Hélène Hauduc - Academia.edu (original) (raw)

Papers by Hélène Hauduc

Water Environment Research, 2020

This study quantifies volatile sulfur compound (VSC) emissions from primary settling tanks and in... more This study quantifies volatile sulfur compound (VSC) emissions from primary settling tanks and investigates their mechanisms of generation. Hydrogen sulfide (H2S) and methyl mercaptan (MM) concentrations in the off‐gas were dominant among the VSCs analyzed, while dimethyl sulfide (DMS) and dimethyl disulfide (DMDS) were under their odor threshold for most sampling dates. H2S emission in primary settling tanks was mainly the result of the stripping of dissolved sulfide (64%) generated in the sewers. Results indicate that MM emission was more dependent on the conditions in the primary clarifiers (only 16% stripping). Prevention of odor emission in primary settling tanks can be achieved by managing biofilms and microbial reactions in the sewer network. Controlling the biomass seeding and fermentation product availability in the primary settling tanks is essential to significantly minimize the kinetics of H2S and MM generation. Overall, the management of sludge blanket heights and thus avoiding time at low oxidation–reduction potential minimized odor emission independent of sewer conditions.

Biotechnology and Bioengineering, 2012

Objective: Predict phosphate P recovery from high-strength wastewaters in a valuable product, suc... more Objective: Predict phosphate P recovery from high-strength wastewaters in a valuable product, such as struvite (MgNH4PO4·6H2O) or hydroxyapatite (Ca5(PO4)3(OH)) Background: 3 different kinetic rate expressions for precipitation have been proposed in literature:  Musvoto et al., 2000  Kazadi Mbamba et al., 2015  Lizarralde et al., 2015 Multiple phosphate precipitation from high-strength wastewaters: Analysis of 3 kinetic models Introduction Kinetic rate expressions for precipitation.

Thèse présentée à la Faculté des études supérieures de l'Université Laval dans le cadre du progra... more Thèse présentée à la Faculté des études supérieures de l'Université Laval dans le cadre du programme de doctorat en Génie des Eaux pour l'obtention du grade de philosophiae doctor (Ph. D.) Avant-Propos Ces travaux de thèse ont été réalisés dans le cadre d'une collaboration entre Cemagref, l'institut de recherche en sciences et technologies pour l'environnement, et l'Université Laval (Québec, Canada). Au Cemagref, les travaux de thèse ont été effectués au sein de l'équipe Epure (Génie des processus épuratoires) de l'unité HBAN (Hydrosystèmes et bioprocédés) du groupement d'Antony (France), et dirigés par Sylvie Gillot. A l'Université Laval, ils ont été réalisés au sein du groupe de recherche modelEAU du département de génie civil et de génie des eaux, et dirigés par Pr. Peter Vanrolleghem. Ces travaux s'inscrivent également dans le cadre d'une cotutelle établie entre l'Université Laval et l'école doctorale ABIES de l'Institut des Sciences et Industries du Vivant et de l'Environnement (AgroParisTech, Paris, France), dont Alain Bermond a assuré la correspondance pour ce projet. Ces travaux ont été également encadrés par Alain Héduit et Leiv Rieger. Les travaux de thèse ont été développés en lien avec les travaux du Task Group « Good Modelling Practice » (TG-GMP, https://iwa-gmp-tg.cemagref.fr/) de l'International Water Association, dont l'objectif est d'élaborer une procédure de bonnes pratiques en matière de modélisation des boues activées. Ce groupe de travail est dirigé par Leiv Rieger et est composé de 6 autres membres : Sylvie Gillot, Günter Langergraber, Takayuki Ohtsuki, Andrew Shaw, Imre Takács et Stefan Winkler. Cette collaboration a fait l'objet de deux articles présentés dans la thèse :

A total of 31 quantitative quality criteria to compare measured with simulated time series in env... more A total of 31 quantitative quality criteria to compare measured with simulated time series in environmental modelling are critically reviewed. They are grouped using two classification schemes. A methodology to evaluate and compare the criteria is proposed and tested on a case study. This methodology includes a two stage cluster analysis using Kendall rank correlation and dendograms to identify independent quality criteria. Independent quality criteria allow for a comprehensive model assessment and are a prerequisite for multi-objective parameter estimation.

Proceedings of the Water Environment Federation

Techniques Sciences Méthodes, 2015

L’analyse du fonctionnement des stations d’epuration et a fortiori l’utilisation d’outils de mode... more L’analyse du fonctionnement des stations d’epuration et a fortiori l’utilisation d’outils de modelisation dynamique de ce fonctionnement s’appuient sur un ensemble de donnees issues de mesures pouvant etre entachees d’erreurs. Ces donnees, acquises pour l’autosurveillance de l’installation ou pour son exploitation doivent donc etre validees de maniere systematique afin de decrire au mieux le systeme de traitement et eventuellement de les utiliser en modelisation. Dans cet article, la procedure d’analyse et de consolidation des donnees developpee par le groupe de travail « Good Modelling Practice » de l’IWA a ete appliquee aux donnees de fonction - nement d’une station d’epuration dimensionnee pour traiter les eaux residuaires urbaines de 230000 equivalent-habitant (EH). L’analyse de ces donnees a permis l’identification de certaines mesures erronees, concernant principalement les debits d’alimentation des reacteurs biologiques. Celles-ci ont ete consolidees a partir de bilans hydrauliques et massiques realises a l’echelle de la station. Les donnees consolidees permettent de decrire precisement les principaux parametres de fonctionnement de la station, tels que les charges recues, la production de boues, l’âge de boues et la consommation d’oxygene.

Phosphorus: Polluter and Resource of the Future – Removal and Recovery from Wastewater, Jun 15, 2018

La modelisation du fonctionnement des stations d'epuration est un outil largement utilise not... more La modelisation du fonctionnement des stations d'epuration est un outil largement utilise notamment pour l'optimisation et la rehabilitation des ouvrages existants et le dimensionnement de nouvelles installations. S'assurer d'une bonne qualite des modeles est donc primordial. Or, d'apres les resultats d'une enquete internationale effectuee aupres de 96 utilisateurs potentiels de modeles, deux etapes dans l'utilisation des modeles sont considerees comme particulierement delicates: le choix du modele a utiliser parmi les modeles disponibles et l'etape de calage de ces modeles. Le travail presente visait a fournir des elements pour lever des obstacles a une utilisation plus generalisee des modeles biocinetiques a boues activees. Il a porte sur sept des modeles publies : (1) ASM1, (2) ASM2d, (3) ASM3, (4) ASM3+BioP, (5) ASM2d+TUD, (6) Barker & Dold et (7) UCTPHO+. Dans un premier temps, une analyse des connaissances pratiques des modeles a ete effectuee a...

IFAC-PapersOnLine, Jul 1, 2017

The quality of simulation results can be significantly affected by errors in the published model ... more The quality of simulation results can be significantly affected by errors in the published model (typing, inconsistencies, gaps or conceptual errors) and/or in the underlying numerical model description. Seven of the most commonly used activated sludge models have been investigated to point out the typing errors, inconsistencies and gaps in the model publications: ASM1; ASM2d; ASM3; ASM3 + Bio-P; ASM2d + TUD; New General; UCTPHO+. A systematic approach to verify models by tracking typing errors and inconsistencies in model development and software implementation is proposed. Then, stoichiometry and kinetic rate expressions are checked for each model and the errors found are reported in detail. An attached spreadsheet (see http://www.iwaponline.com/wst/06104/0898.pdf) provides corrected matrices with the calculations of all stoichiometric coefficients for the discussed biokinetic models and gives an example of proper continuity checks. A systematic approach for model verification: Ap...

Water Science and Technology, 2011

This study aims at synthesizing experiences in the practical application of ASM type models. The ... more This study aims at synthesizing experiences in the practical application of ASM type models. The information is made easily accessible to model users by creating a database of modelling projects. This database includes answers to a questionnaire that was sent out to model users in 2008 to provide inputs for a Scientific and Technical Report of the IWA Task Group on Good Modelling Practice-Guidelines for use of activated sludge models, and a literature review on published modelling projects. The database is analysed to determine which biokinetic model parameters are usually changed by modellers, in which ranges, and what values are typically used for seven selected activated sludge models. These results should help model users in the calibration step, by providing typical parameter values as a starting point and ranges as a guide. However, the proposed values should be used with great care since they are the result of averaging practical experience and not taking into account specific parameter correlations.

A dynamic physico-chemical model for chemical phosphorus removal in wastewater is presented as a ... more A dynamic physico-chemical model for chemical phosphorus removal in wastewater is presented as a tool to optimize chemical dosing simultaneously while ensuring compliant effluent phosphorus concentration. This new model predicts the kinetic and stoichiometric variable processes of precipitation of hydrous ferric oxides (HFO), phosphates adsorption and co-precipitation. It is combined with chemical equilibrium and physical precipitation reactions in order to model observed bulk dynamics in terms of pH. The model is calibrated and validated based on previous studies and experimental data from Smith et al. (2008) and Szabo et al. (2008) as a first step for full-plant implementation. The simulation results show that the structure of the model describes adequately the mechanisms of adsorption and co-precipitation of phosphate species onto HFO and that the model is robust under various experimental conditions.

Many unit process models are available in the field of wastewater treatment. All of these models ... more Many unit process models are available in the field of wastewater treatment. All of these models use their own notation, causing problems for documentation, implementation and connection of different models (using different sets of state variables). The main goal of this paper is to propose a new notational framework which allows unique and systematic naming of state variables and parameters of biokinetic models in the wastewater treatment field. The symbols are based on one main letter that gives a general description of the state variable or parameter and several subscript levels that provide greater specification. Only those levels that make the name unique within the model context are needed in creating the symbol. The paper describes specific problems encountered with the currently used notation, presents the proposed framework and provides additional practical examples. The overall result is a framework that can be used in whole plant modelling, which consists of different fields such as activated sludge, anaerobic digestion, sidestream treatment, membrane bioreactors, metabolic approaches, fate of micropollutants and biofilm processes. The main objective of this consensus building paper is to establish a consistent set of rules that can be applied to existing and most importantly, future models. Applying the proposed notation should make it easier for everyone active in the wastewater treatment field to read, write and review documents describing modelling projects.

Environmental Modelling and Software

In various cases in environmental modeling, modelers need to account for multiple variables and m... more In various cases in environmental modeling, modelers need to account for multiple variables and multiple objectives in systems with many processes occurring at different time scales. To assist the modeler to choose a relevant pool of efficiency criteria, a method is proposed to identify dissimilar criteria. A total of 30 efficiency criteria used in environmental modeling are critically reviewed and classified into six groups according to different modeling objectives. After accounting for equivalence of functional form 18 criteria remain for further analysis. To quantify the dissimilarity for the remaining criteria a methodology based on the ratio of shared parameter sets in regions of good performance is proposed. Then, for a wastewater treatment plant case-study the dissimilarity of efficiency criteria is analyzed as a function of target variables and operating conditions.

Environmental Modelling & Software, 2015

ABSTRACT In various cases in environmental modeling, modelers need to account for multiple variab... more ABSTRACT In various cases in environmental modeling, modelers need to account for multiple variables and multiple objectives in systems with many processes occurring at different time scales. To assist the modeler to choose a relevant pool of efficiency criteria, a method is proposed to identify dissimilar criteria. A total of 30 efficiency criteria used in environmental modeling are critically reviewed and classified into six groups according to different modeling objectives. After accounting for equivalence of functional form 18 criteria remain for further analysis. To quantify the dissimilarity for the remaining criteria a methodology based on the ratio of shared parameter sets in regions of good performance is proposed. Then, for a wastewater treatment plant case-study the dissimilarity of efficiency criteria is analyzed as a function of target variables and operating conditions.