Efficient application of Jordanian glass sand for the adsorptive removal of methylene blue from aqueous media

Abstract

Silicates are the pure source of silica sand or glass sand found in vast amounts in south Jordan. It is worth studying the ability of silica glass sand (SGS) powder prepared from natural silica sand to act as an adsorbent to remove methylene blue (MB) dye from polluted water. The SGS material was systematically analyzed by various spectroscopic techniques. The various experimental factors such as dosage, MB concentration, pH, contact time, and temperature, were evaluated. Adsorption isotherms and kinetics data were studied by the pseudo-first-order, pseudo-second-order, and intraparticle diffusion models. The thermodynamic parameters, ΔG°, ΔH°, and ΔS° were computed and found to be, 0.438 kJ/mol, –3.20 kJ/mol, and –8.613 J/mol·K, respectively. The results indicated that the maximum removal of MB dye was found at low pH values. The collected isotherm data were best fitted by the Langmuir isotherm, and the maximum adsorption capacity of dye onto SGS was 3.28 mg/g. The thermodynamic results demonstrated that the adsorption of the MB occurs spontaneously as an exothermic process. The results confirmed the effectiveness of the prepared low-cost silica sand (SGS) as an adsorbent with excellent recyclability for the remediation of water contaminated by MB dye generated from industry.