Design criteria :

The "urban sewage treatment plant pollutant discharge standard" (GB 189182002)

Design principles

Design requirements based on reliable data, comprehensive analysis of the factors affecting the quality and quantity, the design parameters are reasonable; Design requirements of advanced technology and practical. Design requirements to deal with stable operation and reasonable cost, require active and prudent to adopt the new technology, which is proved reliable by practice; The design requirements as far as possible, combined with the water plant in the geographical environment, the requirements of a comprehensive consideration of various impact requirements, to coordinate the relationship between altitude layout, Plane layout and pipeline layout; Design requirements to avoid or reduce the secondary pollution to the environment, requires the proper disposal of gate slag generated in the process, heavy sand and sludge and odor. The design requirements of the operation management should be convenient, reliable and economical and practical as the standard, taking into account the safety factors and long-term planning.

Main technical data

This design uses the AAO technology, which biological treatment in the same biological pool. A single biological pool is pided into five corridors, in accordance with the anaerobic, anoxic and aerobic sequence. This method is characterized by the following points: anaerobic, anoxic and aerobic stage of organic coordination; The process is simple, and the hydraulic retention time is less than that of other processes; Filamentous bacteria will not be a large number of breeding, will not be the occurrence of sludge expansion. The technology is mature, the treatment effect is stable, and the management and maintenance is simple, the initial investment cost is small.

The description includes the comparison of the process plan, the determination of the technological process, the design calculation of the main structures, the general layout of the sewage treatment plant, the height layout and the economic analysis of the project.

Using the process of sewage treatment: grille + sewage lifting pumping station + fine grille and sink sand pool +AAO biological reaction tank + secondary sedimentation tank + pool disinfection process. Sludge treatment processes include: sludge thickening pool + sludge pond + sludge dewatering equipment.

The grid consists of a set of parallel metal bars, frames and related devices. The grille is tilted in the sewage water inlet channel. The grille is located in the front of the sewage treatment plant. It is used to remove the heavy floating or suspended solids in the waste water to prevent them from blocking or damaging the related equipment in the subsequent processing structures.

Sand sedimentation basin with flat flow type grit chamber. It is the method of gravity sedimentation to make relatively large density of inorganic particles sink to prevents the device from being blocked or damaged in subsequent processing structures.

Through the anaerobic, anoxic and aerobic three different environments of microbial flora, it achieve the purpose of removing nitrogen and scale. AAO process uses two groups. The two sedimentation tanks select the flow type sedimentation tank, using the center of the water. It has the advantages of good running effect and convenient management. Specific treatment results are COD=99mg L-, BOD=29.5mg L-, SS=29.5mg L-, NH3-N=24.5mg L-,TN≤19.5mg L-,TP≤1.95mg L-.

The sludge treatment structures consist of three parts, the sludge concentration tank, the sludge storage tank and the sludge dewatering system. The sludge thickening pool is vertical. The main function of the reservoir is to regulate the amount of sludge, adding reagent and heating in advance. The sludge dewatering system reduced the water content from 95% to 60%~80%.

After treatment of waste water discharged into the vicinity of the river, Effluent index  is required to achieve the "urban sewage treatment plant pollutant discharge standard indicators of water requirements" (GB 189182002) second standards: COD≤100mg L-, BOD≤30mg L-, SS≤30mg L-, NH3-N≤25mg L-,TN≤20mg L-,TP≤2.0mg L-. At the same time, the design of the structure meets the requirement of design water quantity. The layout of the entire sewage treatment plant is in accordance with the relevant design specifications and met the requirements of the vertical design requirements of the sewage and the layout of the comprehensive consideration of the layout requirements. 日处理50000立方米某小城镇污水处理厂的设计+CAD图纸(2):http://www.751com.cn/huaxue/lunwen_57564.html