TY - JOUR
T1 - Chromium adsorption into a macroporous resin based on vinylpyridine–divinylbenzene copolymers
T2 - thermodynamics, kinetics, and process dynamic in a fixed bed column
AU - Arcos-Casarrubias, José Antonio
AU - Cruz-Díaz, Martín R.
AU - Cardoso-Martínez, Judith
AU - Vázquez-Arenas, Jorge
AU - Caballero-Domínguez, Francisco Vidal
N1 - Publisher Copyright:
© 2017, Springer Science+Business Media, LLC, part of Springer Nature.
PY - 2018/1/1
Y1 - 2018/1/1
N2 - The synthesis of the poly(4-vinylpyridine-co-ethylvinylbenzene) resin is investigated and its performance to remove Cr(VI) from aqueous solutions is evaluated as a function of pH using batch and fixed bed column adsorptions. The rate of Cr(VI) removal is observed to increase as the pH solution shifts to acidic conditions due to an enhanced protonation of the 4-vinylpyridine group in the polymer, which favors its electrostatic attraction with Cr(VI) oxyanions. This finding is supported with Density Functional Theory (DFT) calculations, revealing that the interaction between CrO42- (predominant species at pH < 6) and protonated 4VP is more favorable than a bond formed with HCrO4- species (pH > 6) due to a higher charge delocalization arising in the O atoms. Experimental isotherms are approximated with the Langmuir and Radke-Prausnitz adsorption models. This former approach generates the best fitting to the data, whereby it was incorporated into a nonlinear transient model to account for the Cr(VI) adsorption in a fixed bed, and evaluating its capacity to predict experimental adsorption data. The model enables to infer that the resin presents a fast kinetic for Cr(VI) sorption, and the Cr(VI) intra-particle diffusion across the adsorbent pores is the rate-determining step for sorption.
AB - The synthesis of the poly(4-vinylpyridine-co-ethylvinylbenzene) resin is investigated and its performance to remove Cr(VI) from aqueous solutions is evaluated as a function of pH using batch and fixed bed column adsorptions. The rate of Cr(VI) removal is observed to increase as the pH solution shifts to acidic conditions due to an enhanced protonation of the 4-vinylpyridine group in the polymer, which favors its electrostatic attraction with Cr(VI) oxyanions. This finding is supported with Density Functional Theory (DFT) calculations, revealing that the interaction between CrO42- (predominant species at pH < 6) and protonated 4VP is more favorable than a bond formed with HCrO4- species (pH > 6) due to a higher charge delocalization arising in the O atoms. Experimental isotherms are approximated with the Langmuir and Radke-Prausnitz adsorption models. This former approach generates the best fitting to the data, whereby it was incorporated into a nonlinear transient model to account for the Cr(VI) adsorption in a fixed bed, and evaluating its capacity to predict experimental adsorption data. The model enables to infer that the resin presents a fast kinetic for Cr(VI) sorption, and the Cr(VI) intra-particle diffusion across the adsorbent pores is the rate-determining step for sorption.
KW - Chromium adsorption
KW - Density functional theory
KW - Fixed bed column
KW - Mathematical modelling
KW - Vinylpyridine–divinylbenzene copolymer
UR - http://www.scopus.com/inward/record.url?scp=85035747481&partnerID=8YFLogxK
U2 - 10.1007/s10450-017-9925-y
DO - 10.1007/s10450-017-9925-y
M3 - Artículo
AN - SCOPUS:85035747481
SN - 0929-5607
VL - 24
SP - 105
EP - 120
JO - Adsorption
JF - Adsorption
IS - 1
ER -