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Author Van Winckel, T.; Ngo, N.; Sturm, B.; Al-Omari, A.; Wett, B.; Bott, C.; Vlaeminck, S.E.; De Clippeleir, H. pdf  url
doi  openurl
  Title Enhancing bioflocculation in high-rate activated sludge improves effluent quality yet increases sensitivity to surface overflow rate Type A1 Journal article
  Year (down) 2022 Publication Chemosphere Abbreviated Journal Chemosphere  
  Volume 308 Issue 2 Pages 136294-11  
  Keywords A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL)  
  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.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000863979600006 Publication Date 2022-09-06  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0045-6535; 1879-1298 ISBN Additional Links UA library record; WoS full record  
  Impact Factor 8.8 Times cited Open Access OpenAccess  
  Notes Approved Most recent IF: 8.8  
  Call Number UA @ admin @ c:irua:190187 Serial 7154  
Permanent link to this record
 

 
Author Ngo, K.N.; Tampon, P.; Van Winckel, T.; Massoudieh, A.; Sturm, B.; Bott, C.; Wett, B.; Murthy, S.; Vlaeminck, S.E.; DeBarbadillo, C.; De Clippeleir, H. pdf  url
doi  openurl
  Title Introducing bioflocculation boundaries in process control to enhance effluent quality of high‐rate contact‐stabilization systems Type A1 Journal article
  Year (down) 2022 Publication Water environment research Abbreviated Journal Water Environ Res  
  Volume 94 Issue 8 Pages e10772-17  
  Keywords A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL)  
  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.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000840360100001 Publication Date 2022-07-23  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1061-4303; 1554-7531 ISBN Additional Links UA library record; WoS full record  
  Impact Factor 3.1 Times cited Open Access OpenAccess  
  Notes Approved Most recent IF: 3.1  
  Call Number UA @ admin @ c:irua:189409 Serial 7174  
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Author Van Winckel, T.; Vlaeminck, S.E.; Al-Omari, A.; Bachmann, B.; Sturm, B.; Wett, B.; Takács, I.; Bott, C.; Murthy, S.N.; De Clippeleir, H. pdf  url
doi  openurl
  Title Screen versus cyclone for improved capacity and robustness for sidestream and mainstream deammonification Type A1 Journal article
  Year (down) 2019 Publication Environmental Science: Water Research & Technology Abbreviated Journal  
  Volume 5 Issue 10 Pages 1769-1781  
  Keywords A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL)  
  Abstract Deammonification systems are being implemented as cost- and resource-efficient nitrogen removal processes. However, their complexity is a major hurdle towards successful transposition from side- to mainstream application. Merely out-selecting nitrite oxidizing bacteria (NOB) or retaining anammox bacteria (AnAOB) does not guarantee efficient mainstream deammonification. This paper presents for the first time the interactions and synergies between kinetic selection, through management of residual substrates, and physical selection, through separation of solid retention times (SRTs). This allowed the formulation of tangible operational recommendations for successful deammonification. Activity measurements were used to establish retention efficiencies (η) for AnAOB for full-scale cyclones and rotating drum screens installed at a sidestream and mainstream deammonification reactor (Strass, Austria). In the sidestream reactor, using a screen (η = 91%) instead of a cyclone (η = 88%) may increase the capacity by up to 29%. For the mainstream reactor, higher AnAOB retention efficiencies achieved by the screen (η = 72%) compared to the cyclone (η = 42%) induced a prospective increase in capacity by 80–90%. In addition, the switch in combination with bioaugmentation from the sidestream made the process less dependent on nitrite availability, thus aiding in the outselection of NOB. This allowed for a more flexible (intermittent) aeration strategy and a reduced need for tight SRT control for NOB washout. A sensitivity analysis explored expected trends to provide possible operational windows for further calibration. In essence, characterization of the physical selectors at full scale allowed a deeper understanding of operational windows of the process and quantification of capacity, ultimately leading to a more space and energy conservation process.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000487968200013 Publication Date 2019-08-20  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2053-1400 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor Times cited Open Access  
  Notes Approved no  
  Call Number UA @ admin @ c:irua:162540 Serial 8498  
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Author Seuntjens, D.; Han, M.; Kerckhof, F.-M.; Boon, N.; Al-Omari, A.; Takacs, I.; Meerburg, F.; De Mulder, C.; Wett, B.; Bott, C.; Murthy, S.; Carvajal Arroyo, J.M.; De Clippeleir, H.; Vlaeminck, S.E. pdf  url
doi  openurl
  Title Pinpointing wastewater and process parameters controlling the AOB to NOB activity ratio in sewage treatment plants Type A1 Journal article
  Year (down) 2018 Publication Water research Abbreviated Journal  
  Volume 138 Issue Pages 37-46  
  Keywords A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL)  
  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 = 1.061.07). 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.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000431747300005 Publication Date 2017-11-24  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0043-1354; 1879-2448 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor Times cited Open Access  
  Notes Approved no  
  Call Number UA @ admin @ c:irua:149976 Serial 8385  
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Author Van Winckel, T.; Al-Omari, A.; Takás, I.; Wett, B.; Bachmann, B.; Sturm, B.; Bott, C.; Vlaeminck, S.E.; Murthy, S.; De Clippeleir, H. openurl 
  Title Conceptual framework for deammonification in a combined floc-granule system : impact of aeration control, external selector and bioaugmentation based on full-scale data from WWTP in Strass Type P3 Proceeding
  Year (down) 2017 Publication Abbreviated Journal  
  Volume Issue Pages 16 p. T2 - IWA 2017 Conference on Sustainable Wast  
  Keywords P3 Proceeding; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL)  
  Abstract  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos Publication Date  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN ISBN Additional Links UA library record  
  Impact Factor Times cited Open Access  
  Notes Approved no  
  Call Number UA @ admin @ c:irua:151109 Serial 7722  
Permanent link to this record
 

 
Author Han, M.; Vlaeminck, S.E.; Al-Omari, A.; Wett, B.; Bott, C.; Murthy, S.; De Clippeleir, H. doi  openurl
  Title Uncoupling the solids retention times of flocs and granules in mainstream deammonification : a screen as effective out-selection tool for nitrite oxidizing bacteria Type A1 Journal article
  Year (down) 2016 Publication Bioresource technology Abbreviated Journal  
  Volume 221 Issue Pages 195-204  
  Keywords A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL)  
  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 <10 mg N/L was achieved using this novel approach combining biological selection with physical separation, opening up the path towards energy positive sewage treatment. (C) 2016 Elsevier Ltd. All rights reserved.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000386241000025 Publication Date 2016-09-08  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0960-8524 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor Times cited Open Access  
  Notes Approved no  
  Call Number UA @ admin @ c:irua:138157 Serial 8705  
Permanent link to this record
 

 
Author Han, M.; De Clippeleir, H.; Al-Omari, A.; Wett, B.; Vlaeminck, S.E.; Bott, C.; Murthy, S. doi  openurl
  Title Impact of carbon to nitrogen ratio and aeration regime on mainstream deammonification Type A1 Journal article
  Year (down) 2016 Publication Water science and technology Abbreviated Journal  
  Volume 74 Issue 2 Pages 375-384  
  Keywords A1 Journal article; Sustainable Energy, Air and Water Technology (DuEL)  
  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 degrees 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.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000380765500011 Publication Date 2016-04-30  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0273-1223; 1996-9732 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor Times cited Open Access  
  Notes Approved no  
  Call Number UA @ admin @ c:irua:135032 Serial 8062  
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Author Van Winckel, T.; De Clippeleir, H.; Yapuwa, H.; Wett, B.; Bott, C.; Sturm, B.; Vlaeminck, S.E.; Al-Omari, A.; Murthy, S. openurl 
  Title Lets settle together? Extending external selection from mainstream deammonification to high-rate activated sludge Type P3 Proceeding
  Year (down) 2016 Publication Abbreviated Journal  
  Volume Issue Pages 13 p. T2 - WEF/IWA Nutrient Removal and Recovery C  
  Keywords P3 Proceeding; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL)  
  Abstract  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos Publication Date  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN ISBN Additional Links UA library record  
  Impact Factor Times cited Open Access  
  Notes Approved no  
  Call Number UA @ admin @ c:irua:151131 Serial 8171  
Permanent link to this record
 

 
Author Van Winckel, T.; De Clippeleir, H.; Mancell-Egala, A.; Rahman, A.; Wett, B.; Bott, C.; Sturm, B.; Vlaeminck, S.E.; Al-Omari, A.; Murthy, S. openurl 
  Title Balancing flocs and granules by external selectors to increase capacity in high-rate activated sludge systems Type P3 Proceeding
  Year (down) 2016 Publication Abbreviated Journal  
  Volume Issue Pages 6 p. T2 - WEFTEC.16, 24 - 28 September 2016, New O  
  Keywords P3 Proceeding; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL)  
  Abstract  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos Publication Date  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN ISBN Additional Links UA library record  
  Impact Factor Times cited Open Access  
  Notes Approved no  
  Call Number UA @ admin @ c:irua:151122 Serial 7548  
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