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Kalvapalle PB, Sridhar S, Silberg JJ, Stadler LB. Long-duration environmental biosensing by recording analyte detection in DNA using recombinase memory. Appl Environ Microbiol 2024; 90:e0236323. [PMID: 38551351 PMCID: PMC11022584 DOI: 10.1128/aem.02363-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2024] [Accepted: 02/20/2024] [Indexed: 04/18/2024] Open
Abstract
Microbial biosensors that convert environmental information into real-time visual outputs are limited in their sensing abilities in complex environments, such as soil and wastewater, due to optical inaccessibility. Biosensors that could record transient exposure to analytes within a large time window for later retrieval represent a promising approach to solve the accessibility problem. Here, we test the performance of recombinase-memory biosensors that sense a sugar (arabinose) and a microbial communication molecule (3-oxo-C12-L-homoserine lactone) over 8 days (~70 generations) following analyte exposure. These biosensors sense the analyte and trigger the expression of a recombinase enzyme which flips a segment of DNA, creating a genetic memory, and initiates fluorescent protein expression. The initial designs failed over time due to unintended DNA flipping in the absence of the analyte and loss of the flipped state after exposure to the analyte. Biosensor performance was improved by decreasing recombinase expression, removing the fluorescent protein output, and using quantitative PCR to read out stored information. Application of memory biosensors in wastewater isolates achieved memory of analyte exposure in an uncharacterized Pseudomonas isolate. By returning these engineered isolates to their native environments, recombinase-memory systems are expected to enable longer duration and in situ investigation of microbial signaling, cross-feeding, community shifts, and gene transfer beyond the reach of traditional environmental biosensors.IMPORTANCEMicrobes mediate ecological processes over timescales that can far exceed the half-lives of transient metabolites and signals that drive their collective behaviors. We investigated strategies for engineering microbes to stably record their transient exposure to a chemical over many generations through DNA rearrangements. We identify genetic architectures that improve memory biosensor performance and characterize these in wastewater isolates. Memory biosensors are expected to be useful for monitoring cell-cell signals in biofilms, detecting transient exposure to chemical pollutants, and observing microbial cross-feeding through short-lived metabolites within cryptic methane, nitrogen, and sulfur cycling processes. They will also enable in situ studies of microbial responses to ephemeral environmental changes, or other ecological processes that are currently challenging to monitor non-destructively using real-time biosensors and analytical instruments.
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Affiliation(s)
| | - Swetha Sridhar
- Systems, Synthetic, and Physical Biology Graduate Program, Rice University, Houston, Texas, USA
| | - Jonathan J. Silberg
- Department of BioSciences, Rice University, Houston, Texas, USA
- Department of Bioengineering, Rice University, Houston, Texas, USA
- Department of Chemical and Biomolecular Engineering, Rice University, Houston, Texas, USA
| | - Lauren B. Stadler
- Department of Civil and Environmental Engineering, Rice University, Houston, Texas, USA
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2
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Alsanea A, Bounaga A, Danouche M, Lyamlouli K, Zeroual Y, Boulif R, Zhou C, Rittmann B. Optimizing Autotrophic Sulfide Oxidation in the Oxygen-Based Membrane Biofilm Reactor to Recover Elemental Sulfur. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:21736-21743. [PMID: 38085930 DOI: 10.1021/acs.est.3c05785] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2023]
Abstract
Biological sulfide oxidation is an efficient means to recover elemental sulfur (S0) as a valuable resource from sulfide-bearing wastewater. This work evaluated the autotrophic sulfide oxidation to S0 in the O2-based membrane biofilm reactor (O2-MBfR). High recovery of S0 (80-90% of influent S) and high sulfide oxidation (∼100%) were simultaneously achieved when the ratio of O2-delivery capacity to sulfide-to S0 surface loading (SL) (O2/S2- → S0 ratio) was around 1.5 (g O2/m2-day/g O2/m2-day). On average, most of the produced S0 was recovered in the MBfR effluent, although the biofilm could be a source or sink for S0. Shallow metagenomic analysis of the biofilm showed that the top sulfide-oxidizing genera present in all stages were Thauera, Thiomonas, Thauera_A, and Pseudomonas. Thiomonas or Pseudomonas was the most important genus in stages that produced almost only S0 (i.e., the O2/S2- → S0 ratio around 1.5 g of the O2/m2-day/g O2/m2-day). With a lower sulfide SL, the S0-producing genes were sqr and fccAB in Thiomonas. With a higher sulfide SL, the S0-producing genes were in the soxABDXYZ system in Pseudomonas. Thus, the biofilm community of the O2-MBfR adapted to different sulfide-to-S0 SLs and corresponding O2-delivery capacities. The results illustrate the potential for S0 recovery using the O2-MBfR.
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Affiliation(s)
- Anwar Alsanea
- Biodesign Swette Center for Environmental Biotechnology, Arizona State University, P.O. Box 875017, Tempe, Arizona 85287-5701, United States
| | - Ayoub Bounaga
- Chemical & Biochemical Sciences Department, Mohammed VI Polytechnic University, Benguerir 43150, Morocco
| | - Mohammed Danouche
- Chemical & Biochemical Sciences Department, Mohammed VI Polytechnic University, Benguerir 43150, Morocco
| | - Karim Lyamlouli
- College of Sustainable Agriculture and Environmental Sciences, Agrobioscience Program, Mohammed VI Polytechnic University, Benguerir 43150, Morocco
| | - Youssef Zeroual
- Situation Innovation, OCP Group, BP 118, Jorf Lasfar, El Jadida 24000, Morocco
| | - Rachid Boulif
- Chemical & Biochemical Sciences Department, Mohammed VI Polytechnic University, Benguerir 43150, Morocco
| | - Chen Zhou
- Biodesign Swette Center for Environmental Biotechnology, Arizona State University, P.O. Box 875017, Tempe, Arizona 85287-5701, United States
| | - Bruce Rittmann
- Biodesign Swette Center for Environmental Biotechnology, Arizona State University, P.O. Box 875017, Tempe, Arizona 85287-5701, United States
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Yoon S, Heo H, Han H, Song DU, Bakken LR, Frostegård Å, Yoon S. Suggested role of NosZ in preventing N 2O inhibition of dissimilatory nitrite reduction to ammonium. mBio 2023; 14:e0154023. [PMID: 37737639 PMCID: PMC10653820 DOI: 10.1128/mbio.01540-23] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2023] [Accepted: 07/31/2023] [Indexed: 09/23/2023] Open
Abstract
IMPORTANCE Dissimilatory nitrate/nitrite reduction to ammonium (DNRA) is a microbial energy-conserving process that reduces NO3 - and/or NO2 - to NH4 +. Interestingly, DNRA-catalyzing microorganisms possessing nrfA genes are occasionally found harboring nosZ genes encoding nitrous oxide reductases, i.e., the only group of enzymes capable of removing the potent greenhouse gas N2O. Here, through a series of physiological experiments examining DNRA metabolism in one of such microorganisms, Bacillus sp. DNRA2, we have discovered that N2O may delay the transition to DNRA upon an oxic-to-anoxic transition, unless timely removed by the nitrous oxide reductases. These observations suggest a novel explanation as to why some nrfA-possessing microorganisms have retained nosZ genes: to remove N2O that may otherwise interfere with the transition from O2 respiration to DNRA.
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Affiliation(s)
- Sojung Yoon
- Department of Civil and Environmental Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, South Korea
| | - Hokwan Heo
- Department of Civil and Environmental Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, South Korea
| | - Heejoo Han
- Department of Civil and Environmental Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, South Korea
| | - Dong-Uk Song
- Department of Civil and Environmental Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, South Korea
| | - Lars R. Bakken
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, Ås, Norway
| | - Åsa Frostegård
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, Ås, Norway
| | - Sukhwan Yoon
- Department of Civil and Environmental Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, South Korea
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4
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Siriweera B, Ahmar Siddiqui M, Zou X, Chen G, Wu D. Integrated thiosulfate-driven denitrification, partial nitrification and anammox process in membrane-aerated biofilm reactor for low-carbon, energy-efficient biological nitrogen removal. BIORESOURCE TECHNOLOGY 2023; 382:129212. [PMID: 37230332 DOI: 10.1016/j.biortech.2023.129212] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2023] [Revised: 05/13/2023] [Accepted: 05/18/2023] [Indexed: 05/27/2023]
Abstract
Combining multiple bioprocesses in a single membrane-aerated biofilm reactor (MABR) unit for wastewater treatment is an emerging research focus. This study investigated the feasibility of coupling thiosulfate-driven denitrification (TDD) with partial nitrification and anammox (PNA) in a MABR for the treatment of ammonium-containing wastewater. The integrated bioprocess was tested over a continuous operation period (>130 d) in two MABRs: one with a polyvinylidene fluoride membrane (MABR-1), and the other with micro-porous aeration tubes covered with non-wovenpolyester fabrics (MABR-2). After start-up, the MABR-1 and MABR-2 based on the TDD-PNA process achieved satisfactory total nitrogen removal efficiencies of 63% and 76%, with maximum oxygen utilisation efficiencies of up to 66% and 80% and nitrogen removal fluxes of 1.3 and 4.7 gN/(m2·d), respectively. Predictions from the AQUASIM-model verified the integrated bioprocess. These lab scale findings confirmed the applicability of MABR technology for simultaneous sulfur and nitrogen removal, promising for pilot-scale application.
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Affiliation(s)
- Buddhima Siriweera
- Department of Civil and Environmental Engineering, Water Technology Center, Hong Kong Branch of Chinese National Engineering Research Center for Control & Treatment of Heavy Metal Pollution, The Hong Kong University of Science and Technology, Hong Kong, China
| | - Muhammad Ahmar Siddiqui
- Department of Civil and Environmental Engineering, Water Technology Center, Hong Kong Branch of Chinese National Engineering Research Center for Control & Treatment of Heavy Metal Pollution, The Hong Kong University of Science and Technology, Hong Kong, China
| | - Xu Zou
- Department of Civil and Environmental Engineering, Water Technology Center, Hong Kong Branch of Chinese National Engineering Research Center for Control & Treatment of Heavy Metal Pollution, The Hong Kong University of Science and Technology, Hong Kong, China
| | - Guanghao Chen
- Department of Civil and Environmental Engineering, Water Technology Center, Hong Kong Branch of Chinese National Engineering Research Center for Control & Treatment of Heavy Metal Pollution, The Hong Kong University of Science and Technology, Hong Kong, China
| | - Di Wu
- Department of Civil and Environmental Engineering, Water Technology Center, Hong Kong Branch of Chinese National Engineering Research Center for Control & Treatment of Heavy Metal Pollution, The Hong Kong University of Science and Technology, Hong Kong, China; Centre for Environmental and Energy Research, Ghent University Global Campus, Incheon 21985, South Korea; Department of Green Chemistry and Technology, Ghent University, and Centre for Advanced Process Technology for Urban Resource Recovery (CAPTURE), Ghent 9000, Belgium.
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5
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Wang Z, Jimenez-Fernandez O, Osenbrück K, Schwientek M, Schloter M, Fleckenstein JH, Lueders T. Streambed microbial communities in the transition zone between groundwater and a first-order stream as impacted by bidirectional water exchange. WATER RESEARCH 2022; 217:118334. [PMID: 35397370 DOI: 10.1016/j.watres.2022.118334] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2022] [Revised: 03/15/2022] [Accepted: 03/19/2022] [Indexed: 06/14/2023]
Abstract
The input of nitrate and other agricultural pollutants in higher-order streams largely derives from first-order streams. The streambed as the transition zone between groundwater and stream water has a decisive impact on the attenuation of such pollutants. This reactivity is not yet well understood for lower-order agricultural streams, which are often anthropogenically altered and lack the streambed complexity allowing for extensive hyporheic exchange. Reactive hot spots in such streambeds have been hypothesized as a function of hydrology, which controls the local gaining (groundwater exfiltration) or losing (infiltration) of stream water. However, streambed microbial communities and activities associated with such reactive zones remain mostly uncharted. In this study, sediments of a first-order agriculturally impacted stream in southern Germany were investigated. Along with a hydraulic dissection of distinct gaining and losing reaches of the stream, community composition and the abundance of bacterial communities in the streambed were investigated using PacBio long-read sequencing of bacterial 16S rRNA gene amplicons, and qPCR of bacterial 16S rRNA and denitrification genes (nirK and nirS). We show that bidirectional water exchange between groundwater and the stream represents an important control for sediment microbiota, especially for nitrate-reducing populations. Typical heterotrophic denitrifiers were most abundant in a midstream net losing section, while up- and downstream net gaining sections were associated with an enrichment of sulfur-oxidizing potential nitrate reducers affiliated with Sulfuricurvum and Thiobacillus spp. Dispersal-based community assembly was found to dominate such spots of groundwater exfiltration. Our results indicate a coupling of N- and S-cycling processes in the streambed of an agricultural first-order stream, and a prominent control of microbiology by hydrology and hydrochemistry in situ. Such detailed local heterogeneities in exchange fluxes and streambed microbiomes have not been reported to date, but seem relevant for understanding the reactivity of lower-order streams.
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Affiliation(s)
- Zhe Wang
- Chair of Ecological Microbiology, Bayreuth Center of Ecology and Environmental Research (BayCEER), University of Bayreuth, Bayreuth, Germany; Institute of Groundwater Ecology, Helmholtz Zentrum München - German Research Centre for Environmental Health, Neuherberg, Germany; School of Life Sciences, Technical University of Munich, Freising, Germany
| | - Oscar Jimenez-Fernandez
- Center for Applied Geoscience, University of Tübingen, Tübingen, Germany; Department of Hydrogeology, Helmholtz-Zentrum für Umweltforschung GmbH - UFZ, Leipzig, Germany
| | - Karsten Osenbrück
- Center for Applied Geoscience, University of Tübingen, Tübingen, Germany; Federal Institute for Geosciences and Natural Resources (BGR), Hannover, Germany
| | - Marc Schwientek
- Center for Applied Geoscience, University of Tübingen, Tübingen, Germany
| | - Michael Schloter
- Chair of Soil Science, Technical University of Munich, Freising, Germany; Research Unit for Comparative Microbiome Analyses, Helmholtz Zentrum München - German Research Centre for Environmental Health, Neuherberg, Germany
| | - Jan H Fleckenstein
- Department of Hydrogeology, Helmholtz-Zentrum für Umweltforschung GmbH - UFZ, Leipzig, Germany; Hydrologic Modelling Unit, Bayreuth Center of Ecology and Environmental Research (BayCEER), University of Bayreuth, Bayreuth, Germany
| | - Tillmann Lueders
- Chair of Ecological Microbiology, Bayreuth Center of Ecology and Environmental Research (BayCEER), University of Bayreuth, Bayreuth, Germany.
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6
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Dalcin Martins P, Echeveste Medrano MJ, Arshad A, Kurth JM, Ouboter HT, Op den Camp HJM, Jetten MSM, Welte CU. Unraveling Nitrogen, Sulfur, and Carbon Metabolic Pathways and Microbial Community Transcriptional Responses to Substrate Deprivation and Toxicity Stresses in a Bioreactor Mimicking Anoxic Brackish Coastal Sediment Conditions. Front Microbiol 2022; 13:798906. [PMID: 35283857 PMCID: PMC8906906 DOI: 10.3389/fmicb.2022.798906] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2021] [Accepted: 01/12/2022] [Indexed: 12/25/2022] Open
Abstract
Microbial communities are key drivers of carbon, sulfur, and nitrogen cycling in coastal ecosystems, where they are subjected to dynamic shifts in substrate availability and exposure to toxic compounds. However, how these shifts affect microbial interactions and function is poorly understood. Unraveling such microbial community responses is key to understand their environmental distribution and resilience under current and future disturbances. Here, we used metagenomics and metatranscriptomics to investigate microbial community structure and transcriptional responses to prolonged ammonium deprivation, and sulfide and nitric oxide toxicity stresses in a controlled bioreactor system mimicking coastal sediment conditions. Ca. Nitrobium versatile, identified in this study as a sulfide-oxidizing denitrifier, became a rare community member upon ammonium removal. The ANaerobic Methanotroph (ANME) Ca. Methanoperedens nitroreducens showed remarkable resilience to both experimental conditions, dominating transcriptional activity of dissimilatory nitrate reduction to ammonium (DNRA). During the ammonium removal experiment, increased DNRA was unable to sustain anaerobic ammonium oxidation (anammox) activity. After ammonium was reintroduced, a novel anaerobic bacterial methanotroph species that we have named Ca. Methylomirabilis tolerans outcompeted Ca. Methylomirabilis lanthanidiphila, while the anammox Ca. Kuenenia stuttgartiensis outcompeted Ca. Scalindua rubra. At the end of the sulfide and nitric oxide experiment, a gammaproteobacterium affiliated to the family Thiohalobacteraceae was enriched and dominated transcriptional activity of sulfide:quinone oxidoreductases. Our results indicate that some community members could be more resilient to the tested experimental conditions than others, and that some community functions such as methane and sulfur oxidation coupled to denitrification can remain stable despite large shifts in microbial community structure. Further studies on complex bioreactor enrichments are required to elucidate coastal ecosystem responses to future disturbances.
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Affiliation(s)
| | | | - Arslan Arshad
- Department of Microbiology, RIBES, Radboud University, Nijmegen, Netherlands
| | - Julia M Kurth
- Department of Microbiology, RIBES, Radboud University, Nijmegen, Netherlands
| | - Heleen T Ouboter
- Department of Microbiology, RIBES, Radboud University, Nijmegen, Netherlands
| | | | - Mike S M Jetten
- Department of Microbiology, RIBES, Radboud University, Nijmegen, Netherlands
| | - Cornelia U Welte
- Department of Microbiology, RIBES, Radboud University, Nijmegen, Netherlands
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7
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Ahmar Siddiqui M, Kumar Biswal B, Siriweera B, Chen G, Wu D. Integrated self-forming dynamic membrane (SFDM) and membrane-aerated biofilm reactor (MABR) system enhanced single-stage autotrophic nitrogen removal. BIORESOURCE TECHNOLOGY 2022; 345:126554. [PMID: 34906703 DOI: 10.1016/j.biortech.2021.126554] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/26/2021] [Revised: 12/06/2021] [Accepted: 12/08/2021] [Indexed: 06/14/2023]
Abstract
The membrane aerated biofilm reactor (MABR) is a novel bioreactor technology, facilitating single-stage autotrophic nitrogen removal. Two laboratory-scale MABRs equipped with non-woven fabrics were operated simultaneously without and with a self-forming dynamic membrane (SFDM) filtration module. After 87 days of operation (system start-up), the reactor incorporated with SFDM filtration showed better performance in terms of total nitrogen removal (>80%) and effluent suspended solid (less than1 mg/L) than the MABR in the up flow anaerobic sludge blanket (UASB) configuration (i.e., without SFDM). The incorporation of SFDM has the ability to retain more slow growing biomass (anammox) inside the reactor. Microbial characterization by 16S rRNA-based amplicon sequencing shows that the abundance and composition of microbial communities in two MABR systems were different, i.e., the genusRhodanobacterwas abundant in UASB-MABR, while Calorithrixwas dominant in SFDM-MABR. PCA-based statistical analysis demonstrated a positive association between reactor performance, membrane characteristics and microbial communities.
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Affiliation(s)
- Muhammad Ahmar Siddiqui
- Department of Civil and Environmental Engineering, Water Technology Center, Hong Kong Branch of Chinese National Engineering Research Centre for Control & Treatment of Heavy Metal Pollution, The Hong Kong University of Science & Technology, Clear Water Bay, Kowloon, Hong Kong, PR China
| | - Basanta Kumar Biswal
- Department of Civil and Environmental Engineering, Water Technology Center, Hong Kong Branch of Chinese National Engineering Research Centre for Control & Treatment of Heavy Metal Pollution, The Hong Kong University of Science & Technology, Clear Water Bay, Kowloon, Hong Kong, PR China
| | - Buddhima Siriweera
- Department of Civil and Environmental Engineering, Water Technology Center, Hong Kong Branch of Chinese National Engineering Research Centre for Control & Treatment of Heavy Metal Pollution, The Hong Kong University of Science & Technology, Clear Water Bay, Kowloon, Hong Kong, PR China
| | - Guanghao Chen
- Department of Civil and Environmental Engineering, Water Technology Center, Hong Kong Branch of Chinese National Engineering Research Centre for Control & Treatment of Heavy Metal Pollution, The Hong Kong University of Science & Technology, Clear Water Bay, Kowloon, Hong Kong, PR China
| | - Di Wu
- Department of Civil and Environmental Engineering, Water Technology Center, Hong Kong Branch of Chinese National Engineering Research Centre for Control & Treatment of Heavy Metal Pollution, The Hong Kong University of Science & Technology, Clear Water Bay, Kowloon, Hong Kong, PR China; Center for Environment and Energy Research, Ghent University Global Campus, Incheon, Republic of Korea; Department of Green Chemistry and Technology, Ghent University, Ghent, Belgium.
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8
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He H, Wagner BM, Carlson AL, Yang C, Daigger GT. Recent progress using membrane aerated biofilm reactors for wastewater treatment. WATER SCIENCE AND TECHNOLOGY : A JOURNAL OF THE INTERNATIONAL ASSOCIATION ON WATER POLLUTION RESEARCH 2021; 84:2131-2157. [PMID: 34810302 DOI: 10.2166/wst.2021.443] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
The membrane biofilm reactor (MBfR), which is based on the counter diffusion of the electron donors and acceptors into the biofilm, represents a novel technology for wastewater treatment. When process air or oxygen is supplied, the MBfR is known as the membrane aerated biofilm reactor (MABR), which has high oxygen transfer rate and efficiency, promoting microbial growth and activity within the biofilm. Over the past few decades, laboratory-scale studies have helped researchers and practitioners understand the relevance of influencing factors and biological transformations in MABRs. In recent years, pilot- to full-scale installations are increasing along with process modeling. The resulting accumulated knowledge has greatly improved understanding of the counter-diffusional biological process, with new challenges and opportunities arising. Therefore, it is crucial to provide new insights by conducting this review. This paper reviews wastewater treatment advancements using MABR technology, including design and operational considerations, microbial community ecology, and process modeling. Treatment performance of pilot- to full-scale MABRs for process intensification in existing facilities is assessed. This paper also reviews other emerging applications of MABRs, including sulfur recovery, industrial wastewater, and xenobiotics bioremediation, space-based wastewater treatment, and autotrophic nitrogen removal. In conclusion, commercial applications demonstrate that MABR technology is beneficial for pollutants (COD, N, P, xenobiotics) removal, resource recovery (e.g., sulfur), and N2O mitigation. Further research is needed to increase packing density while retaining efficient external mass transfer, understand the microbial interactions occurring, address existing assumptions to improve process modeling and control, and optimize the operational conditions with site-specific considerations.
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Affiliation(s)
- Huanqi He
- Department of Civil and Environmental Engineering, University of Michigan, 177 EWRE Building, 1351 Beal Street, Ann Arbor, MI 48109, USA E-mail:
| | - Brett M Wagner
- Department of Civil and Environmental Engineering, University of Michigan, 177 EWRE Building, 1351 Beal Street, Ann Arbor, MI 48109, USA E-mail:
| | - Avery L Carlson
- Department of Civil and Environmental Engineering, University of Michigan, 177 EWRE Building, 1351 Beal Street, Ann Arbor, MI 48109, USA E-mail:
| | - Cheng Yang
- Department of Civil and Environmental Engineering, University of Michigan, 177 EWRE Building, 1351 Beal Street, Ann Arbor, MI 48109, USA E-mail:
| | - Glen T Daigger
- Department of Civil and Environmental Engineering, University of Michigan, 177 EWRE Building, 1351 Beal Street, Ann Arbor, MI 48109, USA E-mail:
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