Modified xanthan gum for crystal violet uptake: kinetic, isotherm, and thermodynamic behaviors

Abstract

Modified xanthan gum (XG-AM-TTE) was employed as an adsorbent to study the adsorption behavior, thermodynamics and kinetics of crystal violet (CV) from an aqueous solution. Fourier transform infrared spectroscopy analysis indicates that the functional groups present in the adsorbent, such as carboxyl, ester and hydroxyl groups, are included on the external surface of the material, and these groups are potential active sites for interaction with CV. According to X-ray diffraction results, the structure of XG-AM-TTE after CV adsorption became more disordered, and the microstructure change is an indication of effective adsorption of CV to the surface, with CV becoming remarkably dispersed in the adsorbent according to the scanning electron microscopy observations. The adsorption kinetics and adsorption equilibrium were best described by the pseudo-second-order model and Freundlich isotherms, respectively. The thermodynamic parameters, as the Gibbs-free energy (ΔG), enthalpy (ΔH) and entropy (ΔS), indicated that the adsorption is a spontaneous, endothermic and entropy increase process. The maximum adsorption capacity of XG-AM-TTE was 183 ± 12 mg/g, suggesting that XG-AM-TTE is an efficient adsorbent.

Xanthan Gum Hydrogels as High-Capacity Adsorbents for Dye Removal

“…d -mannose is O -acetylated by pyruvic acid linked at positions 4 and 6, whereas the d -mannose linked to the backbone is O -acetylated by acetate groups at position 6. ,, Copious amounts of Xanthan gum are used in food industries as thickeners because of its high viscosity at low concentration also used in cosmetics and tooth paste industries among others. ,,, In recent years, Xanthan gum has been extensively modified to serve as a dye sorbent by many researchers. For example, acrylamide was grafted to Xanthan gum and incorporated with silica nanoparticles to capture dyes. , Other researchers grafted acrylamide to Xanthan gum and cross-linked with trimethylolpropane triglycidyl ether and used it as an adsorbent to capture the Crystal Violet dye . In another study, acrylic acid was grafted to Xanthan gum to adsorb the Rhodamine dye .…”

“…16,25 Other researchers grafted acrylamide to Xanthan gum and cross-linked with trimethylolpropane triglycidyl ether and used it as an adsorbent to capture the Crystal Violet dye. 26 In another study, acrylic acid was grafted to Xanthan gum to adsorb the Rhodamine dye. 27 A sol−gel-derived Xanthan gum silica nanocomposite was used to capture cationic dyes.…”

Evaluation of Physicochemical and Amphiphilic Properties of New Xanthan Gum Hydrophobically Functionalized Derivatives

“…Several studies on the chemical modification of xanthan gum by various techniques and the grafting of different groups are described in the literature [11,[15][16][17][18]. The nature of the grafted groups differentiates the structural characteristics of the polysaccharides due to various physicochemical and biological properties [19].…”

Highly reactive adsorbent based on carboxymethyl xanthan gum‐g‐poly(4‐vinylpyridine) copolymer for the potential removal of Acid Orange 10 dye and Cr(VI) ions for water treatment

“…Other researchers grafted acrylamide onto xanthan gum, cross-linked with trimethylolpropane triglycidyl ether and used it as an adsorbent to capture the crystal violet dye. 50 Njuguna et al reported on the synthesis of xanthan gum-based hydrogels XG adsorbents via acrylation with maleic anhydride and thiol-ene cross-linking to remove the gentian violet. 43 Also, graft copolymers based on XG have been effectively used for the adsorption of heavy metals and organic dyes from aqueous solutions.…”

“…Ghorai et al 48,49 grafted acrylamide onto XG and incorporated the graft copolymer with silica nanoparticles to remove methylene blue, methyl violet and Congo red dyes from the aqueous solution. Other researchers grafted acrylamide onto xanthan gum, cross‐linked with trimethylolpropane triglycidyl ether and used it as an adsorbent to capture the crystal violet dye 50 . Njuguna et al reported on the synthesis of xanthan gum‐based hydrogels XG adsorbents via acrylation with maleic anhydride and thiol‐ene cross‐linking to remove the gentian violet 43 .…”