The present lab-scale research reveals the enrichment of anaerobic ammonium oxidation microorganism from methanogenic anaerobic granular sludge and the effect of inorganic carbon(sodium bicarbonate)on anaerobic ammoni...The present lab-scale research reveals the enrichment of anaerobic ammonium oxidation microorganism from methanogenic anaerobic granular sludge and the effect of inorganic carbon(sodium bicarbonate)on anaerobic ammonium oxidation.The enrichment of anammox bacteria was carried out in a 7.0-L sequencing batch reactor(SBR)and the effect of bicarbonate on anammox was conducted in a 3.0-L SBR.Research results,especially the biomass,showed first signs of anammox activity after 54 d cultivation with synthetic wast...展开更多
The anaerobic ammonia oxidation(Anammox) granular sludge bed reactor was started up successfully with nitrifying granular sludge. During the operation, the nitrifying granular sludge was gradually converted into Anamm...The anaerobic ammonia oxidation(Anammox) granular sludge bed reactor was started up successfully with nitrifying granular sludge. During the operation, the nitrifying granular sludge was gradually converted into Anammox granular sludge with good settling property and high conversion activity. The Anammox reactor worked well with the shortest HRT of 2 43 h. Under the condition that HRT w as 6 39 h and influent concentration of ammonia and nitrite was 10 mmol/L, the removal of ammonia and nitrite was 97 17% and 100 00%, respectively. Corresponding volumetric total nitrogen loading rate and volumetric total nitrogen conversion rate were 100 83 mmol/(L·d) and 98 95 mmol/(L·d). The performance of Anammox reactor was efficient and stable.展开更多
Though there are many literatures studying the effects of iron on anammox process,these studies only focus on the reactor performance and/or the microbial community changes,the detailed effects and mechanisms of Fe(II...Though there are many literatures studying the effects of iron on anammox process,these studies only focus on the reactor performance and/or the microbial community changes,the detailed effects and mechanisms of Fe(II)on anammox bacterial activity and physiology have not been explored.In this study,four Fe(II)concentrations(0.03,0.09,0.12 and 0.75 mmol/L)were employed into the enriched anammox culture.The enhancement and inhibition effects of Fe(II)on anammox process and bacterial physiology were investigated.It was discovered that the anammox process and bacterial growth were enhanced by 0.09 and 0.12 mmol/L Fe(II),in which the 0.12 mmol/L Fe(II)had advantage in stimulating the total anammox activity and bacterial abundance,while 0.09 mmol/L Fe(II)enhanced the relative anammox activity better.The anammox activity could be inhibited by 0.75 mmol/L Fe(II)immediately,while the inhibition was recoverable.Both 0.09 and 0.12 mmol/L Fe(II)induced more genes being expressed,while didn’t show a stimulation on the relative expression level of functional genes.And anammox bacteria showed a stress response to detoxify the Fe inhibition once inhibited by 0.75 mmol/L Fe(II).This study provides more information about physiologic response of anammox bacteria to external influence(enhancement and inhibition),and may also instruct the future application of anammox process in treating various sources of wastewater(containing external disturbances such as heavy metals)and/or different treatment strategies(e.g.from side-stream to main-stream).展开更多
Shortcut nitrification-denitrification,anaerobic ammonium oxidation(ANAMMOX),and methanogenesis have been successfully coupled in an Expanded Granular Sludge Bed-Biological Aerated Filter(EGSB-BAF)integrated system.As...Shortcut nitrification-denitrification,anaerobic ammonium oxidation(ANAMMOX),and methanogenesis have been successfully coupled in an Expanded Granular Sludge Bed-Biological Aerated Filter(EGSB-BAF)integrated system.As fed different synthetic wastewater with chemical oxygen demand(COD)of 300-1200 mg·L^(-1)and NH_(4)^(+)-N of 30-120 mg·L^(-1)at the outer recycle ratio of 200%,the influence of influent on ANAMMOX in the integrated system was investigated in this paper.The experimental results showed that higher COD concentration caused an increase in denitrification and methanogenesis but a decrease in ANAMMOX;however,when an influent with the low concentration of COD was used,the opposite changes could be observed.Higher influent NH_(4)^(+)-N concentration favored ANAMMOX when the COD concentration of influent was fixed.Therefore,low COD=NH_(4)^(+)-N ratio would decrease competition for nitrite between ANAMMOX and denitrification,which was favorable for reducing the negative effect of organic COD on ANAMMOX.The good performance of the integrated system indicated that the bacterial community of denitrification,ANAMMOX,and methanogenesis could be dynamically maintained in the sludge of EGSB reactor for a certain range of influent.展开更多
文摘The present lab-scale research reveals the enrichment of anaerobic ammonium oxidation microorganism from methanogenic anaerobic granular sludge and the effect of inorganic carbon(sodium bicarbonate)on anaerobic ammonium oxidation.The enrichment of anammox bacteria was carried out in a 7.0-L sequencing batch reactor(SBR)and the effect of bicarbonate on anammox was conducted in a 3.0-L SBR.Research results,especially the biomass,showed first signs of anammox activity after 54 d cultivation with synthetic wast...
文摘The anaerobic ammonia oxidation(Anammox) granular sludge bed reactor was started up successfully with nitrifying granular sludge. During the operation, the nitrifying granular sludge was gradually converted into Anammox granular sludge with good settling property and high conversion activity. The Anammox reactor worked well with the shortest HRT of 2 43 h. Under the condition that HRT w as 6 39 h and influent concentration of ammonia and nitrite was 10 mmol/L, the removal of ammonia and nitrite was 97 17% and 100 00%, respectively. Corresponding volumetric total nitrogen loading rate and volumetric total nitrogen conversion rate were 100 83 mmol/(L·d) and 98 95 mmol/(L·d). The performance of Anammox reactor was efficient and stable.
基金The authors also appreciate the funding support from Start-up Grant(SUG)Nanyang Technological University,Singapore(M4081483.030).
文摘Though there are many literatures studying the effects of iron on anammox process,these studies only focus on the reactor performance and/or the microbial community changes,the detailed effects and mechanisms of Fe(II)on anammox bacterial activity and physiology have not been explored.In this study,four Fe(II)concentrations(0.03,0.09,0.12 and 0.75 mmol/L)were employed into the enriched anammox culture.The enhancement and inhibition effects of Fe(II)on anammox process and bacterial physiology were investigated.It was discovered that the anammox process and bacterial growth were enhanced by 0.09 and 0.12 mmol/L Fe(II),in which the 0.12 mmol/L Fe(II)had advantage in stimulating the total anammox activity and bacterial abundance,while 0.09 mmol/L Fe(II)enhanced the relative anammox activity better.The anammox activity could be inhibited by 0.75 mmol/L Fe(II)immediately,while the inhibition was recoverable.Both 0.09 and 0.12 mmol/L Fe(II)induced more genes being expressed,while didn’t show a stimulation on the relative expression level of functional genes.And anammox bacteria showed a stress response to detoxify the Fe inhibition once inhibited by 0.75 mmol/L Fe(II).This study provides more information about physiologic response of anammox bacteria to external influence(enhancement and inhibition),and may also instruct the future application of anammox process in treating various sources of wastewater(containing external disturbances such as heavy metals)and/or different treatment strategies(e.g.from side-stream to main-stream).
基金This research was supported by the Natural Science Foundation of China(Grant No.50378094).
文摘Shortcut nitrification-denitrification,anaerobic ammonium oxidation(ANAMMOX),and methanogenesis have been successfully coupled in an Expanded Granular Sludge Bed-Biological Aerated Filter(EGSB-BAF)integrated system.As fed different synthetic wastewater with chemical oxygen demand(COD)of 300-1200 mg·L^(-1)and NH_(4)^(+)-N of 30-120 mg·L^(-1)at the outer recycle ratio of 200%,the influence of influent on ANAMMOX in the integrated system was investigated in this paper.The experimental results showed that higher COD concentration caused an increase in denitrification and methanogenesis but a decrease in ANAMMOX;however,when an influent with the low concentration of COD was used,the opposite changes could be observed.Higher influent NH_(4)^(+)-N concentration favored ANAMMOX when the COD concentration of influent was fixed.Therefore,low COD=NH_(4)^(+)-N ratio would decrease competition for nitrite between ANAMMOX and denitrification,which was favorable for reducing the negative effect of organic COD on ANAMMOX.The good performance of the integrated system indicated that the bacterial community of denitrification,ANAMMOX,and methanogenesis could be dynamically maintained in the sludge of EGSB reactor for a certain range of influent.
