摘要:本设计是关于D市B区的排水工程设计，其包括两个设计内容：排水系统设计与污水处理厂设计。根据毕业设计的原始资料及设计要求，排水系统需按照完全分流制进行设计，污水处理厂出水则需脱氮除磷，出水水质达到一级A标准，并且污水经处理后30%作为市政杂用水。

　　　排水系统中的雨、污管渠分别进行布置。污水管道采用平行式布置方式，将该排水区域分为三块，并对排水干管进行了设计流量计算与水力计算。雨水管道进行汇水面积的划分后，按照雨水就近排放入河的原则布置雨水管道，对管道进行设计流量计算和水力计算。由于该区域有两条河流贯通城市，故当有排水管道穿过时，管道需采取倒虹管方式过河。

　　　污水管网收集的水量全部送至污水处理厂，一级处理中，污水直接进入间隙为20mm的机械细格栅进行处理，以免对后续处理单元或工艺管线造成损害。格栅后为两座四格平流式沉砂池，用以去除密度较大的无机颗粒，提高污泥有机组分的含率。沉砂池出来后污水进入长宽均为56.3m的调节池进行流量调节。污水生物处理阶段采用的是SBR工艺，该工艺综合了活性污泥法连续推流式曝气池工艺的优点，采用多点进水方式，进水时间1.5h，曝气时间2.6h，沉淀时间1.4h工艺流程简单，运行灵活性强，具有稳定除磷脱氮的效果，且不需设初沉池和二沉池，大大减少了占地面积，反应池体积78746m3。SBR反应池的出水直接进入臭氧消毒阶段，出水达标排放，其中30%出水进入普通快滤池过滤后作为市政回用水。SBR反应池的剩余污泥经污泥提升泵站提升至污泥浓缩池，然后经带式压滤机后进行污泥肥化处理。

　　　在完成污水和污泥构筑物的设计计算后，综合考虑各方面因素对污水处理厂进行平面布置，对连接各构筑物的管渠进行选径、确定流速及水利坡降，然后进行水力损失计算，根据水力损失计算对污水和污泥高程进行了计算和布置。

关键词 污水管网；雨水管网；SBR；深度处理；污泥堆肥

Abstract:This design is about D municipal drainage engineering design B area, the two design content includes: the drainage system design and the design of sewage treatment plant. According to the original data and the design requirements of graduation design, the drainage system should be carried out in accordance with the completely separate system design, sewage treatment plant effluent, denitrification and phosphorus removal, effluent water quality reach the standard level A, and 30% water after being treated as A municipal miscellaneous water.

    Drainage system in the rain, sewage pipe drainage arrangement, respectively. Sewage pipes adopts parallel arrangement, the drainage area can be divided into three pieces, and probes into the main drain design flow calculation and hydraulic calculation. Rainwater catchment area after the division of pipeline, according to the principle of rainwater discharge into the river to the nearest rainwater pipeline, pipeline for the design discharge calculation and hydraulic calculation. Because there are two rivers in the region through the city, so when have drainage pipe through the pipeline needs to take the way across the river inverted siphon pipe.

    Sewage pipe network to collect all sent to the sewage treatment plant, water in the primary treatment of sewage directly into the gap of 20 mm machine fine grille for processing, in order to avoid damage to subsequent processing unit or process line. Grid after two to four flat flow grit chamber, used to remove larger inorganic particle density, increase the rate of sludge organic components. Grit chamber out sewage into the width are 56.3 m after adjusting pool for flow control. Is SBR technology on wastewater biological treatment stage, the process combines continuous push flow aeration tank by activated sludge process, the advantages of using more water, feed time of 1.5 h, aeration time 2.6 h, precipitation time 1.4 h technological process is simple, operation flexibility is strong, has the stable phosphorus removal effect of nitrogen, and don't need to be at the beginning of a pond, and the second pond, greatly reduces the area of reaction tank volume of 78746 m3. SBR reaction pool ozone disinfection water directly into the stage of the effluent discharging standard, 30% of them enter the ordinary fast filtration process as a municipal water back into the water. The sludge SBR reaction pool of surplus sludge pumping station up to the sludge concentration pool, then after the belt filter press sludge fertilizer treatment.

    After finished the design of the sewage and sludge structure calculation, considering the factors of sewage treatment plant layout, various structures of the connection of tube drainage to choose size, determine the flow velocity and hydraulic gradient, and hydraulic loss calculation, according to the hydraulic loss calculation of sewage and sludge elevation calculation and layout.

Keywords  sewage pipe network  Rain water pipe network   SBR   Deep treatment   Sewage sludge composting