title: The role of residual quantities of suspended sludge on nitrogen removal efficiency in a deammonifying moving bed biofilm reactor.
abstract: In a moving bed biofilm reactor (MBBR) system, the vast majority of biomass is immobilized as biofilm besides small amounts of suspension. In this study, the influence of the individual biomass components of a deammonifying MBBR, the biofilm on carriers (BC), residual suspended biomass (SB) with a volatile suspended solids concentration of 0.09±0.03g/L, and its combination (BC+SB) on nitrogen removal efficiency was investigated. While the performance was highest for BC+SB (0.42kgN/(m(3)·d)), it was reduced by a factor of 3.5 for BC solely. SB itself was only capable of nitrite accumulation. This suggests a high abundance of AOBs within suspension besides the coexistence of AOBs and anammox bacteria in the biofilm, which could be supported by results using fluorescence in situ hybridization(FISH). Thus, small amounts of suspended microorganisms can positively influence the deammonification's efficiency. If this fraction is partially washed out, the system recovers nevertheless within hours.
authors: Chair of Urban Water Systems Engineering, Technical University of Munich, Am Coulombwall 3, 85748 Garching, Germany.
authors: Carmen
authors: C
authors: Leix
authors: Chair of Urban Water Systems Engineering, Technical University of Munich, Am Coulombwall 3, 85748 Garching, Germany.
authors: Jörg E
authors: JE
authors: Drewes
authors: Chair of Urban Water Systems Engineering, Technical University of Munich, Am Coulombwall 3, 85748 Garching, Germany. Electronic address: k.koch@tum.de.
authors: Konrad
authors: K
authors: Koch
mesh_terms: D001419:Bacteria; D018441:Biofilms; D018533:Biomass; D019149:Bioreactors / Q000382:microbiology*; D058440:Denitrification; D017404:In Situ Hybridization, Fluorescence; D009584:Nitrogen / Q000737:chemistry; D012722:Sewage / Q000382:microbiology*
chemical_list: D012722:Sewage; D009584:Nitrogen
keywords: Anammox; Deammonification; FISH; MBBR; Nitrogen removal efficiency