To explore the adaptive mechanisms of the partial nitritation-anammox(PNA)process under high salinity stress during kitchen wastewater treatment,focusing on their physiological and molecular responses through metageno...To explore the adaptive mechanisms of the partial nitritation-anammox(PNA)process under high salinity stress during kitchen wastewater treatment,focusing on their physiological and molecular responses through metagenomic analysis.An airlift inner-circulation partition bioreactor(AIPBR)was developed,featuring an inner cylinder and a flow guide tube to create distinct oxygen gradients,facilitating the study of microbial adaptation under varying salt conditions.The AIPBR was operated with synthetic wastewater containing ammonium concentrations of 1800±100 mg/L and salinity gradients ranging from 1 to 10 g/L,followed by a fixed salinity period at 6 g/L,with ammonium concentrations approximately 850 mg/L.High-throughput metagenomic analysis revealed shifts in functional genes and metabolic pathways in response to salinity stress.Anammox bacteria adapted by enriching genes involved in the synthesis of osmoprotective compounds and activating energy-producing pathways like the tricarboxylic acid cycle(TCA).These adaptations,along with modifications in membrane composition,were essential for sustaining system stability under elevated salinity.Under prolonged high salinity stress,anaerobic ammonium oxidizing(AnAOB)exhibited improved salt tolerance,maintaining a total nitrogen removal efficiency above 85%and stabilizing after an adaptation phase.The metagenomic data revealed a marked enrichment of genes associated with ion transport,stress response mechanisms,and DNA repair pathways.Changes in microbial community composition favored salt-tolerant species,supporting system stability.These findings highlight the applicability of the developed bioreactor for scaling up the PNA process to handle high-salinity wastewater,providing a promising avenue for sustainable nitrogen removal in challenging environments.展开更多
Anammox bacteria in constructed wetlands(CWs)play pivotal role in sustainable nitrogen transformation,yet existing studies lack comprehensive analysis of environmental gradients and microbial interactions,both key fac...Anammox bacteria in constructed wetlands(CWs)play pivotal role in sustainable nitrogen transformation,yet existing studies lack comprehensive analysis of environmental gradients and microbial interactions,both key factors in anammox bacteria enrichment.This study investigated the mechanisms driving anammox bacteria enrichment in lab-scale simulated CWs treating high-nitrogen wastewater,focusing on bacterial community re-sponses across wetland layers with various strategies,including continuous up-flow influent,nitrogen loading increase,effluent recirculation,intermittent influent,and anammox bacteria inoculation.Results showed that total relative and absolute abundances of anammox bacteria ranged from 0.77%to 12.50%and from 0.13 to 6.46×10^(7) copies/g,respectively.Dissolved oxygen and pH had significant positive correlations with the absolute abundance of anammox bacteria,while organic matter and nitrate negatively impacted their relative abundance.Permutational multivariate analysis of variance indicated that spatial heterogeneity explained more variation in anammox bacteria abundance(43.44%)compared to operational strategies(8.58%).In terms of microbial interactions,60 dominant species exhibited potential correlations with anammox bacteria,comprising 170 interactions(105 positive and 65 negative),which suggested that anammox bacteria generally foster cooperative relationships with dominant bacteria.Notably,significant interspecies interactions were observed between Candidatus Kuenenia(dominant anammox bacteria in CWs)and species within the genera Chitinivibrio-nia and Anaerolineaceae,suggesting that microbial interactions primarily manifest as indirect facilitative effects rather than direct mutualistic relationships.Given that the Normalized Stochasticity Ratio in CWs were<50%,this study inferred that environmental gradients have greater influence on anammox bacteria than microbial interactions.展开更多
The removal of nitrogen via the ANAMMOX process is a promising green wastewater treatment technology,with numerous benefits.The incessant studies on the ANAMMOX process over the years due to its long start-up and high...The removal of nitrogen via the ANAMMOX process is a promising green wastewater treatment technology,with numerous benefits.The incessant studies on the ANAMMOX process over the years due to its long start-up and high operational cost has positively influenced its technological advancement,even though at a rather slow pace.At the moment,relatively newANAMMOX technologies are being developedwith the goal of treating lowcarbon wastewater at low temperatures,tackling nitrite and nitrate accumulation and methane utilization from digestates while also recovering resources(phosphorus)in a sustainable manner.This review compares and contrasts the handful of ANAMMOX-based processes developed thus far with plausible solutions for addressing their respective bottlenecks hindering full-scale implementation.Ultimately,future prospects for advancing understanding of mechanisms and engineering application of ANAMMOX process are posited.As a whole,technological advances in process design and patents have greatly contributed to better understanding of the ANAMMOX process,which has greatly aided in the optimization and industrialization of the ANAMMOX process.This review is intended to provide researchers with an overview of the present state of research and technological development of the ANAMMOX process,thus serving as a guide for realizing energy autarkic future practical applications.展开更多
Two anaerobic ammonia oxidation(anammox)systems,one with adding nano-scale zerovalent iron modified biochar(nZVI@BC)and the other with adding biochar,were constructed to explore the feasibility of nZVI@BC for enhancin...Two anaerobic ammonia oxidation(anammox)systems,one with adding nano-scale zerovalent iron modified biochar(nZVI@BC)and the other with adding biochar,were constructed to explore the feasibility of nZVI@BC for enhancing the resistance of low-nitrogen anammox processes to low temperatures.The results showed that the average nitrogen removal efficiency with nZVI@BC addition at lowtemperatureswas maintained at about 80%,while that with biochar addition gradually decreased to 69.49%.The heme-c content of biomass with nZVI@BC was significantly higher by 36.60%-91.45%.Additional,nZVI@BC addition resulted in more extracellular polymeric substances,better biomass granulation,and a higher abundance of anammox bacteria.In particularly,anammox genes hzsA/B/C,hzo and hdh played a pivotal role in maintaining nitrogen removal performance at 15℃.These findings suggest that nZVI@BC has the potential to enhance the resistance of low-nitrogen anammox processes to low temperatures,making it a valuable approach for practical applications in low-nitrogen and low-temperature wastewater treatment.展开更多
Soil denitrification,anammox,and Feammox are key for nitrogen(N)removal in agriculture.Despite potassium(K)fertilizer enhancing N efficiency,their role in regulation of these processes is unclear.A soil column incubat...Soil denitrification,anammox,and Feammox are key for nitrogen(N)removal in agriculture.Despite potassium(K)fertilizer enhancing N efficiency,their role in regulation of these processes is unclear.A soil column incubation with 15N isotope tracingwas conducted to explore millimeter-scale interactions of N and K on these pathways in soil fertilization zones.After 28 days,individual applications of N and K reduced denitrification-nitrogen removal rate(DNRR),anammox-nitrogen removal rate(ANRR),and feammox-nitrogen removal rate(FNRR)compared to a non-fertilizer control.N fertilizer had a greater effect than K,likely due to the high consumption of dissolved organic carbon by N fertilizer or the increased soil organic matter decomposition by K fertilizer.Combing of N and K increased DNRR,ANRR and FNRR rates by 31%,3090%and 244%compared to single N,and by-53.7%,885%and 222%compared to single K.These effects diminished with depth and distance from fertilizer sites.The effects of N fertilizer on these N removal processes might be regulate abundance of key microbes(e.g.,Limnobacter and Clostridium)and key gene(nirK,hzsB,ACM and Geo)by providing N substrates,while K enhances N metabolism efficiency through enzyme activation,indicated by the downregulation of certain genes(hzsB,ACM and Geo)and a negative correlation with N removal by simultaneously increasing gene expression and enzyme activity.These findings provide insights into how N and K together enhance N removal,emphasizing their importance for optimizing this process.展开更多
基金supported by China Hunan Provincial Science&Technology Department(No.2023NK2031)the Natural Science Foundation of Hunan Province(No.2023JJ40031)the Ministry of Human Resources and Social Security(No.H20240365).
文摘To explore the adaptive mechanisms of the partial nitritation-anammox(PNA)process under high salinity stress during kitchen wastewater treatment,focusing on their physiological and molecular responses through metagenomic analysis.An airlift inner-circulation partition bioreactor(AIPBR)was developed,featuring an inner cylinder and a flow guide tube to create distinct oxygen gradients,facilitating the study of microbial adaptation under varying salt conditions.The AIPBR was operated with synthetic wastewater containing ammonium concentrations of 1800±100 mg/L and salinity gradients ranging from 1 to 10 g/L,followed by a fixed salinity period at 6 g/L,with ammonium concentrations approximately 850 mg/L.High-throughput metagenomic analysis revealed shifts in functional genes and metabolic pathways in response to salinity stress.Anammox bacteria adapted by enriching genes involved in the synthesis of osmoprotective compounds and activating energy-producing pathways like the tricarboxylic acid cycle(TCA).These adaptations,along with modifications in membrane composition,were essential for sustaining system stability under elevated salinity.Under prolonged high salinity stress,anaerobic ammonium oxidizing(AnAOB)exhibited improved salt tolerance,maintaining a total nitrogen removal efficiency above 85%and stabilizing after an adaptation phase.The metagenomic data revealed a marked enrichment of genes associated with ion transport,stress response mechanisms,and DNA repair pathways.Changes in microbial community composition favored salt-tolerant species,supporting system stability.These findings highlight the applicability of the developed bioreactor for scaling up the PNA process to handle high-salinity wastewater,providing a promising avenue for sustainable nitrogen removal in challenging environments.
基金supported by Natural Science Foundation of Xiamen,China(No.3502Z20227232)the STS Project of Fujian-CAS(No.2023T3018)Bureau of International Cooperation,Chinese Academy of Sciences(No.322GJHZ2022035MI).
文摘Anammox bacteria in constructed wetlands(CWs)play pivotal role in sustainable nitrogen transformation,yet existing studies lack comprehensive analysis of environmental gradients and microbial interactions,both key factors in anammox bacteria enrichment.This study investigated the mechanisms driving anammox bacteria enrichment in lab-scale simulated CWs treating high-nitrogen wastewater,focusing on bacterial community re-sponses across wetland layers with various strategies,including continuous up-flow influent,nitrogen loading increase,effluent recirculation,intermittent influent,and anammox bacteria inoculation.Results showed that total relative and absolute abundances of anammox bacteria ranged from 0.77%to 12.50%and from 0.13 to 6.46×10^(7) copies/g,respectively.Dissolved oxygen and pH had significant positive correlations with the absolute abundance of anammox bacteria,while organic matter and nitrate negatively impacted their relative abundance.Permutational multivariate analysis of variance indicated that spatial heterogeneity explained more variation in anammox bacteria abundance(43.44%)compared to operational strategies(8.58%).In terms of microbial interactions,60 dominant species exhibited potential correlations with anammox bacteria,comprising 170 interactions(105 positive and 65 negative),which suggested that anammox bacteria generally foster cooperative relationships with dominant bacteria.Notably,significant interspecies interactions were observed between Candidatus Kuenenia(dominant anammox bacteria in CWs)and species within the genera Chitinivibrio-nia and Anaerolineaceae,suggesting that microbial interactions primarily manifest as indirect facilitative effects rather than direct mutualistic relationships.Given that the Normalized Stochasticity Ratio in CWs were<50%,this study inferred that environmental gradients have greater influence on anammox bacteria than microbial interactions.
基金supported by the National Natural Science Foundation of China (No.51508366)the Natural Science Foundation of Jiangsu Province (No.BK20201450)the Jiangsu Qinglan Project,Kunshan Science and Technology Planning Project (No.KSF202108).
文摘The removal of nitrogen via the ANAMMOX process is a promising green wastewater treatment technology,with numerous benefits.The incessant studies on the ANAMMOX process over the years due to its long start-up and high operational cost has positively influenced its technological advancement,even though at a rather slow pace.At the moment,relatively newANAMMOX technologies are being developedwith the goal of treating lowcarbon wastewater at low temperatures,tackling nitrite and nitrate accumulation and methane utilization from digestates while also recovering resources(phosphorus)in a sustainable manner.This review compares and contrasts the handful of ANAMMOX-based processes developed thus far with plausible solutions for addressing their respective bottlenecks hindering full-scale implementation.Ultimately,future prospects for advancing understanding of mechanisms and engineering application of ANAMMOX process are posited.As a whole,technological advances in process design and patents have greatly contributed to better understanding of the ANAMMOX process,which has greatly aided in the optimization and industrialization of the ANAMMOX process.This review is intended to provide researchers with an overview of the present state of research and technological development of the ANAMMOX process,thus serving as a guide for realizing energy autarkic future practical applications.
基金supported by the China Postdoctoral Science Foundation(No.2020M671624)the State Key Laboratory of Pollution Control and Resource Reuse(No.PCRRF20011).
文摘Two anaerobic ammonia oxidation(anammox)systems,one with adding nano-scale zerovalent iron modified biochar(nZVI@BC)and the other with adding biochar,were constructed to explore the feasibility of nZVI@BC for enhancing the resistance of low-nitrogen anammox processes to low temperatures.The results showed that the average nitrogen removal efficiency with nZVI@BC addition at lowtemperatureswas maintained at about 80%,while that with biochar addition gradually decreased to 69.49%.The heme-c content of biomass with nZVI@BC was significantly higher by 36.60%-91.45%.Additional,nZVI@BC addition resulted in more extracellular polymeric substances,better biomass granulation,and a higher abundance of anammox bacteria.In particularly,anammox genes hzsA/B/C,hzo and hdh played a pivotal role in maintaining nitrogen removal performance at 15℃.These findings suggest that nZVI@BC has the potential to enhance the resistance of low-nitrogen anammox processes to low temperatures,making it a valuable approach for practical applications in low-nitrogen and low-temperature wastewater treatment.
基金supported by the National Natural Science Foundation of China(Nos.32271726 and 32171648)the Natural Science Foundation of Hubei Province of China(No.2022CFB030)。
文摘Soil denitrification,anammox,and Feammox are key for nitrogen(N)removal in agriculture.Despite potassium(K)fertilizer enhancing N efficiency,their role in regulation of these processes is unclear.A soil column incubation with 15N isotope tracingwas conducted to explore millimeter-scale interactions of N and K on these pathways in soil fertilization zones.After 28 days,individual applications of N and K reduced denitrification-nitrogen removal rate(DNRR),anammox-nitrogen removal rate(ANRR),and feammox-nitrogen removal rate(FNRR)compared to a non-fertilizer control.N fertilizer had a greater effect than K,likely due to the high consumption of dissolved organic carbon by N fertilizer or the increased soil organic matter decomposition by K fertilizer.Combing of N and K increased DNRR,ANRR and FNRR rates by 31%,3090%and 244%compared to single N,and by-53.7%,885%and 222%compared to single K.These effects diminished with depth and distance from fertilizer sites.The effects of N fertilizer on these N removal processes might be regulate abundance of key microbes(e.g.,Limnobacter and Clostridium)and key gene(nirK,hzsB,ACM and Geo)by providing N substrates,while K enhances N metabolism efficiency through enzyme activation,indicated by the downregulation of certain genes(hzsB,ACM and Geo)and a negative correlation with N removal by simultaneously increasing gene expression and enzyme activity.These findings provide insights into how N and K together enhance N removal,emphasizing their importance for optimizing this process.
