Study On MBR Coupled Anammox Process

Anaerobic ammonium oxidizing bacteria is a kind of microorganisms capable of converting ammonia nitrogen and nitrite nitrogen into nitrogen.The anaerobic ammonium oxidation technology derived from this method is a new type of nitrogen removal process.Compared with the traditional nitrification-denitrification process,it has the following advantages:no need to add carbon source,high load,low operating cost,low residual sludge production and so on;and MBR is a sewage treatment process that combines activated sludge process and membrane separation technology.Practice shows that it has the characteristics of good effluent quality,low energy consumption and convenient operation.This study designed and developed the A²-ANAMMOX-MBR coupling process based on the principles and advantages of the above two.Taking the sewage of a university campus as the treatment object,by investigating the daily operating conditions of the reactor such as pH,temperature,DO,HRT,membrane pressure,and the inlet and outlet water quality indexes of NH₄⁺-N,NO₂^--N,TN,COD,etc.,simultaneously sampling The analysis and treatment of effluent's physicochemical properties,organic components,membrane fouling,and microbial diversity in the reaction system were carried out to explore the treatment effect,operating conditions and process coupling mechanism.The time can be divided into three stages:start-up operation in stage ?,adjust to lower DO to transition in stage ?,and addition of anammox bacteria in stage ?.The main conclusions are as follows:?1?In the stage ?,when the average influent NH₄⁺-N is higher than the stage ?,the average removal rate can reach about 86.5%,and the stage ? has a removal rate of85.4%;and the third stage is also the case where the influent average TN is higher than the stage ?,the average removal rate can reach about 72.9%,which is obviously better than the 61.88% of the stage ?.The COD removal effect remains relatively stable in the whole process,the average effluent concentration is about 35.9 mg/L,and the average removal rate can reach about 72.8%.The changing trend of NO₂^--N at different stages reveals a certain microbial reaction mechanism.?2?In the dissolved organic matter in the effluent of the stage ? reaction system,the average proportion of humic substances reached about 69.01%,the proteinaceous matter was about 30.99%,the structure became stable,and the treatment of organic matter in the influent water by the microorganisms was relatively complete.The determination and analysis of dissolved organic matter in water can provide some theoretical guidance for further reduction of COD index and subsequent improvement of process.?3?The efficient and stable filtration of the membrane module causes most of the suspended pollutants in the sewage to be trapped in the reaction system and further decomposed by the microorganisms.The average removal rate of turbidity is as high as 95.51%;for the ceramic flat membrane with membrane fouling The treatment method of sodium hypochlorite chemical immersion and manual brushing can effectively solve the situation that the membrane flux decreases,and the membrane flux level before the treatment can be recovered.?4?In the analysis of microbial diversity,the microbial community in the reaction system changed greatly during the two sampling processes,mainly because the microbial community structure changed from complex to relatively simple,and the proportion of some strains decreased.In the more accurate classification of genus,Nitrospira accounted for up to 13.87%of the sample just added to anammox bacteria,and anaerobic bacterium?Candidatus Kuenenia?was about 7.1%.Nitrosomonas is about 1.9%;in the sludge samples at the end of the system operation,about 16.74%of the Acinetobacter,about 2.24%of the Nitrospira,The anaerobic genus?Candidatus Kuenenia?,which accounts for about 1.53%,accounts for about 1% of the genus Nitrosomonas,which are relatively stable main genera.