title: Improving phosphorus removal in aerobic granular sludge processes through selective microbial management.
abstract: This study aimed to improve phosphorus removal in aerobic granular sludge sequential batch reactors (AGS-SBR) by a differential selection of the granules containing the highest proportion of phosphate accumulating organisms (PAOs). The abundance of PAOs in granules with different density was analyzed by PCR-DGGE, pyrosequencing and qPCR. Dense granules contained a higher proportion of Candidatus Accumulibacter (PAO) with a 16S rRNA gene frequency up to 45%. Starting with an AGS-SBR with low height/diameter ratio performing unstable P removal, two strategies of biomass removal were assessed. First, a high selective pressure (short settling time) was applied and second, an increase of the settling time was combined with a homogeneous purge of the sludge bed. The first strategy resulted in a reduction of P removal efficiency while the second improved and stabilized P removal over 90%. This study offers a new approach of biomass management in AGS-SBR.
authors.affiliation: Laboratory of Food and Environmental Microbiology, Université catholique de Louvain, Louvain-la-Neuve, Belgium.
authors.forename: Olivier
authors.initials: O
authors.lastname: Henriet
authors.affiliation: CEBEDEAU, Research and Expertise Center for Water, Allée de la découverte, 11 (B53), Quartier Polytech 1, B-4000 Liège, Belgium.
authors.forename: Christophe
authors.initials: C
authors.lastname: Meunier
authors.affiliation: CEBEDEAU, Research and Expertise Center for Water, Allée de la découverte, 11 (B53), Quartier Polytech 1, B-4000 Liège, Belgium.
authors.forename: Paul
authors.initials: P
authors.lastname: Henry
authors.affiliation: Laboratory of Food and Environmental Microbiology, Université catholique de Louvain, Louvain-la-Neuve, Belgium. Electronic address: jacques.mahillon@uclouvain.be.
authors.forename: Jacques
authors.initials: J
authors.lastname: Mahillon
mesh_terms: D020562:Betaproteobacteria / Q000235:genetics; D018533:Biomass; D019149:Bioreactors / Q000382:microbiology*; D010758:Phosphorus / Q000737:chemistry / Q000302:isolation & purification; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012722:Sewage / Q000737:chemistry*
chemical_list: D012336:RNA, Ribosomal, 16S; D012722:Sewage; D010758:Phosphorus
keywords: Aerobic granular sludge; Bacterial diversity; High-throughput sequencing; Microbial management; Phosphorus removal; Wastewater treatment