000年)，分别超地面水IV类标准29倍和28倍；/L，。流经市区的C河则是一条排污干沟，其污染物浓度更高，河水常年呈棕黑色、有臭味，完全丧失了使用功能。整个城市被黑、臭水所包围，城市环境质量很差。地面水体的严重污染也污染了市区浅层地下水，从而严重危及市区30万人的生活用水和工业用水。
该市地面水污染问题严重的限制了工业的发展和城市化的进程。按地面水使用目标和保护目标，A河定为IV类地面水域。按此标准该市不但不能发展，还要“关停并转”一大批工厂。为实现本市及区域河流水质变清的目标，该市决定建设城市污水处理厂。

自然地理
① 地理位置
该市位于京广线中段，市区地理坐标为东经112°、北纬33°。辖区东西长约124Km、南北宽51Km，呈东西向带状。， Km2。
② 地形地貌
该市属黄淮平面西部，地势为西北高、东南低，自西北向东南缓慢