Model-based analysis of microbial consortia and microbial products in an anammox biofilm reactor

Abstract A mathematical model for a granular biofilm reactor for leachate treatment was validated by long-term measured data to investigate the mechanisms and drivers influencing biological nitrogen removal and microbial consortia dynamics. The proposed model, based on Activated Sludge Model (ASM1), included anaerobic ammonium oxidation (anammox), nitrifying and heterotrophic denitrifying bacteria which can attach and grow on granular activated carbon (GAC) particles. Two kinetic descriptions for the model were proposed: with and without soluble microbial products (SMP) and extracellular polymeric substance (EPS). The model accuracy was checked using recorded total inorganic nitrogen concentrations in the effluent and estimated relative abundance of active bacteria using quantitative fluorescence in-situ hybridization (qFISH). Results suggested that the model with EPS kinetics fits better for the relative abundance of anammox bacteria and nitrifying bacteria compared to the model without EPS. The model with EPS and SMP confirms that the growth and existence of heterotrophs in anammox biofilm systems slightly increased due to including the kinetics of SMP production in the model. During the one-year simulation period, the fractions of autotrophs and EPS in the biomass were almost stable but the fraction of heterotrophs decreased which is correlated with the reduction in nitrogen surface loading on the biofilm.

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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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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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Nitrogen removal via a single-stage PN–Anammox process in a novel combined biofilm reactor

Water Science & Technology ◽

10.2166/wst.2017.572 ◽

2017 ◽

Vol 77 (6) ◽

pp. 1483-1492 ◽

Cited By ~ 6

Author(s):

Yue-mei Han ◽

Feng-xia Liu ◽

Xiao-fei Xu ◽

Zhuo Yan ◽

Zhi-jun Liu

Keyword(s):

Total Nitrogen ◽

Nitrogen Removal ◽

Ammonia Oxidation ◽

Biofilm Reactor ◽

Nitrifying Bacteria ◽

Anammox Bacteria ◽

Ammonia Oxidizing Bacteria ◽

High Ammonia ◽

Total Nitrogen Removal ◽

Anammox Process

Abstract This study developed a partial nitrification (PN) and anaerobic ammonia oxidation (Anammox) process for treating high-ammonia wastewater using an innovative biofilm system in which ammonia oxidizing bacteria grew on fluidized Kaldnes (K1) carriers and Anammox bacteria grew on fixed acryl resin carriers. The airlift loop biofilm reactor (ALBR) was stably operated for more than 4 months under the following conditions: 35 ± 2 °C, pH 7.5–8.0 and dissolved oxygen (DO) of 0.5–3.5 mg/L. The results showed that the total nitrogen removal efficiency reached a maximum of 75% and the total nitrogen removal loading rate was above 0.4 kg/(d·m3). DO was the most efficient control parameter in the mixed biofilm system, and values below 1.5 mg/L were observed in the riser zone for the PN reaction, while values below 0.8 mg/L were observed in the downer zone for the Anammox reaction. Scanning electron microscopy and Fluorescence In Situ Hybridization images showed that most of the nitrifying bacteria were distributed on the K1 carriers and most of the Anammox bacteria were distributed within the acryl resin carriers. Therefore, the results indicate that the proposed combined biofilm system is easy to operate and efficient for the treatment of high-ammonia wastewater.

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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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Enrichment of Anaerobic Ammonium Oxidation (Anammox) Bacteria for Biological Nitrogen Removal of Wastewater

Jurnal Teknologi ◽

10.11113/jt.v62.1874 ◽

2013 ◽

Vol 62 (2) ◽

Author(s):

Norjan Yusof ◽

Hanisom Abdullah ◽

Syakirah Samsudin ◽

Mohd Ali Hassan

Keyword(s):

Batch Reactor ◽

Anaerobic Ammonium Oxidation ◽

Anammox Bacteria ◽

Ammonium Oxidation ◽

Leachate Treatment ◽

16S Rrna Sequence ◽

Bottom Part ◽

Enrichment Cultures ◽

Anammox Activity ◽

Biological Nitrogen

Anaerobic ammonium oxidation (anammox) bacteria enrichment was explored for the potential application of ammonium rich wastewater removal. Samples of sludge from mature and young landfill leachate treatment plants were screened and used as inocula for anammox enrichment cultures. Enrichments were monitored for N-NH3, N-NO2- and N-NO3- to detect anammox potential activity. Six of the twelve enrichment cultures showed anammox activity after more than five months of enrichment period. All enrichment cultures that gave positive results were obtained from bottom part of sequencing batch reactor (SBR) lagoon indicating localization of anammox bacteria in anaerobic condition. Polymerase Chain Reaction (PCR) with specific primers targeting anammox and planctomycete were able to amplify the 16S rRNA sequence for anammox bacteria under PCR optimum condition. However, only three of six positive samples were successfully sequenced. DNA sequence analysis using NCBI (BLAST) and RDP showed that the anammox bacterial sequences of the investigated samples were identified as Candidatus Kuenenia stuttgartiensis with similarity of 100% (NCBI) and 99.3% (RDP).

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Effect of Shear Stress on Detachment in Biofilm Reactor under Low C/N Ratio

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.955-959.681 ◽

2014 ◽

Vol 955-959 ◽

pp. 681-686 ◽

Cited By ~ 1

Author(s):

Yin Jun ◽

Heng Juan Xu

Keyword(s):

Shear Stress ◽

Relative Abundance ◽

Oxidation Rate ◽

Mixed Population ◽

Biofilm Reactor ◽

Hydrodynamic Condition ◽

Ammonium Oxidation ◽

Constant Flow ◽

Nitrification Process ◽

Pyrosequencing Analysis

The aim of this study is to evaluate the effect of shear stress on detachment and nitrification process in a mixed-population biofilm. The biofilm was grown under constant flow condition with low C/N ratio. During the experiment, ammonium oxidation rate reached above 99%. Sloughing events happened mainly under constant hydrodynamic condition. Detachment experiment showed that it’s not possible to control the occurrence of sloughing events by controlling shear stress. Pyrosequencing analysis of the biofilm showed that Proteobacteria and Bacteroidetes were the two most abundant phyla, but detachment would influence the relative abundance of AOB and NOB in biofilm to affect the nitrification process.

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Effects of carbon sources, COD/NO2−-N ratios and temperature on the nitrogen removal performance of the simultaneous partial nitrification, anammox and denitrification (SNAD) biofilm

Water Science & Technology ◽

10.2166/wst.2017.035 ◽

2017 ◽

Vol 75 (7) ◽

pp. 1712-1721 ◽

Cited By ~ 14

Author(s):

Zhaoming Zheng ◽

Yun Li ◽

Jun Li ◽

Yanzhuo Zhang ◽

Wei Bian ◽

...

Keyword(s):

Carbon Source ◽

Nitrogen Removal ◽

Municipal Wastewater ◽

Inorganic Nitrogen ◽

Carbon Sources ◽

Biofilm Reactor ◽

Partial Nitrification ◽

Anammox Bacteria ◽

Coupling Process ◽

Anammox Activity

The aim of the present work was to evaluate the effects of carbon sources and chemical oxygen demand (COD)/NO2−-N ratios on the anammox–denitrification coupling process of the simultaneous partial nitrification, anammox and denitrification (SNAD) biofilm. Also, the anammox activities of the SNAD biofilm were investigated under different temperature. Kaldnes rings taken from the SNAD biofilm reactor were operated in batch tests to determine the nitrogen removal rates. As a result, with the carbon source of sodium acetate, the appropriate COD/NO2−-N ratios for the anammox–denitrification coupling process were 1 and 2. With the COD/NO2−-N ratios of 1, 2, 3, 4 and 5, the corresponding NO2−-N consumption via anammox was 87.1%, 52.2%, 29.3%, 23.7% and 16.3%, respectively. However, with the carbon source of sodium propionate and glucose, the anammox bacteria was found to perform higher nitrite competitive ability than denitrifiers at the COD/NO2−-N ratio of 5. Also, the SNAD biofilm could perform anammox activity at 15 °C with the nitrogen removal rate of 0.071 kg total inorganic nitrogen per kg volatile suspended solids per day. These results indicated that the SNAD biofilm process might be feasible for the treatment of municipal wastewater at normal temperature.

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Environmental factors determining distribution and activity of anammox bacteria in minerotrophic fen soils

FEMS Microbiology Ecology ◽

10.1093/femsec/fiz191 ◽

2019 ◽

Vol 96 (2) ◽

Author(s):

Alexandre Bagnoud ◽

Sylvia Guye-Humbert ◽

Brigitte Schloter-Hai ◽

Michael Schloter ◽

Jakob Zopfi

Keyword(s):

Agricultural Land ◽

Inorganic Nitrogen ◽

16S Rrna Gene Sequencing ◽

Anammox Bacteria ◽

Peat Bogs ◽

Rrna Gene ◽

Ammonium Oxidation ◽

Buffer Zones ◽

Wet Meadow ◽

N Removal

ABSTRACT In contrast to the pervasive occurrence of denitrification in soils, anammox (anaerobic ammonium oxidation) is a spatially restricted process that depends on specific ecological conditions. To identify the factors that constrain the distribution and activity of anammox bacteria in terrestrial environments, we investigated four different soil types along a catena with opposing ecological gradients of nitrogen and water content, from an amended pasture to an ombrotrophic bog. Anammox was detected by polymerase chain reaction (PCR) and quantitative PCR (qPCR) only in the nitrophilic wet meadow and the minerotrophic fen, in soil sections remaining water-saturated for most of the year and whose interstitial water contained inorganic nitrogen. Contrastingly, aerobic ammonia oxidizing microorganisms were present in all examined samples and outnumbered anammox bacteria usually by at least one order of magnitude. 16S rRNA gene sequencing revealed a relatively high diversity of anammox bacteria with one Ca. Brocadia cluster. Three additional clusters could not be affiliated to known anammox genera, but have been previously detected in other soil systems. Soil incubations using 15N-labeled substrates revealed that anammox processes contributed about <2% to total N2 formation, leaving nitrification and denitrification as the dominant N-removal mechanism in these soils that represent important buffer zones between agricultural land and ombrotrophic peat bogs.

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Nitrification and autotrophic denitrification of source-separated urine

Water Science & Technology ◽

10.2166/wst.2003.0031 ◽

2003 ◽

Vol 48 (1) ◽

pp. 119-130 ◽

Cited By ~ 61

Author(s):

K.M. Udert ◽

C. Fux ◽

M. Münster ◽

T.A. Larsen ◽

H. Siegrist ◽

...

Keyword(s):

Ammonia Oxidation ◽

Batch Reactor ◽

Nitrate Solution ◽

Ammonia Concentration ◽

Biofilm Reactor ◽

Anammox Bacteria ◽

Nitrification Rate ◽

Ammonium Oxidation ◽

Ammonium Nitrate Solution ◽

Total Ammonia

In laboratory experiments, source-separated urine was stabilised with nitrification and denitrified via nitritation and anaerobic ammonium oxidation. The highest total ammonia concentration in the influent was 7,300 gN/m3, the maximum pH 9.2. In a moving bed biofilm reactor (MBBR) with Kaldnes® biofilm carriers, we stabilised urine as a 1:1 ammonium nitrate solution. The maximum nitrification rate was 380 gN/m3/d corresponding to 1.7 gN/m2biofilm/d. Nitrite ammonium solutions were produced in a continuous flow stirred tank reactor (CSTR) with 4.8 days sludge retention time (SRT) at 30°C and in a sequencing batch reactor (SBR) with more than 30 days SRT. Nitrate build-up was negligible in both reactors. Nitritation rates were 780 gN/m3/d in the CSTR and 280 gN/m3/d in the SBR, respectively. However, shortening the cycles would increase nitritation in the SBR. High concentrations of nitrous acid, salts, and presumably hydroxylamine suppressed nitrite oxidation in the nitritation reactors. In all three nitrification reactors, maximally 50% of the influent total ammonia was oxidised without pH control. None of the common inhibition or limitation approaches could explain why ammonia oxidation always stopped at pH values around 6. In a batch experiment, we showed that source-separated urine can be denitrified autotrophically by anammox bacteria.

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Metagenomics Response of Anaerobic Ammonium Oxidation (anammox) Bacteria to Bio-Refractory Humic Substances in Wastewater

Water ◽

10.3390/w11020365 ◽

2019 ◽

Vol 11 (2) ◽

pp. 365 ◽

Cited By ~ 1

Author(s):

Yabing Meng ◽

Li-Nan Huang ◽

Fangang Meng

Keyword(s):

Humic Substances ◽

Anammox Bacteria ◽

Ammonium Oxidation ◽

Leachate Treatment ◽

Term Operation ◽

Comparative Metagenomics ◽

Electron Shuttles ◽

One Year ◽

High Level

Anammox-based processes have been widely applied for the treatment of wastewater (e.g., wastewater irrigation systems and constructed wetland) which consists of bio-refractory humic substances. Nonetheless, the impacts of bio-refractory humic substances on anammox consortia are rarely reported. In the present study, three identical lab-scale anammox reactors (i.e., HS0, HS1 and HS10), two of which were dosed with humic substances at 1 and 10 mg·L−1, respectively, were operated for nearly one year. The long-term operation of the reactors showed that the presence of humic substances in influent had no significant influence on nitrogen removal rates. Despite this, comparative metagenomics showed changes in anammox microbiota structure during the exposure to humic substance; e.g., the relative abundance of Candidatus Kuenenia was lower in HS10 (18.5%) than that in HS0 (22.8%) and HS1 (21.7%). More specifically, a lower level of humic substances (1 mg·L−1) in influent led to an increase of genes responsible for signal transduction, likely due to the role of humic substances as electron shuttles. In contrast, a high level of humic substances (10 mg·L−1) resulted in a slight decrease of functional genes associated with anammox metabolism. This may partially be due to the biodegradation of the humic substances. In addition, the lower dosage of humic substances (1 mg·L−1) also stimulated the abundance of hzs and hdh, which encode two important enzymes in anammox reaction. Overall, this study indicated that the anammox system could work stably over a long period under humic substances, and that the process was feasible for leachate treatment.

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