title: Biodegradation of persistent organics can overcome adsorption-desorption hysteresis in biological activated carbon systems.
abstract: In Biological Activated Carbon (BAC) systems, persistent organic pollutants can be removed through a combination of adsorption, desorption and biodegradation. These processes might be affected by the presence of other organics, especially by the more abundant easily-biodegradable organics, like acetate. In this research these relations are quantified for the removal of the persistent pharmaceutical metoprolol. Acetate did not affect the adsorption and desorption of metoprolol, but it did greatly enhance the metoprolol biodegradation. At least part of the BAC biomass growing on acetate was also able to metabolise metoprolol, although metoprolol was only converted after the acetate was depleted. The presence of easily-degradable organics like acetate in the feeding water is therefore beneficial for the removal of metoprolol in BAC systems. The isotherms obtained from metoprolol adsorption and desorption experiments showed that BAC systems are subject to hysteresis; for AC bioregeneration to take place the microbial biomass has to reduce the concentration at the AC-biomass interface 2.7 times compared to the concentration at which the carbon was being loaded. However, given the threshold concentration of the MET degrading microorganisms (<0.08 μg/L) versus the average influent concentration (1.3 μg/L), bioregeneration is feasible.
authors: Kaunas University of Technology, Chemical Faculty of Technology, Department of Environmental Technologies, Radvilenu St. 19, LT-50254 Kaunas, Lithuania; Wetsus, European Centre of Excellence for Sustainable Water Technology, Oostergoweg 9, P.O. Box 1113, 8900 CC Leeuwarden, The Netherlands. Electronic address: vytautas.abromaitis@ktu.lt.
authors: V
authors: V
authors: Abromaitis
authors: Kaunas University of Technology, Chemical Faculty of Technology, Department of Environmental Technologies, Radvilenu St. 19, LT-50254 Kaunas, Lithuania.
authors: V
authors: V
authors: Racys
authors: WLN, Rijksstraatweg 85, 9756 AD Glimmen, The Netherlands.
authors: P
authors: P
authors: van der Marel
authors: Wetsus, European Centre of Excellence for Sustainable Water Technology, Oostergoweg 9, P.O. Box 1113, 8900 CC Leeuwarden, The Netherlands.
authors: R J W
authors: RJ
authors: Meulepas
mesh_terms: D000327:Adsorption; D001673:Biodegradation, Environmental; D018533:Biomass; D019149:Bioreactors; D002244:Carbon; D002606:Charcoal / Q000378:metabolism; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000378:metabolism*
chemical_list: D014874:Water Pollutants, Chemical; D002606:Charcoal; D002244:Carbon
keywords: Biological activated carbon; Bioregeneration; Bisolute adsorption and desorption; Hysteresis; Metoprolol; Persistent pharmaceuticals