Modelling of activated sludge acclimisation to a non-ionic surfactant

• Published in: Water science and technology Vol. 43; no. 7; pp. 9 - 17
• Main Authors: CARVALHO, G, NOPENS, I, NOVAIS, J. M, VANROLLEGHEM, P. A, PINHEIRO, H. M
• Format: Conference Proceeding Journal Article
• Language: English
• Published: Oxford Pergamon Press 01.01.2001; IWA Publishing
• Subjects: Acclimatization; Activated sludge; Applied sciences; Bacteria - growth & development; Batch reactors; Biodegradability; Biodegradation; Biodegradation, Environmental; Biological and medical sciences; Biological treatment of waters; Biomass; Bioreactors; Biotechnology; Carbon sources; Computer simulation; Degradation; Environment and pollution; Exact sciences and technology; Food sources; Fundamental and applied biological sciences. Psychology; General purification processes; Growth; Industrial applications and implications. Economical aspects; Kinetics; Metabolites; Microorganisms; Modelling; Models, Biological; Oxygen Consumption; Parameter estimation; Pollution; Polyethylene Glycols; Ratios; Reaction kinetics; Sewage; Sludge; Surface-Active Agents; Surfactants; Waste Disposal, Fluid - methods; Wastewater; Wastewater treatment; Wastewaters; Water Pollutants, Chemical; Water treatment and pollution; Activated sludge; Parameter estimation; Non ionic surfactant; Respirometry; Waste water purification; Modeling; Biological purification
• ISBN: 1900222574; 9781900222570
• ISSN: 0273-1223; 1996-9732
• DOI: 10.2166/wst.2001.0377

A model is proposed to describe activated sludge acclimatisation to a non-ionic surfactant. The model was calibrated automatically, using WEST, a specific software environment for wastewater treatment model building, simulation and parameter estimation. The assays have been performed in a sequencing-batch reactor (SBR), using a non-ionic surfactant as sole carbon source and non-acclimatised sludge. The best fitting model was based on the assumption of three sequentially degraded COD fractions, where the second fraction is a metabolite of the original molecule and the third fraction is a more slowly biodegradable metabolite resulting from the secondary degradation. For primary degradation, hydrolysis with no associated growth was assumed. The growth of microorganisms responsible for degradation of the second and third COD fractions was presumed to follow Haldane and first order kinetics, respectively. The model was able to fit four consecutive assays of the same acclimatisation process, using Brij 30 as carbon source, with different food/microorganism ratios. The parameters obtained showed that the (self-)inhibition of the growth on the second COD fraction decreased along acclimatisation.