title: Proliferation of glycogen accumulating organisms induced by Fe(III) dosing in a domestic wastewater treatment plant.
abstract: To meet the effluent requirements given for the sensitive receiving body, the Southpest Wastewater Treatment Plant of Budapest, Hungary uses a combined activated sludge-biofilter system with chemical precipitation for P removal. Causes of the proliferation of glycogen accumulating organisms (GAOs) observed in the unaerated/oxic activated sludge unit of this system were investigated both in full-scale and in lab-scale experiments combined with a detailed analysis of the microbial communities. Concentration profile measurements throughout the 8-stage activated sludge unit indicated anaerobic conditions in the first two unaerated reactors and low orthophosphate level (< 1 mg l(-1)) in all of the stages that could not be attributed to the influent quality, but to Fe (III)-dosing to the returned activated sludge. Microbiological analysis revealed the presence of GAOs from the GB group in the Gammaproteobacteria and occasionally tetrad-forming organisms from Actinobacteria, and the absence of Rhodocyclus-related polyphosphate accumulating organisms (PAOs) in the activated sludge samples. Comparative lab-scale studies carried out in two identically arranged UCT-systems with staged anoxic reactors also confirmed that Fe (III)-dosing may result in phosphorus deficiency of the microbial niche, leading to the suppression of growth and EBPR activity of PAOs and to the proliferation of GAOs.
authors.affiliation: Department of Agricultural Chemical Technology, Budapest University of Technology and Economics, Szt. Gellért tér 4., H-111 Budapest, Hungary.
authors.forename: A
authors.initials: A
authors.lastname: Jobbágy
authors.forename: B
authors.initials: B
authors.lastname: Literáthy
authors.forename: M T
authors.initials: MT
authors.lastname: Wong
authors.forename: G
authors.initials: G
authors.lastname: Tardy
authors.forename: W T
authors.initials: WT
authors.lastname: Liu
mesh_terms: D001483:Base Sequence; D017931:DNA Primers; D052918:Environmental Restoration and Remediation; D005290:Ferric Compounds / Q000378:metabolism*; D006003:Glycogen / Q000378:metabolism*; D017404:In Situ Hybridization, Fluorescence; D007220:Industrial Waste; D014871:Water Microbiology; D014874:Water Pollutants, Chemical / Q000302:isolation & purification / Q000378:metabolism*
chemical_list: D017931:DNA Primers; D005290:Ferric Compounds; D007220:Industrial Waste; D014874:Water Pollutants, Chemical; D006003:Glycogen