Mechanism Study On The Effect Of Ammonia Nitrogen Loading Gradient On The Treatment Of High Concentration Ammonia Nitrogen Wastewater By Anaerobic Ammonium Oxidizing Bacteria

As a new biological denitrification technology,anaerobic ammonia oxidation possesses extraordinary development potential.No organic carbon like glucose or starch is added for electron donors providing.In this manner,not only a large amount of costs can be saved,but also a secondary pollution of water source would be prevented.However,there exist some imperfections during the actual operation:(1)the anaerobic ammonia oxidation bacteria growth slow,and the screening as well as enrichment time is long.(2)the higher ammonia nitrogen and nitrate nitrogen concentration of influent can inhibit the denitrification ability of anaerobic ammonia oxidation bacteria.To further study these problems,SBR is selected as the setup to vaccinate activated sludge which had run 8 months in EGSB anaerobic reactor of Huaqiang Chemical.Simultaneously,simulatived high nitrogen simulation is used for anaerobic ammonia oxidation bacteria concentration screening.Then based on the research mentioned above,the efficiency and mechanisms of nitrogen removal under different ammonia nitrogen concentration gradient were studied.Furthermore,it was the first time to study the denitrification efficiency under the critical ammonia and nitrate nitrogen concentration.The results showed that:(1)After 102 days training,SBR reactor successfully enriched anaerobic ammonia oxidation bacteria.When ammonia nitrogen and nitrate nitrogen concentration is respectively 150 mg/L,the SBR reactor can still effectively and stably run.Ammonia nitrogen and nitrate nitrogen concentration can respectively keep under 10 mg/L and 1mg/L,with removal ratio over 91% and 99%.(2)According to the cultivation difficulty and time of anaerobic ammonia oxidation bacteria enrichment,three parameters were extracted.The three parameters referred to ratio of ammonia nitrogen,nitrite nitrogen and nitrate nitrogen,nitrate nitrogen and pH changes.Thought that all parameters have their own limitations,them can be adopted for anaerobic ammonia oxidation bacteria enrichment of practical process after composite and summary.(3)The anaerobic ammonia oxidation bacteria can degrade a certain concentration of simulated high ammonia nitrogen after two stages domestication of different concentration gradient.Unfortunately,if the high ammonia nitrogen of influent surpassed that of SBR system without domestication,microbial activity and nitrogen removal were restricted.In the phase I,the domestication time was 88 d.Influent concentration of ammonia nitrogen increased from 150 mg/L to 550 mg/L,effluent concentration of ammonia nitrogen and nitrate nitrogen remained around 41.53 mg/L and 5.34 mg/L.In the phase II,domestication time was 30 d,influent ammonia nitrogen and nitrate nitrogen were respectively arose from 600 mg/L and 650 mg/L to 1100 mg/L and 1150 mg/L,and effluent concentration of that were boosted 70.36 mg/L and 6.42 mg/L up to 528.46 mg/L and 680.12 mg/L.However,with the further improvement of influent ammonia nitrogen concentration,the anaerobic ammonia oxidation system crashed because of higher influent ammonia nitrogen load.Experimental data showed that the critical threshold of influent mmonia nitrogen and nitrate nitrogen were respectively 900 mg/L and 950 mg/L.(4)By adding 171 mg/L hydroxylamine hydrochloride and reducing the ammonia nitrogen and nitrate nitrogen concentration,the collapsed SBR system can be recovered after 52 d experimental debugging.(5)The threshold of influent ammonia nitrogen and nitrate nitrogen concentration was 900 mg/L and 950 mg/L.Through single factor experiment,it was concluded that optimal pH temperature were 8 and 33? respectively.(6)Keeping the ammonia nitrogen and nitrate nitrogen concentration respectively around 900 mg/L and 950 mg/L,pH of 8,the system temperature of 33?,HRT of 48 h,effluent ammonia nitrogen concentration was stabilized near 130 mg/L,which maintained removal ratio stability and effluent nitrate nitrogen concentration can maintained near 84%.In general,SBR anaerobic ammonia oxidation reactor can effectively and stability run.