Study On Design Of The Cyclic Oxidation Pond Process For Rural Domestic Wastewater Treatment

At present, The rapid development of the village and the construction ofinfrastructure is an important way to promote socialist new rural construction. Andsewage treatment obviously is an important part of the construction of infrastructure.Domestic sewage is a major part of village drainage, which has the characteristics ofsmall quantity, emissions dispersion and irregular, great variation water quantity andquality etc.Especially the problem of cut-off, high concentration and large flow in therainy season. But in village areas, development of efficient technology andapplication concerned about wastewater treatment process are still lagging behind. Asa result, these wastewater flow into the water bodies directly, causing seriousenvironmental pollution. Therefore, it has a significant practical importance indeveloping a new wastewater treatment process, which is simple, compact, efficient,stable and economic to maintain the quality of treated wastewater stable.This topic considering the characteristics of village sewage, and the cyclicoxidation pond process was designed and researched to treat rural domesticwastewater. The oxidation pond process is a sewage treatment pond which is based onthe after artificial appropriate modification of land and set the cofferdam andimpermeable layer. It is mainly rely on the function of natural biological purificationto treat wastewater. The wastewater flows slowly and stay a long time in the pond.The wastewater is purified, with the organic matter in the wastewater being degradedby the microbial and aquatic plants. The cyclic oxidation pond is fully considering thecharacteristics of rural domestic waste which is include seasonal, imperfection ofcollection, and the scouring of the rain etc. And make traditional oxidation pond toachieve a better quality. Since this process considering the sewage circulating in thesystem, therefore also has the characteristics of oxidation ditch. This topic fromSewage treatment–oxidation pond Project of Qiji Town, Shandong Province. Thisproject combined with landscape design and will become the hydrophilic environment.The oxidation pond and fishpond in combination with each other and water backflowafter the fishpond. The whole process forms the three-dimensional environment system and ecosystem.This design with rural domestic sewage as the treatment object and to design thesewage treatment–oxidation pond. Qiji Town has an expansively pond, which iscompletely used as the resources of the sewage treatment. This design is adjustmeasures to local conditions and main design results are as follows:（1） The cyclic oxidation pond process covers an area of15250m², the averagepool depth of2.5m, effective volume is22650m³. The volume of the facultativeaeration pond （the main structure） is5300m³, and the effective pool depth is3m. Thesystem considering the forward design, and can be used more than20years if thesystem running normally.（2） The size of collecting well is L×B×H＝2m×1.2m×1.8m. The size of simpleregulation sedimentation tank is L×B×H=12m×10m×3.3m. The facultative aeration pondis existing pond which is changed shape and revetted. And in that setting the aerators.The NO.1to NO.4fishpod both are existing pons which are changed shape andrevetted. And around them planting green belts.（3） Between the NO.4fishpond and the facultative aeration pond sets returnpiping. Water circulating and the backflow dilution ratio is100%.It’s also has thecharacteristics of oxidation ditch. And it has ability of nitrogen and phosphorus on thebasis of sewage reaching the effluent standard.（4） This design with Qiji Town domestic sewage as the treatment object. Thecapacity of sewage treatment300m³/d. System for the removal rate of COD and BOD₅canreach more than90%. The removal rate of NH₃-N can reach more than83%.The design of this system break through the contradiction between the economyand technology, which is exist in construction process of domestic sewage treatmentfacilities. Make full use of the rural rich land resources and reduce the infrastructureand operating costs. It also has the characteristics of simple, efficient and stable at thesame time, and can provide the reference for the actual production and operation ofthe process in other similar areas.