Experimental study of the removal of copper ions using hydrogels of xanthan, 2-acrylamido-2-methyl-1-propane sulfonic acid, montmorillonite: Kinetic and equilibrium study

• Published in: Carbohydrate polymers 2016-05, Vol.142, p.124-132
• Main Authors: Aflaki Jalali, Marzieh, Dadvand Koohi, Ahmad, Sheykhan, Mehdi
• Format: Article
• Language: English
• Subjects: 2-Acrylamido-2-methyl-1-propane sulfonic acid; Acrylamides - chemistry; Adsorption; Alkanesulfonates - chemistry; Bentonite - chemistry; Cations, Divalent - isolation & purification; Composite; Copper - isolation & purification; Copper adsorption; Hydrogel; Hydrogels - chemistry; Kinetics; Polysaccharides, Bacterial - chemistry; Thermodynamics; Water - analysis; Water Pollutants, Chemical - isolation & purification; Water Purification - methods; Xanthan gum
• ISSN: 0144-8617; 1879-1344
• DOI: 10.1016/j.carbpol.2016.01.033

•The usage of XG polysaccharide and AMPS monomer as novel hydrogel composites.•Incorporation of MMT within the hydrogel matrix and effect of it on the adsorption.•Characterization of XG, XG-g-P(AMPS) and XG-g-P(AMPS)/MMT hydrogels.•Adsorption isotherm, adsorption kinetics and thermodynamic parameters were studied. In this paper, removal of copper ions from aqueous solution using novel xanthan gum (XG) hydrogel, xanthan gum-graft-2-acrylamido-2-methyl-1-propane sulfonic acid (XG-g-P(AMPS)) hydrogel and xanthan gum-graft-2-acrylamido-2-methyl-1-propane sulfonic acid/montmorillonite (XG-g-P(AMPS)/MMT) hydrogel composite were studied. The structure and morphologies of the xanthan-based hydrogels were characterized by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscope (SEM). Adsorbents comprised a porous crosslink structure with side chains that carried carboxyl, hydroxyl and sulfonate. Maximum adsorption was observed in the pH=5.2, initial concentrations of Cu2+=321.8mg/L, Temperature=45°C, contact time=5h with 0.2g/50mL of the hydrogels. Adsorption process was found to follow Langmuir isotherm model with maximum adsorption capacity of 24.57, 39.06 and 29.49mg/g for the XG, XG-g-P(AMPS) and XG-g-P(AMPS)/MMT, respectively. Adsorption kinetics data fitted well with pseudo second order model. The negative ΔG° values and the positive ΔS° confirmed that the adsorption was a spontaneous process. The positive ΔH° values suggested that the adsorption was endothermic in nature.