Biological Denitrification And Phosphorus Removal Characteristics By The Anaerobic (Anoxic)/Aerobic Biofilter System

Nitrogen（N）and phosphorus(P) are the essential nutrients for microbial growth, it is thedirect cause of eutrophication. Anaerobic (anoxic)/aerobic alternating biofilter (AABF) not onlyhas the simultaneous denitrification and phosphorus removal function, but also saves carbonsources. This research used an alternating anaerobic/aerobic biofilter (AABF) to treat wastewatercontaining N and P, using dynamic feeding carbon sources to improve the effect of system for Premoval and recovery，and improve AABF denitrification efficiency. Research the concentrationof ammonia nitrogen and nitrate nitrogen to the influence of AABF different location P release andremoval, and N distribution in the reactor. Explore the best method for using GC-MS to detect thePHAs in biofilm, and analyze the operation of dynamic feeding carbon sources stimulates Prelease for AABF denitrification and P removal effect. The main research results are as follows:(1) After dynamic feeding carbon sources, TP and TN removal rate are improved obviously,AABF biofilm synthetics large number of PHAs, PHB in PHAs has increased significantly, whichmainly used for P removal in PAOs. The proportion of PHAs and PHB of cell dry weight haveincreased, concentration of biofilm PHAs and PHB were significantly improved, demonstratingthat dynamic feeding carbon sources for AABF biofilm storages PHAs has significant effect.(2) The concentration of ammonia nitrogen and nitrate nitrogen has a great influence onAABF P release. Make four nitrogen water conditions: low ammonia nitrogen, high ammonianitrogen, nitrate nitrogen, high nitrate nitrogen, AABF P release and absorption changes as: AABFP release most is40±2mg·L-1, when inflow low ammonia nitrogen；the P release is35±1.8mg·L-1，when inflow high ammonia nitrogen. After entering nitrate nitrogen, AABF P release decreasedsignificantly, and the higher the inflow concentration of nitrate nitrogen, the lower the amount of Prelease.(3) The final P concentration of AABF effluent was3.5±0.18mg·L-1, when AABFrespectively fed with the low ammonia nitrogen, low nitrate nitrogen, and high nitrate. Under thecondition of high ammonia nitrogen loading, AABF effluent P concentration was4.5±0.22mg·L-1. The rank of the magnificence of the impaction of the nitrogen sources on the concentration ofeffluent P and P uptake rate is as follows: the P uptake rate was reduced when AABF respectivelysubjected to low ammonia, high ammonia nitrogen, ammonia nitrogen, nitrate nitrogen, and nitratenitrogen in sequences.(4) Ammonia nitrogen removal rate was high in AABF which reached to more than90%when the AABF subjected to low and high concentrations of Ammonia nitrogen source and thelowest concentration of ammonia nitrogen effluent was0.15mg·L-1and1.5±0.5mg·L-1respectively. The maximum TN removal rate of78%was achieved, when AABF subjected tohigh nitrate. TN removal rate decreased when AABF was fed with low ammonia, high ammoniaand low nitrate nitrogen and the lowest TN removal rate was47%.(5) The optimum analysis method of PHAs in biofilm was established using the GasChromatography-Mass Spectrometer. It was conducive to detect component and concentration ofPHAs accurately, when extraction and digestion were operated step by step. The results showedthat PHAs in the biofilm dry cells was1-10%and12-30%respectively before and after dynamicfeeding carbon sources, the most abundant in biofilm monomer was3-hydroxy butyric acid.