The feasibility of the nitrous organic wastewater treated was studied in seven anaerobic sequencing batch reactors（ASBRs） （0^#-6^#） which had been run under stable anaerobic ammonium oxidation （Anammox）. By mean...The feasibility of the nitrous organic wastewater treated was studied in seven anaerobic sequencing batch reactors（ASBRs） （0^#-6^#） which had been run under stable anaerobic ammonium oxidation （Anammox）. By means of monitoring and data analysis of COD, NH4^#-N, NO2^--N, NO3^--N and pH, and of microbial test, the results revealed that the optimal Anammox performance was achieved from 2^# reactor in which COD/NH4^＋ -N was 1.65, Anammox bacteria and denitrification bacteria could coexist, and Anammox reaction and denitrification reaction could occur simultaneously in the reactors. The ratio of NH4^＋-N consumed ： NO2^- -N consumed ： NO3^- -N produced was 1：1.38：0.19 in 0^# reactor which was not added glucose in the wastewater. When different ratio of COD and NH4^＋-N was fed for the reactors, the ratio of NO2^- -N consumed： NH4^＋-N consumed was in the range of 1.51-2.29 and the ratio of NO;-N produced： NH4^＋ -N consumed in the range of 0 -0.05.展开更多
An innovative shortcut biological nitrogen removal system, consisting of an aerobic submerged membrane bioreactor （MBR） and an anaerobic packed-bed biofilm reactor （PBBR）, was evaluated for treating high strength ...An innovative shortcut biological nitrogen removal system, consisting of an aerobic submerged membrane bioreactor （MBR） and an anaerobic packed-bed biofilm reactor （PBBR）, was evaluated for treating high strength ammonium-bearing wastewater. The system was seeded with enriched ammonia-oxidizing bacteria （AOB） and operated without sludge purge with a decreased hydraulic retention time （HRT） through three phases. MBR was successful in both maintaining nitrite ratio over 0.95 and nitrification efficiency higher than 98% at HRT of 24 h, and PBBR showed satisfactory denitrification efficiency with very low effluent nitrite and nitrate concentration （both below 3 mg/L）. By examining the nitrification activity of microorganism, it was found that the specifc ammonium oxidization rate （SAOR） increased from 0.17 to 0.51 g N/（g VSS.d） and then decreased to 0.22 g N/（g VSS.d） at the last phase, which resulted from the accumulation of extracellular polymers substances （EPS） and inert matters enwrapping around the zoogloea. In contrast, the average specific nitrite oxidization rate （SNOR） is 0.002 g N/（g VSS.d）, only 1% of SAOR. Because very little Nitrobactor has been detected by fluorescence in situ hybridization （FISH）, it is confirmed that the stability of high nitrite accumulation in MBR is caused by a large amount of AOB.展开更多
Nitrification is a key step in the global nitrogen cycle.Compared with autotrophic nitrification,heterotrophic nitrification remains poorly understood.In this study,Halomonas venusta MA-ZP17-13,isolated from seawater ...Nitrification is a key step in the global nitrogen cycle.Compared with autotrophic nitrification,heterotrophic nitrification remains poorly understood.In this study,Halomonas venusta MA-ZP17-13,isolated from seawater in shrimp aquaculture (Penaeus vannamei),could simultaneously undertake nitrification and denitrification.With the initial ammonium concentration at 100 mg/L,the maximum ammonium-nitrogen removal rate reached98.7%under the optimal conditions including C/N concentration ratio at 5.95,p H at 8.93,and Na Cl at 2.33%.The corresponding average removal rate was 1.37 mg/(L·h)(according to nitrogen) in 3 d at 11.2℃.By whole genome sequencing and analysis,nitrification-and denitrification-related genes were identified,including ammonia monooxygenase,nitrate reductase,nitrite reductase,nitric oxide dioxygenase and nitric oxide synthase;while no gene encoding hydroxylamine oxidase was identified,it implied the existence of a novel nitrification pathway from hydroxylamine to nitrate.These results indicate heterotrophic bacterium H.venusta MA-ZP17-13 can undertake simultaneous nitrification and denitrification at low temperature and has potential for NH_(4)^(+)-N/NH_(3)-N removal in marine aquaculture systems.展开更多
To achieve high efficiency of nitrogen and phosphorus removal and to investigate the rule of simultaneous nitrification and denitrification phosphorus removal （SNDPR）, a whole course of SNDPR damage and recovery was...To achieve high efficiency of nitrogen and phosphorus removal and to investigate the rule of simultaneous nitrification and denitrification phosphorus removal （SNDPR）, a whole course of SNDPR damage and recovery was studied in a pilot-scale, anaerobicanoxic oxidation ditch （OD）, where the volumes of anaerobic zone, anoxic zone, and ditches zone of the OD system were 7, 21, and 280 L, respectively. The reactor was fed with municipal wastewater with a flow rate of 336 L/d. The concept of simultaneous nitrification and denitrification （SND） rate （rSND） was put forward to quantify SND. The results indicate that： （1） high nitrogen and phosphorus removal efficiencies were achieved during the stable SND phase, total nitrogen （TN） and total phosphate （TP） removal rates were 80% and 85%, respectively; （2） when the system was aerated excessively, the stability of SND was damaged, and rSND dropped from 80% to 20% or less; （3） the natural logarithm of the ratio of NOx to NH4^＋ in the effluent had a linear correlation to oxidation-reduction potential （ORP）; （4） when NO3^- was less than 6 mg/L, high phosphorus removal efficiency could be achieved; （5） denitrifying phosphorus removal （DNPR） could take place in the anaerobic-anoxic OD system. The major innovation was that the SND rate was devised and quantified.展开更多
文摘The feasibility of the nitrous organic wastewater treated was studied in seven anaerobic sequencing batch reactors（ASBRs） （0^#-6^#） which had been run under stable anaerobic ammonium oxidation （Anammox）. By means of monitoring and data analysis of COD, NH4^#-N, NO2^--N, NO3^--N and pH, and of microbial test, the results revealed that the optimal Anammox performance was achieved from 2^# reactor in which COD/NH4^＋ -N was 1.65, Anammox bacteria and denitrification bacteria could coexist, and Anammox reaction and denitrification reaction could occur simultaneously in the reactors. The ratio of NH4^＋-N consumed ： NO2^- -N consumed ： NO3^- -N produced was 1：1.38：0.19 in 0^# reactor which was not added glucose in the wastewater. When different ratio of COD and NH4^＋-N was fed for the reactors, the ratio of NO2^- -N consumed： NH4^＋-N consumed was in the range of 1.51-2.29 and the ratio of NO;-N produced： NH4^＋ -N consumed in the range of 0 -0.05.
文摘An innovative shortcut biological nitrogen removal system, consisting of an aerobic submerged membrane bioreactor （MBR） and an anaerobic packed-bed biofilm reactor （PBBR）, was evaluated for treating high strength ammonium-bearing wastewater. The system was seeded with enriched ammonia-oxidizing bacteria （AOB） and operated without sludge purge with a decreased hydraulic retention time （HRT） through three phases. MBR was successful in both maintaining nitrite ratio over 0.95 and nitrification efficiency higher than 98% at HRT of 24 h, and PBBR showed satisfactory denitrification efficiency with very low effluent nitrite and nitrate concentration （both below 3 mg/L）. By examining the nitrification activity of microorganism, it was found that the specifc ammonium oxidization rate （SAOR） increased from 0.17 to 0.51 g N/（g VSS.d） and then decreased to 0.22 g N/（g VSS.d） at the last phase, which resulted from the accumulation of extracellular polymers substances （EPS） and inert matters enwrapping around the zoogloea. In contrast, the average specific nitrite oxidization rate （SNOR） is 0.002 g N/（g VSS.d）, only 1% of SAOR. Because very little Nitrobactor has been detected by fluorescence in situ hybridization （FISH）, it is confirmed that the stability of high nitrite accumulation in MBR is caused by a large amount of AOB.
基金The COMRA Program under contract No. DY135-B2-01the Xiamen Ocean Economic Innovation and Development Demonstration Project under contract No. 16PZP001SF16the National Infrastructure of Natural Resources for Science and Technology Program of China under contract No. NIMR-2017-9。
文摘Nitrification is a key step in the global nitrogen cycle.Compared with autotrophic nitrification,heterotrophic nitrification remains poorly understood.In this study,Halomonas venusta MA-ZP17-13,isolated from seawater in shrimp aquaculture (Penaeus vannamei),could simultaneously undertake nitrification and denitrification.With the initial ammonium concentration at 100 mg/L,the maximum ammonium-nitrogen removal rate reached98.7%under the optimal conditions including C/N concentration ratio at 5.95,p H at 8.93,and Na Cl at 2.33%.The corresponding average removal rate was 1.37 mg/(L·h)(according to nitrogen) in 3 d at 11.2℃.By whole genome sequencing and analysis,nitrification-and denitrification-related genes were identified,including ammonia monooxygenase,nitrate reductase,nitrite reductase,nitric oxide dioxygenase and nitric oxide synthase;while no gene encoding hydroxylamine oxidase was identified,it implied the existence of a novel nitrification pathway from hydroxylamine to nitrate.These results indicate heterotrophic bacterium H.venusta MA-ZP17-13 can undertake simultaneous nitrification and denitrification at low temperature and has potential for NH_(4)^(+)-N/NH_(3)-N removal in marine aquaculture systems.
文摘To achieve high efficiency of nitrogen and phosphorus removal and to investigate the rule of simultaneous nitrification and denitrification phosphorus removal （SNDPR）, a whole course of SNDPR damage and recovery was studied in a pilot-scale, anaerobicanoxic oxidation ditch （OD）, where the volumes of anaerobic zone, anoxic zone, and ditches zone of the OD system were 7, 21, and 280 L, respectively. The reactor was fed with municipal wastewater with a flow rate of 336 L/d. The concept of simultaneous nitrification and denitrification （SND） rate （rSND） was put forward to quantify SND. The results indicate that： （1） high nitrogen and phosphorus removal efficiencies were achieved during the stable SND phase, total nitrogen （TN） and total phosphate （TP） removal rates were 80% and 85%, respectively; （2） when the system was aerated excessively, the stability of SND was damaged, and rSND dropped from 80% to 20% or less; （3） the natural logarithm of the ratio of NOx to NH4^＋ in the effluent had a linear correlation to oxidation-reduction potential （ORP）; （4） when NO3^- was less than 6 mg/L, high phosphorus removal efficiency could be achieved; （5） denitrifying phosphorus removal （DNPR） could take place in the anaerobic-anoxic OD system. The major innovation was that the SND rate was devised and quantified.
