title: Concentration-driven models revisited: towards a unified framework to model settling tanks in water resource recovery facilities.
abstract: A new perspective on the modelling of settling behaviour in water resource recovery facilities is introduced. The ultimate goal is to describe in a unified way the processes taking place both in primary settling tanks (PSTs) and secondary settling tanks (SSTs) for a more detailed operation and control. First, experimental evidence is provided, pointing out distributed particle properties (such as size, shape, density, porosity, and flocculation state) as an important common source of distributed settling behaviour in different settling unit processes and throughout different settling regimes (discrete, hindered and compression settling). Subsequently, a unified model framework that considers several particle classes is proposed in order to describe distributions in settling behaviour as well as the effect of variations in particle properties on the settling process. The result is a set of partial differential equations (PDEs) that are valid from dilute concentrations, where they correspond to discrete settling, to concentrated suspensions, where they correspond to compression settling. Consequently, these PDEs model both PSTs and SSTs.
authors.affiliation: modelEAU, Département de génie civil et de génie des eaux, Université Laval, Québec, QC, Canada E-mail: elena.torfs@ugent.be; elena.torfs.1@ulaval.ca; BIOMATH, Department of Mathematical Modelling, Statistics and Bioinformatics, Ghent University, Coupure links 653, Ghent B-9000, Belgium.
authors.forename: Elena
authors.initials: E
authors.lastname: Torfs
authors.forename: M Carmen
authors.initials: MC
authors.lastname: Martí
authors.affiliation: ICube, UMR 7357, ENGEES, CNRS, Université de Strasbourg, 2 rue Boussingault, Strasbourg 67000, France.
authors.forename: Florent
authors.initials: F
authors.lastname: Locatelli
authors.affiliation: BIOMATH, Department of Mathematical Modelling, Statistics and Bioinformatics, Ghent University, Coupure links 653, Ghent B-9000, Belgium.
authors.forename: Sophie
authors.initials: S
authors.lastname: Balemans
authors.affiliation: CI2MA and Departamento de Ingeniería Matemática, Facultad de Ciencias Físicas y Matemáticas, Universidad de Concepción, Casilla 160-C, Concepción, Chile.
authors.forename: Raimund
authors.initials: R
authors.lastname: Bürger
authors.affiliation: Centre for Mathematical Sciences, Lund University, P.O. Box 118, Lund S-221 00, Sweden.
authors.forename: Stefan
authors.initials: S
authors.lastname: Diehl
authors.affiliation: ICube, UMR 7357, ENGEES, CNRS, Université de Strasbourg, 2 rue Boussingault, Strasbourg 67000, France.
authors.forename: Julien
authors.initials: J
authors.lastname: Laurent
authors.affiliation: modelEAU, Département de génie civil et de génie des eaux, Université Laval, Québec, QC, Canada E-mail: elena.torfs@ugent.be; elena.torfs.1@ulaval.ca.
authors.forename: Peter A
authors.initials: PA
authors.lastname: Vanrolleghem
authors.affiliation: ICube, UMR 7357, ENGEES, CNRS, Université de Strasbourg, 2 rue Boussingault, Strasbourg 67000, France.
authors.forename: Pierre
authors.initials: P
authors.lastname: François
authors.affiliation: BIOMATH, Department of Mathematical Modelling, Statistics and Bioinformatics, Ghent University, Coupure links 653, Ghent B-9000, Belgium.
authors.forename: Ingmar
authors.initials: I
authors.lastname: Nopens
mesh_terms: D005427:Flocculation; D008962:Models, Theoretical; D011312:Pressure; D012722:Sewage / Q000032:analysis*; D013535:Suspensions; D014876:Water Pollution / Q000032:analysis*; D018508:Water Purification / Q000379:methods*; D062066:Water Resources
chemical_list: D012722:Sewage; D013535:Suspensions