Research On The Process Of Small Town Sewage TreamentPlant In South Of Shanxi Province

This paper is a research on the aspect of selecting sewage treatment plant for Yecun Town Shangluo City. The main contents include selecting and preliminary calculating about the sewage treatment plant 、sewer network as well as every structures in treatment process.Firstly, the paper described the purpose and significance of this subject, presented a namber of huge impediments about current sanitation problems in our small towns, illustrated some research status about urban sewage treatment both at home and abroad, then proposed the necessity of this research.Secondly, detailed analysis of the status quo about natural conditions、water supply and drainage coditions in Yecun Town Shangluo City, then futher elaborated related national policies on urban sewage treatment and the important function this town can make in the “South”project. The service scope of wastewater treatment plant is 3.45 square kilometers. Design life recently in 2020, long-term 2030. Predicted the amount of sewage according to the comprehensive water consumption quota of the city, the sewage discharge coefficient and the popularization rate of the network. According to the influent water quality data provided by Shangluo city sewage treatment plant. Using Guarantee rate method, and compared with the results by using pollutant discharge equivalent when lack of data to analysis the influent water quality, the quality is intended to be CODcr≤390mg/L、BOD5≤190mg/L、SS≤220mg/L、TN≤48mg/L、NH3-N≤30mg/L、TP≤4.5mg/L,combined with the local weather、topography and the master plan of Yecun town, determined the candidate sites of sewage treatment plant. Compared many aspects, such as economic and technology, operation and maintenance or treatment effect ect, then in order to meet the "urban sewage treatment plant pollutant discharge standard"(GB18918-2002) rigid index level A standard, compared the results by comprehensive score method and a weighted scoring method, the craft of this subject is intended to be grid well→lift pump→conditioning tank→sand-basin→Carrousel oxidation ditch → precipitation → filter → disinfection → standarded discharge or reuse. Analyzed the sludge treatment and utilization as well as the problem about secondary contamination. Used the Principle of activated sludge reaction kinetics to calculation and select models to every structure.Finallt, analyzed the drainage system, decied pipeline alignment, calculated the pipe diameter and the number of inspection wells, then calculated construction investment of sewage treatment plant and pipe network in detail, the total investment is 47628400 yuan.