Assessment of Rhus Pentaphylla-sulfuric acid activated carbon performance for cadmium ions adsorption: mechanism, response surface methodology optimisation, and cost estimation
Mohssine Ghazoui, Otmane Boudouch, Youssef Miyah, Mohammed Benjellοun, Aboubacar Sidigh Sylla, Kawtar Moulakhnif, Kawtar Fikri-Benbrahim, Ibrahim Touzani, Reda Elkacmi
Abstract
This research aims to optimise the kinetics, isotherms, and thermodynamics of a new adsorbent derived from Rhus Pentaphylla grains to efficiently remove Cd(II) from aqueous solutions. The synthesis of the activated carbon was conducted under specific parameters, including the impregnation time, impregnation ratio, and activation temperature. The Rhus Pentaphylla grains were characterised using TG/DTG, while the optimal activated carbon was characterised using SEM, BET, XRD, FTIR, and pHpzc. Adsorption capacity tests revealed a high potential for Cd(II) removal, and the Langmuir isotherm model accurately described the experimental data. The pseudo-second-order kinetic model exhibited high applicability, indicating that the adsorbent has significant potential as a wastewater treatment material. Thermodynamic studies revealed that the removal process of cadmium ions was endothermic. The adsorbent demonstrated an iodine adsorption capacity ranging from 483.18–992.18 mg g−1. Additionally, it exhibited an effective removal efficiency for Cd (II) over 85%. The low cost of the adsorption onto Rhus Pentaphylla-H2SO4 activated carbon (Rp-H2SO4-AC), approximately $0.9984 L−1, demonstrates its high effectiveness for heavy metals removal on an industrial scale.