title: Start-up of an anaerobic fluidized bed reactor treating synthetic carbohydrate rich wastewater.
abstract: The present work studied the start-up process of a mesophilic (37 ± 2 °C) anaerobic fluidized bed reactor (AFBR) operated at a hydraulic retention time (HRT) of 20 days using synthetic carbohydrate rich wastewater. Anox Kaldness-K1 carriers were used as biofilm carrier material. The reactor performance and biofilm formation were evaluated during the process. The start-up process at lower liquid recirculation flow rate enhanced the biofilm formation and reactor performance. The organic substrate composition had a major impact on early colonization of methanogenic archaea onto the surface of the Kaldness carriers during the start-up process. Specific organic substrates favouring the growth of methanogenic archaea, such as acetate, are preferred in order to facilitate the subsequent biofilm formation and AFBR start-up. The supply of 'bio-available' nutrients and trace elements, in particular iron, had an important role on optimal methanogenic activity and speeding-up of the biofilm development on the Kaldness carriers. This paper provides possible strategies to optimize the various operational parameters that influence the initial biofilm formation and development in an AFBR and similar high rate anaerobic reactors, hence can be used to reduce the long time required for process start-up.
authors.affiliation: Department of Civil and Mechanical Engineering, University of Cassino and Southern Lazio, via Di Biasio 43, 03043 Cassino, FR, Italy; Department of Civil, Architectural and Environmental Engineering, University of Naples Federico II, via Claudio 21, 80125 Naples, Italy.
authors.forename: Martha M
authors.initials: MM
authors.lastname: Yeshanew
authors.affiliation: Department of Mathematics and Applications Renato Caccioppoli, University of Naples Federico II, via Cintia, Monte S. Angelo, I-80126 Naples, Italy. Electronic address: luigi.frunzo@unina.it.
authors.forename: Luigi
authors.initials: L
authors.lastname: Frunzo
authors.affiliation: Department of Civil, Architectural and Environmental Engineering, University of Naples Federico II, via Claudio 21, 80125 Naples, Italy.
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Luongo
authors.affiliation: Department of Civil, Architectural and Environmental Engineering, University of Naples Federico II, via Claudio 21, 80125 Naples, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Pirozzi
authors.affiliation: UNESCO-IHE Institute for Water Education, Westvest 7, 2611 AX Delft, The Netherlands.
authors.forename: Piet N L
authors.initials: PNL
authors.lastname: Lens
authors.affiliation: Department of Civil and Mechanical Engineering, University of Cassino and Southern Lazio, via Di Biasio 43, 03043 Cassino, FR, Italy.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Esposito
mesh_terms: D000641:Ammonia / Q000378:metabolism; D000693:Anaerobiosis; D001105:Archaea; D018441:Biofilms / Q000254:growth & development; D056804:Biofuels; D057919:Biological Oxygen Demand Analysis; D019149:Bioreactors / Q000382:microbiology; D002241:Carbohydrates / Q000032:analysis; D004867:Equipment Design; D005232:Fatty Acids, Volatile / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D008697:Methane / Q000378:metabolism; D059013:Microbial Consortia; D014865:Waste Disposal, Fluid / Q000295:instrumentation* / Q000379:methods*; D062065:Wastewater / Q000737:chemistry*
chemical_list: D000641:Ammonia; D056804:Biofuels; D002241:Carbohydrates; D005232:Fatty Acids, Volatile; D008697:Methane; D062065:Wastewater
keywords: Anaerobic fluidized bed reactor; Liquid recirculation; Methane yield; Start-up; Substrate type; Trace metals