Application of the NDHA model to describe N2O dynamics in activated sludge mixed culture biomass

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Abstract

A pseudo-mechanistic model describing three biological nitric oxide (NO) and nitrous oxide (N2O) production pathways was calibrated for an activated sludge mixed culture biomass treating municipal wastewater with laboratory-scale experiments. The model (NDHA) comprehensively describes N2O producing pathways by both autotrophic ammonium oxidizing and heterotrophic bacteria. Extant respirometric assays and anaerobic batch experiments were designed to calibrate the endogenous, heterotrophic denitrification and autotrophic ammonium/nitrite oxidation processes together with the associated net N2O production. Ten parameters describing heterotrophic processes and seven for autotrophic processes were estimated accurately (variance/mean < 25%). The model predicted the N2O and NO dynamics at varying dissolved oxygen, ammonium and nitrite levels and was validated with a different set of batch experiments with the same biomass. Aerobic ammonium oxidation experiments at two oxygen levels used for model evaluation (2 and 0.5 mg/L) indicated that the nitrifier denitrification (42, 64%) and heterotrophic denitrification (7, 17%) pathways increased and dominated the total N2O production at high nitrite and low oxygen concentrations; while the nitrifier nitrification pathway showed the largest contribution at high dissolved oxygen levels (51, 19%). The uncertainty of the biological parameter estimates was propagated to N2O model outputs via Monte Carlo simulations as 95% confidence intervals. The accuracy of the estimated parameters corresponded to a low uncertainty of the N2O emission factors (4.6 ± 0.6% and 1.2 ± 0.1%).
Original languageEnglish
Publication date2018
Number of pages4
Publication statusPublished - 2018
Event6th IWA/WEF Water Resource Recovery Modelling Seminar (WRRmod 2018) - Quebec, Canada
Duration: 10 Mar 201814 Mar 2018
Conference number: 6

Conference

Conference6th IWA/WEF Water Resource Recovery Modelling Seminar (WRRmod 2018)
Number6
CountryCanada
CityQuebec
Period10/03/201814/03/2018

Keywords

  • Modelling
  • ASM
  • Nitrous oxide
  • Uncertainty
  • Activated sludge

Cite this

Domingo-Felez, C., & Smets, B. F. (2018). Application of the NDHA model to describe N2O dynamics in activated sludge mixed culture biomass. Abstract from 6th IWA/WEF Water Resource Recovery Modelling Seminar (WRRmod 2018), Quebec, Canada.
Domingo-Felez, Carlos ; Smets, Barth F. / Application of the NDHA model to describe N2O dynamics in activated sludge mixed culture biomass. Abstract from 6th IWA/WEF Water Resource Recovery Modelling Seminar (WRRmod 2018), Quebec, Canada.4 p.
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title = "Application of the NDHA model to describe N2O dynamics in activated sludge mixed culture biomass",
abstract = "A pseudo-mechanistic model describing three biological nitric oxide (NO) and nitrous oxide (N2O) production pathways was calibrated for an activated sludge mixed culture biomass treating municipal wastewater with laboratory-scale experiments. The model (NDHA) comprehensively describes N2O producing pathways by both autotrophic ammonium oxidizing and heterotrophic bacteria. Extant respirometric assays and anaerobic batch experiments were designed to calibrate the endogenous, heterotrophic denitrification and autotrophic ammonium/nitrite oxidation processes together with the associated net N2O production. Ten parameters describing heterotrophic processes and seven for autotrophic processes were estimated accurately (variance/mean < 25{\%}). The model predicted the N2O and NO dynamics at varying dissolved oxygen, ammonium and nitrite levels and was validated with a different set of batch experiments with the same biomass. Aerobic ammonium oxidation experiments at two oxygen levels used for model evaluation (2 and 0.5 mg/L) indicated that the nitrifier denitrification (42, 64{\%}) and heterotrophic denitrification (7, 17{\%}) pathways increased and dominated the total N2O production at high nitrite and low oxygen concentrations; while the nitrifier nitrification pathway showed the largest contribution at high dissolved oxygen levels (51, 19{\%}). The uncertainty of the biological parameter estimates was propagated to N2O model outputs via Monte Carlo simulations as 95{\%} confidence intervals. The accuracy of the estimated parameters corresponded to a low uncertainty of the N2O emission factors (4.6 ± 0.6{\%} and 1.2 ± 0.1{\%}).",
keywords = "Modelling, ASM, Nitrous oxide, Uncertainty, Activated sludge",
author = "Carlos Domingo-Felez and Smets, {Barth F.}",
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Domingo-Felez, C & Smets, BF 2018, 'Application of the NDHA model to describe N2O dynamics in activated sludge mixed culture biomass', 6th IWA/WEF Water Resource Recovery Modelling Seminar (WRRmod 2018), Quebec, Canada, 10/03/2018 - 14/03/2018.

Application of the NDHA model to describe N2O dynamics in activated sludge mixed culture biomass. / Domingo-Felez, Carlos; Smets, Barth F.

2018. Abstract from 6th IWA/WEF Water Resource Recovery Modelling Seminar (WRRmod 2018), Quebec, Canada.

Research output: Contribution to conferenceConference abstract for conferenceResearchpeer-review

TY - ABST

T1 - Application of the NDHA model to describe N2O dynamics in activated sludge mixed culture biomass

AU - Domingo-Felez, Carlos

AU - Smets, Barth F.

PY - 2018

Y1 - 2018

N2 - A pseudo-mechanistic model describing three biological nitric oxide (NO) and nitrous oxide (N2O) production pathways was calibrated for an activated sludge mixed culture biomass treating municipal wastewater with laboratory-scale experiments. The model (NDHA) comprehensively describes N2O producing pathways by both autotrophic ammonium oxidizing and heterotrophic bacteria. Extant respirometric assays and anaerobic batch experiments were designed to calibrate the endogenous, heterotrophic denitrification and autotrophic ammonium/nitrite oxidation processes together with the associated net N2O production. Ten parameters describing heterotrophic processes and seven for autotrophic processes were estimated accurately (variance/mean < 25%). The model predicted the N2O and NO dynamics at varying dissolved oxygen, ammonium and nitrite levels and was validated with a different set of batch experiments with the same biomass. Aerobic ammonium oxidation experiments at two oxygen levels used for model evaluation (2 and 0.5 mg/L) indicated that the nitrifier denitrification (42, 64%) and heterotrophic denitrification (7, 17%) pathways increased and dominated the total N2O production at high nitrite and low oxygen concentrations; while the nitrifier nitrification pathway showed the largest contribution at high dissolved oxygen levels (51, 19%). The uncertainty of the biological parameter estimates was propagated to N2O model outputs via Monte Carlo simulations as 95% confidence intervals. The accuracy of the estimated parameters corresponded to a low uncertainty of the N2O emission factors (4.6 ± 0.6% and 1.2 ± 0.1%).

AB - A pseudo-mechanistic model describing three biological nitric oxide (NO) and nitrous oxide (N2O) production pathways was calibrated for an activated sludge mixed culture biomass treating municipal wastewater with laboratory-scale experiments. The model (NDHA) comprehensively describes N2O producing pathways by both autotrophic ammonium oxidizing and heterotrophic bacteria. Extant respirometric assays and anaerobic batch experiments were designed to calibrate the endogenous, heterotrophic denitrification and autotrophic ammonium/nitrite oxidation processes together with the associated net N2O production. Ten parameters describing heterotrophic processes and seven for autotrophic processes were estimated accurately (variance/mean < 25%). The model predicted the N2O and NO dynamics at varying dissolved oxygen, ammonium and nitrite levels and was validated with a different set of batch experiments with the same biomass. Aerobic ammonium oxidation experiments at two oxygen levels used for model evaluation (2 and 0.5 mg/L) indicated that the nitrifier denitrification (42, 64%) and heterotrophic denitrification (7, 17%) pathways increased and dominated the total N2O production at high nitrite and low oxygen concentrations; while the nitrifier nitrification pathway showed the largest contribution at high dissolved oxygen levels (51, 19%). The uncertainty of the biological parameter estimates was propagated to N2O model outputs via Monte Carlo simulations as 95% confidence intervals. The accuracy of the estimated parameters corresponded to a low uncertainty of the N2O emission factors (4.6 ± 0.6% and 1.2 ± 0.1%).

KW - Modelling

KW - ASM

KW - Nitrous oxide

KW - Uncertainty

KW - Activated sludge

M3 - Conference abstract for conference

ER -

Domingo-Felez C, Smets BF. Application of the NDHA model to describe N2O dynamics in activated sludge mixed culture biomass. 2018. Abstract from 6th IWA/WEF Water Resource Recovery Modelling Seminar (WRRmod 2018), Quebec, Canada.