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Wett B, Aichinger P, Murthy S. Converting rectangular and circular primary tanks into the AAA biologically enhanced clarification settler. Water Environ Res 2024; 96:e11023. [PMID: 38647151 DOI: 10.1002/wer.11023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2023] [Revised: 03/14/2024] [Accepted: 03/23/2024] [Indexed: 04/25/2024]
Abstract
The frequent design challenge for existing water resource recovery facilities targets the accommodation of an ~50% load increase within the existing infrastructure and footprint. Off-loading this organic load at the top-end of the plant and redirection toward the digesters has proven the most efficient way of process intensification. The Triple A settler is an "activated primary treatment," stands for alternating activated adsorption, and can be retrofitted into existing rectangular or circular (mostly) primary tanks at a hydraulic retention time of 2 h and a sludge retention time of about 0.5 days. Several technology implementations demonstrate flexible designs adjusting to existing tank geometries and depths of 2.5 to 5.0 m. Different implementation scales from dry-weather flow rates ranging from 0.1 to 10 mgd show generic applicability of the functional principles at any scale: Biosorption, bioflocculation, and assimilation provide the key added value in pretreatment efficiencies of ~60/25/33 in %COD/%N/%P removal compared with application of pure physics in primary settling with typical 33%/9%/11% removal, respectively. PRACTITIONERS POINTS: Triple A is a hybrid form of A-stage and contact stabilizer for advanced primary treatment. Besides COD and TSS, also, P and N can be removed via Triple A. Triple A can be retrofitted in existing rectangular or circular tanks. This high-rate process does not worsen the conditions for enhanced biological phosphorus removal. Energy efficiency, capacity increase, and operational benefits are the main goals of Triple A.
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2
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Daigger GT, Kuo J, Derlon N, Houweling D, Jimenez JA, Johnson BR, McQuarrie JP, Murthy S, Regmi P, Roche C, Sturm B, Wett B, Winkler M, Boltz JP. Biological and physical selectors for mobile biofilms, aerobic granules, and densified-biological flocs in continuously flowing wastewater treatment processes: A state-of-the-art review. Water Res 2023; 242:120245. [PMID: 37356157 DOI: 10.1016/j.watres.2023.120245] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/21/2023] [Revised: 06/14/2023] [Accepted: 06/16/2023] [Indexed: 06/27/2023]
Abstract
There have been significant advances in the use of biological and physical selectors for the intensification of continuously flowing biological wastewater treatment (WWT) processes. Biological selection allows for the development of large biological aggregates (e.g., mobile biofilm, aerobic granules, and densified biological flocs). Physical selection controls the solids residence times of large biological aggregates and ordinary biological flocs, and is usually accomplished using screens or hydrocyclones. Large biological aggregates can facilitate different biological transformations in a single reactor and enhance liquid and solids separation. Continuous-flow WWT processes incorporating biological and physical selectors offer benefits that can include reduced footprint, lower costs, and improved WWT process performance. Thus, it is expected that both interest in and application of these processes will increase significantly in the future. This review provides a comprehensive summary of biological and physical selectors and their design and operation.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | | | | | | | - Joshua P Boltz
- Woodard & Curran, 3907 Langley Ave., Foley, AL 36535, USA.
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3
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Van Winckel T, Ngo N, Sturm B, Al-Omari A, Wett B, Bott C, Vlaeminck SE, De Clippeleir H. Enhancing bioflocculation in high-rate activated sludge improves effluent quality yet increases sensitivity to surface overflow rate. Chemosphere 2022; 308:136294. [PMID: 36084824 DOI: 10.1016/j.chemosphere.2022.136294] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/21/2022] [Revised: 08/02/2022] [Accepted: 08/29/2022] [Indexed: 06/15/2023]
Abstract
High-rate activated sludge (HRAS) relies on good bioflocculation and subsequent solid-liquid separation to maximize the capture of organics. However, full-scale applications often suffer from poor and unpredictable effluent suspended solids (ESS). While the biological aspects of bioflocculation are thoroughly investigated, the effects of fines (settling velocity < 0.6 m3/m2/h), shear and surface overflow rate (SOR) are unclear. This work tackled the impact of fines, shear, and SOR on the ESS in absence of settleable influent solids. This was assessed on a full-scale HRAS step-feed (SF) and pilot-scale HRAS contact-stabilization (CS) configuration using batch settling tests, controlled clarifier experiments, and continuous operation of reactors. Fines contributed up to 25% of the ESS in the full-scale SF configuration. ESS decreased up to 30 mg TSS/L when bioflocculation was enhanced with the CS configuration. The feast-famine regime applied in CS promoted the production of high-quality extracellular polymeric substances (EPS). However, this resulted in a narrow and unfavorable settling velocity distribution, with 50% ± 5% of the sludge mass settling between 0.6 and 1.5 m3/m2/h, thus increasing sensitivity towards SOR changes. A low shear environment (20 s-1) before the clarifier for at least one min was enough to ensure the best possible settling velocity distribution, regardless of prior shear conditions. Overall, this paper provides a more complete view on the drivers of ESS in HRAS systems, creating the foundation for the design of effective HRAS clarifiers. Tangible recommendations are given on how to manage fines and establish the optimal settling velocity of the sludge.
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Affiliation(s)
- Tim Van Winckel
- Center of Microbial Ecology and Technology (CMET), Faculty of Bioscience Engineering, Ghent University, 9000, Gent, Belgium; District of Columbia Water and Sewer Authority, Blue Plains Advanced Wastewater Treatment Plant, 5000 Overlook Ave, SW, Washington DC, 20032, USA; Department of Civil, Environmental and Architectural Engineering, The University of Kansas, KS, USA
| | - Nam Ngo
- District of Columbia Water and Sewer Authority, Blue Plains Advanced Wastewater Treatment Plant, 5000 Overlook Ave, SW, Washington DC, 20032, USA; Department of Civil and Environmental Engineering, The Catholic University of America, Washington DC, USA
| | - Belinda Sturm
- Department of Civil, Environmental and Architectural Engineering, The University of Kansas, KS, USA
| | - Ahmed Al-Omari
- District of Columbia Water and Sewer Authority, Blue Plains Advanced Wastewater Treatment Plant, 5000 Overlook Ave, SW, Washington DC, 20032, USA
| | | | | | - Siegfried E Vlaeminck
- Research Group of Sustainable Energy, Air and Water Technology, Department of Bioscience Engineering, University of Antwerp, 2020, Antwerpen, Belgium.
| | - Haydée De Clippeleir
- District of Columbia Water and Sewer Authority, Blue Plains Advanced Wastewater Treatment Plant, 5000 Overlook Ave, SW, Washington DC, 20032, USA
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4
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Ngo KN, Tampon P, Van Winckel T, Massoudieh A, Sturm B, Bott C, Wett B, Murthy S, Vlaeminck SE, DeBarbadillo C, De Clippeleir H. Introducing bioflocculation boundaries in process control to enhance effluent quality of high-rate contact-stabilization systems. Water Environ Res 2022; 94:e10772. [PMID: 35965329 DOI: 10.1002/wer.10772] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2022] [Revised: 06/30/2022] [Accepted: 07/01/2022] [Indexed: 06/15/2023]
Abstract
High-rate activated sludge (HRAS) systems suffer from high variability of effluent quality, clarifier performance, and carbon capture. This study proposed a novel control approach using bioflocculation boundaries for wasting control strategy to enhance effluent quality and stability while still meeting carbon capture goals. The bioflocculation boundaries were developed based on the oxygen uptake rate (OUR) ratio between contactor and stabilizer (feast/famine) in a high-rate contact stabilization (CS) system and this OUR ratio was used to manipulate the wasting setpoint. Increased oxidation of carbon or decreased wasting was applied when OUR ratio was <0.52 or >0.95 to overcome bioflocculation limitation and maintain effluent quality. When no bioflocculation limitations (OUR ratio within 0.52-0.95) were detected, carbon capture was maximized. The proposed control concept was shown for a fully automated OUR-based control system as well as for a simplified version based on direct waste flow control. For both cases, significant improvements in effluent suspended solids level and stability (<50-mg TSS/L), solids capture over the clarifier (>90%), and COD capture (median of 32%) were achieved. This study shows how one can overcome the process instability of current HRAS systems and provide a path to achieve more reliable outcomes. PRACTITIONER POINTS: Online bioflocculation boundaries (upper and lower limit) were defined by the OUR ratio between contactor and stabilizer (feast/famine). To maintain effluent quality, carbon oxidation was minimized when bioflocculation was not limited (0.52-0.95 OUR ratio) and increased otherwise. A fully automated control concept was piloted, also a more simplified semiautomated option was proposed. Wasting control strategies with bioflocculation boundaries improved effluent quality while meeting carbon capture goals. Bioflocculation boundaries are easily applied to current wasting control schemes applied to HRAS systems (i.e., MLSS, SRT, and OUR controls).
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Affiliation(s)
- Khoa Nam Ngo
- Blue Plains Advanced Wastewater Treatment Plant, District of Columbia Water and Sewer Authority, Washington, DC, USA
- Department of Civil and Environmental Engineering, The Catholic University of America, Washington, DC, USA
| | - Patrexia Tampon
- Blue Plains Advanced Wastewater Treatment Plant, District of Columbia Water and Sewer Authority, Washington, DC, USA
- Department of Civil and Environmental Engineering, The Catholic University of America, Washington, DC, USA
| | - Tim Van Winckel
- Research Group of Sustainable Energy, Air and Water Technology, Department of Bioscience Engineering, University of Antwerp, Antwerp, Belgium
| | - Arash Massoudieh
- Department of Civil and Environmental Engineering, The Catholic University of America, Washington, DC, USA
| | - Belinda Sturm
- Department of Civil, Environmental and Architectural engineering, The University of Kansas, Lawrence, Kansas, USA
| | - Charles Bott
- Hampton Roads Sanitation District, Virginia Beach, Virginia, USA
| | | | | | - Siegfried E Vlaeminck
- Research Group of Sustainable Energy, Air and Water Technology, Department of Bioscience Engineering, University of Antwerp, Antwerp, Belgium
| | - Christine DeBarbadillo
- Blue Plains Advanced Wastewater Treatment Plant, District of Columbia Water and Sewer Authority, Washington, DC, USA
| | - Haydée De Clippeleir
- Blue Plains Advanced Wastewater Treatment Plant, District of Columbia Water and Sewer Authority, Washington, DC, USA
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5
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Podmirseg SM, Gómez-Brandón M, Muik M, Stres B, Hell M, Pümpel T, Murthy S, Chandran K, Park H, Insam H, Wett B. Microbial response on the first full-scale DEMON® biomass transfer for mainstream deammonification. Water Res 2022; 218:118517. [PMID: 35512538 DOI: 10.1016/j.watres.2022.118517] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2021] [Revised: 04/16/2022] [Accepted: 04/24/2022] [Indexed: 06/14/2023]
Abstract
Sidestream partial nitritation and deammonification (pN/A) of high-strength ammonia wastewater is a well-established technology. Its expansion to the mainstream is, however mainly impeded by poor retention of anaerobic ammonia oxidizing bacteria (AnAOB), insufficient repression of nitrite oxidizing bacteria (NOB) and difficult control of soluble chemical oxygen demand and nitrite levels. At the municipal wastewater treatment plant in Strass (Austria) the microbial consortium was exhaustively monitored at full-scale over one and a half year with regular transfer of sidestream DEMON® biomass and further retention and enrichment of granular anammox biomass via hydrocyclone operation. Routine process parameters were surveyed and the response and evolution of the microbiota was followed by molecular tools, ex-situ activity tests and further, AnAOB quantification through particle tracking and heme measurement. After eight months of operation, the first anaerobic, simultaneous depletion of ammonia and nitrite was observed ex-situ, together with a direction to higher nitrite generation (68% of total NOx-N) as compared to nitrate under aerobic conditions. Our dissolved oxygen (DO) scheme allowed for transient anoxic conditions and had a strong influence on nitrite levels and the NOB community, where Nitrobacter eventually dominated Nitrospira. The establishment of a minor but stable AnAOB biomass was accompanied by the rise of Chloroflexi and distinct emergence of Chlorobi, a trend not seen in the sidestream system. Interestingly, the most pronounced switch in the microbial community and noticeable NOB repression occurred during unfavorable conditions, i.e. the cold winter season and high organic load. Further abatement of NOB was achieved through bioaugmentation of aerobic ammonia oxidizing bacteria (AerAOB) from the sidestream-DEMON® tank. Performance of the sidestream pN/A was not impaired by this operational scheme and the average volumetric nitrogen removal rate of the mainstream even doubled in the second half of the monitoring campaign. We conclude that a combination of both, regular sidestream-DEMON® biomass transfer and granular SRT increase via hydrocyclone operation was crucial for AnAOB establishment within the mainstream.
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Affiliation(s)
- Sabine Marie Podmirseg
- Department of Microbiology, University of Innsbruck, Technikerstraße 25d, 6020 Innsbruck, Austria; alpS GmbH, Grabenweg 68, 6020 Innsbruck, Austria.
| | - María Gómez-Brandón
- Department of Microbiology, University of Innsbruck, Technikerstraße 25d, 6020 Innsbruck, Austria; alpS GmbH, Grabenweg 68, 6020 Innsbruck, Austria; Grupo Ecoloxía Animal (GEA), Centro di Investigación Mariña (CIM), Universidade de Vigo, E-36310, Spain
| | - Markus Muik
- Department of Microbiology, University of Innsbruck, Technikerstraße 25d, 6020 Innsbruck, Austria.
| | - Blaz Stres
- University of Ljubljana, Biotechnical Faculty, Jamnikarjeva 101, 1000 Ljubljana, Slovenia; University of Ljubljana, Faculty of Geodetic and Civil Engineering, Jamova 2, 1000 Ljubljana, Slovenia
| | - Martin Hell
- Achental-Inntal-Zillertal Water Board, Hausnummer 150, 6261 Strass i.Z., Austria.
| | - Thomas Pümpel
- Department of Microbiology, University of Innsbruck, Technikerstraße 25d, 6020 Innsbruck, Austria.
| | | | - Kartik Chandran
- Department of Earth and Environmental Engineering, Columbia University, 500 West 120th Street, NY 10027, United States.
| | - Hongkeun Park
- Department of Earth and Environmental Engineering, Columbia University, 500 West 120th Street, NY 10027, United States.
| | - Heribert Insam
- Department of Microbiology, University of Innsbruck, Technikerstraße 25d, 6020 Innsbruck, Austria.
| | - Bernhard Wett
- ARAconsult GmbH, Unterbergerstraße 1, 6020 Innsbruck, Austria.
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6
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Fofana R, Peng B, Huynh H, Sajjad M, Jones K, Al-Omari A, Bott C, Vela JD, Murthy S, Wett B, Debarbadillo C, De Clippeleir H. Erratum: Media selection for anammox-based polishing filters: Balancing anammox enrichment and retention with filtration function. Water Environ Res 2022; 94:e10753. [PMID: 35716128 DOI: 10.1002/wer.10753] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
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7
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Fofana R, Peng B, Huynh H, Sajjad M, Jones K, Al-Omari A, Bott C, Delgado Vela J, Murthy S, Wett B, Debarbadillo C, De Clippeleir H. Media selection for anammox-based polishing filters: Balancing anammox enrichment and retention with filtration function. Water Environ Res 2022; 94:e10724. [PMID: 35614874 DOI: 10.1002/wer.10724] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/01/2021] [Revised: 04/13/2022] [Accepted: 05/01/2022] [Indexed: 06/15/2023]
Abstract
Retrofitting conventional denitrification filters into partial denitrification-anammox (PdNA)- or anammox (AnAOB)-based filters will reduce the needs for external carbon addition. The success of AnAOB-based filters depends on anammox growth and retention within such filters. Studies have overlooked the importance of media selection and its impact on AnAOB capacity, head loss progression dynamics, and shear conditions applied onto the AnAOB biofilm. The objective of this study was to evaluate viable media types (10 types) that can enhance AnAOB rates for efficient nitrogen removal in filters. Given the higher backwash requirement and lower AnAOB capacity of the conventionally used sand, expanded clay (3-5 mm) was recommended for AnAOB-based filters in this study. Owing to its surface characteristics, expanded clay had higher AnAOB activity (304- vs. 104-g NH4 + -N/m2 /day) and higher AnAOB retention (43% more) than sand. Increasing the iron content of expanded clay to 37% resulted in an increase in zeta potential, which led to 56% more anammox capacity compared to expanded clay with 7% iron content. This work provides insight into the importance of media types in the growth and retention of AnAOB in filters, and this knowledge could be used as basis in the development of PdNA filters. PRACTITIONER POINTS: Expanded clay showed the lowest head loss buildup and most likely will result in longer runtime for full-scale PdNA applications The highest AnAOB rates were achieved in expanded clay types and sand compared with smaller media typically used in biofiltration Expanded clay resulted in better AnAOB retention under shear, whereas sand could not withstand shear and required more frequent backwashing Expanded clay iron coating enhanced AnAOB enrichment and retention, most likely due to increased surface roughness and/or positive charge.
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Affiliation(s)
- Rahil Fofana
- DC Water & Sewer Authority, Washington, District of Columbia, USA
- Howard University, Washington, District of Columbia, USA
| | - Bo Peng
- DC Water & Sewer Authority, Washington, District of Columbia, USA
| | - Huu Huynh
- DC Water & Sewer Authority, Washington, District of Columbia, USA
| | - Mehran Sajjad
- DC Water & Sewer Authority, Washington, District of Columbia, USA
| | - Kimberly Jones
- Howard University, Washington, District of Columbia, USA
| | - Ahmed Al-Omari
- DC Water & Sewer Authority, Washington, District of Columbia, USA
| | - Charles Bott
- Hampton Roads Sanitation District, Virginia Beach, Virginia, USA
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Roche C, Donnaz S, Murthy S, Wett B. Biological process architecture in continuous-flow activated sludge by gravimetry: Controlling densified biomass form and function in a hybrid granule-floc process at Dijon WRRF, France. Water Environ Res 2022; 94:e1664. [PMID: 34806253 DOI: 10.1002/wer.1664] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2021] [Revised: 10/25/2021] [Accepted: 11/09/2021] [Indexed: 06/13/2023]
Abstract
Full-scale demonstration of activated sludge conversion into a granule-floc hybrid process was implemented in Dijon (France) water resource recovery facility (WRRF). Biomass densification was achieved based on external gravimetric selection using hydrocyclones within continuous-flow anaerobic-anoxic-oxic (A2 O) biological nutrient removal (BNR) bioreactor. The goal was to optimize settleability of biological sludge by lowering and stabilizing sludge volume index (SVI) to improve process robustness and resiliency. Process proved to stabilize operation and to uncouple the total solids residence time (SRT) between floc and granule morphologies. The densified biomass initially produced stable SVI < 100 ml/g for a period of 4 months and thereafter a steady state year-round SVI below 50 ml/g, including the winter period during which the control train SVI expansion >200 ml/g. The densified biomass successfully broke the vicious cycle of interannual bulking. Form and function interrelationship is proposed for the densified biomass (hybrid floc-granule). The concept of biological architecture is proposed as the purposeful control of granule and floc proportions, with a proposed "form factor" ratio of 1:2 granule to floc, that produce a "SRT uncoupling function factor" ratio of 4:1 granule to floc, further resulting in very stable settling and effluent functionalities. PRACTITIONER POINTS: Controlling granule-floc proportions allows for sludge volume index (SVI) operational adjustment, which further allows for increased clarified design accuracy. One-third aggregates dramatically improved settling characteristics: 20% and 35% of AGS ensures SVIs below 100 and 50 ml/g, respectively. Densified biomass enables new SRT and clarifier flux rates approaches for engineering and operation practices: Doubling typical surface loading rates from 6.0-8.5 to 15-20 kg m-2 h-1 and surface overflow rates from 0.6-0.8 to 1.5-2.4 m/h SRT uncoupling of 1:4 is achieved between floc and granule, enabling specific niche environment for fast and slow growing organisms.
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Wett B, Brückl A, Aichinger P, Ingerle K. All you need is air-Alternating activated sludge system BIOCOS without electromechanical equipment. Water Environ Res 2021; 93:1315-1321. [PMID: 33484610 DOI: 10.1002/wer.1516] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Revised: 11/11/2020] [Accepted: 11/24/2020] [Indexed: 06/12/2023]
Abstract
Exclusively air-driven operation is an essential feature of the cyclic activated sludge process BIOCOS. Switching the air-flow between diffusers, agitation, and recycle air-lift keeps operation and maintenance simple and leads to significant energy savings used for mechanical devices. The overall energy demand for the whole biological system with settling was found to be below 20 kWh/PE.a. This hybrid technology shows a constant water level characteristic for continuous flow systems and time-based control. Modular rectangular tank configuration and high solids operation targets a compact footprint. Process wise, the settling sludge blanket in the two alternating settling tanks was found to contribute considerably to post-denitrification and enhances phosphorus removal. During the last years, approximately 200 BIOCOS plants have been implemented mainly in Germany, Austria, Spain, and China, some of the operational results are presented in this paper. PRACTITIONERS POINTS: BIOCOS is a hybrid process with alternating settling tanks at constant water level. The performance of demonstration plants shows high resilience against hydraulic and organic peak loads. The energy demand for the process was found to be very small. The process is driven with no electromechanical equipment but one main blower station. The sludge blanket in the alternating settler significantly contributes to denitrification and phosphorus removal.
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Ali P, Zalivina N, Le T, Riffat R, Ergas S, Wett B, Murthy S, Al-Omari A, deBarbadillo C, Bott C, De Clippeleir H. Primary sludge fermentate as carbon source for mainstream partial denitrification-anammox (PdNA). Water Environ Res 2021; 93:1044-1059. [PMID: 33277759 DOI: 10.1002/wer.1492] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2020] [Revised: 11/05/2020] [Accepted: 11/24/2020] [Indexed: 06/12/2023]
Abstract
Primary sludge fermentate, a concentrated hydrolyzed wastewater carbon, was evaluated for use as an alternative carbon source for mainstream partial denitrification-anammox (PdNA) in a suspended growth activated sludge process in terms of partial denitrification (PdN) efficiency, PdNA nitrogen removal contributions, and final effluent quality. Fermenter operation at a 2-day sludge retention time (SRT) resulted in the maximum achievable yield of 0.14 ± 0.05 g sCOD/g VSS without release of excessive ammonia and phosphorus to the system. Based on the results of batch experiments, fermentate addition led to PdN efficiency of 93 ± 14%, which was similar to acetate at a nitrate residual of 2-3 mg N/L. In the pilot-scale mainstream deammonification reactor, PdN efficiency using fermentate was 49 ± 24%, which was lower than acetate (66 ± 24% during acetate period I and 70 ± 21% during acetate period II), most probably due to lower nitrate and ammonium kinetics in the PdN zone. Methanol cost-saving potential for the application of PdNA as the main short-cut nitrogen pathway was estimated to be 30% to 55% depending on the PdN efficiency achieved. PRACTITIONER POINTS: Primary sludge fermentate was evaluated as an alternative carbon source for mainstream partial denitrification-anammox (PdNA). Fermenter operated at a 1 to 2 day SRT resulted in the maximum achievable yield without the release of excessive ammonia and phosphorus to the system. Although 93% partial denitrification efficiency was achieved with fermentate in batch experiments, around 49% PdN efficiency was achieved in pilot studies. Application of PdNA with fermentate can result in significant methanol cost savings.
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Affiliation(s)
- Priyanka Ali
- Department of Civil and Environmental Engineering, The George Washington University, Washington, DC, USA
- DC Water and Sewer Authority, Washington, DC, USA
| | - Nadezhda Zalivina
- DC Water and Sewer Authority, Washington, DC, USA
- Department of Civil & Environmental Engineering, University of South Florida, Tampa, FL, USA
| | - Tri Le
- DC Water and Sewer Authority, Washington, DC, USA
- Environmental Engineering, The Catholic University of America, Washington, DC, USA
| | - Rumana Riffat
- Department of Civil and Environmental Engineering, The George Washington University, Washington, DC, USA
| | - Sarina Ergas
- Department of Civil & Environmental Engineering, University of South Florida, Tampa, FL, USA
| | | | | | | | | | - Charles Bott
- Hampton Roads Sanitation District, Virginia Beach, VA, USA
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11
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Ngo KN, Van Winckel T, Massoudieh A, Wett B, Al-Omari A, Murthy S, Takács I, De Clippeleir H. Towards more predictive clarification models via experimental determination of flocculent settling coefficient value. Water Res 2021; 190:116294. [PMID: 33360101 DOI: 10.1016/j.watres.2020.116294] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Revised: 07/26/2020] [Accepted: 08/11/2020] [Indexed: 06/12/2023]
Abstract
Improved settleability has become an essential feature of new wastewater treatment innovations. To accelerate adoption of such new technologies, improved clarifier models are needed to help with designing and predicting improvement in settleability. In general, the level of mathematics of settling clarifier models has gone far beyond the level of existing experimental methods available to support these models. To date, even for simple one-dimensional (1D) clarifier models, no experimental method has been described for flocculent settling coefficient (rp). As a consequence, rp cannot be considered as a sludge characteristic and is used as a calibration parameter to achieve observed effluent quality. In this study, we focused on the development of an empirical function based on a simple and practical experimental approach for the calculation of the rp value from sludge characteristics. This approach provided a similar approach as currently taken for hindered settling coefficient calculations (Veslind equation) and allowed for the model to predict effluent quality, thus increasing the power of the 1D model. The threshold of flocculation (TOF), which describes the collision efficiency of particles, directly correlated with the effluent quality of the five tested activated sludge systems and was selected as experimental method. The proposed empirical function between TOF and rp was validated for four years of validating data with five different sludge types operated under different operational conditions and configurations. The good effluent quality prediction with this approach brings us one step closer in making the clarification models more predictive towards effluent quality and clarifier performance.
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Affiliation(s)
- Khoa Nam Ngo
- District of Columbia Water and Sewer Authority, Blue Plains Advanced Wastewater Treatment Plant, Washington DC, USA; Department of Civil and Environmental Engineering, The Catholic University of America, USA.
| | - Tim Van Winckel
- District of Columbia Water and Sewer Authority, Blue Plains Advanced Wastewater Treatment Plant, Washington DC, USA; Center of Microbial Ecology and Technology (CMET), Faculty of Bioscience Engineering, Ghent University, Gent, Belgium
| | - Arash Massoudieh
- Department of Civil and Environmental Engineering, The Catholic University of America, USA
| | | | - Ahmed Al-Omari
- District of Columbia Water and Sewer Authority, Blue Plains Advanced Wastewater Treatment Plant, Washington DC, USA
| | | | | | - Haydée De Clippeleir
- District of Columbia Water and Sewer Authority, Blue Plains Advanced Wastewater Treatment Plant, Washington DC, USA
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12
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Wett B, Aichinger P, Hell M, Andersen M, Wellym L, Fukuzaki Y, Cao YS, Tao G, Jimenez J, Takacs I, Bott C, Murthy S. Operational and structural A-stage improvements for high-rate carbon removal. Water Environ Res 2020; 92:1983-1989. [PMID: 32358850 DOI: 10.1002/wer.1354] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Revised: 04/22/2020] [Accepted: 04/25/2020] [Indexed: 06/11/2023]
Abstract
Biosorption of organics is investigated at two sites in order to optimize operation and infrastructure for carbon removal and redirection in upstream, high-rate processes. Sufficient process temperature and stable mixed liquor solids concentration were established as the key impact parameters for the process performance. Improved COD removal was achieved by either substantially enhanced aeration (elevated metabolic state) or by enhanced flocculation capability (dosed chemicals). Separation and thickening of organics are typically operated as continuous-flow processes. The optimization of performance parameters led to a new A-stage process named alternating activated adsorption. The AAA process is presented as a novel configuration linking biosorption and thickening capabilities in an alternating scheme without mechanical equipment. The performance data from its first trial indicate benefits from process dynamics including high organics capture rates and thickening capabilities reaching solid concentrations higher than 40 g(TSS)/L. COD removal could be increased further by adding biologically generated polymer, that is waste sludge from B-stage. © 2020 Water Environment Federation PRACTITIONERS POINTS: Enhanced preliminary treatment helps to increase capacity and energy efficiency. Low RAS rates, SRT control, aeration, high temperatures, and metal dosing are key performance parameters for removal rates and energy efficiency. The Triple-A process offers new possibilities for A-stage in terms of performance increase and flexibility showing similar or better results compared with conventional A-stage. Adding B-sludge improved COD and nutrient removal rates. High preliminary removal rates of COD and N foster sidestream processes.
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Affiliation(s)
| | | | | | | | - Lie Wellym
- DHI Water & Environment Pte Ltd, Singapore City, Singapore
| | | | - Ye Shi Cao
- Public Utilities Board (PUB), Singapore City, Singapore
| | - Guihe Tao
- Public Utilities Board (PUB), Singapore City, Singapore
| | | | | | - Charles Bott
- Hampton Roads Sanitation District, Virginia Beach, Virginia, USA
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13
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Le T, Peng B, Su C, Massoudieh A, Torrents A, Al-Omari A, Murthy S, Wett B, Chandran K, deBarbadillo C, Bott C, De Clippeleir H. Nitrate residual as a key parameter to efficiently control partial denitrification coupling with anammox. Water Environ Res 2019; 91:1455-1465. [PMID: 31074914 DOI: 10.1002/wer.1140] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2019] [Revised: 04/24/2019] [Accepted: 05/02/2019] [Indexed: 05/26/2023]
Abstract
Despite the increased research efforts, full-scale implementation of shortcut nitrogen removal strategies has been challenged by the lack of consistent nitrite-oxidizing bacteria out-selection. This paper proposes an alternative path using partial denitrification (PdN) selection coupled with anaerobic ammonium-oxidizing bacteria (AnAOB). A nitrate residual concentration (>2 mg N/L) was identified as the crucial factor for metabolic PdN selection using acetate as a carbon source, unlike the COD/N ratio which was often suggested. Therefore, a novel and simple acetate dosing control strategy based on maintaining a nitrate concentration was tested in the absence and presence of AnAOB, achieving PdN efficiencies above 80%. The metabolic-based PdN selection allowed for flexibility to move between PdN and full denitrification when required to meet effluent nitrate levels. Due to the independence of this strategy on species selection and management of nitrite competition, this novel approach will guarantee nitrite availability for AnAOB under mainstream conditions unlike shortcut nitrogen removal approaches based on NOB out-selection. Overall, a COD addition of only 2.2 g COD/g TIN removed was needed for the PdN-AnAOB concept showing its potential for significant savings in external carbon source needs to meet low TIN effluent concentrations making this concept a competitive alternative. PRACTITIONER POINTS: Nitrate residual is the key control parameter for partial denitrification selection. Metabolic selection allowed for flexibility of moving from partial to full denitrification. 2.2 g COD/g TIN removed was needed for partial denitrification-anammox process.
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Affiliation(s)
- Tri Le
- Environmental Engineering, The Catholic University of America, Washington, District of Columbia
- DC Water and Sewer Authority, Washington, District of Columbia
| | - Bo Peng
- DC Water and Sewer Authority, Washington, District of Columbia
- Department of Civil & Environmental Engineering, University of Maryland, College Park, Maryland
| | - Chunyang Su
- DC Water and Sewer Authority, Washington, District of Columbia
| | - Arash Massoudieh
- Environmental Engineering, The Catholic University of America, Washington, District of Columbia
| | - Alba Torrents
- Department of Civil & Environmental Engineering, University of Maryland, College Park, Maryland
| | - Ahmed Al-Omari
- DC Water and Sewer Authority, Washington, District of Columbia
| | - Sudhir Murthy
- DC Water and Sewer Authority, Washington, District of Columbia
| | | | - Kartik Chandran
- Department of Earth and Environmental Engineering, Columbia University, New York, New York
| | | | - Charles Bott
- Hampton Roads Sanitation District, Virginia Beach, Virginia
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14
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Le T, Peng B, Su C, Massoudieh A, Torrents A, Al-Omari A, Murthy S, Wett B, Chandran K, DeBarbadillo C, Bott C, De Clippeleir H. Impact of carbon source and COD/N on the concurrent operation of partial denitrification and anammox. Water Environ Res 2019; 91:185-197. [PMID: 30699248 DOI: 10.1002/wer.1016] [Citation(s) in RCA: 48] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2018] [Revised: 09/11/2018] [Accepted: 09/21/2018] [Indexed: 06/09/2023]
Abstract
In this study, concurrent operation of anammox and partial denitrification within a nonacclimated mixed culture system was proposed. The impact of carbon sources (acetate, glycerol, methanol, and ethanol) and COD/NO3- -N ratio on partial denitrification selection under both short- and long-term operations was investigated. Results from short-term testing showed that all carbon sources supported partial denitrification. However, acetate and glycerol were preferred due to their display of efficient partial denitrification selection, which may be related to their different electron transport pathways in comparison with methanol. Long-term operation confirmed results of batch tests by showing the contribution of partial denitrification to nitrate removal above 90% after acclimation in both acetate and glycerol reactors. In contrast, methanol showed challenges of maintaining efficient partial denitrification. COD/NO3- -N ratio mainly controlled the rate of nitrate reduction and not directly partial denitrification selection; thus, it should be used to balance between denitrification rate and anammox rate. PRACTITIONER POINTS: The authors aimed to investigate the impact of carbon sources and COD/NO3-N ratio on partial denitrification selection. All the carbon sources supported partial denitrification as long as the nitrite sink was available. 90% partial denitrification could be achieved with both acetate and glycerol in long-term operations. COD/NO3-N ratio did not directly control partial denitrification but can be used to balance between denitrification rate and anammox rate.
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Affiliation(s)
- Tri Le
- Environmental Engineering, The Catholic University of America, Washington, DC
- DC Water and Sewer Authority, Washington, District of Columbia
| | - Bo Peng
- DC Water and Sewer Authority, Washington, District of Columbia
- Department of Civil and Environmental Engineering, University of Maryland, College Park, Maryland
| | - Chunyang Su
- DC Water and Sewer Authority, Washington, District of Columbia
| | - Arash Massoudieh
- Environmental Engineering, The Catholic University of America, Washington, DC
| | - Alba Torrents
- Department of Civil and Environmental Engineering, University of Maryland, College Park, Maryland
| | - Ahmed Al-Omari
- DC Water and Sewer Authority, Washington, District of Columbia
| | - Sudhir Murthy
- DC Water and Sewer Authority, Washington, District of Columbia
| | | | - Kartik Chandran
- Department of Earth and Environmental Engineering, Columbia University, New York, New York
| | | | - Charles Bott
- Hampton Roads Sanitation District, Virginia Beach, Virginia
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Aichinger P, DeBarbadillo C, Al-Omari A, Wett B. 'Hot topic' - combined energy and process modeling in thermal hydrolysis systems. Water Sci Technol 2019; 79:84-92. [PMID: 30816865 DOI: 10.2166/wst.2019.018] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
The thermal hydrolysis process (THP) is applied to enhance biogas production in anaerobic digestion (AD), reduce viscosity for improved mixing and dewatering and to reduce and sterilize cake solids. Large heat demands for steam production rely on dynamic effects like sludge throughput, gas availability and THP process parameters. Here, we propose a combined energy and process model suitable to describe the dynamic behaviour of THP in a full-plant context. The process model addresses interactions of THP with operational conditions covered by the AD model obeying mass continuity. Energy conservation is considered in balancing and converting various energy species dominated by thermal heat and calorific energy. The combined energy and process model was then applied on the THP at Blue Plains advanced WWTP (DC Water) to analyse the process and assess potential energy optimizations. It was found that dynamic effects like mismatched steam production and consumption, temporary gas shortages and underloaded units are responsible for energy inefficiencies with losses in electricity-production up to 29%.
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Affiliation(s)
- Peter Aichinger
- Unit of Environmental Engineering, University of Innsbruck, Technikerstrasse 13, 6020 Innsbruck, Austria E-mail: ; ARAconsult GmbH, Unterbergerstrasse 1, 6020 Innsbruck, Austria
| | | | - Ahmed Al-Omari
- DC Water, 5000 Overlook Avenue, SW Washington, DC 20032, USA
| | - Bernhard Wett
- ARAconsult GmbH, Unterbergerstrasse 1, 6020 Innsbruck, Austria; Dynamita Process Modelling, 7 Lieu-dit Eoupe, La Redoute, 26110 Nyons, France
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16
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Hauduc H, Al-Omari A, Wett B, Jimenez J, De Clippeleir H, Rahman A, Wadhawan T, Takacs I. Colloids, flocculation and carbon capture - a comprehensive plant-wide model. Water Sci Technol 2019; 79:15-25. [PMID: 30816858 DOI: 10.2166/wst.2018.454] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
The implementation of carbon capture technologies such as high-rate activated sludge (HRAS) systems are gaining interests in water resource and recovery facilities (WRRFs) to minimize carbon oxidation and maximize organic carbon recovery and methane potential through biosorption of biodegradable organics into the biomass. Existing activated sludge models were developed to describe chemical oxygen demand (COD) removal in activated sludge systems operating at long solids retention times (SRT) (i.e. 3 days or longer) and fail to simulate the biological reactions at low SRT systems. A new model is developed to describe colloidal material removal and extracellular polymeric substance (EPS) generation, flocculation, and intracellular storage with the objective of extending the range of whole plant models to very short SRT systems. In this study, the model is tested against A-stage (adsorption) pilot reactor performance data and proved to match the COD and colloids removal at low SRT. The model was also tested on longer SRT systems where effluents do not contain much residual colloids, and digestion where colloids from decay processes are present.
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Affiliation(s)
| | - Ahmed Al-Omari
- DC Water, 5000 Overlook Ave. SW, Washington, DC 20032, USA
| | - Bernhard Wett
- ARA Consult GmbH, Unterbergerstraße 1, Innsbruck, Austria
| | - Jose Jimenez
- Brown and Caldwell, 2301 Lucien Way, Suite 250, Maitland, FL 32751, USA
| | | | - Arifur Rahman
- Freese and Nichols, Inc., 2711 N Haskell Avenue, Suite 3300, Dallas, TX 75204, USA
| | | | - Imre Takacs
- Dynamita SARL, 7 LD Eoupe, Nyons, France E-mail:
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17
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Schoepp T, Bousek J, Beqaj A, Fiedler C, Wett B, Fuchs W, Ertl T, Weissenbacher N. Nitrous oxide emissions of a mesh separated single stage deammonification reactor. Water Sci Technol 2018; 78:2239-2246. [PMID: 30699075 DOI: 10.2166/wst.2018.500] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
It is widely accepted that partial nitrification by ANAMMOX has the potential to become one of the key processes in wastewater treatment. However, large greenhouse gas emissions have been panobserved in many cases. A novel mesh separated reactor, developed to allow continuous operation of deammonification at smaller scale without external biomass selection, was compared to a conventional single-chamber deammonification sequencing batch reactor (SBR), where both were equally-sized pilot-scale reactors. The mesh reactor consisted of an aerated and an anoxic zone separated by a mesh. The resulting differences in the structure of the microbial community were detected by next-generation sequencing. When both systems were operated in a sequencing batch mode, both systems had comparable nitrous oxide emission factors in the range of 4% to 5% of the influent nitrogen load. A significant decrease was observed after switching from sequencing batch mode to continuous operation.
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Affiliation(s)
- T Schoepp
- Institute of Sanitary Engineering and Water Pollution Control, University of Natural Resources and Life Sciences, Muthgasse 18, 1190 Wien, Vienna, Austria E-mail:
| | - J Bousek
- Institute for Environmental Biotechnology, IFA-Tulln, University of Natural Resources and Life Sciences, Konrad-Lorenz Straße 20, 3430 Tulln, Vienna, Austria
| | - A Beqaj
- Institute of Sanitary Engineering and Water Pollution Control, University of Natural Resources and Life Sciences, Muthgasse 18, 1190 Wien, Vienna, Austria E-mail:
| | - C Fiedler
- Institute of Sanitary Engineering and Water Pollution Control, University of Natural Resources and Life Sciences, Muthgasse 18, 1190 Wien, Vienna, Austria E-mail:
| | - B Wett
- ARAconsult, Unterbergerstr. 1, 6020 Innsbruck, Austria
| | - W Fuchs
- Institute for Environmental Biotechnology, IFA-Tulln, University of Natural Resources and Life Sciences, Konrad-Lorenz Straße 20, 3430 Tulln, Vienna, Austria
| | - T Ertl
- Institute of Sanitary Engineering and Water Pollution Control, University of Natural Resources and Life Sciences, Muthgasse 18, 1190 Wien, Vienna, Austria E-mail:
| | - N Weissenbacher
- Institute of Sanitary Engineering and Water Pollution Control, University of Natural Resources and Life Sciences, Muthgasse 18, 1190 Wien, Vienna, Austria E-mail:
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18
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Zhang Q, Vlaeminck SE, DeBarbadillo C, Su C, Al-Omari A, Wett B, Pümpel T, Shaw A, Chandran K, Murthy S, De Clippeleir H. Supernatant organics from anaerobic digestion after thermal hydrolysis cause direct and/or diffusional activity loss for nitritation and anammox. Water Res 2018; 143:270-281. [PMID: 29986237 DOI: 10.1016/j.watres.2018.06.037] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2018] [Revised: 06/05/2018] [Accepted: 06/16/2018] [Indexed: 06/08/2023]
Abstract
Treatment of sewage sludge with a thermal hydrolysis process (THP) followed by anaerobic digestion (AD) enables to boost biogas production and minimize residual sludge volumes. However, the reject water can cause inhibition to aerobic and anoxic ammonium-oxidizing bacteria (AerAOB & AnAOB), the two key microbial groups involved in the deammonification process. Firstly, a detailed investigation elucidated the impact of different organic fractions present in THP-AD return liquor on AerAOB and AnAOB activity. For AnAOB, soluble compounds linked to THP conditions and AD performance caused the main inhibition. Direct inhibition by dissolved organics was also observed for AerAOB, but could be overcome by treating the filtrate with extended aerobic or anaerobic incubation or with activated carbon. AerAOB additionally suffered from particulate and colloidal organics limiting the diffusion of substrates. This was resolved by improving the dewatering process through an optimized flocculant polymer dose and/or addition of coagulant polymer to better capture the large colloidal fraction, especially in case of unstable AD performance. Secondly, a new inhibition model for AerAOB included diffusion-limiting compounds based on the porter-equation, and achieved the best fit with the experimental data, highlighting that AerAOB were highly sensitive to large colloids. Overall, this paper for the first time provides separate identification of organic fractions within THP-AD filtrate causing differential types of inhibition. Moreover, it highlights the combined effect of the performance of THP, AD and dewatering on the downstream autotrophic nitrogen removal kinetics.
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Affiliation(s)
- Qi Zhang
- DC Water, 5000 Overlook Ave. SW, Washington, DC, 20032, USA; Center for Microbial Ecology and Technology (CMET), Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, Gent, 9000, Belgium; Department of Earth and Environmental Engineering, Columbia University, 500 West 120th Street, New York, USA
| | - Siegfried E Vlaeminck
- Center for Microbial Ecology and Technology (CMET), Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, Gent, 9000, Belgium; Research Group of Sustainable Energy, Air and Water Technology, Department of Bioscience Engineering, University of Antwerp, Groenenborgerlaan 171, Antwerpen, 2020, Belgium.
| | | | - Chunyang Su
- DC Water, 5000 Overlook Ave. SW, Washington, DC, 20032, USA
| | - Ahmed Al-Omari
- DC Water, 5000 Overlook Ave. SW, Washington, DC, 20032, USA
| | - Bernhard Wett
- ARAconsult, Unterbergerstr.1, Innsbruck, A-6020, Austria
| | - Thomas Pümpel
- Institut für Mikrobiologie, Technikerstr. 25, Innsbruck, A-6020, Austria
| | - Andrew Shaw
- Black & Veatch, 8400 Ward Parkway, Kansas City, MO, 64114, USA
| | - Kartik Chandran
- Department of Earth and Environmental Engineering, Columbia University, 500 West 120th Street, New York, USA
| | - Sudhir Murthy
- DC Water, 5000 Overlook Ave. SW, Washington, DC, 20032, USA
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19
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Seuntjens D, Han M, Kerckhof FM, Boon N, Al-Omari A, Takacs I, Meerburg F, De Mulder C, Wett B, Bott C, Murthy S, Carvajal Arroyo JM, De Clippeleir H, Vlaeminck SE. Pinpointing wastewater and process parameters controlling the AOB to NOB activity ratio in sewage treatment plants. Water Res 2018; 138:37-46. [PMID: 29571087 DOI: 10.1016/j.watres.2017.11.044] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2017] [Revised: 10/23/2017] [Accepted: 11/21/2017] [Indexed: 06/08/2023]
Abstract
Even though nitrification/denitrification is a robust technology to remove nitrogen from sewage, economic incentives drive its future replacement by shortcut nitrogen removal processes. The latter necessitates high potential activity ratios of ammonia oxidizing to nitrite oxidizing bacteria (rAOB/rNOB). The goal of this study was to identify which wastewater and process parameters can govern this in reality. Two sewage treatment plants (STP) were chosen based on their inverse rAOB/rNOB values (at 20 °C): 0.6 for Blue Plains (BP, Washington DC, US) and 1.6 for Nieuwveer (NV, Breda, NL). Disproportional and dissimilar relationships between AOB or NOB relative abundances and respective activities pointed towards differences in community and growth/activity limiting parameters. The AOB communities showed to be particularly different. Temperature had no discriminatory effect on the nitrifiers' activities, with similar Arrhenius temperature dependences (ΘAOB = 1.10, ΘNOB = 1.06-1.07). To uncouple the temperature effect from potential limitations like inorganic carbon, phosphorus and nitrogen, an add-on mechanistic methodology based on kinetic modelling was developed. Results suggest that BP's AOB activity was limited by the concentration of inorganic carbon (not by residual N and P), while NOB experienced less limitation from this. For NV, the sludge-specific nitrogen loading rate seemed to be the most prevalent factor limiting AOB and NOB activities. Altogether, this study shows that bottom-up mechanistic modelling can identify parameters that influence the nitrification performance. Increasing inorganic carbon in BP could invert its rAOB/rNOB value, facilitating its transition to shortcut nitrogen removal.
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Affiliation(s)
- Dries Seuntjens
- Center for Microbial Ecology and Technology (CMET), Faculty of Bioscience Engineering, Ghent University, Belgium
| | - Mofei Han
- Center for Microbial Ecology and Technology (CMET), Faculty of Bioscience Engineering, Ghent University, Belgium; DC WATER, District of Columbia, USA
| | - Frederiek-Maarten Kerckhof
- Center for Microbial Ecology and Technology (CMET), Faculty of Bioscience Engineering, Ghent University, Belgium
| | - Nico Boon
- Center for Microbial Ecology and Technology (CMET), Faculty of Bioscience Engineering, Ghent University, Belgium
| | | | | | - Francis Meerburg
- Center for Microbial Ecology and Technology (CMET), Faculty of Bioscience Engineering, Ghent University, Belgium
| | - Chaïm De Mulder
- Biomath, Faculty of Bioscience Engineering, Ghent University, Belgium
| | | | - Charles Bott
- Hampton Roads Sanitation District (HRSD), Virginia Beach, USA
| | | | - Jose Maria Carvajal Arroyo
- Center for Microbial Ecology and Technology (CMET), Faculty of Bioscience Engineering, Ghent University, Belgium
| | | | - Siegfried E Vlaeminck
- Center for Microbial Ecology and Technology (CMET), Faculty of Bioscience Engineering, Ghent University, Belgium; Research Group of Sustainable Energy, Air and Water Technology, Faculty of Science, University of Antwerp, Belgium.
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20
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Rahman A, Meerburg FA, Jimenez J, Ravadagundhi S, Wett B, Bott C, Al-Omari A, Riffat R, Murthy S, De Clippeleir H. Reply for comment on "Bioflocculation management through high-rate contact-stabilization: A promising technology to recover organic carbon from low-strength wastewater by Rahman, A., Meerburg, F. A., Ravadagundhi, S., Wett, B., Jimenez, J., Bott, C., Al-Omari, A., Riffat, R., Murthy, S. and De Clippeleir, H. [Water Research 104 (2016) 485-496]". Water Res 2017; 126:527-529. [PMID: 28865669 DOI: 10.1016/j.watres.2017.08.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2017] [Accepted: 08/05/2017] [Indexed: 06/07/2023]
Affiliation(s)
- Arifur Rahman
- Department of Civil & Environmental Engineering, The George Washington University, 2121 Eye Street, NW, Washington, DC 20052, USA.
| | - Francis A Meerburg
- Center for Microbial Ecology and Technology (CMET), Ghent University, Coupure Links 653, 9000 Ghent, Belgium
| | - Jose Jimenez
- Brown and Caldwell, 2301 Lucien Way, Suite 250, Maitland, FL 32751, USA
| | | | - Bernhard Wett
- ARA Consult GmbH, Unterbergerstrasse 1, 6020 Innsbruck, Austria
| | - Charles Bott
- Hampton Roads Sanitation District, 1436 Air Rail Ave., Virginia Beach, VA 23455, USA
| | - Ahmed Al-Omari
- DC Water, 5000 Overlook Ave., SW, Washington, DC 20032, USA
| | - Rumana Riffat
- Department of Civil & Environmental Engineering, The George Washington University, 2121 Eye Street, NW, Washington, DC 20052, USA
| | - Sudhir Murthy
- DC Water, 5000 Overlook Ave., SW, Washington, DC 20032, USA
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21
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Miller MW, Elliott M, DeArmond J, Kinyua M, Wett B, Murthy S, Bott CB. Controlling the COD removal of an A-stage pilot study with instrumentation and automatic process control. Water Sci Technol 2017; 75:2669-2679. [PMID: 28617287 DOI: 10.2166/wst.2017.153] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The pursuit of fully autotrophic nitrogen removal via the anaerobic ammonium oxidation (anammox) pathway has led to an increased interest in carbon removal technologies, particularly the A-stage of the adsorption/bio-oxidation (A/B) process. The high-rate operation of the A-stage and lack of automatic process control often results in wide variations of chemical oxygen demand (COD) removal that can ultimately impact nitrogen removal in the downstream B-stage process. This study evaluated the use dissolved oxygen (DO) and mixed liquor suspended solids (MLSS) based automatic control strategies through the use of in situ on-line sensors in the A-stage of an A/B pilot study. The objective of using these control strategies was to reduce the variability of COD removal by the A-stage and thus the variability of the effluent C/N. The use of cascade DO control in the A-stage did not impact COD removal at the conditions tested in this study, likely because the bulk DO concentration (>0.5 mg/L) was maintained above the half saturation coefficient of heterotrophic organisms for DO. MLSS-based solids retention time (SRT) control, where MLSS was used as a surrogate for SRT, did not significantly reduce the effluent C/N variability but it was able to reduce COD removal variation in the A-stage by 90%.
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Affiliation(s)
- Mark W Miller
- Brown and Caldwell, 309 East Morehead Street, Suite 160, Charlotte, NC 28202, USA E-mail:
| | - Matt Elliott
- Civil and Environmental Engineering Department, Old Dominion University, Norfolk, VA 23529, USA and AECOM 277 Bendix Road, Suite 500, Virginia Beach, VA 23452, USA
| | - Jon DeArmond
- Carollo Engineers Inc., 1089 West Morse Blvd. Suite A, Winter Park, FL 32789, USA
| | - Maureen Kinyua
- Earth and Environmental Engineering Department, Columbia University, 500 West 120th Street, New York, NY 10027, USA and Civil and Environmental Engineering Department, University of California Davis, 3120 Ghausi Hall, Davis, CA 95616, USA
| | - Bernhard Wett
- ARA Consult GmbH, Unterbergerstraße 1, A-6020, Innsbruck, Austria
| | - Sudhir Murthy
- DC Water and Sewer Authority, 5000 Overlook Ave. SW, Washington, DC 20032, USA
| | - Charles B Bott
- Hampton Roads Sanitation District, 1436 Air Rail Ave., Virginia Beach, VA 23455, USA
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22
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Stewart HA, Al-Omari A, Bott C, De Clippeleir H, Su C, Takacs I, Wett B, Massoudieh A, Murthy S. Dual substrate limitation modeling and implications for mainstream deammonification. Water Res 2017; 116:95-105. [PMID: 28324710 DOI: 10.1016/j.watres.2017.03.021] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/11/2016] [Revised: 03/07/2017] [Accepted: 03/08/2017] [Indexed: 06/06/2023]
Abstract
Substrate limitation occurs frequently in wastewater treatment and knowledge about microbial behavior at limiting conditions is essential for the use of biokinetic models in system design and optimization. Monod kinetics are well-accepted for modeling growth rates when a single substrate is limiting, but several models exist for treating two or more limiting substrates simultaneously. In this study three dual limitation models (multiplicative, minimum, and Bertolazzi) were compared based on experiments using nitrite-oxidizing bacteria (limited by dissolved oxygen and nitrite) and ANaerobic AMMonia-OXidizing bacteria or Aanammox (limited by ammonium and nitrite) within mixed liquor from deammonification pilots. A deterministic likelihood-based parameter estimation followed by Bayesian inference was used to estimate model-specific parameters. The minimum model outperformed the other two by a slight margin in three separate analyses. 1) Parameters estimated using the minimum model were closest to parameters estimated from single limitation batch tests. 2) Among simulations based on each model's own estimated parameters, the minimum model best described the experimental observations. 3) Among simulations based on parameters estimated from single limitation, the minimum model best described the experimental observations. The dual substrate model selected among the three studied can effect a 75% process performance variation based on simulations of a full-scale mainstream deammonification system.
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Affiliation(s)
- Heather A Stewart
- The Catholic University of America, Washington, DC, USA; CH2M Hill, USA
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23
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Han M, Vlaeminck SE, Al-Omari A, Wett B, Bott C, Murthy S, De Clippeleir H. Uncoupling the solids retention times of flocs and granules in mainstream deammonification: A screen as effective out-selection tool for nitrite oxidizing bacteria. Bioresour Technol 2016; 221:195-204. [PMID: 27639672 DOI: 10.1016/j.biortech.2016.08.115] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2016] [Revised: 08/29/2016] [Accepted: 08/30/2016] [Indexed: 05/06/2023]
Abstract
This study focused on a physical separator in the form of a screen to out-select nitrite oxidizing bacteria (NOB) for mainstream sewage treatment. This separation relied on the principle that the NOB prefer to grow in flocs, while anammox bacteria (AnAOB) reside in granules. Two types of screens (vacuum and vibrating) were tested for separating these fractions. The vibrating screen was preferred due to more moderate normal forces and additional tangential forces, better balancing retention efficiency of AnAOB granules (41% of the AnAOB activity) and washout of NOB (92% activity washout). This operation resulted in increased NOB out-selection (AerAOB/NOB ratio of 2.3) and a total nitrogen removal efficiency of 70% at influent COD/N ratio of 1.4. An effluent total nitrogen concentration <10mgN/L was achieved using this novel approach combining biological selection with physical separation, opening up the path towards energy positive sewage treatment.
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Affiliation(s)
- M Han
- Center for Microbial Ecology and Technology (CMET), Ghent University, Gent, Belgium; DC Water, DC, USA; Department of Civil & Environmental Engineering, Bucknell University, Lewisburg, PA, USA
| | - S E Vlaeminck
- Center for Microbial Ecology and Technology (CMET), Ghent University, Gent, Belgium; Research Group of Sustainable Energy, Air and Water Technology, Department of Bioscience Engineering, University of Antwerp, Antwerpen, Belgium.
| | | | - B Wett
- ARAconsult, Innsbruck, Austria
| | - C Bott
- Hampton Roads Sanitation District, Virginia Beach, USA
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24
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Rahman A, Meerburg FA, Ravadagundhi S, Wett B, Jimenez J, Bott C, Al-Omari A, Riffat R, Murthy S, De Clippeleir H. Bioflocculation management through high-rate contact-stabilization: A promising technology to recover organic carbon from low-strength wastewater. Water Res 2016; 104:485-496. [PMID: 27589209 DOI: 10.1016/j.watres.2016.08.047] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2016] [Revised: 08/11/2016] [Accepted: 08/21/2016] [Indexed: 06/06/2023]
Abstract
A series of pilot-scale studies were performed to compare conventional high-rate activated sludge systems (HRAS) (continuous stirred tank reactor (CSTR) and plug flow (PF) reactor configurations) with high-rate contact-stabilization (CS) technology in terms of carbon recovery potential from chemically enhanced primary treatment effluent at a municipal wastewater treatment plant. This study showed that carbon redirection and recovery could be achieved at short solids retention time (SRT). However, bioflocculation became a limiting factor in the conventional HRAS configurations (total SRT ≤ 1.2 days). At a total SRT ≤1.1 day, the high-rate CS configuration allowed better carbon removal (52-59%), carbon redirection to sludge (0.46-0.55 g COD/g CODadded) and carbon recovery potential (0.33-0.34 gCOD/gCODadded) than the CSTR and PF configurations (28-37% COD removal, carbon redirection of 0.32-0.45 g COD/g CODadded and no carbon harvesting). The presence of a stabilization phase (famine), achieved by aerating the return activated sludge (RAS), followed by low dissolved oxygen contact with the influent (feast) was identified as the main reason for improved biosorption capacity, bioflocculation and settleability in the CS configuration. This study showed that high-rate CS is a promising technology for carbon and energy recovery from low-strength wastewaters.
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Affiliation(s)
- Arifur Rahman
- Department of Civil & Environmental Engineering, The George Washington University, 800 22nd Street, NW, Washington, DC 20052, USA; DC Water, 5000 Overlook Ave., SW., Washington, DC 20032, USA.
| | - Francis A Meerburg
- Center for Microbial Ecology and Technology (CMET), Ghent University, Coupure Links 653, 9000 Ghent, Belgium
| | | | - Bernhard Wett
- ARA Consult GmbH, Unterbergerstrasse 1, 6020 Innsbruck, Austria
| | - Jose Jimenez
- Brown and Caldwell, 2301 Lucien Way, Suite 250, Maitland, FL 32751, USA
| | - Charles Bott
- Hampton Roads Sanitation District, 1436 Air Rail Ave., Virginia Beach, VA 23455, USA
| | - Ahmed Al-Omari
- DC Water, 5000 Overlook Ave., SW., Washington, DC 20032, USA
| | - Rumana Riffat
- Department of Civil & Environmental Engineering, The George Washington University, 800 22nd Street, NW, Washington, DC 20052, USA
| | - Sudhir Murthy
- DC Water, 5000 Overlook Ave., SW., Washington, DC 20032, USA
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25
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Garrido-Baserba M, Asvapathanagul P, McCarthy GW, Gocke TE, Olson BH, Park HD, Al-Omari A, Murthy S, Bott CB, Wett B, Smeraldi JD, Shaw AR, Rosso D. Linking biofilm growth to fouling and aeration performance of fine-pore diffuser in activated sludge. Water Res 2016; 90:317-328. [PMID: 26760484 DOI: 10.1016/j.watres.2015.12.011] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2015] [Revised: 11/18/2015] [Accepted: 12/09/2015] [Indexed: 06/05/2023]
Abstract
Aeration is commonly identified as the largest contributor to process energy needs in the treatment of wastewater and therefore garners significant focus in reducing energy use. Fine-pore diffusers are the most common aeration system in municipal wastewater treatment. These diffusers are subject to fouling and scaling, resulting in loss in transfer efficiency as biofilms form and change material properties producing larger bubbles, hindering mass transfer and contributing to increased plant energy costs. This research establishes a direct correlation and apparent mechanistic link between biofilm DNA concentration and reduced aeration efficiency caused by biofilm fouling. Although the connection between biofilm growth and fouling has been implicit in discussions of diffuser fouling for many years, this research provides measured quantitative connection between the extent of biofouling and reduced diffuser efficiency. This was clearly established by studying systematically the deterioration of aeration diffusers efficiency during a 1.5 year period, concurrently with the microbiological study of the biofilm fouling in order to understand the major factors contributing to diffuser fouling. The six different diffuser technologies analyzed in this paper included four different materials which were ethylene-propylene-diene monomer (EPDM), polyurethane, silicone and ceramic. While all diffusers foul eventually, some novel materials exhibited fouling resistance. The material type played a major role in determining the biofilm characteristics (i.e., growth rate, composition, and microbial density) which directly affected the rate and intensity at what the diffusers were fouled, whereas diffuser geometry exerted little influence. Overall, a high correlation between the increase in biofilm DNA and the decrease in αF was evident (CV < 14.0 ± 2.0%). By linking bacterial growth with aeration efficiency, the research was able to show quantitatively the causal connection between bacterial fouling and energy wastage during aeration.
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Affiliation(s)
- Manel Garrido-Baserba
- Department of Civil & Environmental Engineering, University of California, Irvine, CA 92697-2175, USA.
| | - Pitiporn Asvapathanagul
- Department of Civil & Environmental Engineering, University of California, Irvine, CA 92697-2175, USA; Department of Civil Engineering and Construction Engineering Management, California State University, Long Beach, CA 90840, USA
| | - Graham W McCarthy
- Department of Civil & Environmental Engineering, University of California, Irvine, CA 92697-2175, USA
| | - Thomas E Gocke
- Department of Civil & Environmental Engineering, University of California, Irvine, CA 92697-2175, USA
| | - Betty H Olson
- Department of Civil & Environmental Engineering, University of California, Irvine, CA 92697-2175, USA; Water-Energy Nexus Center, University of California, Irvine, CA 92697-2175, USA
| | - Hee-Deung Park
- School of Civil, Environmental and Architectural Engineering, Korea University, Anam-Dong, Seongbuk-Gu, Seoul 136-713, South Korea
| | - Ahmed Al-Omari
- DC Water, 5000 Overlook Ave SW, Washington, DC 20032, USA
| | - Sudhir Murthy
- DC Water, 5000 Overlook Ave SW, Washington, DC 20032, USA
| | - Charles B Bott
- Hampton Roads Sanitation District, Virginia Beach, VA 23471-0911, USA
| | - Bernhard Wett
- ARAconsult, Unterbergerstraße 1, A-6020 Innsbruck, Austria
| | - Joshua D Smeraldi
- United States Environmental Protection Agency, 1200 Pennsylvania Ave NW, Washington, DC 20460, USA
| | - Andrew R Shaw
- Black & Veatch, 8400 Ward Pkwy, Kansas City, MO 64114, USA
| | - Diego Rosso
- Department of Civil & Environmental Engineering, University of California, Irvine, CA 92697-2175, USA; Water-Energy Nexus Center, University of California, Irvine, CA 92697-2175, USA.
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Zhang Q, De Clippeleir H, Su C, Al-Omari A, Wett B, Vlaeminck SE, Murthy S. Deammonification for digester supernatant pretreated with thermal hydrolysis: overcoming inhibition through process optimization. Appl Microbiol Biotechnol 2016; 100:5595-606. [DOI: 10.1007/s00253-016-7368-0] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2015] [Revised: 01/30/2016] [Accepted: 02/01/2016] [Indexed: 11/30/2022]
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Han M, De Clippeleir H, Al-Omari A, Wett B, Vlaeminck SE, Bott C, Murthy S. Impact of carbon to nitrogen ratio and aeration regime on mainstream deammonification. Water Sci Technol 2016; 74:375-384. [PMID: 27438242 DOI: 10.2166/wst.2016.202] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
While deammonification of high-strength wastewater in the sludge line of sewage treatment plants has become well established, the potential cost savings spur the development of this technology for mainstream applications. This study aimed at identifying the effect of aeration and organic carbon on the deammonification process. Two 10 L sequencing bath reactors with different aeration frequencies were operated at 25°C. Real wastewater effluents from chemically enhanced primary treatment and high-rate activated sludge process were fed into the reactors with biodegradable chemical oxygen demand/nitrogen (bCOD/N) of 2.0 and 0.6, respectively. It was found that shorter aerobic solids retention time (SRT) and higher aeration frequency gave more advantages for aerobic ammonium-oxidizing bacteria (AerAOB) than nitrite oxidizing bacteria (NOB) in the system. From the kinetics study, it is shown that the affinity for oxygen is higher for NOB than for AerAOB, and higher dissolved oxygen set-point could decrease the affinity of both AerAOB and NOB communities. After 514 days of operation, it was concluded that lower organic carbon levels enhanced the activity of anoxic ammonium-oxidizing bacteria (AnAOB) over denitrifiers. As a result, the contribution of AnAOB to nitrogen removal increased from 40 to 70%. Overall, a reasonably good total removal efficiency of 66% was reached under a low bCOD/N ratio of 2.0 after adaptation.
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Affiliation(s)
- M Han
- Center for Microbial Ecology and Technology (LabMET), Ghent University, CoupureLinks 653, 9000 Ghent, Belgium; DC WATER, 500 Overlook Ave SW, Washington, DC, USA
| | | | - A Al-Omari
- DC WATER, 500 Overlook Ave SW, Washington, DC, USA
| | - B Wett
- ARAconsult, Unterbergerstr. 1, 6020 Innsbruck, Austria
| | - S E Vlaeminck
- Center for Microbial Ecology and Technology (LabMET), Ghent University, CoupureLinks 653, 9000 Ghent, Belgium; Research Group of Sustainable Energy, Air and Water Technology, Department of Bioscience Engineering, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerpen, Belgium E-mail:
| | - C Bott
- Hampton Road Sanitation District, 1436 Air Rail Ave, Virginia Beach, VA, USA
| | - S Murthy
- DC WATER, 500 Overlook Ave SW, Washington, DC, USA
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28
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Rahman A, Meerburg F, Ravadagundhi S, Wett B, Jimenez JA, Bott C, Al-Omari A, Riffat R, Murthy S, De Clippeleir H. Impact of RAS Aeration on Bioflocculation and Carbon Redirection in High-Rate Activated Sludge Processes. ACTA ACUST UNITED AC 2016. [DOI: 10.2175/193864716819712890] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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29
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Jimenez J, Miller M, Bott C, Murthy S, De Clippeleir H, Wett B. High-rate activated sludge system for carbon management--Evaluation of crucial process mechanisms and design parameters. Water Res 2015; 87:476-482. [PMID: 26260539 DOI: 10.1016/j.watres.2015.07.032] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/03/2015] [Revised: 06/19/2015] [Accepted: 07/19/2015] [Indexed: 06/04/2023]
Abstract
The high-rate activated sludge (HRAS) process is a technology suitable for the removal and redirection of organics from wastewater to energy generating processes in an efficient manner. A HRAS pilot plant was operated under controlled conditions resulting in concentrating the influent particulate, colloidal, and soluble COD to a waste solids stream with minimal energy input by maximizing sludge production, bacterial storage, and bioflocculation. The impact of important process parameters such as solids retention time (SRT), hydraulic residence time (HRT) and dissolved oxygen (DO) levels on the performance of a HRAS system was demonstrated in a pilot study. The results showed that maximum removal efficiencies of soluble COD were reached at a DO > 0.3 mg O2/L, SRT > 0.5 days and HRT > 15 min which indicates that minimizing the oxidation of the soluble COD in the high-rate activated sludge process is difficult. The study of DO, SRT and HRT exhibited high degree of impact on the colloidal and particulate COD removal. Thus, more attention should be focused on controlling the removal of these COD fractions. Colloidal COD removal plateaued at a DO > 0.7 mg O2/L, SRT > 1.5 days and HRT > 30 min, similar to particulate COD removal. Concurrent increase in extracellular polymers (EPS) production in the reactor and the association of particulate and colloidal material into sludge flocs (bioflocculation) indicated carbon capture by biomass. The SRT impacted the overall mass and energy balance of the high-rate process indicating that at low SRT conditions, lower COD mineralization or loss of COD content occurred. In addition, the lower SRT conditions resulted in higher sludge yields and higher COD content in the WAS.
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Affiliation(s)
- Jose Jimenez
- Brown and Caldwell, 2301 Lucien Way, Suite 250, Maitland, FL, USA.
| | - Mark Miller
- Department of Civil and Environmental Engineering, Virginia Polytechnic Institute and State University, Blacksburg, VA, USA
| | - Charles Bott
- Hampton Road Sanitation District, 1436 Air Rail Avenue, Virginia Beach, VA, USA
| | | | | | - Bernhard Wett
- ARA Consult, Unterbergerstraße, 6020 Innsbruck, Austria
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30
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Aichinger P, Wadhawan T, Kuprian M, Higgins M, Ebner C, Fimml C, Murthy S, Wett B. Synergistic co-digestion of solid-organic-waste and municipal-sewage-sludge: 1 plus 1 equals more than 2 in terms of biogas production and solids reduction. Water Res 2015; 87:416-423. [PMID: 26260541 DOI: 10.1016/j.watres.2015.07.033] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2015] [Revised: 07/08/2015] [Accepted: 07/20/2015] [Indexed: 06/04/2023]
Abstract
Making good use of existing water infrastructure by adding organic wastes to anaerobic digesters improves the energy balance of a wastewater treatment plant (WWTP) substantially. This paper explores co-digestion load limits targeting a good trade-off for boosting methane production, and limiting process-drawbacks on nitrogen-return loads, cake-production, solids-viscosity and polymer demand. Bio-methane potential tests using whey as a model co-substrate showed diversification and intensification of the anaerobic digestion process resulting in a synergistical enhancement in sewage sludge methanization. Full-scale case-studies demonstrate organic co-substrate addition of up to 94% of the organic sludge load resulted in tripling of the biogas production. At organic co-substrate addition of up to 25% no significant increase in cake production and only a minor increase in ammonia release of ca. 20% have been observed. Similar impacts were measured at a high-solids digester pilot with up-stream thermal hydrolyses where the organic loading rate was increased by 25% using co-substrate. Dynamic simulations were used to validate the synergistic impact of co-substrate addition on sludge methanization, and an increase in hydrolysis rate from 1.5 d(-1) to 2.5 d(-1) was identified for simulating measured gas production rate. This study demonstrates co-digestion for maximizing synergy as a step towards energy efficiency and ultimately towards carbon neutrality.
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Affiliation(s)
- Peter Aichinger
- University of Innsbruck, 6020 Innsbruck, Austria; alpS - Centre for Climate Change Adaptation, 6020 Innsbruck, Austria
| | - Tanush Wadhawan
- Dynamita SARL, Nyons, France; DC WATER, 5000 Overlook Ave., SW Washington, DC 20032, USA
| | - Martin Kuprian
- University of Innsbruck, 6020 Innsbruck, Austria; alpS - Centre for Climate Change Adaptation, 6020 Innsbruck, Austria
| | | | - Christian Ebner
- alpS - Centre for Climate Change Adaptation, 6020 Innsbruck, Austria; Abwasserverband Zirl u.U., 6170 Zirl, Austria
| | | | - Sudhir Murthy
- DC WATER, 5000 Overlook Ave., SW Washington, DC 20032, USA
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31
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Wett B, Podmirseg SM, Gómez-Brandón M, Hell M, Nyhuis G, Bott C, Murthy S. Expanding DEMON Sidestream Deammonification Technology Towards Mainstream Application. Water Environ Res 2015; 87:2084-2089. [PMID: 26652120 DOI: 10.2175/106143015x14362865227319] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
A cross-Atlantic R&D-cooperation involving three large utilities investigated the feasibility of mainstream deammonification-the application of partial nitritation/anammox for full-plant treatment of municipal wastewater at ambient temperatures. Two major process components have been implemented, 1) bioaugmentation of aerobic- and anaerobic ammonia oxidizers (AOB and AMX) from the DEMON-sidestream sludge liquor treatment to the mainstream and 2) implementation of hydrocyclones to select for anammox granules and retain them in the system. Different operation modes have been tested at laboratory- and pilot-scale in order to promote the short-cut (more direct anammox route) in nitrogen removal metabolism. At the full-scale installation at Strass WWTP, stable repression of nitrite oxidizing biomass (NOB) has been achieved for several months. Significant anammox enrichment in the mainstream has been monitored while high efficiency in the sidestream-process has been maintained (96% annual average ammonia removal).
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Affiliation(s)
- B Wett
- ARAconsult, A-6020 Innsbruck, Austria
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32
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Regmi P, Holgate B, Miller MW, Park H, Chandran K, Wett B, Murthy S, Bott CB. Nitrogen polishing in a fully anoxic anammox MBBR treating mainstream nitritation-denitritation effluent. Biotechnol Bioeng 2015; 113:635-42. [DOI: 10.1002/bit.25826] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2015] [Revised: 08/07/2015] [Accepted: 08/23/2015] [Indexed: 11/11/2022]
Affiliation(s)
- Pusker Regmi
- Brown and Caldwell; 1600 Duke Street, Suite 310 Alexandria VA 22314
| | | | - Mark W. Miller
- Civil and Environment Engineering Department; Virginia Tech; Blacksburg VA
| | - Hongkeun Park
- Department of Earth and Environmental Engineering; Columbia University; New York NY
| | - Kartik Chandran
- Department of Earth and Environmental Engineering; Columbia University; New York NY
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33
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Regmi P, Bunce R, Miller MW, Park H, Chandran K, Wett B, Murthy S, Bott CB. Ammonia-based intermittent aeration control optimized for efficient nitrogen removal. Biotechnol Bioeng 2015; 112:2060-7. [DOI: 10.1002/bit.25611] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2014] [Accepted: 04/02/2015] [Indexed: 11/09/2022]
Affiliation(s)
- Pusker Regmi
- Brown and Caldwell; 1600 Duke Street, Suite 310 Alexandria Virginia 22314
| | | | - Mark W. Miller
- Civil and Environment Engineering Department; Virginia Tech; Blacksburg Virginia
| | - Hongkeun Park
- Department of Earth and Environmental Engineering; Columbia University; New York City New York
| | - Kartik Chandran
- Department of Earth and Environmental Engineering; Columbia University; New York City New York
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34
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Schaubroeck T, De Clippeleir H, Weissenbacher N, Dewulf J, Boeckx P, Vlaeminck SE, Wett B. Environmental sustainability of an energy self-sufficient sewage treatment plant: improvements through DEMON and co-digestion. Water Res 2015; 74:166-79. [PMID: 25727156 DOI: 10.1016/j.watres.2015.02.013] [Citation(s) in RCA: 64] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2014] [Revised: 01/18/2015] [Accepted: 02/08/2015] [Indexed: 05/06/2023]
Abstract
It is still not proven that treatment of sewage in a wastewater treatment plant (WWTP) is (in every case) environmentally friendly. To address this matter, we have applied a state-of-the-art life cycle assessment (LCA) to an energy self-sufficient WWTP in Strass (Austria), its supply chain and the valorization of its 'products': produced electricity out of biogas from sludge digestion and the associated stabilized digestate, applied as agricultural fertilizer. Prominent aspects of our study are: a holistic environmental impact assessment, measurement of greenhouse gas emissions (including N2O), and accounting for infrastructure, replacement of conventional fertilizers and toxicity of metals present in the stabilized digestate. Additionally, the environmental sustainability improvement by implementing one-stage partial nitritation/anammox (e.g. DEMON(®)) and co-digestion was also assessed. DEMON on the digesters reject water leads to a considerable saving of natural resources compared to nitritiation/denitritation (about 33% of the life cycle resource input), this through the lowering of sludge consumption for N-removal, and thus increasing electricity production via a higher sludge excess. However, its N2O emission could be restrained through further optimization as it represents a large share (30-66%) of the plants' damaging effect on human health, this through climate change. The co-substrate addition to the digester resulted in no significant improvement of the digestion process but induced net electricity generation. If respective amounts of conventional fertilizers are replaced, the land application of the stabilized digestate is environmentally friendly through prevention of natural resource consumption and diversity loss, but possibly not regarding human health impact due the presence of toxic heavy metals, mainly Zn, in the digestate. The outcomes show that the complete life cycle results in a prevention of resource extraction from nature and a potential mitigation of diversity loss (though for some impact categories no quantification of associated diversity loss is possible) but it also leads to a damaging effect on human health, mainly via climate change and heavy metal toxicity. Since it is for now impossible to aggregate the impact to these different aspects in a sound manner, it is not yet possible to consider in this case the studied system as environmentally friendly. Generally, the field of LCA needs further development to present a better and single outcome.
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Affiliation(s)
- Thomas Schaubroeck
- Research Group ENVOC, Ghent University, Coupure Links 653, 9000 Gent, Belgium.
| | - Haydée De Clippeleir
- Laboratory of Microbial Ecology and Technology (LabMET), Ghent University, Coupure Links 653, 9000 Ghent, Belgium; Department of Earth and Environmental Engineering, Columbia University, New York 10027, USA
| | - Norbert Weissenbacher
- University of Natural Resources and Life Sciences Vienna, Muthgasse 18, 1190 Vienna, Austria
| | - Jo Dewulf
- Research Group ENVOC, Ghent University, Coupure Links 653, 9000 Gent, Belgium
| | - Pascal Boeckx
- Laboratory of Applied Physical Chemistry (ISOFYS), Ghent University, Coupure Links 653, 9000 Gent, Belgium
| | - Siegfried E Vlaeminck
- Laboratory of Microbial Ecology and Technology (LabMET), Ghent University, Coupure Links 653, 9000 Ghent, Belgium
| | - Bernhard Wett
- ARAconsult, Unterbergerstr. 1, A-6020 Innsbruck, Austria
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35
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Jiang D, Khunjar WO, Wett B, Murthy SN, Chandran K. Characterizing the metabolic trade-off in Nitrosomonas europaea in response to changes in inorganic carbon supply. Environ Sci Technol 2015; 49:2523-2531. [PMID: 25546702 DOI: 10.1021/es5043222] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The link between the nitrogen and one-carbon cycles forms the metabolic basis for energy and biomass synthesis in autotrophic nitrifying organisms, which in turn are crucial players in engineered nitrogen removal processes. To understand how autotrophic nitrifying organisms respond to inorganic carbon (IC) conditions that could be encountered in engineered partially nitrifying systems, we investigated the response of one of the most extensively studied model ammonia oxidizing bacteria, Nitrosomonas europaea (ATCC19718), to three IC availability conditions: excess gaseous and excess ionic IC supply (40× stoichiometric requirement), excess gaseous IC supply (4× stoichiometric requirement in gaseous form only), and limiting IC supply (0.25× stoichiometric requirement). We found that, when switching from excess gaseous and excess ionic IC supply to excess gaseous IC supply, N. europaea chemostat cultures demonstrated an acclimation period that was characterized by transient decreases in the ammonia removal efficiency and transient peaks in the specific oxygen uptake rate. Limiting IC supply led to permanent reactor failures (characterized by biomass washout and failure of ammonia removal) that were preceded by similar decreases in the ammonia removal efficiency and peaks in the specific oxygen uptake rate. Notably, both excess gaseous IC supply and limiting IC supply elicited a previously undocumented increase in nitric and nitrous oxide emissions. Further, gene expression patterns suggested that excess gaseous IC supply and limiting IC supply led to consistent up-regulation of ammonia respiration genes and carbon assimilation genes. Under these conditions, interrogation of the N. europaea proteome revealed increased levels of carbon fixation and transport proteins and decreased levels of ammonia oxidation proteins (active in energy synthesis pathways). Together, the results indicated that N. europaea mobilized enhanced IC scavenging pathways for biosynthesis and turned down respiratory pathways for energy synthesis, when challenged with excess gaseous IC supply and limiting IC supply.
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Affiliation(s)
- D Jiang
- Department of Earth and Environmental Engineering, Columbia University , 500 W. 120th Street, Mudd 918, New York, New York 10027-4711, United States
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36
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Nogaj T, Randall A, Jimenez J, Takacs I, Bott C, Miller M, Murthy S, Wett B. Modeling of organic substrate transformation in the high-rate activated sludge process. Water Sci Technol 2015; 71:971-979. [PMID: 25860698 DOI: 10.2166/wst.2015.051] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
This study describes the development of a modified activated sludge model No.1 framework to describe the organic substrate transformation in the high-rate activated sludge (HRAS) process. New process mechanisms for dual soluble substrate utilization, production of extracellular polymeric substances (EPS), absorption of soluble substrate (storage), and adsorption of colloidal substrate were included in the modified model. Data from two HRAS pilot plants were investigated to calibrate and to validate the proposed model for HRAS systems. A subdivision of readily biodegradable soluble substrate into a slow and fast fraction were included to allow accurate description of effluent soluble chemical oxygen demand (COD) in HRAS versus longer solids retention time (SRT) systems. The modified model incorporates production of EPS and storage polymers as part of the aerobic growth transformation process on the soluble substrate and transformation processes for flocculation of colloidal COD to particulate COD. The adsorbed organics are then converted through hydrolysis to the slowly biodegradable soluble fraction. Two soluble substrate models were evaluated during this study, i.e., the dual substrate and the diauxic models. Both models used two state variables for biodegradable soluble substrate (SBf and SBs) and a single biomass population. The A-stage pilot typically removed 63% of the soluble substrate (SB) at an SRT <0.13 d and 79% at SRT of 0.23 d. In comparison, the dual substrate model predicted 58% removal at the lower SRT and 78% at the higher SRT, with the diauxic model predicting 32% and 70% removals, respectively. Overall, the dual substrate model provided better results than the diauxic model and therefore it was adopted during this study. The dual substrate model successfully described the higher effluent soluble COD observed in the HRAS systems due to the partial removal of SBs, which is almost completely removed in higher SRT systems.
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Affiliation(s)
- Thomas Nogaj
- Department of Civil and Environmental Engineering, University of Central Florida, Orlando, FL, USA
| | - Andrew Randall
- Department of Civil and Environmental Engineering, University of Central Florida, Orlando, FL, USA
| | - Jose Jimenez
- Brown and Caldwell, 850 Trafalgar Court, Suite 300, Maitland, FL, USA E-mail:
| | | | - Charles Bott
- Hampton Roads Sanitation District, 1436 Air Rail Ave., Virginia Beach, VA, USA
| | - Mark Miller
- Civil and Environment Engineering Department, Virginia Tech, Blacksburg, VA, USA
| | - Sudhir Murthy
- DC Water Authority, 5000 Overlook Ave. SW, Washington, DC, USA
| | - Bernhard Wett
- ARA Consult GmbH, Unterbergerstraße 1, Innsbruck, Austria
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Sabine Marie P, Pümpel T, Markt R, Murthy S, Bott C, Wett B. Comparative evaluation of multiple methods to quantify and characterise granular anammox biomass. Water Res 2015; 68:194-205. [PMID: 25462728 DOI: 10.1016/j.watres.2014.10.005] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2014] [Revised: 10/01/2014] [Accepted: 10/05/2014] [Indexed: 06/04/2023]
Abstract
Six methodologically different approaches were evaluated and compared regarding their suitability to quantify and characterise granular anammox biomass. The investigated techniques were gravimetric analysis (GA), activity measurements (AM), Coulter counter analysis (CC), quantitative PCR (qPCR), heme protein quantification (HQ) and the novel image analysis technique Particle Tracking (PT). The focus was set on the development of fast, economic and user-friendly approaches for potential implementation in regular wastewater treatment plant (WWTP) monitoring. To test the effectiveness of each technique, two sample matrices were chosen at the WWTP Strass (Austria): i) sludge liquor of the DEMON tank, treating ammonium-rich reject water of anaerobic digestion via the deammonification process and rich in anammox biomass (SL), and ii) the mainstream biological stage, that has been enriched with anammox biomass for more than two years (B). In both of these plants hydro-cyclones are installed for density-fractioning of the sludge into a low- and a high-density fraction, thus leading to a characteristic anammox distribution in the investigated sample set. All investigated methods could statistically discriminate the SL samples. Heme quantification and qPCR were also able to correctly classify the B-samples and both methods showed a Pearson's correlation coefficient of 0.81. An asset of the PT and CC method is the additional qualitative characterization of granule size distribution that can help to better understand and optimise general process operation (cyclone operation duration and construction characteristics). In combination these two methods were able to elucidate the relationship of gross granule volume and actual biomass, excluding the dead volume of inner cavities and exopolymers. We found a linear sphere-equivalent-radius correction factor (3.96 ± 0.15) for investigated anammox granules, that can be used for the fast and reliable PT technique to avoid biomass overestimation. We also recommend routine HQ and PT analysis as ideal monitoring strategy for anammox abundance in wastewater facilities with the HQ technique entailing the further advantage of being also suited for non-granular anammox biomass.
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Affiliation(s)
- Podmirseg Sabine Marie
- Institute of Microbiology, University of Innsbruck, Technikerstraße 25d, 6020 Innsbruck, Austria.
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Regmi P, Holgate B, Fredericks D, Miller MW, Wett B, Murthy S, Bott CB. Optimization of a mainstream nitritation-denitritation process and anammox polishing. Water Sci Technol 2015; 72:632-642. [PMID: 26247763 DOI: 10.2166/wst.2015.261] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
This paper deals with an almost 1-year long pilot study of a nitritation-denitritation process that was followed by anammox polishing. The pilot plant treated real municipal wastewater at ambient temperatures. The effluent of high-rate activated sludge process (hydraulic retention time, HRT=30 min, solids retention time=0.25 d) was fed to the pilot plant described in this paper, where a constant temperature of 23 °C was maintained. The nitritation-denitritation process was operated to promote nitrite oxidizing bacteria out-selection in an intermittently aerated reactor. The intermittent aeration pattern was controlled using a strategy based on effluent ammonia and nitrate+nitrite concentrations. The unique feature of this aeration control was that fixed dissolved oxygen set-point was used and the length of aerobic and anoxic durations were changed based on the effluent ammonia and nitrate+nitrite concentrations. The anaerobic ammonia oxidation (anammox) bacteria were adapted in mainstream conditions by allowing the growth on the moving bed bioreactor plastic media in a fully anoxic reactor. The total inorganic nitrogen (TIN) removal performance of the entire system was 75±15% during the study at a modest influent chemical oxygen demand (COD)/NH4+-N ratio of 8.9±1.8 within the HRT range of 3.1-9.4 h. Anammox polishing contributed 11% of overall TIN removal. Therefore, this pilot-scale study demonstrates that application of the proposed nitritation-denitritation system followed by anammox polishing is capable of relatively high nitrogen removal without supplemental carbon and alkalinity at a low HRT.
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Affiliation(s)
- Pusker Regmi
- Brown and Caldwell, 1600 Duke Street, Suite 310, Alexandria, VA 22314, USA E-mail: ;
| | | | | | - Mark W Miller
- Civil and Environment Engineering Department, Virginia Tech, Blacksburg, VA 24060, USA
| | | | - Sudhir Murthy
- DC Water Authority, 5000 Overlook Ave. SW, Washington, DC 20032, USA
| | - Charles B Bott
- Hampton Roads Sanitation District, 1436 Air Rail Ave., Virginia Beach, VA 23455, USA
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Al-Omari A, Wett B, Nopens I, De Clippeleir H, Han M, Regmi P, Bott C, Murthy S. Model-based evaluation of mechanisms and benefits of mainstream shortcut nitrogen removal processes. Water Sci Technol 2015; 71:840-847. [PMID: 25812092 DOI: 10.2166/wst.2015.022] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The main challenge in implementing shortcut nitrogen removal processes for mainstream wastewater treatment is the out-selection of nitrite oxidizing bacteria (NOB) to limit nitrate production. A model-based approach was utilized to simulate the impact of individual features of process control strategies to achieve NO(-)(2)-N shunt via NOB out-selection. Simulations were conducted using a two-step nitrogen removal model from the literature. Nitrogen shortcut removal processes from two case studies were modeled to illustrate the contribution of NOB out-selection mechanisms. The paper highlights a comparison between two control schemes; one was based on online measured ammonia and the other was based on a target ratio of 1 for ammonia vs. NOx (nitrate + nitrite) (AVN). Results indicated that the AVN controller possesses unique features to nitrify only that amount of nitrogen that can be denitrified, which promotes better management of incoming organics and bicarbonate for a more efficient NOB out-selection. Finally, the model was used in a scenario analysis, simulating hypothetical optimized performance of the pilot process. An estimated potential saving of 60% in carbon addition for nitrogen removal by implementing full-scale mainstream deammonification was predicted.
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Affiliation(s)
- Ahmed Al-Omari
- Department of Mathematical Modelling, Statistics and Bio-informatics, Ghent University, Coupure Links 653, 9000 Ghent, Belgium E-mail: ; DC Water and Sewer Authority, 20032 Washington, DC, USA
| | - Bernhard Wett
- ARAconsult, Unterbergerstr.1, A-6020 Innsbruck, Austria
| | - Ingmar Nopens
- Department of Mathematical Modelling, Statistics and Bio-informatics, Ghent University, Coupure Links 653, 9000 Ghent, Belgium E-mail:
| | - Haydee De Clippeleir
- Department of Earth and Environmental Engineering, Columbia University, New York, NY, USA
| | - Mofei Han
- Laboratory of Microbial Ecology and Technology (LabMET), Ghent University, Ghent, Belgium
| | - Pusker Regmi
- Civil and Environment Engineering Department, Old Dominion University, Norfolk, VA 23529, USA
| | - Charles Bott
- Hampton Roads Sanitation District, Virginia Beach, VA 23455, USA
| | - Sudhir Murthy
- DC Water and Sewer Authority, 20032 Washington, DC, USA
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Nogaj TM, Randall AA, Jimenez JA, Takacs I, Bott CB, Miller MW, Murthy S, Wett B. Mathematical Modeling Of The High Rate Activated Sludge System: Optimizing The Cod:N Ratio In The Process Effluent. ACTA ACUST UNITED AC 2014. [DOI: 10.2175/193864714815941009] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Wadhawan T, Khan E, Clippeleir HD, Al-Omari A, Wett B, Takács I, Jimenez JA, Murthy S. The Effect Of Sludge Age On Biokinetic Coefficients. ACTA ACUST UNITED AC 2014. [DOI: 10.2175/193864714815940514] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Regmi P, Miller MW, Holgate B, Bunce R, Park H, Chandran K, Wett B, Murthy S, Bott CB. Control of aeration, aerobic SRT and COD input for mainstream nitritation/denitritation. Water Res 2014; 57:162-71. [PMID: 24721663 DOI: 10.1016/j.watres.2014.03.035] [Citation(s) in RCA: 245] [Impact Index Per Article: 24.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/27/2013] [Revised: 02/10/2014] [Accepted: 03/14/2014] [Indexed: 05/06/2023]
Abstract
This work describes the development of an intermittently aerated pilot-scale process (V = 0.34 m(3)) operated without oxidized nitrogen recycle and supplemental carbon addition optimized for nitrogen removal via nitritation/denitritation. The aeration pattern was controlled using a novel aeration strategy based on set-points for reactor ammonia, nitrite and nitrate concentrations with the aim of maintaining equal effluent ammonia and nitrate + nitrite (NOx) concentrations. Further, unique operational and process control strategies were developed to facilitate the out-selection of nitrite oxidizing bacteria (NOB) based on optimizing the chemical oxygen demand (COD) input, imposing transient anoxia, aggressive solids retention time (SRT) operation towards ammonia oxidizing bacteria (AOB) washout and high dissolved oxygen (DO) (>1.5 mg/L). Sustained nitrite accumulation (NO2-N/NOx-N = 0.36 ± 0.27) was observed while AOB activity was greater than NOB activity (AOB: 391 ± 124 mgN/L/d, NOB: 233 ± 151 mgN/L/d, p < 0.001) during the entire study. The reactor demonstrated total inorganic nitrogen (TIN) removal rate of 151 ± 74 mgN/L/d at an influent COD/ [Formula: see text] -N ratio of 10.4 ± 1.9 at 25 °C. The TIN removal efficiency was 57 ± 25% within the hydraulic retention time (HRT) of 3 h and within an SRT of 4-8 days. Therefore, this pilot-scale study demonstrates that application of the proposed online aeration control is able to out-select NOB in mainstream conditions providing relatively high nitrogen removal without supplemental carbon and alkalinity at a low HRT.
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Affiliation(s)
- Pusker Regmi
- Civil and Environment Engineering Department, Old Dominion University, Norfolk, VA 23529, USA.
| | - Mark W Miller
- Civil and Environment Engineering Department, Virginia Tech, Blacksburg, VA 24060, USA
| | - Becky Holgate
- Civil and Environment Engineering Department, Old Dominion University, Norfolk, VA 23529, USA
| | | | - Hongkeun Park
- Department of Earth and Environmental Engineering, Columbia University, 500 West 120th Street, New York, NY 10027, USA
| | - Kartik Chandran
- Department of Earth and Environmental Engineering, Columbia University, 500 West 120th Street, New York, NY 10027, USA
| | - Bernhard Wett
- ARA Consult, Unterbergerstr.1, 6020 Innsbruck, Austria
| | - Sudhir Murthy
- DC Water Authority, 5000 Overlook Ave. SW, Washington DC 20032, USA
| | - Charles B Bott
- Hampton Roads Sanitation District, 1436 Air Rail Ave., Virginia Beach, VA 23455, USA
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Wett B, Takács I, Batstone D, Wilson C, Murthy S. Anaerobic model for high-solids or high-temperature digestion - additional pathway of acetate oxidation. Water Sci Technol 2014; 69:1634-1640. [PMID: 24759522 DOI: 10.2166/wst.2014.047] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Current anaerobic digestion models cannot properly simulate processes that are operated under high solids concentrations or high temperatures. A modification to existing models has been implemented by adding important missing degradation pathways, to accommodate these systems without artificially recalibrating the model parameters. Specifically, we implemented the alternate acetate oxidizing mechanism that is more tolerant to ammonia than the standard aceticlastic pathway. Inhibition values were estimated and an empirical function has been used to apply ammonia inhibition. The model also relates metabolic activity to un-ionised species such as undissociated acetic acid as substrate (although not obligatory for all organisms) and unionised ammonia as inhibitor. The model relies on an equilibrium chemistry module (e.g. including the phosphate buffer), resulting in more accurate pH predictions, which is crucial for proper modeling of CO2 and NH3 stripping. Calibration results from three case-studies modeling thermal hydrolysis and subsequent digestion of sludge are presented.
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Affiliation(s)
- B Wett
- ARAconsult, Unterbergerstr.1, A-6020 Innsbruck, Austria E-mail:
| | - I Takács
- Dynamita, 66 bis Avenue du Parc d'Espagne, Pessac, Bordeaux, France
| | - D Batstone
- Advanced Water Management Centre, The University of Queensland, St Lucia 4072, Australia
| | - C Wilson
- Department of Civil & Environmental Engineering, Virginia Tech, Blacksburg, VA 24060, USA
| | - S Murthy
- DC Water, DWT, 5000 Overlook Ave, SW Washington, DC 20032, USA
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Suzuki R, Murthy S, Mah J, Wett B, Novak J, Higgins M, DeBarbadillo C. Maximizing Gas Production at Blue Plains AWTP for High-Loaded Digestion Process. ACTA ACUST UNITED AC 2013. [DOI: 10.2175/193864713813674225] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Miller MW, Jimenez J, Murthy S, Kinnear D, Wett B, Bott CB. Mechanisms of COD removal in the adsorption stage of the A/B process. ACTA ACUST UNITED AC 2013. [DOI: 10.2175/193864713813673721] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Wett B, Omari A, Podmirseg SM, Han M, Akintayo O, Gómez Brandón M, Murthy S, Bott C, Hell M, Takács I, Nyhuis G, O'Shaughnessy M. Going for mainstream deammonification from bench to full scale for maximized resource efficiency. Water Sci Technol 2013; 68:283-9. [PMID: 23863418 DOI: 10.2166/wst.2013.150] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
A three-pronged coordinated research effort was undertaken by cooperating utilities at three different experimental scales investigating bioaugmentation, enrichment and performance of anammox organisms in mainstream treatment. Two major technological components were applied: density-based sludge wasting by a selective cyclone to retain anammox granules and intermittent aeration to repress nitrite oxidizers. This paper evaluates process conditions and operation modes to direct more nitrogen to the resource-saving metabolic route of deammonification.
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Affiliation(s)
- B Wett
- ARAconsult, Unterbergerstr.1, A-6020 Innsbruck, Austria.
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Stinson B, Murthy S, Bott C, Wett B, Al-Omari A, Bowden G, Mokhyerie Y, De Clippeleir H. Roadmap Toward Energy Neutrality & Chemical Optimization at Enhanced Nutrient Removal Facilities. ACTA ACUST UNITED AC 2013. [DOI: 10.2175/193864713813525888] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Stinson B, Murthy S, Bott C, Wett B, Bailey W, Al-Omari A, Bowden G, Mokhayeri Y, De Clippeleir H. Roadmap To Energy & Chemical Optimization Through The Use of Mainstream Deammonification at Enhanced Nutrient Removal Facilities. ACTA ACUST UNITED AC 2013. [DOI: 10.2175/193864713813673596] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Wilson CA, Novak J, Takacs I, Wett B, Murthy S. The kinetics of process dependent ammonia inhibition of methanogenesis from acetic acid. Water Res 2012; 46:6247-56. [PMID: 23062786 DOI: 10.1016/j.watres.2012.08.028] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2011] [Revised: 08/16/2012] [Accepted: 08/19/2012] [Indexed: 05/24/2023]
Abstract
Advanced anaerobic digestion processes aimed at improving the methanization of sewage sludge may be potentially impaired by the production of inhibitory compounds (e.g. free ammonia). The result of methanogenic inhibition is relatively high effluent concentrations of acetic acid and other soluble organics, as well as reduced methane yields. An extreme example of such an advanced process is the thermal hydrolytic pretreatment of sludge prior to high solids digestion (THD). Compared to a conventional mesophilic anaerobic digestion process (MAD), THD operates in a state of constant inhibition driven by high free ammonia concentrations, and elevated pH values. As such, previous investigations of the kinetics of methanogenesis from acetic acid under uninhibited conditions do not necessarily apply well to the modeling of extreme processes such as THD. By conducting batch ammonia toxicity assays using biomass from THD and MAD reactors, we compared the response of these communities over a broad range of ammonia inhibition. For both processes, increased inhibitor concentrations resulted in a reduction of biomass growth rate (r(max) = μ(max)∙X) and a resulting decrease in the substrate half saturation coefficient (K(S)). These two parameters exhibited a high degree of correlation, suggesting that for a constant transport limited system, the K(S) was mostly a linear function of the growth rate. After correcting for reactor pH and temperature, we found that the THD and MAD biomass were both able to perform methanogenesis from acetate at high free ammonia concentrations (equivalent to 3-5 g/L total ammonia nitrogen), albeit at less than 30% of their respective maximum rates. The reduction in methane production was slightly less pronounced for the THD biomass than for MAD, suggesting that the long term exposure to ammonia had selected for a methanogenic pathway less dependent on those organisms most sensitive to ammonia inhibition (i.e. aceticlastic methanogens).
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Miller MW, Bunce R, Regmi P, Hingley DM, Kinnear D, Murthy S, Wett B, Bott CB. A/B Process Pilot Optimized for Nitrite Shunt: High Rate Carbon Removal Followed by BNR with Ammonia-Based Cyclic Aeration Control. ACTA ACUST UNITED AC 2012. [DOI: 10.2175/193864712811709607] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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