Synthesis of New Cyclodextrin-Based Adsorbents to Remove Direct Red 83:1
Author/s
Pellicer, José Antonio; Fortea Gorbe, María Isabel; Auñón Calles, David; Gabaldón, José Antonio; Rodríguez López, María Isabel; [et al.]Date
2020Discipline/s
Ingeniería, Industria y ConstrucciónSubject/s
CyclodextrinsAdsorption
Polymerization
Wastewater treatment
Pulsed light
Abstract
Two cyclodextrins (CDs), γ– and hydroxypropyl (HP)–γ–CDs were used to synthesize
new adsorbents by using epichlorohydrin (EPI) as cross-linking agent in order to remove Direct Red
83:1 (DR) from water. Both polymers were characterized in terms of Fourier spectroscopy, nuclear
magnetic resonance, particle size distribution and thermogravimetric analysis. Experimental data
for both polymers were well fitted to the pseudo-second order and intraparticle diffusion model,
indicating that in the adsorption both chemical and physical interactions are essential in the removal of
DR. Three different isotherm models were analyzed, concluding that γ–CDs–EPI followed the Temkin
isotherm and HP–γ–CDs-EPI the Freundlich isotherm, these results suggested that the adsorption
was happening onto heterogeneous surfaces. The results of the Gibbs free energy showed that the
adsorption was spontaneous at room temperature. In order to eliminate the remaining dye after the
polymer treatment, and adva...