The Pilot Study Of Reversed A~2/O Process For Biological Nitrogen & Phosphorus Removal And Mechanism

This study compared the differences of reversed A~2/O process with conventional A~2/O process in pollutant removal efficiency by pilot test, studied reversed A~2/O process of nitrogen and phosphorus removal mechanism by the static experiment; FISH technique was used to determine the characteristic of microbial.With a view to probe the biochemical mechanism of the reversed A~2/O and effect of this process under different water quality and environment ,to confirm the better running parameter of this process.The results showed that (1) the two processes had the similar capability in removal of ammonia-nitrogen and organic contamination under different operating conditions.When the water temperature is above 10℃, ammonia-nitrogen removals are all very well. The ammonia-nitrogen nitrification rate can be as high as 90% or more , but reversed A~2/O process has better adaptability of the removal of ammonia-nitrogen than the A~2/O process at low temperatures. The reversed A~2/O process of Ortho-P and TP in the effluent were lower than A~2/O process, The reversed A~2/O process, the average effluent Ortho-P were below 0.50 mg/L, the average effluent TP under 0.60 mg/L, removal rate is above 80%, and the removal effect was more stable. (2) Through the determination of the SOUR of activated sludge, we can see the anaerobic time didn't affect the microbial metabolic activity.However, there was an optimum anaerobic time, the optimal value of this study lasted for 2h for the anaerobic, the microbial metabolic activity of the reversed A~2/O process is better than the A~2/O process; Through static test analysis of the PHB transformation mechanism, we can see PHB generated in static test in anaerobic running on A~2/O process was significantly higher than that the reversed A~2/O processt, but the PHB content into the aerobic was opposite in two systems. (3) Studied microbial communities during the experiment by Fluorescent in situ hybridization(FISH) technology, the proportion of PAOs in activated sludge microorganisms in the inversed A~2/O process was significantly higher than A~2/O process, and superiority in competition with the GAOs...