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1.
Chemosphere ; 278: 130414, 2021 Mar 29.
Artículo en Inglés | MEDLINE | ID: mdl-33819887

RESUMEN

The arsenic in livestock wastewater would induce adverse impact on the biological treatment technology such as anaerobic ammonium oxidation (anammox) process. Extracellular polymeric substances (EPS) play an important role in resisting such toxicity. Unfortunately, the role of EPS in protecting anammox from As(III) and the mechanisms underlying the protection still remains unclear. This work comprehensively evaluated the acute toxicity of arsenic on anammox sludge and investigated the binding property and interaction mechanism. The results revealed that the half maximal inhibitory concentration (IC50) of As(III) on anammox sludge was estimated to be 408 mg L-1, which decreased to 41.97 mg L-1 when EPS was exfoliated. Complexation and hydrophobic interactions were the leading forces in preventing arsenic invasion. Protein was the main component that complexes with As(III), and O-H, -NH, -CO were binding sites. The response sequence of organic component in EPS to As(III) was ordered as hydrocarbons-proteins-polysaccharides-aliphatic amines.

2.
Bioresour Technol ; 333: 125186, 2021 Apr 16.
Artículo en Inglés | MEDLINE | ID: mdl-33892423

RESUMEN

Two types of anaerobic ammonium oxidation (anammox) seed sludge were selected to evaluate their responses to copper nanoparticles (CuNPs) exposure. Antibiotic-exposed anammox granules (R1) were more likely to be inhibited by 5.0 mg L-1 CuNPs than the normal anammox granules (C1). The nitrogen removal efficiency (NRE) of C1 decreased by 9.00% after two weeks of exposure to CuNPs, whereas that of R1 decreased by 20.32%. Simultaneously, the abundance of Candidatus. Kuenenia decreased by 27.65% and 36.02% in C1 and R1 under CuNPs stress conditions, respectively. Generally, R1 was more susceptible to CuNPs than C1. The correlation analysis indicated that the horizontal transfer of antibiotic resistance genes and copA triggered by intI1 facilitated the generation of multiresistance in the anammox process. Moreover, the potential multiresistance mechanism of anammox bacteria was hypothesized based on previous results. The results will generate new ideas for the treatment of complex wastewater using the anammox process.

3.
Bioresour Technol ; 330: 124945, 2021 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-33735733

RESUMEN

The influence of copper ion (Cu2+) on anaerobic ammonium oxidation (anammox) performance and microbial community structures after oxytetracycline (OTC) stress recovery were assessed. Experimental results demonstrated that anammox performance were stressed by 1.0 mg L-1 Cu2+ and inhibitions were reversible with total nitrogen removal rate higher than 3.08 ± 0.2 kg N m-3 d-1. The residual OTC in the anammox sludge could combine with Cu2+ introduced and thereby retarded inhibition on performance in the presence of 2.0 mg L-1 Cu2+. Moreover, the positive relation of dominant bacterium Ca. Anammoxoglobus with the abundance of functional genes and parts of antibiotic resistance genes were observed, suggesting that regain of performance was the results of the gradual domestication of latent resistant species after inhibition. This investigation reveals new insights into resistance of anammox performance for Cu2+ and OTC.


Asunto(s)
Microbiota , Oxitetraciclina , Anaerobiosis , Antibacterianos/farmacología , Reactores Biológicos , Cobre , Farmacorresistencia Microbiana/genética , Nitrógeno , Oxidación-Reducción , Oxitetraciclina/farmacología , Aguas del Alcantarillado
4.
Artículo en Inglés | MEDLINE | ID: mdl-33705092

RESUMEN

Single-atom catalysts (SACs) have attracted great attention due to their high atom-utilization and catalytic efficiency. However, a universal synthetic route is still lacking, which restricts the SAC-related investigation and application. Here, we report a simple and cost-effective method to fabricate transition metal SACs through ion exchange and annealing procedures. Benefiting from the "egg-box" structure property of alginate, the metal ion can be effectively anchored into the organic center. Using CuCl2 as a representative transition metal ion, the Cu SAC structure was synthesized and identified by aberration-corrected high-angle annular dark-field scanning transmission electron microscopy and X-ray absorption fine structure spectroscopy. Through optimizing CuCl2 concentration, the obtained Cu SAC exhibited a good oxygen reduction reaction activity, whose onset potential, half wave potential, and limiting current density are all comparable to those of 20 wt % Pt/C. Cu-N4 was identified as the responsible catalytic site. More importantly, other transition metal SACs can be easily synthesized via altering metallic solution, which proves the universality of our proposed method. This work may be valuable for the cost-effective and universal SAC synthetic method development.

5.
J Environ Manage ; 286: 112267, 2021 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-33667820

RESUMEN

Antibiotic pollution is becoming increasingly severe due to its extensive use. The potential application of the anaerobic ammonium oxidation (anammox) process in the treatment of wastewater containing antibiotics has attracted much attention. As common antibiotics, spiramycin (SPM) and streptomycin (STM) are widely used to treat human and animal diseases. However, their combined effects on the anammox process remain unknown. Therefore, this study systematically evaluated the response of the anammox process to both antibiotics. The half maximal inhibitory concentrations of SPM and STM were determined. The continuous-flow anammox system could adapt to SPM and STM at low concentrations, while antibiotics at high concentrations exhibited inhibitory effects. When the concentrations reached 5 mg L-1 SPM and 50 mg L-1 STM, the nitrogen removal efficiency dramatically decreased and then rapidly recovered within 8 days. Correspondingly, the abundances of dominant bacteria and genes also changed with antibiotic concentrations. In general, the anammox process showed a stable performance and a high resistance to SPM and STM, suggesting that acclimatization by elevating the concentrations was beneficial for the anammox process to obtain resistance to different antibiotics with high concentrations. This study provides guidance for the stable operation of anammox-based biological treatment of antibiotics containing wastewater.


Asunto(s)
Compuestos de Amonio , Macrólidos , Aminoglicósidos , Anaerobiosis , Animales , Antibacterianos , Reactores Biológicos , Humanos , Nitrógeno , Oxidación-Reducción , Aguas Residuales
6.
Bioresour Technol ; 329: 124918, 2021 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-33684839

RESUMEN

Sulfur-driven autotrophic denitrification (SDAD) is feasible for the treatment of low-C/N-ratio and sulfur-laden wastewaters. The nitrite accumulated in SDAD will affect the performance and stability of the system but can be a potential electron acceptor. Thus, single- and multiple-electron acceptor-mediated SDAD systems were investigated. Batch assays revealed that nitrite and nitrate were the preferential options in the SDAD system with single and multiple electron acceptors, respectively. Synchronous nitrogen and sulfur removal was successfully achieved in continuous flow experiments with multiple electron acceptors, and the system could adapt well to high concentrations of sulfide, nitrate and nitrite (i.e., 720, 108 and 64.8 mg L-1, respectively), with the predominant genera shifting from Thiobacillus (48.88%) at the initial stage to unclassified_p_Firmicute (34.24%) and Syner-01 (12.31%) at the last stage. This work provides a fundamental basis for applying and regulating SDAD with multiple electron acceptors for the remediation of nitrogen- and sulfide- laden wastewaters.


Asunto(s)
Microbiota , Nitrógeno , Procesos Autotróficos , Reactores Biológicos , Desnitrificación , Electrones , Nitratos , Azufre
7.
Bioresour Technol ; 319: 124106, 2021 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-32949830

RESUMEN

The individual and combined impacts of copper ion (Cu2+) and oxytetracycline (OTC) on anaerobic ammonium oxidation (anammox) performance and its self-recovery process were examined. Experimental results showed that the anammox performance and activity of anammox bacteria were inhibited by 1.0 mg L-1 OTC, Cu2+ and OTC + Cu2+, and both single and combined inhibitions were reversible. The abundance of functional genes and parts of antibiotic resistance genes (ARGs) were positively related to the dominant bacterium Ca. Kuenenia, implying that the recovery of the performance was associated with the progressive induction of potentially resistant species after inhibition. The above outcomes illustrated that anammox bacteria were stressed by metals and antibiotics, but they still could remove nitrogen at a rate higher than 20.6 ± 0.8 kg N m-3 d-1, providing guidance for engineering applications of anammox processes.


Asunto(s)
Compuestos de Amonio , Microbiota , Oxitetraciclina , Antibacterianos/farmacología , Reactores Biológicos , Cobre , Farmacorresistencia Microbiana/genética , Nitrógeno , Oxidación-Reducción , Oxitetraciclina/farmacología
8.
J Hazard Mater ; 403: 123641, 2021 02 05.
Artículo en Inglés | MEDLINE | ID: mdl-33264860

RESUMEN

The increase of emerging contaminants, such as surfactants, is one of the major challenges to biological wastewater treatment. However, the potential impact of linear alkylbenzene sulphonates (LAS), a major class of anionic surfactants, on anammox process is unclear. The long-term effects of sodium dodecyl benzene sulfonate (SDBS, as a model LAS) on reactor performance, microbial community and sludge properties were investigated in this study. The presence of 5 mg L-1 SDBS promoted the release of extracellular microbial products from anammox granules and the wash-out of anammox population via effluent. Despite sludge disaggregation, the reactor performance was robust to the exposure of 5 mg L-1 SDBS due to functional redundancy. With the further increase of SDBS to 10 mg L-1, the metabolic activity of anammox biomass and the transcription and post-translation of hydrazine dehydrogenase were significantly decreased. The potential mechanism might be associated with the damage on cell membrane that induced the leakage of intracellular matrix. These results highlight the need to consider the potential risk of LAS to operation of anammox process in biological wastewater treatment plant.

9.
Environ Sci Technol ; 54(20): 12959-12966, 2020 Oct 20.
Artículo en Inglés | MEDLINE | ID: mdl-32970415

RESUMEN

The implementation of mainstream anammox has gained increasing attention. In this study, the feasibility of using sidestream anammox granules to start up mainstream reactors was investigated by comparing two switching strategies. A maximum nitrogen removal potential of 3.6 ± 0.2 kg N m-3 d-1 was obtained for the reactor after direct switching to mainstream conditions (70 mg TN L-1, 15 °C). Nevertheless, the reactor preacclimatized to 25 °C (Ma) exhibited a higher nitrogen removal potential of 7.0 ± 0.3 kg N m-3 d-1 at 15 °C, which is the highest volumetric nitrogen removal rate of mainstream anammox reactors to date. Candidatus Kuenenia stuttgartiensis was identified as the dominant anammox bacterium, and its relative abundance in two reactors remained stable throughout the whole operation (200 days). Moreover, with the aid of acclimatization, the activation energy was reduced and the specific growth rate became higher. These results indicated that the physiological evolution of the dominant anammox bacterium instead of interspecies selection was the main reason for the high potential during the switch to mainstream conditions. Therefore, using sidestream anammox granules as seed sludge to start up mainstream reactors was demonstrated to be feasible, and a switching strategy of acclimatization at 25 °C was recommended.

10.
Sci Total Environ ; 747: 141464, 2020 Dec 10.
Artículo en Inglés | MEDLINE | ID: mdl-32795803

RESUMEN

The preservation of anammox granules is of great significance for the rapid start-up of the anammox process and improvement of performance stability. Therefore, it is necessary to explore an economical and stable preservation strategy. Exogenous extracellular polymeric substances (EPS) were used as protective agents for the preservation of anammox granules in this study. In brief, EPS from anammox sludge (A-EPS) and denitrifying sludge (D-EPS) were added to preserve anammox sludge at 4 °C and room temperature (15-20 °C). The results showed that A-EPS addition at 4 °C was the optimal condition for the preservation of anammox granules. After 90 days of preservation, the specific anammox activity (SAA) of the anammox granules remained at 92.7 ± 2.2 mg N g-1 VSS day-1 (remaining ratio of 33.4%), while that of the sludge with D-EPS addition at the same temperature was only 77.1 ± 3.2 mg N g-1 VSS day-1 (remaining ratio of 27.8%). The nitrogen removal efficiency of the experimental group with D-EPS at room temperature was 85.9%, and that of the A-EPS group reached 90.6% under the same temperature conditions. The abundance of the functional genes hzsA, hdh and nirS of the sludge (4 °C; A-EPS addition) after recovery were 138.5%, 317.1%, and 375.9%, respectively, of those of sludge from the D-EPS-added group at the same temperature. RDA revealed the contribution of proteins to the preservation process. Overall, this study provides an economical and robust strategy for the preservation of anammox granules.

11.
Biodegradation ; 31(4-6): 223-234, 2020 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-32524306

RESUMEN

In order to explore the performance, kinetics characteristics and enhancement mechanisms in anammox process under ferrous iron enhanced conditions, a laboratory-scale UASB anammox reactor has been built up and operated for 534 days. Experimental results showed that the Anammox process was successfully started up in a short operation period and the TNRE reached 83.34 ± 2.96% with a maximum total nitrogen removal rate of 14.4 kg m-3 d-1 after long-term operated under influent Fe(II) concentration of 5.3 mg L-1. Simulation results using different kinetic models showed that the Stover-Kincannon model and the Grau second-order model were useful for describing the anammox performance under Fe(II) enhanced conditions. Extracellular polymeric substance (EPS) act a pivotal part in the granulation of Anammox sludge and the improvement of anammox activity. Iron improved the hydrophobicity of the sludge by reducing the PN/PS ratios, and also increased the Anammox granular diameter. The granular diameter of higher than 2.00 accounted for 58.3% of the total sludge. At the same time, the presence of iron decreased EPS levels, and also decreased the iron adsorption ability to sludge. More iron was transported into Anammox, which improved the nitrogen removal ability in the Anammox reactor.

12.
J Hazard Mater ; 398: 122965, 2020 11 05.
Artículo en Inglés | MEDLINE | ID: mdl-32474323

RESUMEN

The performance of anaerobic ammonium oxidation (anammox) granules were studied under long-term exposure to Fe3O4 NPs. The Fe3O4 NPs had no negative impacts on nitrogen removal performance with the addition of 2-200 mg L-1. The specific anammox activity (SAA) slightly decreased from 287.0 ± 13.2 to -253.0 ± 9.2 mg TN g-1VSS d-1 with the increase in Fe3O4 NPs level from 2 to 60 mg L-1, and then significantly enhanced to 381.8 ± 15.7 mg TN g-1VSS d-1 at 200 mg L-1 Fe3O4 NPs. And the change trends of the heme c content, extracellular polymeric substance amount and settling velocity were consistent with that of SAA. The Candidatus_Kuenenia was the dominant species during the entire experiment and its relative abundance was up to 33.4 % at the end the experiment. The results provide some useful information for comprehending the impact of Fe3O4 NPs on the performance of wastewater biological treatment systems.

13.
Water Environ Res ; 92(11): 1899-1909, 2020 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-32306497

RESUMEN

Anaerobic ammonium oxidation (anammox) is a novel process of deammonification that exhibits superior ecological and economic potential compared to that of traditional heterotrophic processes. Although this process has been successfully implemented in treating high-strength nitrogen-contaminated wastewater, it still faces many challenges in treating mainstream municipal wastewater. This review aims to provide an overview of the status and challenges of mainstream anammox-based processes. The different configurations and crucial factors are discussed in this review. Finally, the future needs for feasible application are stated. PRACTITIONER POINTS: Factors restricting mainstream application of anammox-based processes are reviewed. Control strategies for selecting and maintaining anammox bacteria are discussed. Recent advances in nitrite production via partial nitrification or denitrification are summarized. Future needs for the feasible application of anammox-based nitrogen removal technology for mainstream municipal wastewater treatment are outlined.


Asunto(s)
Compuestos de Amonio , Aguas Residuales , Reactores Biológicos , Desnitrificación , Nitrógeno , Oxidación-Reducción
14.
Bioresour Technol ; 307: 123264, 2020 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-32244076

RESUMEN

Nanoparticles and antibiotics, the two most frequently detected emerging pollutants from different wastewater sources, are eventually discharged into wastewater treatment plants. In this study, the widely used materials CuNPs and oxytetracycline (OTC) were selected as target pollutants to investigate their joint effects on anaerobic ammonium oxidation (anammox). The results indicated that the environmental concentration slightly inhibited the performance of the reactors, while the performance rapidly deteriorated within a week under high-level combined shocks (5.0 mg L-1 CuNPs and 2.0 mg L-1 OTC). After the second shock (2.5 mg L-1 CuNPs and 2.0 mg L-1 OTC), the resistance of anammox bacteria was enhanced, with an elevated relative abundance of Candidatus Kuenenia and absolute abundance of hzsA, nirS, and hdh. Moreover, the extracellular polymeric substance (EPS) content and specific anammox activity (SAA) showed corresponding changes. Improved sludge resistance was observed with increasing CuNP and OTC doses, which accelerated the recovery of performance.


Asunto(s)
Nanopartículas , Oxitetraciclina , Reactores Biológicos , Cobre , Matriz Extracelular de Sustancias Poliméricas , Nitrógeno , Oxidación-Reducción , Aguas del Alcantarillado
15.
Sci Total Environ ; 723: 138094, 2020 Jun 25.
Artículo en Inglés | MEDLINE | ID: mdl-32224402

RESUMEN

The preservation of anaerobic ammonia oxidation (anammox) consortia is crucial for the rapid start-up and the process stability of the anammox based bioreactor. This work proposed and evaluated the feasibility of an anammox consortia preservation strategy, in which the anammox sludge was transformed into intermediate anoxic sulfide oxidation (ASO) functional microorganisms. Initially, the ASO process was successfully started up by inoculating anammox sludge and the overall sulfide and nitrate removal rates stabilized at 57.5 ± 0.22 and 10.0 ± 0.18 kg m-3 day-1, respectively. Then, the bioreactor function was reversely transformed into anammox, whose nitrogen removal rate reached 1.68 kg m-3 day-1. Granule characteristics analysis revealed that both biomass and extracellular polymeric substance content returned to their original states after the reverse start-up. Although the population of Candidatus_Kuenenia was greatly declined during ASO process, its richness was successfully recovered after the reverse start-up of the anammox process. The inferred metagenomes analysis demonstrated that the shifts in functional microorganisms were related to variation in the main metabolic pathways. The specific activities of anammox and ASO both are regarded as key indicators for the successful start-up of bioreactor. This work revealed a novel technique for the preservation of anammox consortia and might be a potential strategy for overcoming the drawback of long start-up time.


Asunto(s)
Reactores Biológicos , Matriz Extracelular de Sustancias Poliméricas , Anaerobiosis , Nitrógeno , Oxidación-Reducción , Aguas del Alcantarillado , Sulfuros
16.
J Environ Manage ; 262: 110375, 2020 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-32250829

RESUMEN

The extensive application of antibiotics, and the occurrence and spread of antibiotic resistance genes (ARGs) shade health risks to human and animal. The long-term effects of sulfamethoxazole (SMX) and tetracycline (TC) on denitrification process were evaluated in this study, with the focus on nitrogen removal performance, microbial community and ARGs. Results showed that low-concentration SMX and TC (<0.2 mg L-1) initially caused a deterioration in nitrogen removal performance, while higher concentrations (0.4-20 mg L-1) of both antibiotics had no further inhibitory influences. The abundances of ARGs in both systems generally increased during the whole period, and most of them had significant correlations with intI1, especially efflux-pump genes. Castellaniella, which was the dominant genus under antibiotic pressure, might be potential resistant bacteria. These findings provide an insight into the toxic effects of different antibiotics on denitrification process, and guides future efforts to control antibiotics pollution in ecosystems.


Asunto(s)
Antibacterianos , Microbiota , Animales , Desnitrificación , Farmacorresistencia Microbiana , Genes Bacterianos
17.
Sci Total Environ ; 719: 137513, 2020 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-32120111

RESUMEN

Anaerobic ammonium oxidation (anammox) bacteria are sensitive and susceptible to operating condition fluctuations that can lead to the instability of a bioreactor. Through multivariate spectral analysis, the dynamic changes of intracellular and extracellular metabolites of anammox sludge under the declined temperature stress were characterized. It was found that effluent fluorescence components were positively related to the bacterial activity, and the response of the protein-like substances to the temperature change was more sensitive than that of humic substances. Under the transient disturbance during temperature change from 35 to 15 °C, anammox system tended to considerably excrete extracellular polymeric substances to resist the low temperature inhibition. However, the long-term exposure of the sludge at 10 °C resulted in the considerably inhibition of sludge activity, granular disintegration and heterotrophic denitrification bacteria increase. The two-dimensional correlation analysis further revealed that the humic acid in extracellular polymeric substances was preferentially responded to the temperature change than protein. Anammox bacteria tended to increase the intracellular protein and electron transfer-related reactive substance excretion to counteract the low temperature inhibition. Herein, both the intra- and extra-cellular response characteristics of anammox sludge to temperature variation were successfully resolved via the combined spectra. This work provides a comprehensive understanding on the mechanism of anammox sludge to temperature variation and may be valuable for the development of bioreactor monitoring techniques.


Asunto(s)
Reactores Biológicos , Compuestos de Amonio , Anaerobiosis , Nitrógeno , Oxidación-Reducción , Aguas del Alcantarillado , Temperatura
18.
Chemosphere ; 244: 125577, 2020 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-32050350

RESUMEN

Persulfate based advanced oxidation process is a promising technology for refractory contaminants removal. Cobalt is considered as the most efficient metal in catalyzing peroxymonosulfate decomposition. Although different cobalt based nanomaterials have been developed, easy aggregation and metal ion leaching during catalytic reaction would result in its deficiency. To address the above issue, in this work, carbon supported Co/CoO core-shell nanocomposite was in-situ fabricated by using polyphenol-metal coordinate as precursor. Results indicated that cobalt nanoparticle with size of 10 nm was successfully prepared and well dispersed within the carbon matrix. By using as-prepared material as catalyst, 50 mg/L orange II was completely removed under the condition of 0.2 g/L peroxymonosulfate, 0.05 g/L catalyst, pH = 4.0-10.0. Both sulfate and hydroxyl radicals were formed during peroxymonosulfate decomposition, while sulfate radical dominated the pollutant removal. Mechanism study revealed that the cobalt was the key site for catalyzing peroxymonosulfate decomposition. This work might provide valuable information in designing and fabricating metal anchored carbon composite catalyst for efficiently and cost-effectively activate peroxymonosulfate.


Asunto(s)
Colorantes/química , Nanocompuestos/química , Peróxidos/química , Compuestos Azo , Bencenosulfonatos , Carbono/química , Catálisis , Cobalto/química , Modelos Químicos , Oxidación-Reducción , Sulfatos
19.
Bioresour Technol ; 302: 122885, 2020 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-32014733

RESUMEN

Sulfide has attracted increasing attention due to its odor nuisance, toxicity and corrosion. Although variations in the nitrogen removal performance of anammox under sulfide stress have been reported previously, understanding the microorganisms at the molecular level is of greater significance. This study first deciphered the microbial community and functional gene response of anammox sludge to sulfide stress. Results showed that 20 mg L-1 sulfide could reduce specific anammox activity by 61.7%. The protein-like substances within extracellular polymeric substances were quenched at the end of the experiment. Moreover, the relative abundance of Candidatus Kuenenia significantly decreased from 28.7% to 6.4% while Thiobacillus increased from 0 to 7.2% due to sulfide stress. Furthermore, the abundances of functional genes (hzsA, hdh, nirK and nirS) significantly decreased when the sulfide concentration reached 20 mg L-1. These findings provide a further theoretical basis for the anammox process for nitrogen removal from wastewater containing sulfide.


Asunto(s)
Microbiota , Aguas del Alcantarillado , Reactores Biológicos , Nitrógeno , Oxidación-Reducción , Sulfuros , Aguas Residuales
20.
Sci Total Environ ; 713: 136609, 2020 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-31955101

RESUMEN

A laboratory-scale up-flow anaerobic sludge blanket reactor was used to investigate the effects of temperature-based (single and combined with loading) shocks on the performance of anaerobic ammonium oxidation (anammox) reactor. The reactor was tolerant to 15 °C and 25 °C shocks; however, temperature shock of 55 °C led to severe accumulation of effluent NO2--N (>100 mg L-1), which induced substrate inhibition. Although the shock experiments achieved a maximum effluent NO2--N concentration of 205.4 mg L-1 after a hydraulic retention time-substrate concentration shock at 25 °C, the inhibition was still reversible. During the experiments, the content of extracellular polymeric substances (EPS) increased significantly after each shock to protect the anammox bacteria, and the value decreased correspondingly at the end of the recovery phase. The specific anammox activity showed the opposite tendency compared with that of the EPS. The performance of anammox reactor under a series of short-term temperature shocks was investigated, and the results can provide new ideas for future research.


Asunto(s)
Compuestos de Amonio/metabolismo , Anaerobiosis , Bacterias , Reactores Biológicos , Nitrógeno , Oxidación-Reducción , Aguas del Alcantarillado , Temperatura
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