abstract
Fly ash, a residue produced from pine gasification, was used as precursor of carbon-based materials assayed in acetaminophen adsorption. Materials prepared by activation with K2CO3, presented high porosity development (A(BET) approximate to 1200 m(2) g(-1)) and samples calcined at 900 degrees C presented high volumes of large micropores and mesopores. Kinetic and equilibrium acetaminophen adsorption data showed that the process obeys to the pseudo-second order kinetic equation and Langmuir model, respectively. The rate of acetaminophen adsorption depends of the presence of larger micropores. For the lab-made samples monolayer adsorption capacities attained values similar to those of commercial carbons. The influence of the micropore size distribution of the carbons in the acetaminophen adsorption process justified the lower adsorption affinities of the lab-made carbons. The importance of pores of a specific dimension (0.7 nm) to enhance the affinity of the molecule towards the carbon surface was demonstrated. The increase of temperature lead to higher monolayer adsorption capacities, most likely due to the easier accessibility of the acetaminophen species to the narrowest micropores. (C) 2013 Elsevier B.V. All rights reserved.
keywords
ACTIVATED CARBONS; PHYSICAL ACTIVATION; SURFACE-CHEMISTRY; AQUEOUS-SOLUTIONS; FLY-ASH; IBUPROFEN; REMOVAL; WASTE; SORPTION; GASES
subject category
Engineering
authors
Galhetas, M; Mestre, AS; Pinto, ML; Gulyurtlu, I; Lopes, H; Carvalho, AP
our authors
Moisés Luzia Pinto
Research AssistantGroups
acknowledgements
The authors thank Norit (Salmon & Cia) and Quimitejo for the commercial activated carbons supplied, NS and VP respectively. Margarida Galhetas and Ana S. Mestre thank FCT for a Ph.D. grant (SFRH/BD/69909/2010) and a Post-Doc grant (SFRH/BPD/86693/2012), respectively. FCT is also acknowledged for the pluriannual funding of CQB (Project PEst-OE/QUI/UI0612/2013).