Anaerobic Ammonium Oxidation Process Based On Membrane Bioreactor And Sequencing Batch Reactor

Due to low energy consumption, less sludge production, saving external carbon source, ANAMMOX has attracted a lot of attention among the new biological nitrogen removal processes. Seed sludge and operating strategies of the reactor are two important factors affecting this process. In this study, how different inoculated sludge, temperature, and HRT effect on ANAMMOX is analyzed through the nitrogen removal efficiency and ANAMMOX activity. Membrane fouling in MBR for the ANAMMOX process is also involved. All these research will provide ANAMMOX with technical support and experience for its practical engineering applications.In this research, we investigate the effects on MBR-ANAMMOX of three inoculated sludges and different HRT, and the effects on SBR-ANAMMOX of different temperatures. Conventional analysis is applied to analyze nitrogen removal and ANAMMOX activity. T-RFLP and FISH & CLSM were used to study the presence of ANAMMOX bacteria and their distribution. SEM and the extraction of microbial metabolites help express membrane fouling.Results demonstrated that all reactors inoculating three kinds of seed sludges showed ANAMMOX activity. Compared the differences of nitrogen removal and ANAMMOX activity, MBR2# was the best, MBR1# followed, MBR3# the worst. FISH & CLSM detected the presence of ANAMMOX bacteria in the reactors, and the quantity in MBR3# is less than MBR1# and MBR2#, which was consistent with the Macro-phenomenon.For membrane fouling on MBR-ANAMMOX, both TMP changes were following changes of membrane fouling, but the pollution cycle of MBR1# is longer than MBR2#, SEM pictures of film showed inorganic fouling by salts of influent, Microbial-Contamination caused by trapped bacterial, and the irreversible fouling result from bacterial inside the film. Protein contamination of the MBR2# membrane surface was more than MBR1#, polysaccharide quite. Both membrane surface and the mixture, the concentration of adhesion-type EPS was higher than SMP. Overall, membrane pollution in MBR2# was more serious than in MBR1#.At both room temperature(25℃) and 35℃, nitrogen removal of the two SBR has similar tendency. When stable operation, total nitrogen removal in SBR2# (35℃) 11.9% higher than SBR1#. However, the average removal of total nitrogen load just has a difference of 0.015mg-N / (mg-VSS.d), so in actual operation, we can reduce the temperature appropriately. At the beginning of reducing MBR1#'s HRT, the efficiency and ANAMMOX activity decreased, but after 25 days of adjustment, both removal of total nitrogen load and ANAMMOX activity increases, indicating that HRT could be reduced.Batch test verified there were some nitrifying bacteria AOB survival in the reactor, no denitrification occurred when no organic carbon source.TOC in the reactor only was below 10mg/L, so we can consider the reactor can be no denitrification occurred. Test results about NOB showed a peculiar phenomenon. Without oxygen, all nitrite can be converted into nitrate, and in the anaerobic environment, nitrite can also be changed, the biggest removal rate was up to 88% after 4 day, but DO was not enough to complete the oxidation; however, the specific pathway of this process is to be studied.