The present study investigates the enrichment of anaerobic ammonium oxidation(anammox)bacteria in the marine environment using sediment samples obtained from the East China Sea and discusses the nitrogen removal effic...The present study investigates the enrichment of anaerobic ammonium oxidation(anammox)bacteria in the marine environment using sediment samples obtained from the East China Sea and discusses the nitrogen removal efficiency of marine anammox bioreactor.Enrichment of anammox bacteria with simultaneous removal of nitrite and ammonium ions was observed in the Anaerobic Sequencing Batch Reactor under a total nitrogen loading rate of 0.37kg-N m-3day-1.In this study,The nitrogen removal efficiency was up to 80%and the molar-reaction ratio of ammonium,nitrite and nitrate was 1.0:1.22:0.22 which was a little different from a previously reported ratio of 1.0:1.32:0.26 in a freshwater system.展开更多
This study is focused on investigation of biofilms formed in an anaerobic laboratory-scale bioreactor fed with medium for anammox bacteria oxidizing ammonia with nitrite. The mixed culture of anammox bacteria was enri...This study is focused on investigation of biofilms formed in an anaerobic laboratory-scale bioreactor fed with medium for anammox bacteria oxidizing ammonia with nitrite. The mixed culture of anammox bacteria was enriched from the microbial community that sampled from the activated sludge of a denitrifying reactor at a wastewater treatment station located in the Sochi region, Russia. This community forms biofilms on the surface of the flexible polymer brush carriers, which are used for biomass immobilization in both laboratory and full-scale bioreactors. Anammox bacteria were discovered in the activated sludge community. The anammox community was enriched by incubation in an up-flow laboratory-scale anaerobic bioreactor with a flexible brush carrier. In the course of ~3 years, the loading rate of nitrogen substrates (ammonium and nitrite) increased from 100 to 5000 mg N L-1 day-1. The concentration of the substrates in the upper part of the reactor was 40 times less than in the influent. The pH values were 7.5 at the bottom and up to 9 in the upper part up of the reactor. Biofilms of two types developed in the reactor. Bunches of irregular spherical granules formed on the carrier filaments, while films of irregular thickness containing submerged spherical granules were formed on the walls of reactor. The anammox population was found to consist of at least three active species: a new strain of Candidatus “Jettenia asiatica” named “strain ecos” and two species of the genus Candidatus “Brocadia”. Other types of bacteria found in the community, including members of phylum Chloroflexi, were presumably involved in biofilm spatial organization.展开更多
Anammox bacteria grow slowly and can be affected by large pH fluctuations.Using suitable buffers could make the start-up of anammox reactors easy and rapid.In this study,the effects of three kinds of buffers on the ni...Anammox bacteria grow slowly and can be affected by large pH fluctuations.Using suitable buffers could make the start-up of anammox reactors easy and rapid.In this study,the effects of three kinds of buffers on the nitrogen removal and growth characteristics of anammox sludge were investigated.Reactors with CO_(2)/NaHCO_(3)buffer solution(CCBS)performed the best in nitrogen removal,while 4-(2-hydroxyerhyl)piperazine-1-ethanesulfonic acid(HEPES)and phosphate buffer solution(PBS)inhibited the anammox activity.Reactors with 50 mmol/L CCBS could start up in 20 days,showing the specific anammox activity and anammox activity of 1.01±0.10 gN/(gVSS·day)and 0.83±0.06 kgN/(m^(3)·day),respectively.Candidatus Kuenenia was the dominant anammox bacteria,with a relative abundance of 71.8%.Notably,anammox reactors could also start quickly by using 50 mmol/L CCBS under nonstrict anaerobic conditions.These findings are meaningful for the quick start-up of engineered anammox reactors and prompt enrichment of anammox bacteria.展开更多
文摘The present study investigates the enrichment of anaerobic ammonium oxidation(anammox)bacteria in the marine environment using sediment samples obtained from the East China Sea and discusses the nitrogen removal efficiency of marine anammox bioreactor.Enrichment of anammox bacteria with simultaneous removal of nitrite and ammonium ions was observed in the Anaerobic Sequencing Batch Reactor under a total nitrogen loading rate of 0.37kg-N m-3day-1.In this study,The nitrogen removal efficiency was up to 80%and the molar-reaction ratio of ammonium,nitrite and nitrate was 1.0:1.22:0.22 which was a little different from a previously reported ratio of 1.0:1.32:0.26 in a freshwater system.
文摘This study is focused on investigation of biofilms formed in an anaerobic laboratory-scale bioreactor fed with medium for anammox bacteria oxidizing ammonia with nitrite. The mixed culture of anammox bacteria was enriched from the microbial community that sampled from the activated sludge of a denitrifying reactor at a wastewater treatment station located in the Sochi region, Russia. This community forms biofilms on the surface of the flexible polymer brush carriers, which are used for biomass immobilization in both laboratory and full-scale bioreactors. Anammox bacteria were discovered in the activated sludge community. The anammox community was enriched by incubation in an up-flow laboratory-scale anaerobic bioreactor with a flexible brush carrier. In the course of ~3 years, the loading rate of nitrogen substrates (ammonium and nitrite) increased from 100 to 5000 mg N L-1 day-1. The concentration of the substrates in the upper part of the reactor was 40 times less than in the influent. The pH values were 7.5 at the bottom and up to 9 in the upper part up of the reactor. Biofilms of two types developed in the reactor. Bunches of irregular spherical granules formed on the carrier filaments, while films of irregular thickness containing submerged spherical granules were formed on the walls of reactor. The anammox population was found to consist of at least three active species: a new strain of Candidatus “Jettenia asiatica” named “strain ecos” and two species of the genus Candidatus “Brocadia”. Other types of bacteria found in the community, including members of phylum Chloroflexi, were presumably involved in biofilm spatial organization.
基金supported by the National Natural Science Foundation of China(No.52070162)。
文摘Anammox bacteria grow slowly and can be affected by large pH fluctuations.Using suitable buffers could make the start-up of anammox reactors easy and rapid.In this study,the effects of three kinds of buffers on the nitrogen removal and growth characteristics of anammox sludge were investigated.Reactors with CO_(2)/NaHCO_(3)buffer solution(CCBS)performed the best in nitrogen removal,while 4-(2-hydroxyerhyl)piperazine-1-ethanesulfonic acid(HEPES)and phosphate buffer solution(PBS)inhibited the anammox activity.Reactors with 50 mmol/L CCBS could start up in 20 days,showing the specific anammox activity and anammox activity of 1.01±0.10 gN/(gVSS·day)and 0.83±0.06 kgN/(m^(3)·day),respectively.Candidatus Kuenenia was the dominant anammox bacteria,with a relative abundance of 71.8%.Notably,anammox reactors could also start quickly by using 50 mmol/L CCBS under nonstrict anaerobic conditions.These findings are meaningful for the quick start-up of engineered anammox reactors and prompt enrichment of anammox bacteria.
