Cationic resin polymer A®IRC-50 as an effective adsorbent for the removal of Cr(III), Cu(II), and Ag(I) from aqueous solutions: A kinetic, mathematical, thermodynamic and modeling study

Abstract

Adsorption has emerged as a reliable and cost-effective method for the depollution of wastewater containing multivalent heavy metals. However, there is still a need to optimize the process to achieve better efficacy. Consequently, This study focuses on the adsorption of three different metal ions, namely Cr (III), Cu (II), and Ag (I), using a cationic resin polymer called A®IRC-50 as the organic adsorbent. The high adsorption capacity of this polymeric material was investigated concerning various physicochemical parameters, including the dose of the cationic adsorbent, contact time, initial pH of the metallic solution, concentration of multivalent metals, and temperature (from 25 °C to 55 °C). The characterization of the adsorbent was performed using GTA/GTD, SEM spectroscopy, and EDX analysis. The kinetics of the adsorption phenomenally were evaluated exploited pseudo-1st-order and pseudo-2sec-order models. The maximum amount of adsorption of the different metals studied are estimated at 171.33 mg.g−1 of the Cu(II), 90.16 mg.g−1 of the Cr(III) and 87.55 mg.g−1 of the Ag(I) at m = 0.1 g. The adsorption mechanism was determined by employing isothermal adsorption models such as Langmuir, Freundlich, and Temkin. The experimental results present demonstrated that the adsorption kinetics of the metals on the cationic polymer A®IRC-50 resin followed the pseudo-second-order model(100 mg.g−1 of Cr(III), 166.67 mg.g−1 of Cu(II) and 100 mg.g−1 of Ag(I)). The adsorption isotherms of the multivalent metal cations by the cationic polymeric A®IRC-50 resin were well-described by the Freundlich model, and the maximum capacities of the adsorption process were determined using the Freundlich isothermal model equation. The adsorption of multivalent heavy metals on the artificial polymer was found to be spontaneous and endothermic. The obtained ΔH values (46.85 Kj.mol−1, 31.61 Kj.mol−1 and 35.50 Kj.mol−1 of the various metals Cr(III), Cu(II) and Ag(I) respectively), suggest that the interactions between the cationic polymer A®IRC-50 resin and the multivalent heavy metals are primarily physical. Finally, various thermodynamic technics between three metals study indicate as well ΔG° (−0.83 at −5.64 kJ. mol−1) that the adsorption is impetuous and endothermic.