title: Rapid adaptation of activated sludge bacteria into a glycogen accumulating biofilm enabling anaerobic BOD uptake.
abstract: Glycogen accumulating organisms (GAO) are known to allow anaerobic uptake of biological oxygen demand (BOD) in activated sludge wastewater treatment systems. In this study, we report a rapid transition of suspended activated sludge biomass to a GAO dominated biofilm by selective enrichment using sequences of anaerobic loading followed by aerobic exposure of the biofilm to air. The study showed that within eight weeks, a fully operational, GAO dominated biofilm had developed, enabling complete anaerobic BOD uptake at a rate of 256mg/L/h. The oxygen uptake by the biofilm directly from the atmosphere had been calculated to provide significant energy savings. This study suggests that wastewater treatment plant operators can convert activated sludge systems readily into a "passive aeration" biofilm that avoids costly oxygen transfer to bulk wastewater solution. The described energy efficient BOD removal system provides an opportunity to be coupled with novel nitrogen removal processes such as anammox.
authors.affiliation: School of Engineering and Information Technology, Murdoch University, 90 South Street, Murdoch 6150, Western Australia, Australia.
authors.forename: Md Iqbal
authors.initials: MI
authors.lastname: Hossain
authors.affiliation: School of Veterinary and Life Sciences, Murdoch University, 90 South Street, Murdoch 6150, Western Australia, Australia.
authors.forename: Andrea
authors.initials: A
authors.lastname: Paparini
authors.affiliation: School of Engineering and Information Technology, Murdoch University, 90 South Street, Murdoch 6150, Western Australia, Australia. Electronic address: R.Cord-Ruwisch@murdoch.edu.au.
authors.forename: Ralf
authors.initials: R
authors.lastname: Cord-Ruwisch
mesh_terms: D000222:Adaptation, Physiological; D000693:Anaerobiosis; D001419:Bacteria / Q000378:metabolism*; D018441:Biofilms; D057919:Biological Oxygen Demand Analysis; D018533:Biomass; D019149:Bioreactors / Q000382:microbiology*; D006003:Glycogen / Q000378:metabolism*; D059013:Microbial Consortia / Q000502:physiology; D009584:Nitrogen / Q000378:metabolism; D010100:Oxygen / Q000378:metabolism; D054813:Polyhydroxyalkanoates / Q000378:metabolism; D012722:Sewage / Q000382:microbiology*; D014865:Waste Disposal, Fluid / Q000295:instrumentation* / Q000379:methods
chemical_list: D054813:Polyhydroxyalkanoates; D012722:Sewage; D006003:Glycogen; D009584:Nitrogen; D010100:Oxygen
keywords: Activated sludge; Biofilm; Energy-efficient BOD removal; Glycogen accumulating organism (GAO); Wastewater