Recovery profile of anaerobic ammonium oxidation (anammox) bacteria inhibited by ZnO nanoparticles

Abstract The potential effects of nanoparticles (NPs) on biological treatment processes have become significant due to their increasing industrial applications. The purpose of this research was to investigate the self-recovery ability of anammox bacteria following to acute ZnO NPs toxicity. In this context, a 2-liter lab-scale anammox reactor was operated for 550 days to enrich the biomass required to the batch exposure tests. Anammox culture was firstly exposed to four different doses of ZnO NPs (50, 75, 100 and 200 mg/L) for 24 h. Then, the ZnO NPs were removed and self-recovery performance of the anammox bacteria was assessed by evaluating the nitrogen removal capacities for 72 h. Besides the nitrogen removal performance, extracellular polymeric substances (EPS) production was also detected to deeply understand the response of the enriched anammox culture against ZnO NPs exposure. The results revealed that, sudden and high load of ZnO NPs (100 and 200 mg/L) resulted in persistent impairment on the nitrogen removal performance of the enriched anammox culture. However, relatively lower doses (50 and 75 mg/L) caused deceleration of the nitrogen removal performance during the recovery period. In addition, EPS content in the reactor decreased along with escalating load of ZnO NPs.

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Enhanced Nitrogen Removal from Domestic Wastewater by Partial-Denitrification/Anammox in an Anoxic/Oxic Biofilm Reactor

Processes ◽

10.3390/pr10010109 ◽

2022 ◽

Vol 10 (1) ◽

pp. 109

Author(s):

Yu Huang ◽

Yongzhen Peng ◽

Donghui Huang ◽

Jiarui Fan ◽

Rui Du

Keyword(s):

Nitrogen Removal ◽

Oxygen Demand ◽

Domestic Wastewater ◽

Biofilm Reactor ◽

Anammox Bacteria ◽

Stable Operation ◽

Ammonium Oxidation ◽

N Accumulation ◽

Carbon Demand ◽

Oxidation Efficiency

A partial-denitrification coupling with anaerobic ammonium oxidation (anammox) process (PD/A) in a continuous-flow anoxic/oxic (A/O) biofilm reactor was developed to treat carbon-limited domestic wastewater (ammonia (NH4+-N) of 55 mg/L and chemical oxygen demand (COD) of 148 mg/L in average) for about 200 days operation. Satisfactory NH4+-N oxidation efficiency above 95% was achieved with rapid biofilm formation in the aerobic zone. Notably, nitrite (NO2−-N) accumulation was observed in the anoxic zone, mainly due to the insufficient electron donor for complete nitrate (NO3−-N) reduction. The nitrate-to-nitrite transformation ratio (NTR) achieved was as high as 64.4%. After the inoculation of anammox-enriched sludge to anoxic zones, total nitrogen (TN) removal was significantly improved from 37.3% to 78.0%. Anammox bacteria were effectively retained in anoxic biofilm utilizing NO2−-N produced via the PD approach and NH4+-N in domestic wastewater, with the relative abundance of 5.83% for stable operation. Anammox pathway contributed to TN removal by a high level of 38%. Overall, this study provided a promising method for mainstream nitrogen removal with low energy consumption and organic carbon demand.

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Anaerobic ammonium oxidation in polyvinyl alcohol and sodium alginate immobilized biomass system: a potential tool to maintain anammox biomass in application

Water Science & Technology ◽

10.2166/wst.2013.762 ◽

2013 ◽

Vol 69 (4) ◽

pp. 718-726 ◽

Cited By ~ 17

Author(s):

Gang-Li Zhu ◽

Jia Yan ◽

Yong-You Hu

Keyword(s):

Polyvinyl Alcohol ◽

Sodium Alginate ◽

Nitrogen Removal ◽

Enrichment Culture ◽

Batch Reactor ◽

Anaerobic Ammonium Oxidation ◽

Anammox Bacteria ◽

Ammonium Oxidation ◽

Gel Beads ◽

Key Factor

Anaerobic ammonium oxidation (anammox) has been proved to be a promising nitrogen removal method for treating ammonium-rich wastewater. However, because of the low-growth rate of anammox bacteria, maintenance of a sufficient amount of anammox biomass in reactor became a key factor in application. Gel immobilization is an efficient method to prevent biomass from being washed out and to promote hyper-concentrated cultures. This study focused on a nitrogen removal process by anammox enrichment culture immobilized in polyvinyl alcohol and sodium alginate (PVA-SA) gel beads. The rapid startup of reactor demonstrated that gel entrapment was supposed to be a highly effective technique for immobilizing anammox bacteria. The anammox bacteria present in the enrichment were identified to be Jettenia-like species (>98%). Moreover, the effect of hydraulic retention time (HRT), pH, and temperature on immobilized anammox processes were investigated. The effect of pH and temperature on the anammox process was evidently weakened in PVA-SA immobilized gel beads, however, the effect of HRT on the anammox reaction was enhanced. Therefore, a stable operated reactor could be obtained in an anaerobic sequencing batch reactor, which proved gel immobilization was an excellent method to maintain the biomass in anammox reactor for application.

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Coupled anaerobic ammonium oxidation and hydrogenotrophic denitrification for simultaneous NH4-N and NO3-N removal

Water Science & Technology ◽

10.2166/wst.2018.459 ◽

2018 ◽

Vol 79 (5) ◽

pp. 975-984 ◽

Cited By ~ 4

Author(s):

Tatsuru Kamei ◽

Rawintra Eamrat ◽

Kenta Shinoda ◽

Yasuhiro Tanaka ◽

Futaba Kazama

Keyword(s):

Nitrogen Removal ◽

Inorganic Nitrogen ◽

Nitrate Removal ◽

Fixed Bed ◽

Anaerobic Ammonium Oxidation ◽

Anammox Bacteria ◽

Ammonium Oxidation ◽

N Removal ◽

Anammox Process

Abstract Nitrate removal during anaerobic ammonium oxidation (anammox) treatment is a concern for optimization of the anammox process. This study demonstrated the applicability and long-term stability of the coupled anammox and hydrogenotrophic denitrification (CAHD) process as an alternative method for nitrate removal. Laboratory-scale fixed bed anammox reactors (FBR) supplied with H2 to support denitrification were operated under two types of synthetic water. The FBRs showed simultaneous NH4-N and NO3-N removal, indicating that the CAHD process can support NO3-N removal during the anammox process. Intermittent H2 supply (e.g. 5 mL/min for a 1-L reactor, 14/6-min on/off cycle) helped maintain the CAHD process without deteriorating its performance under long-term operation and resulted in a nitrogen removal rate of 0.21 kg-N/m3/d and ammonium, nitrate, and dissolved inorganic nitrogen removal efficiencies of 73.4%, 80.4%, and 77%, respectively. The microbial community structure related to the CAHD process was not influenced by changes in influent water quality, and included the anammox bacteria ‘Candidatus Jettenia’ and a Sulfuritalea hydrogenivorans-like species as the dominant bacteria even after long-term reactor operation, suggesting that these bacteria are key to the CAHD process. These results indicate that the CAHD process is a promising method for enhancing the efficiency of anammox process.

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Microbiological conversions in nitrogen removal

Water Science & Technology ◽

10.2166/wst.1998.0002 ◽

1998 ◽

Vol 38 (1) ◽

pp. 1-7 ◽

Cited By ~ 53

Author(s):

M. C. M. Van Loosdrecht ◽

M. S. M. Jetten

Keyword(s):

Wastewater Treatment ◽

Nitrogen Removal ◽

Organic Substrate ◽

Heterotrophic Nitrification ◽

Aerobic Denitrification ◽

Ammonium Oxidation ◽

Treatment Processes ◽

Nitrogen Conversion ◽

The Many ◽

Wastewater Treatment Systems

Nitrogen conversion processes are essential for most wastewater treatment systems. Due to the many possible conversions, and the complexity of analysing the reactions under actual conditions, there is much room for confusion. This review provides an overview of the possible microbiological nitrogen conversions described in literature. The relevance of these conversions with respect to wastewater treatment processes is discussed. Rates described for aerobic denitrification or denitrification by autotrophic nitrifiers are so low that these conversions probably do not play a significant role under practical conditions. Heterotrophic nitrification may be of relevance only when the wastewater contains a high COD/N ratio (>10). Anaerobic ammonium oxidation can occur in fully autotrophic systems with very long sludge retention times or biofilm systems. This conversion offers great opportunities since it allows us to denitrify with ammonium as electron donor, i.e. no organic substrate is needed in the nitrogen removal process.

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Vegetation effects on anammox spatial distribution and nitrogen removal in constructed wetlands treated with domestic sewage

Water Science & Technology ◽

10.2166/wst.2014.388 ◽

2014 ◽

Vol 70 (8) ◽

pp. 1370-1375 ◽

Cited By ~ 3

Author(s):

Ling Wang ◽

Tian Li

Keyword(s):

Spatial Distribution ◽

Root System ◽

Constructed Wetlands ◽

Nitrogen Removal ◽

Sharp Decrease ◽

Middle Layer ◽

Anammox Bacteria ◽

Acorus Calamus ◽

Ammonium Oxidation ◽

Reduced Rate

In this study, two horizontal subsurface-flow constructed wetlands (CWs) (planted and unplanted) were constructed and compared to investigate the effects of vegetation on nitrogen removal and anammox (anaerobic ammonium oxidation) spatial distribution and enrichment. Calamus (Acorus calamus L.), which has a large root system, was selected as the vegetation. Removal of total nitrogen from the planted wetland was much higher than that from the unplanted one. Radial oxygen loss from calamus provided the planted wetland with better oxygen restoration ability, benefitting ammonium removal in the CW, especially when anammox was inhibited under winter temperatures. Enrichment of anammox bacteria in planted wetlands was much greater than that in unplanted ones. The greatest enrichment of anammox bacteria occurred in the middle layer, which had a better anaerobic environment and moderate root system. The reduced rate of metabolism in plants during winter led to a sharp decrease in anammox bacteria copy numbers in the planted wetland. Under cold temperature, the degree of enrichment with anammox bacteria in the planted wetland was similar to or slightly superior to that in the unplanted wetland.

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Nitrogen removal and microbial communities of a completely autotrophic nitrogen removal over nitrite (CANON) sequencing batch biofilm reactor (SBBR) at different inorganic carbon (IC) concentrations

Water Science & Technology ◽

10.2166/wst.2020.203 ◽

2020 ◽

Vol 81 (5) ◽

pp. 1071-1079

Author(s):

Caimeng Wang ◽

Lirong Lei ◽

Fangrui Cai ◽

Youming Li

Keyword(s):

Nitrogen Removal ◽

Inorganic Nitrogen ◽

Biofilm Reactor ◽

Anammox Bacteria ◽

Ammonium Oxidation ◽

Sequencing Batch Biofilm Reactor ◽

Microbial Analysis ◽

Total Inorganic Nitrogen ◽

Canon Process ◽

Autotrophic Nitrogen Removal

Abstract In this study, the completely autotrophic nitrogen removal over nitrite (CANON) process was initiated in a sequencing batch biofilm reactor (SBBR). Then the reactor was operated under different IC/N ratios. The total inorganic nitrogen removal efficiency (TINRE) at IC/N ratios of 0.75, 1.0, 1.25, 1.5 and 2.0 were 37.0 ± 11.0%, 58.9 ± 10.2%, 73.9 ± 3.2%, 73.6 ± 1.8% and 72.6 ± 2.0%, respectively. The suitable range of IC/N ratio in this research is 1.25–2.0. The poor nitrogen removal performance at IC/N ratio of 0.75 was due to the lack of growth substrate for AnAOB and low pH simultaneously; at IC/N ratio of 1.0 this was because the substrate concentration was insufficient for fully recovering the AnAOB activities. Microbial analysis indicated that Nitrosomonas, Nitrospira and Candidatus Brocadia were the main ammonium oxidation bacteria (AOB), nitrite oxidation bacteria (NOB) and anammox bacteria (AnAOB), respectively. In addition, at IC ratios of 1.25 or higher, denitrification was promoted with the rise of IC/N ratio, which might be because the change of IC concentrations caused cell lysis of microorganisms and provided organic matter for denitrification.

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Nitrogen removal during the cold season by constructed floating wetlands planted with Oenanthe javanica

Marine and Freshwater Research ◽

10.1071/mf17156 ◽

2018 ◽

Vol 69 (5) ◽

pp. 635 ◽

Cited By ~ 5

Author(s):

Penghe Wang ◽

Nasreen Jeelani ◽

Jie Zuo ◽

Hui Zhang ◽

Dehua Zhao ◽

...

Keyword(s):

Waste Water ◽

Nitrogen Removal ◽

Nitrite Reductase ◽

Waste Water Treatment ◽

Microbial Community Composition ◽

Cold Season ◽

Anammox Bacteria ◽

Ammonium Oxidation ◽

Oenanthe Javanica ◽

Floating Wetlands

Constructed floating wetlands (CFWs) are used to treat waste waters of various origins either alone or as part of waste water treatment trains. The aim of the present study was to determine the extent of nitrogen removal by CFWs planted with Oenanthe javanica (Blume) DC. at low temperatures (<10°C) and whether CFWs with vesuvianite as a substrate perform better than those without substrate. A batch model was used, with CFWs planted with O. javanica (Tc), CFWs without O. javanica (Ts), CFWs without substrate (Tp) and floating mats only (To) as a control. The average removal rates of NH4+-N, NO3–-N and total nitrogen were 78.3, 44.4 and 49.7% respectively in Tc; 72.0, 40.0 and 39.5% respectively in Ts; and 73.1, 33.7 and 44.0% respectively in Tp. In addition to a gradual increase in chemical oxygen demand during the experimental period, Tc had higher microbial richness and diversity, as well as a higher abundance of bacteria, archaea, anaerobic ammonium oxidation (Anammox) bacteria and key genes (ammonia mono-oxygenase, amoA, nitrous oxide reductase, nosZ, dissimilatory cd1-containing nitrite reductase, nirS, and dissimilatory copper-containing nitrite reductase, nirK) involved in nitrogen metabolism in the substrate than Ts. Further analysis of microbial community composition revealed a difference at multiple taxonomic levels among different systems. These results demonstrate the positive roles of O. javanica and vesuvianite in CFWs in nitrogen removal from waste water during the cold season (mean water temperature <10°C).

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Start-Up of Anammox SBR from Non-Specific Inoculum and Process Acceleration Methods by Hydrazine

Water ◽

10.3390/w13030350 ◽

2021 ◽

Vol 13 (3) ◽

pp. 350

Author(s):

Ivar Zekker ◽

Oleg Artemchuk ◽

Ergo Rikmann ◽

Kelvin Ohimai ◽

Gourav Dhar Bhowmick ◽

...

Keyword(s):

Nitrogen Removal ◽

Biological Nutrient Removal ◽

Anaerobic Sludge ◽

Anammox Bacteria ◽

Ammonium Oxidation ◽

Reject Water ◽

Start Up ◽

Anammox Activity ◽

Optimum Salinity ◽

Anammox Process

Biological nutrient removal from wastewater to reach acceptable levels is needed to protect water resources and avoid eutrophication. The start-up of an anaerobic ammonium oxidation (anammox) process from scratch was investigated in a 20 L sequence batch reactor (SBR) inoculated with a mixture of aerobic and anaerobic sludge at 30 ± 0.5 °C with a hydraulic retention time (HRT) of 2–3 days. The use of NH4Cl, NaNO2, and reject water as nitrogen sources created different salinity periods, in which the anammox process performance was assessed: low (<0.2 g of Cl−/L), high (18.2 g of Cl−/L), or optimum salinity (0.5–2 g of Cl−/L). Reject water feeding gave the optimum salinity, with an average nitrogen removal efficiency of 80%, and a TNRR of 0.08 kg N/m3/d being achieved after 193 days. The main aim was to show the effect of a hydrazine addition on the specific anammox activity (SAA) and denitrification activity in the start-up process to boost the autotrophic nitrogen removal from scratch. The effect of the anammox intermediate hydrazine addition was tested to assess its concentration effect (range of 2–12.5 mg of N2H4/L) on diminishing denitrifier activity and accelerating anammox activity at the same time. Heterotrophic denitrifiers’ activity was diminished by all hydrazine additions compared to the control; 5 mg of N2H4/L added enhanced SAA compared to the control, achieving an SAA of 0.72 (±0.01) mg N/g MLSS/h, while the test with 7.5 mg of N2H4/L reached the highest overall SAA of 0.98 (±0.09) mg N g/MLSS/h. The addition of trace amounts of hydrazine for 6 h was also able to enhance SAA after inhibition by organic carbon source sodium acetate addition at a high C/N ratio of 10/1. The start-up of anammox bacteria from the aerobic–anaerobic suspended biomass was successful, with hydrazine significantly accelerating anammox activity and decreasing denitrifier activity, making the method applicable for side-stream as well as mainstream treatment.

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Enrichment of marine anammox bacteria from seawater-related samples and bacterial community study

Water Science & Technology ◽

10.2166/wst.2010.796 ◽

2010 ◽

Vol 61 (1) ◽

pp. 119-126 ◽

Cited By ~ 16

Author(s):

Y. Kawagoshi ◽

Y. Nakamura ◽

H. Kawashima ◽

K. Fujisaki ◽

K. Furukawa ◽

...

Keyword(s):

Waste Disposal ◽

Nitrogen Removal ◽

Denaturing Gradient Gel Electrophoresis ◽

Enrichment Culture ◽

Removal Rate ◽

Nitrogen Loading ◽

Disposal Site ◽

Anammox Bacteria ◽

Ammonium Oxidation ◽

Waste Disposal Site

Anaerobic ammonium oxidation (anammox) is a novel nitrogen pathway catalyzed by anammox bacteria which are obligate anaerobic chemoautotrophs. In this study, enrichment culture of marine anammox bacteria (MAAOB) from the samples related to seawater was conducted. Simultaneous removal of ammonium and nitrite was confirmed in continuous culture inoculated with sediment of a sea-based waste disposal site within 50 days. However, no simultaneous nitrogen removal was observed in cultures inoculated with seawater-acclimated denitrifying sludge or with muddy sediment of tideland even during 200 days. Nitrogen removal rate of 0.13 kg/m3/day was achieved at nitrogen loading rate of 0.16 kg/m3/day after 320th days in the culture inoculated with the sediment of waste disposal site. The nitrogen removal ratio between ammonium nitrogen and nitrite nitrogen was 1:1.07. Denaturing gradient gel electrophoresis (DGGE) analysis indicated that an abundance of the bacteria close to MAAOB and coexistence of ammonium oxidizing bacteria and denitrifying bacteria in the culture.

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Response and Adaptation of Microbial Community in a CANON Reactor Exposed to an Extreme Alkaline Shock

Archaea ◽

10.1155/2020/8888615 ◽

2020 ◽

Vol 2020 ◽

pp. 1-11

Author(s):

Ruili Yang ◽

Wenlong Mao ◽

Xiaojun Wang ◽

Zhaoji Zhang ◽

Junbin Wu ◽

...

Keyword(s):

Microbial Community ◽

Influencing Factors ◽

Relative Abundance ◽

Nitrogen Removal ◽

Extracellular Polymeric Substances ◽

Recovery Phase ◽

Nitrogen Loading ◽

Anammox Bacteria ◽

Anammox Activity ◽

Canon Process

Responses of a microbial community in the completely autotrophic nitrogen removal over nitrite (CANON) process, which was shocked by a pH of 11.0 for 12 h, were investigated. During the recovery phase, the performance, anaerobic ammonia oxidation (anammox) activity, microbial community, and correlation of bacteria as well as the influencing factors were evaluated synchronously. The performance of the CANON process deteriorated rapidly with a nitrogen removal rate (NRR) of 0.13 kg·m-3·d-1, and Firmicutes, spore-forming bacteria, were the dominant phyla after alkaline shock. However, it could self-restore within 107 days after undergoing four stages, at which Planctomycetes became dominant with a relative abundance of 64.62%. Network analysis showed that anammox bacteria (Candidatus Jettenia, Kuenenia, and Brocadia) were positively related to some functional bacteria such as Nitrosomonas, SM1A02, and Calorithrix. Canonical correspondence analysis presented a strong correlation between the microbial community and influencing factors during the recovery phase. With the increase of nitrogen loading rate, the decrease of free nitrous acid and the synergistic effects, heme c content, specific anammox activity (SAA), NRR, and the abundance of dominant genus increased correspondingly. The increase of heme c content regulates the quorum sensing system, promotes the secretion of extracellular polymeric substances, and further improves SAA, NRR, and the relative abundance of the dominant genus. This study highlights some implications for the recovery of the CANON reactor after being exposed to an alkaline shock.

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