title: Uncertainty and variability in enhanced biological phosphorus removal (EBPR) stoichiometry: consequences for process modelling and optimization.
abstract: The overall potential for enhanced biological phosphorus removal (EBPR) in the activated sludge process is constrained by the availability of volatile fatty acids (VFAs). The efficiency with which polyphosphate accumulating organisms (PAOs) use these VFAs for P-removal, however, is determined by the stoichiometric ratios governing their anaerobic and aerobic metabolism. While changes in anaerobic stoichiometry due to environmental conditions do affect EBPR performance to a certain degree, model-based analyses indicate that variability in aerobic stoichiometry has the greatest impact. Long-term deterioration in EBPR performance in an experimental SBR system undergoing P-limitation can be predicted as the consequence of competition between PAOs and GAOs. However, the observed rapid decrease in P-release after the change in feed composition is not consistent with a gradual shift in population.
authors.affiliation: EnviroSim Associates, Flamborough, ON L9H 7H9, Canada. dwight@envirosim.com
authors.forename: Dwight
authors.initials: D
authors.lastname: Houweling
authors.forename: Yves
authors.initials: Y
authors.lastname: Comeau
authors.forename: Imre
authors.initials: I
authors.lastname: Takács
authors.forename: Peter
authors.initials: P
authors.lastname: Dold
mesh_terms: D000693:Anaerobiosis; D005232:Fatty Acids, Volatile / Q000378:metabolism; D006003:Glycogen / Q000378:metabolism; D008962:Models, Theoretical; D010758:Phosphorus / Q000378:metabolism*; D035501:Uncertainty
chemical_list: D005232:Fatty Acids, Volatile; D010758:Phosphorus; D006003:Glycogen