title: Granularity determination of activated sludge through on-line profiles by means of case-based reasoning.
abstract: Aerobic granulation from floccular sludge is difficult to detect in first stages with the naked eye. This work proposes a combination of multi-way principal components and case-based reasoning to predict the granulation state of a sequencing batch reactor, based solely on the on-line registered profiles of common sensors (i.e. pH, dissolved oxygen and oxidation-reduction potential). The methodology is able to discriminate between two active sludge granularities (floccular and granular). Two different scenarios are presented: one in which both granularities are present, and another scenario for which the granular state is not initially available. Analysis reported pH as the key variable in the transition between both states according to its variation, and that, in general, the granularity of the process can be correctly predicted at the end of the anaerobic phase. This methodology improves process monitoring capabilities during granulation and is an on-line alternative to a microscope analysis before the batch release.
authors.affiliation: Laboratory of Control Engineering and Intelligent Systems (eXiT), University of Girona, Girona, Spain E-mail: xavier.berjaga@udg.edu.
authors.forename: Xavier
authors.initials: X
authors.lastname: Berjaga
authors.affiliation: LEQUIA, Institute of the Environmental, University of Girona, Girona, Spain; Laboratory of Microbial Ecology and Technology (LabMET), Ghent University, Gent, Belgium.
authors.forename: Marta
authors.initials: M
authors.lastname: Coma
authors.affiliation: Laboratory of Control Engineering and Intelligent Systems (eXiT), University of Girona, Girona, Spain E-mail: xavier.berjaga@udg.edu.
authors.forename: Joaquim
authors.initials: J
authors.lastname: Meléndez
authors.affiliation: LEQUIA, Institute of the Environmental, University of Girona, Girona, Spain.
authors.forename: Sebastià
authors.initials: S
authors.lastname: Puig
authors.affiliation: LEQUIA, Institute of the Environmental, University of Girona, Girona, Spain.
authors.forename: Jesús
authors.initials: J
authors.lastname: Colprim
authors.affiliation: Laboratory of Control Engineering and Intelligent Systems (eXiT), University of Girona, Girona, Spain E-mail: xavier.berjaga@udg.edu.
authors.forename: Joan
authors.initials: J
authors.lastname: Colomer
mesh_terms: D019149:Bioreactors; D005160:Facility Design and Construction; D005374:Filtration; D008962:Models, Theoretical; D025341:Principal Component Analysis; D012722:Sewage; D014865:Waste Disposal, Fluid
chemical_list: D012722:Sewage