The Research Of Application Of Cast In Chengnan Sewage Treatment Plant

According to the demanding of State Council's Huai River baisn water pollution protection and treatment layout and ninth five-year plan and Hai'an county collective layout (1995-2010), it is necessary to build the Chengnan sewage treatment plant, which the domestic and industry sewage of southern part of Tong-Yang canal is treated in, in order to improve the water quality of the county seat.Via the monitoring and appraising of the current water environment in Hai'an and combine with the actual instance in Hai'an, the first schedule treatment dimensions is 20 thousand m3/d of the sewage treatment project and 40 thousand m3/d for enlarge building at a specified future date. According to the qualitative analysis of the two selecting location scheme and the analysis of the infection to water environment around which is caused by the water outlet, it is ascertained that the location of the sewage treatment plant adopt the second scheme, located in No. 11 group north side of Ping Cha canal which has a common boundary march with Xiao Jiao Gang river and the water outlet is Ping Cha canal.Combined with the sewager instance in Hai'an, the design unit select CAST treatment technics for this project, and carry through the technical , plane and high design of the whole sewage treatment plant. The design sewage treatment process is Coarse Grid — Influent Pumps — Medium Grid —-Circle-flow Grit Pond — CAST — UV Disinfection, and the waste sludge from CAST will be stored in sludge pond and then pumped to the thickening and dewatering machine and at last the sludge cakes will be send to the landfill.According to the actual influent quality and six monthes operation, to ascertain the feasible function parameter of CAST: the circulate cycle of Single pool is 240 minutes, the influent and aerobic time is 30 minutes, aerobic time is 90 minutes, settle 60mins, effluent time is 40mins, the remain 15mins is idle and DO 0-3.5mg/L. The effluent quality can achieve the first class standard. And the average removel efficiency of CODcr, BOD5, NH3-N and TP are better than the design value.