Ammonium Oxidation Process Research Articles

Advances in the Efficient Enrichment of Anammox Bacteria

Anaerobic ammonia oxidation (anammox) process is known as a low-energy and environmentally friendly process for treating nitrogen-rich wastewater. Anammox bacteria are the key microorganisms to achieve this biological process. However, the efficient enrichment of anammox bacteria has been a bottleneck for its practical application because of their slow growth and high sensitivity, and no pure culture has been found. Therefore, the development of efficient anammox bacterial enrichment techniques is of great theoretical and application value. Solving the problem of anammox bacterial activity and improving the process denitrification performance is one of the current research hotspots. In this paper, three aspects of anammox bacteria are described in terms of their physiological properties, environmental influencing factors, and short-term starvation tolerance; a systematic review of the latest research progress in accelerating the activity of anammox bacteria using enrichment strategies for process regulation, the construction of granulation models, suspended sludge biomass management, and strain preservation. Finally, the future frontier development of anammox bacteria was discussed and foreseen.

Anammox with alternative electron acceptors: perspectives for nitrogen removal from wastewaters.

In the context of the anaerobic ammonium oxidation process (anammox), great scientific advances have been made over the past two decades, making anammox a consolidated technology widely used worldwide for nitrogen removal from wastewaters. This review provides a detailed and comprehensive description of the anammox process, the microorganisms involved and their metabolism. In addition, recent research on the application of the anammox process with alternative electron acceptors is described, highlighting the biochemical reactions involved, its advantages and potential applications for specific wastewaters. An updated description is also given of studies reporting the ability of microorganisms to couple the anammox process to extracellular electron transfer to insoluble electron acceptors; particularly iron, carbon-based materials and electrodes in bioelectrochemical systems (BES). The latter, also referred to as anodic anammox, is a promising strategy to combine the ammonium removal from wastewater with bioelectricity production, which is discussed here in terms of its efficiency, economic feasibility, and energetic aspects. Therefore, the information provided in this review is relevant for future applications.

Selective synthesis of nitrate from air using a plasma-driven gas-liquid relay reaction system

The direct oxidation of nitrogen is a potential pathway to achieving the zero-carbon-emission synthesis of nitric acid or nitrate, because it does not involve ammonia synthesis and additional ammonia oxidation processes. However, the slow kinetics of nitrogen oxidation and the difficult selective control of oxidation products hinder the development of this process. In this study, a plasma-driven gas-liquid relay reaction system was developed to overcome these limitations. A typical feature of this reaction system is that it can efficiently generate NOx under plasma exposure; moreover, the specific anions in the absorption solution can be oxidized to strong oxidants capable of relay oxidation of low-valence nitrogen oxides. This feature allows for the deep oxidation of nitrogen, thus enabling the oxidation products of nitrogen to exist in high-valence states in the absorption solution. For experimental verification, we achieved the 100% selective synthesis of nitrate under plasma exposure, with air as the supply gas and a sodium sulfate solution as the absorption solution.

Multidrug-resistant plasmid RP4 increases NO and N2O yields via the electron transport system in Nitrosomonas europaea ammonia oxidation

Antibiotic resistance genes (ARGs) have recently become an important public health problem and therefore several studies have characterized ARG composition and distribution. However, few studies have assessed their impact on important functional microorganisms in the environment. Therefore, our study sought to investigate the mechanisms through which multidrug-resistant plasmid RP4 affected the ammonia oxidation capacity of ammonia-oxidizing bacteria, which play a key role in the nitrogen cycle. The ammonia oxidation capacity of N. europaea ATCC25978 (RP4) was significantly inhibited, and NO and N2O were produced instead of nitrite. Our findings demonstrated that the decrease in electrons from NH2OH decreased the ammonia monooxygenase (AMO) activity, leading to a decrease in ammonia consumption. In the ammonia oxidation process, N. europaea ATCC25978 (RP4) exhibited ATP and NADH accumulation. The corresponding mechanism was the overactivation of Complex Ⅰ, ATPase, and the TCA cycle by the RP4 plasmid. The genes encoding TCA cycle enzymes related to energy generation, including gltA, icd, sucD, and NE0773, were upregulated in N. europaea ATCC25978 (RP4). These results demonstrate the ecological risks of ARGs, including the inhibition of the ammonia oxidation process and an increased production of greenhouse gases such as NO and N2O.

Influence of Low Air Pressure on the Partial Denitrification-Anammox (PD/A) Process

Low air pressure is a feature of high-altitude regions. Domestic wastewater from such regions typically has a low carbon-to-nitrogen ratio (C/N ratio). These factors combine to make traditional biological nitrogen removal in high-altitude regions inefficient and more energy-intensive. The partial denitrification-anaerobic ammonium oxidation (PD/A) process was reported to remove ammonia nitrogen from municipal sewage, consuming fewer carbon sources and requiring no aeration supply. In this study, we set up laboratory-scale reactors in simulated high-altitude environmental conditions, and studied the effect of air pressure on the PD/A process. We found that low pressure promotes nitrogen removal efficiency (NRE), achieving 93.0 ± 0.3% at 65 kPa, and the contribution rate of anaerobic ammonium oxidation (anammox) to nitrogen removal increased to 77.7%. Lower dissolved oxygen (DO) concentrations caused by lower air pressure were the reason for higher nitrite accumulation efficiency (NAE) in a partial denitrification (PD) system, with measured values of 78.4 ± 2.8% at 65 kPa. The anammox process was promoted by low air pressure, mainly because the low air pressure resulted in higher anaerobic ammonia-oxidizing bacteria activity, with specific anammox activity (SAA) reaching 26.3 mg·N/(g·VSS·d). Although the relative abundance of partial-denitrifying bacteria declined slightly, at 65 kPa compared with 96 kPa, they were still the dominant genus of the PD/A sludge, and continued to generate nitrite nitrogen steadily, even at low air pressures. The anaerobic ammonia-oxidizing bacterial abundance remained relatively stable, but their activity was increased, which aided the PD/A process. This study demonstrates how low pressure promotes the PD/A process, indicating the possibility of sustainable improved nitrogen removal in high-altitude regions.

Integration of the sulfate reduction and anammox processes for enhancing sustainable nitrogen removal in granular sludge reactors

The Anammox and Sulfate Reduction Ammonium Oxidation processes were compared in two granular sequencing batch reactors operated for 160 days under anammox conditions. It was hypothesized that increasing the concentration of SO42− may positively influence the rate of N removal under anaerobic conditions and it was tested whether SO42− reduction and anammox occur independently or are related to each other. The cooperation of N-S cycles by increasing the concentration of influent SO42− to 952 mg S/L in the second reactor, a higher ammonium utilization rate and sulfate utilization rate was achieved compared to the first reactor, i.e., 2.1-fold and 15-fold, respectively. Nitrosomonas played the dominant role in the N metabolism, while Thauera – in the S metabolism. This study highlights the benefits of linking the N-S cycles as an effective approach for the treatment of NH4+ and SO42− – rich wastewater, including lower substrate removal cost and reduced energy consumption.

Nitrogen Contribution Rate of Anammox in Different Systems and Its Relationship with Environmental Factors

Anammox bacteria can remove ammonium directly, which is different from what was previously believed. This is an important process for the global nitrogen cycle. Anammox bacteria were first identified in sewage treatment systems and were later proven to exist widely in natural ecosystems. To better understand the relationship between the anammox reaction and different systems, and to maintain the stability of the nitrogen cycle, anammox functional microorganisms found in different natural environments were summarized. In addition, anammox nitrogen production rate and the contribution of anammox to nitrogen were discussed under different ecological environments. A literature analysis showed that the contribution rate of nitrogen removal of anammox was the highest in the Terrestrial ecosystem, up to 87.5%. The Terrestrial ecosystem is more likely to form an anoxic or even anaerobic environment conducive to anaerobic ammoxidation. Therefore, the control of DO is an important factor in the activity of anaerobic ammoxidation. Other environmental factors affecting the contribution of anammox to nitrogen removal include temperature, pH, organic matter content, inorganic nitrogen concentration, and salinity. However, the dominant influencing factors of anammox reactions in different ecosystems are evidently different. Therefore, the mechanism of the impact of different environmental factors on the anaerobic ammonia oxidation process is necessary to discuss. This provides a scientific basis for the global nitrogen cycle and is of great significance to improve nitrogen’s biogeochemical cycle in the ecosystem.

Micro-aeration and low influent C/N are key environmental factors for achieving ANAMMOX in livestock farming wastewater treatment plants

Anaerobic ammonium oxidation (ANAMMOX)-mediated system is a cost-effective green nitrogen removal process. However, there are few examples of successful application of this advanced wastewater denitrification process in wastewater treatment plants, and the understanding of how to implement anaerobic ammonia oxidation process in full-scale is still limited. In this study, it was found that the abundance of anaerobic ammonia-oxidizing bacteria (AnAOB) in the two livestock wastewater plants named J1 and J2, respectively, showed diametrically opposed trends of waxing and waning with time. The microbial communities of the activated sludge in the two plants at different time were sampled and analyzed by high-throughput sequencing of 16S rRNA genes. Structural equation models (SEMs) were used to reveal the key factors affecting the realization of the ANAMMOX. Changes in the concentration of dissolved oxygen and C/N had a significant effect on the relative abundance of anaerobic ammonia oxidation bacteria (AnAOB). The low concentration of DO (0.2∼0.5 mg/L) could inhibit the activity of nitrifying bacteria (NOB) to achieve partial oxidation of ammonia nitrogen and provide sufficient substrate for the growth of AnAOB, similar to the CANON (Completely Autotrophic Nitrogen removal Over Nitrite). Unlike CANON, heterotrophic denitrification is also a particularly critical part of the livestock wastewater treatment, and a suitable C/N of about 0.6 could reduce the competition risk of heterotrophic microorganisms to AnAOB and ensure a good ecological niche for AnAOB. Based on the results of 16S rRNA and microbial co-occurrence networks, it was discovered that microorganisms in the sludge not only had a richer network interaction, but also achieved a mutually beneficial symbiotic interaction network among denitrifying bacteria (Pseudomonas sp., Terrimonas sp., Dokdonella sp.), AnAOB (Candidatus Brocadia sp.) at DO of 0.2∼0.5 mg/L and C/N of 0.6. Among the top 20 in abundance of genus level, AnAOB had a high relative abundance of 27.66%, followed by denitrifying bacteria of 3.67%, AOB of 0.64% and NOB of 0.26%, which is an essential indicator for the emergence of an AnAOB-dominated nitrogen removal cycle. In conclusion, this study highlights the importance of dissolved oxygen and C/N regulation by analyzing the mechanism of ANAMMOX sludge extinction and growth in two plants under anthropogenic regulation of AnAOB in full-scale wastewater treatment systems.

Nano iron tetroxide-modified rice husk biochar promoted Feammox performance of Klebsiella sp. FC61 and synergistically removed Ni2+ and ciprofloxacin

The iron reduction coupled with ammonia oxidation process (Feammox) is a biological reaction process associated with the nitrogen cycle that has been discovered in recent years. In this study, the iron-reducing bacterium Klebsiella sp. FC61 was attached by synthesizing nano-loadings of iron tetroxide (nFe3O4) onto rice husk biochar (RBC), and the RBC-nFe3O4 was used as an electron shuttle to participate in the biological iron reduction process of soluble and insoluble Fe3+ to improve the ammonia oxidation efficiency to 81.82%. This acceleration of electron transfer increased the carbon consumption rate and further tuned up the COD removal efficiency to 98.00%. The Feammox could be coupled with iron denitrification for internal nitrogen/iron cycling to reduce the accumulation of nitrate by-products and achieve the recycling of iron. In addition, pollutants such as Ni2+, ciprofloxacin, and formed chelates could be removed by pore adsorption and π-π interactions using bio-iron precipitates produced by iron-reducing bacteria.

Iron-loaded sludge biochar alleviates the inhibitory effect of tetracycline on anammox bacteria: Performance and mechanism

The anaerobic ammonia oxidation (anammox) process is sensitive to environmental pollutants, such as antibiotics. In this study, the harmful effect of tetracycline (TC) on the performance of an anammox reactor and the mitigation of TC inhibition by iron-loaded sludge biochar (Fe-BC) were studied by analyzing extracellular polymeric substances (EPS), microbial community structure and functional genes. The total inorganic nitrogen (TIN) removal rate of the TC reactor was reduced by 5.86% compared to that of the control group, while that of the TC + Fe-BC reactor improved by 10.19% compared to that of the TC reactor. Adding Fe-BC increased the activity of anammox sludge by promoting the secretion of EPS (including protein, humic acids and c-Cyts). The results of the enzymolysis experiment showed that protein can improve the activity of anammox sludge, while the ability of polysaccharide to improve the activity of anammox was related to the treated enzymes. In addition, Fe-BC alleviated the inhibitory effect of TC by mediating the anammox electron transfer process. Furthermore, Fe-BC increased the absolute abundance of hdh and hzsB by 2.77 and 1.18 times compared to the TC reactor and improved the relative abundance of Candidatus Brocadia in the absence of TC. The addition of Fe-BC is an effective way to alleviate the inhibitory effect of TC on the anammox process.

Effects of low-intensity ultrasound on anammox granular sludge

Low-intensity ultrasound can effectively shorten the start-up time of the anaerobic ammonia oxidation process and improve nitrogen removal performance. However, the effect of low-intensity ultrasound on the anammox granular sludge structure and the functional bacteria metabolism is still unclear. Herein, the effects of ultrasonic irradiation with different ultrasonic power densities and treatment times on nitrogen removal performance and anammox granular sludge structure were studied. The activity of anammox granular sludge increased by 20.81 % after irradiation (0.2 W/mL ultrasonic power density, 2 min treatment time). When further increased to 0.3 W/mL or 4 min, respectively, sludge activity was inhibited. Under optimal ultrasound parameters, the activity of Nar, NirS, and HZO was increased by 43.98 %, 17.92 %, and 16.49 %, respectively, and the cell membranes permeability was improved. Extracellular polymers and cell cluster shedding improved the mass transfer performance. Excessive ultrasonic energy lead to cell membrane damage or cell rupture.

Biotransformation-mediated detoxification of roxarsone in the anammox process: Gene regulation mechanism

Roxarsone is a common organoarsenic feed additive used in livestock and poultry breeding, while the ecotoxicity of organic arsenic remains a concern. Therefore, the effects of roxarsone on the anaerobic ammonium oxidation (anammox) process and responding mechanism were investigated in this study. The minimum nitrogen removal efficiency (NRE) of anammox process was 64.0% under roxarsone stress. Meanwhile, the reactive oxygen species (ROS) content increased by 1.5–2.3 times, and electron transport system activity (ETSA) decreased by 22.9±5.0%. The total antioxidant capacity (T-AOC) level first increased and then decreased, resulting in an imbalance between ROS production and antioxidant defense. The copy numbers of arsenic resistance genes significantly increased, indicating that roxarsone was transformed in the anammox system. Co-occurrence networks manifested that arsenic resistance genes were significantly positively correlated with dominant genera. The detoxification mediated by biotransformation mitigated the toxicity of roxarsone and the side effects of oxidative stress. This work provides insights into the response and mechanism of anammox consortia to roxarsone and promotes the efficient treatment of wastewater containing organic arsenic by the anammox process.

Isotopic differences and paleoenvironmental significance of nitrogen contained in bulk sedimentary rocks, decarbonated aliquots and kerogen extracts

The stable nitrogen isotopic composition (δ15N) of sedimentary rocks is an important tool for reconstructing the paleo-oceanic nitrogen cycle and has been widely used in palaeoenvironmental studies of the Precambrian and Phanerozoic. Currently, the commonly used parameters are the isotopic compositions of decarbonated samples (δ15NDCN) and kerogen extracts (δ15Nkerogen). However, some studies have shown that there are differences between these two proxies. In addition, differences were found between δ15NDCN and the nitrogen isotopic compositions of untreated samples (δ15Nbulk). In order to explain these phenomena, we selected sedimentary rock samples from different time periods in the Phanerozoic and analyzed nitrogen isotopes after all three treatments (bulk rock, decarbonated rock, and kerogen extracts). We find that (1) δ15Nbulk is greater than δ15NDCN in most samples by 0.6‰ on average, indicating that acid-soluble organic N with higher δ15N values was lost preferentially during decarbonization; (2) δ15NDCN is greater than δ15Nkerogen mainly in anoxic environments, which may be linked to ammonium accumulation in pore fluids or in the water column during deposition and/or diagenesis. For example, the anaerobic ammonia oxidation process and partial assimilation preferentially consume 14NH4+ and enrich 15NH4+ in seawater. Therefore, NH4+ fixed by clay minerals may have a higher δ15N than organic nitrogen; (3) δ15Nkerogen greater than δ15NDCN was observed in a subset of samples and may reflect either preferential release of 14NH4+ from organic matter or biological production of isotopically light NH4+, followed by adsorption to clay minerals. In this case, the δ15N of residual organic nitrogen would be relatively high compared to the released NH4+. However, this scenario is only retained in samples that have not undergone significant post-depositional alteration, which tends to lower δ15Nkerogen and increase δ15NDCN. Differences between the three nitrogen parameters are in many cases small and would not alter overall paleoenvironmental interpretations; however, in some cases, they can be significant and carry additional information about diagenetic conditions that may be unlocked with additional studies on wider range of deposition environments.

Performance of anammox enchanced by pulsed electric fields under added organic carbon sources using integrated network and metagenomics analyses

This paper aims to investigate the function of a pulsed electric field (PEF) in the anaerobic ammonia oxidation (anammox) process after adding certain chemical oxygen demand (COD) through integrated network and metagenomics analyses. The findings showed that the presence of COD was detrimental to anammox, but PEF could significantly reduce the adverse effect. The total nitrogen removal in the reactor for applying PEF was 16.99% higher on average than the reactor for only dosing COD. Additionally, PEF upgraded the abundance of anammox bacteria subordinate to the phylum Planctomycetes by 9.64%. The analysis of molecular ecological networks promulgated that PEF resulted in an increase in network scale and topology complexity, thereby boosting the potential collaboration of the communities. Metagenomics analyses demonstrated that PEF dramatically promoted anammox central metabolism in the presence of COD, specifically enhancing pivotal N functional genes (hzs, hdh, amo, hao, nas, nor and nos).

Light-driven ammonium oxidation to dinitrogen gas by self-photosensitized biohybrid anammox systems

The anaerobic ammonium oxidation (anammox) process exerts a very vital role in the global nitrogen cycle (estimated to contribute 30%-50% N2 production in the oceans) and presents superiority in water/wastewater nitrogen removal performance. Until now, anammox bacteria can convert ammonium (NH4+) to dinitrogen gas (N2) with nitrite (NO2-), nitric oxide (NO), and even electrode (anode) as electron acceptors. However, it is still unclear whether anammox bacteria could utilize photoexcited holes as electron acceptors to directly oxide NH4+ to N2. Here, we constructed an anammox-cadmium sulfide nanoparticles (CdS NPs) biohybrid system. The photoinduced holes from the CdS NPs could be utilized by anammox bacteria to oxidize NH4+ to N2. 15N-isotope labeling experiments demonstrated that NH2OH instead of NO was the real intermediate. Metatranscriptomics data further proved a similar pathway for NH4+ conversion with anodes as electron acceptors. This study provides a promising and energy-efficient alternative for nitrogen removal from water/wastewater.

Enhanced nitrogen removal of the anaerobic ammonia oxidation process by coupling with an efficient nitrate reducing bacterium (Bacillus velezensis M3-1)

Bacillus velezensis M3-1 strain isolated from the sediment of Myriophyllum aquatium constructed wetlands was found to efficiently convert NO3−-N to NO2−-N, and the requirements for carbon source addition were not very rigorous. This work demonstrates, for the first time, the feasibility of using the synergy of anammox and Bacillus velezensis M3-1 microorganisms for nitrogen removal. In this study, the possibility of M3-1 that converted NO3−-N produced by anammox to NO2−-N was verified in an anaerobic reactor. The NO3−-N reduction ability of M3-1 and denitrifying bacteria in coupling system was investigated under different C/N conditions, and it was found that M3-1 used carbon sources preferentially over denitrifying bacteria. By adjusting the ratio of NH4+-N to NO2−-N, it was found that the NO2−-N converted from NO3−-N by M3-1 participated in the original anammox.The nitrogen removal efficacy (NRE) of the coupled system was increased by 12.1%, compared to the control group anammox system at C/N = 2:1. Functional gene indicated that it might be a nitrate reducing bacterium.This study shows that the nitrate reduction rate achieved by the Bacillus velezensis M3-1 can be high enough for removing nitrate produced by anammox process, which would enable improve nitrogen removal from wastewater.

Response of nitrogen removal and microbial community to high concentration of humic acid in the anammox biofilm system

The anaerobic ammonium oxidation (anammox) process is highly effective to remove nitrogen from the wastewater with high ammonia concentration, such as landfill leachate and anaerobic digestion. This kind of wastewater generally contains high content of humic acid, and its effect on anammox is not clear. Therefore, this study investigated the effect of humic acid with high concentration (100–1000 mg/L) on the anammox biofilm system. The nitrogen degradation rates were greatly decreased at the high concentration of humic acid and the reaction time was prolonged by 4 h compared with that lacking humic acid. In the anammox biofilm system, the relative abundance of anammox bacteria Candidatus_Brocadia and Candidatus_Kuenenia decreased from 2.1 % and 15.01 % to 0.6 % and 8.32 %, respectively, while the denitrifying bacteria Thauera increased from zero to 8.86 %. Overall, the high humic acid concentration did not obviously inhibit nitrogen removal performance of anammox system, but affected anammox bacteria activity and microbial community structure.

Fast start-up of anammox process: Effects of extracellular polymeric substances addition on performance, granule properties, and bacterial community structure

The slow startup is the major obstacle to the application of anaerobic ammonium oxidation (anammox) process in mainstream wastewater treatment. Extracellular polymeric substances (EPS) are one potential resource for stable anammox reactor operation. Response surface analysis was used to optimize the specific anammox activity (SAA) with the addition of EPS; SAA was maximum at a temperature of 35 °C and the EPS concentration of 4 mg/L. By comparing the nitrogen removal of anammox reactors with no EPS (R0), immobilized EPS (EPS-alginate beads) (R1), and liquid EPS (R2), we found that EPS-alginate beads significantly speed up the startup of anammox process and enable the start time to be shortened from 31 to 19 days. As a result of the higher MLVSS content, higher zeta potential, and lower SVI30, anammox granules of R1 exhibited a stronger capacity to aggregate. Moreover, EPS extracted from R1 had higher flocculation efficiencies than EPS derived from R0 and R2. Phylogenetic analysis of 16S rRNA genes revealed that the main anammox species in R1 is Kuenenia taxon. To clarify the relative significance of stochastic vs deterministic processes in the anammox community, neutral model and network analysis are employed. In R1, community assembly became more deterministic and stable than in other cultures. Our results show that EPS might inhibit heterotrophic denitrification and thereby promote anammox activity. This study suggested a quick start-up strategy for the anammox process based on resource recovery, which is helpful for environmentally sustainable and energy-efficient wastewater treatment.

Study on the feasibility of carbon source recovery by upflow anaerobic sludge blanket in simulated municipal wastewater

The influence of hydraulic retention time (HRT) on the granulation process, methane-producing capacity, microbial community structure, and pollutant removal efficiency of an up-flow anaerobic sludge blanket (UASB) with simulated municipal wastewater at a mesophilic temperature was investigated. The carbon recovery capacity of the anaerobic fermentation of municipal wastewater at mesophilic temperatures is one of the problems to be investigated for the realisation of carbon neutrality in municipal wastewater treatment plants. In this study, the HRT was gradually shortened (24–6 h), and the effluent chemical oxygen demand (COD), ammonia nitrogen, pH, volatile fatty acid concentration, and specific methanogenic activity (SMA) were investigated. The sludge morphology, the particle size distribution of the different HRT, and changes in the microbial community structure were determined by scanning electron microscopy, wet screening, and high-throughput sequencing. The results indicated that even if the COD concentration was only 300–550 mg/L, with a decrease in HRT, the proportion of granular sludge in the UASB still exceeded 78 %, and the COD removal efficiency reached 82.4 %. The SMA of granular sludge increased with an increase in the size of granules and was 0.289 g CH4-COD/(g VSS d) at an HRT of 6 h, but the proportion of dissolved methane in the effluent accounted for 38–45 % of the total methane production and the proportion of Methanothrix in UASB sludge was 82.44 %. In this study, dense granular sludge was obtained by gradually shortening the HRT to start the UASB, and the lower effluent COD reduced the load of subsequent treatment processes, which could be used as a low carbon/nitrogen ratio influent for activated carbon-activated sludge, activated sludge-microalgae, and partial nitrification-anaerobic ammonia oxidation processes.

Metabolomics and molecular simulation reveal the responding mechanism of anammox consortia to perfluorooctanoic acid by regulating metabolic network

Perfluorooctanoic acid (PFOA) is ubiquitous in aquatic environment, posing serious threats to human health, while the potential of anaerobic ammonium oxidation (anammox) process in treating PFOA-containing wastewater and the response mechanism of anammox consortia to PFOA remain unknown. In this study, the comprehensive effects of PFOA on anammox granules and their interaction mechanism were investigated based on molecular simulation and metabolomic analysis. The environmental concentrations (≤2.0 mg/L) of PFOA had no impact on the anammox process performance. However, microbial consortia structure and functional gene abundances changed under the exposure of PFOA. By contrast, Prokaryotes were more sensitive to PFOA than eukaryotes. In addition, PFOA regulated microbial metabolic pathways, including amino acid metabolism and nucleotide metabolism, by changing the cell energy allocation strategy. Molecular docking simulation suggested that the effects of PFOA on key proteins in anammox bacteria were significantly different. These findings provide insights into the interaction between anammox consortia and PFOA, and further promote the implementation of anammox process to treat fluorine-containing wastewater.