Granular biomass floatation: A simple kinetic/stoichiometric explanation

• Published in: Chemical engineering journal (Lausanne, Switzerland : 1996) Vol. 311; pp. 63 - 71
• Main Authors: Campos, J.L., Val del Río, A., Pedrouso, A., Raux, P., Giustinianovichc, E.A., Mosquera-Corral, A.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.03.2017
• Subjects: Anaerobic; Anammox; Denitrification; Granule; Methane; Nitrogen; Methane; Denitrification; Anammox; Granule; Nitrogen; Anaerobic
• ISSN: 1385-8947; 1873-3212
• DOI: 10.1016/j.cej.2016.11.075

[Display omitted] •Reasons of anammox, denitrifying and anaerobic granules floatation are examined.•Substrates concentration and granules size are the main parameters to be controlled.•Data of literature fit into the zones with risk of floatation defined in this work.•Operating temperature could be used to control floatation episodes. Floatation events are commonly observed in anammox, denitrifying and anaerobic granular systems mostly subjected to overloading conditions. Although several operational strategies have been proposed to avoid floatation of granular biomass, until now, there is no consensus about the conditions responsible for this phenomenon. In the present study, a simple explanation based on kinetic and stoichiometric principles defining the aforementioned processes is provided. The operational zones corresponding to evaluated parameters where risk of floatation exists are defined as a function of substrate concentration in the bulk liquid and the radius of the granule. Moreover, the possible control of biomass floatation by changing the operating temperature was analyzed. Defined operational zones and profiles fit data reported in literature for granular biomass floatation events. From the study the most influencing parameter on floatation occurrence has been identified as the substrate concentration in the bulk media.