title: Microbiology of enhanced biological phosphorus removal in aerated-anoxic Orbal processes.
abstract: The traditional process for enhanced biological phosphorus removal (EBPR) in wastewater treatment involves an anaerobic zone followed by an aerobic zone. Although there is no strict anaerobic zone in aerated-anoxic Orbal processes, phosphorus removal in excess of that required for cell growth does occur. The microbial ecology of polyphosphate-accumulating organisms (PAO) in two full-scale Orbal wastewater treatment plants was investigated using flow cytometry to physically separate PAO from non-PAO and fluorescent in situ hybridization (FISH) to identify organisms. Although Candidatus Accumulibacter phosphatis, an uncultured organism associated with EBPR in acetate-fed laboratory-scale reactors, was detected, it did not seem to be the dominant PAO in these processes. Comparative FISH analyses of the activated sludge and the PAO-rich subpopulation did not reveal the presence of a dominant group of PAO in these full-scale plants. Rather, the analysis suggested that the operational characteristics of aerated-anoxic processes might select for a diverse PAO community that is significantly different from that observed in acetate-fed laboratory reactors or in traditional EBPR configurations.
authors.affiliation: Department of Civil and Environmental Engineering, Unviersity of Wisconsin-Madison, 53706, USA.
authors.forename: Julie L
authors.initials: JL
authors.lastname: Zilles
authors.forename: Jordan
authors.initials: J
authors.lastname: Peccia
authors.forename: Daniel R
authors.initials: DR
authors.lastname: Noguera
mesh_terms: D001421:Bacteria, Anaerobic / Q000235:genetics / Q000502:physiology*; D019149:Bioreactors; D005434:Flow Cytometry; D017404:In Situ Hybridization, Fluorescence; D010758:Phosphorus / Q000302:isolation & purification*; D014865:Waste Disposal, Fluid / Q000379:methods*
chemical_list: D010758:Phosphorus