Study On Reinforcement Phosphorus And Nitrogen Removal Of Wastewater Based On Sequencing Batch Reactor

With water pollution, eutrophication of water body, the acute problem of water-saving and public environmental awareness increases, more and more countries and regions have formulated strict emission standards for nitrogen and phosphorus in sewage, research and development of high-effect nutrient removal wastewater treatment technology has become the focus of subject concerned in the field of water pollution control projects .Denitrifying phosphorus removing bacteria is one of facultative denitrifying microorganism, it can release phosphorus on anaerobic phase, and on anoxic phase, it takes NO3--N for the electronic accepter, phosphorus is assimilated superfluously at the same time to nitrate is reverted to nitorgen, combined biological phosphorus removal and denitrifying nitrogen removal . The research of this thesis was fed with synthetic municipal wastewater, denitrifying phosphorus removal bacteria was naturalized and enriched by means of two phase in sequencing batch reactor, and the operating conditions of nutrient removal was optimized. The influence of added carbon and nitrate concentration on the nutrient removal was systematically studied, the removal effect of COD,nitrogen and phosphorus was also studied.According to orthogonal test result (four factors and four levels ) ,A/AO-SBR system was acquired best operating conditions of anaerobic time for 2h, anoxic time for 3.5h, aerobic time for 0.5h, precipitation and water drainage time for 1.0h, aerobic time is a pivotal factor that affected the system of nutrient removal. By inject in different concentration of COD, experiments show that if the initial COD concentration is too low, which results in the nitrates residue to the next anaerobic phase inhibited the initial phosphorus release obviously. On the other hand, If the initial COD concentration was too high, which Poly-p bacteria, residual COD carried over was in excess to the PHB saturation of to anoxic phase inhibited the subsequent denitrifying phosphorus uptake, the experiment acquired better concentration of COD was about 300 mg/L. Inject in different concentration of NO3--N on anoxic phase, it could gain better effect of phosphorus removal concentration of NO3--N is 30mg/L. On the best operating condition of the long and steady run for the system of nutrient removal, the removal rate of COD,phosphorus,ammonia and TN is 91.31%,90.94%,98.70% and 94.12%.Through establishing in material balance equation of SBR system and working out effluent concentration of COD calculation formula was Cω= rCω0 ? 54.00t X ? 4.19ty;Through searching the kinetic mode of the system of denitrifying phosphorus removal, the followings were deduced: the kinetic mode of PO43--P that was released in anaerobic course was Pt = P0 - 2.02 Xt 2+ 6.84Xt(0≤t≤2)and the kinetic mode of PO43--P that was absorbed in anoxic course was Pt ' = P0 -6.46t 2+ 13.68 X+ 11.62(0≤t≤3.5).