The Feasibility Analysis Of The Sewage Treatment Project And The Research On Drainage System Optimization Of Baishui

With the fast development of Baishui in recent years, the city’s drainage networkand the sewerage treatment system cannot fit its developing speed.At present,thebuilt-up area of Baishui covers5km2, resident population is550thousand.The city’sdrainage network for an equivalent population is350thousand.The status quo ofdrainage in Baishui is rainwater and sewage system. The drainage pipes are made ofreinforced concrete, their diameters differ from400to1000mm, the total length is29.94km.There is a sewage plant has been built in the city, called Chengnan sewagetreatment plant. Its treatment scale is10000m3/d. The treatment process is SBR. BaishuiRiver is the receiving water when the processing is done.According to the status quo of drainage in Baishui, there is a series of problems ofits drainage system.For example, the design standard of drainage pipeline in early daysis low. The diameter is small, which make the pipe under full pipe flow state. Thesewage treatment facilities are imperfect, the collection efficiency is low, the need onenlarging the servive area of city’s drainage system is urgent. Also, the aged drainagepipeline restrict the city’s economic development, which can be the main reason thataffects the city’s development.To solve those problems, we took a research on the city’s aged drainage system andraised a optimization plan of the drainage system. Quicken the rain sewage diversion onthe main roads of the city and deliver the sewage to the sewage treatment plant. Withthe development of Baishui, we should complete the construction of the sewage mainline and branch line inside the city step by step until the formation of a completedsewage collection and treatment system. Through our research, we try to improve thetreatments of the county’s domestic sewage and industrial sewage, aiming to solve the contradiction that all kinds of the county’s sewage drains into Baishui River directlywithout any treatment which can pollute the water environment of Baishui River, LuoheRiver and Weihe River, and to lay the foundation of Baishui county’s development.The main contents of this text:（1）By investigating and literature reviewing on Baishui county, combining withspecialized planning on drainage of Baishui county, make systematic review on thepresent drainage and sewage treatment system of Bashui county.（2）Establish the optimization plan of drainage system’s construction of Baishuicounty. The drainage system of Baishui is the rain and sewage diversion system. Builda new sewage treatment plant inside the city called Baishui sewage treatment plant. Weseparated the city into two drainage collection systems: Chengnan drainage collectionsystem and industrial zone drainage collection system. The total area is911.79ha. Thereare17main pipes in the drainage system. The collected drainage will be finallydelivered to the Chengnan sewage treatment plant and Baishui sewage treatment plant.We slso separated the city into8rainwater areas. Set8gutter inlet to collect therainwater and all the rainwater drains off into the Baishui River or the gullies nearby.（3）Combining the research data with the demand of comprehensive treatmentproject of water environment in Weihe River basin to calculate the sewage quantity ofBaishui county scientifically,and establish the water quality of inlet water and outletwater.（4）According to the outlet water’s status quo of Baishui county, industrial planand urbanization process, we can establish a reasonable drainage treatment scale andimplementation plan. In2015, the treatment scale of Baishui sewage treatment plant is16000m3/d. In2025, the treatment scale will expand to28000m3/d.（5）Make a comparison on CASS、A/O and oxidation ditch process. Integrate theactual situation of Baishui county, we choose CASS process to be the drainagetreatment of Baishui sewage treatment plant.（6）According to CASS process, compute the technological parameter of everyprocessing unit.