The Study On Denitrifying Phosphorus Removal Of A～2/O Process

The standard of wastewater discharge was controlled more strictly with the severe eutrophication question occurred. Therefore, the wastewater techniques developed gradually from the period of pure COD removal to the period of simultaneous COD, nitrogen and phosphorus removal. Today, the nitrogen and phosphorus removal technology aimed for eutrophication control has been the focused study in the wastewater treatment area.Because of many advantages like simple structure, short total HRT, cost efficient, easy control, and so on, the A~2/O process has been wildly used in the municipal wastewater treatment plant for nutrient removal purpose. But the traditional A~2/O process has some disadvantages like competition of carbon source, contradiction of SRT, difficulty to improve the total nitrogen removal efficiency and so on. The Denitrifying phosphorus removal technique as a new prominent biological wastewater treatment technique can partially resolve some of the contradictions in A~2/O process.In order to accelerate the investigation development of A~2/O process, in particular to accelerate the application of A~2/O process for the low C/N wastewater treatment, the continuous model dynamic experiment operated with artificial municipal wastewater was carried out. The feasibility of introducing denitrifying phosphorus removal to A~2/O process and the influencing factors on the denitrifying phosphorus removal were studied systematically for the first time. The characters and biofacies of the activated sludge, simultaneously the variation of pH and ORP in this system were systematically studied. Based on this, The feasibility of introducing partial nitrification to A~2/O process where denitrifying phosphorus removal exist by low DO control method, the influencing factors and control parameters were systematically studied. The effect of the partial nitrification and other phenomenons along with the introducing partial nitrification on denitrifying phosphorus removal system in simultaneously nitrogen and phosphorus removal system was systematically studied for the first...