Dephosphorization And Denitrification By Integrated Systerm With Five Tanks

Integrated denitrification and pHospHorus removal activated sludge system with five tanks is a new technology. The characteristics and operational parameters of in the integrated system with five tanks were fully discussed by pilot scale experiments. Some essentials were introduced, including the components, the theory,the operating course and the technological peculiarity of integrated activated sludge system with five tanks. The system was compared with orbal and A2/O. The system is characteristic of high denitrification and phosphorus removal rate ,small possessive room, automatic circulation, simple and convenient operation.The results are as follows:1,The integrated system with five tanks can operate well as A2/O process.Its nitrification and phosphorus removal rates are markedly higher than that of conventional A2/O process . This system don't need sludge reflow and mixed fluid reflow,economizing electricity and low operating fund. Accordingly this system is a proper process for municipal and rural sewage treatment.2,The integrated system with five tanks can be used in the sewage treatment for denitrification and phosphorus removal. Under proper conditions, the removal rates of T-P can reach 90% and T-P in the effluent is stabilized under0.5mg/L. The removal rates of T-N can reach 80% and the removal rate of NH4+-N can reach 87%.3,The changes of DO and pH under different aeration intensity indicated that the characteristic point appeared clearly under the optimal aeration intensity, which could be used as control parameters of real operation.4,The HRT of integrated system with five tanks is different with traditional calculation methods. The length of HRT, which is beneficial to the removal of COD and NH4+-N, also should limitted while thinking about the removal rate of T-P and T-N. The optical time is 13 hours.5,The cycling periods should be carefully controlled. The system can operate well at 8h periods with the main phase 90min,the transition phase 120min and the precipitating phase 30min.6,SRT should not be short because of denitrification and phosphorus removal.The optical SRT should be 12 days.