Mono and binary component adsorption of phenol and cadmium using adsorbent derived from peanut shells

Abstract

This study analyses the removal of phenol and cadmium ion (Cd2+) using activated carbon obtained from peanut shells. No previous studies have reported the use of this adsorbent material on the binary removal of these contaminants. The results obtained after carrying out the characterisation indicated that the carbonaceous material was mesoporous, predominantly amorphous, with the presence of surface hydroxyl, carboxyl and carbonyl groups. The kinetic evolution was rapid for the first few minutes and equilibrium was attained within 180 min. It was observed that the best model to fit the experimental data was the pseudo-second-order model. With regard to the monocomponent equilibrium data, the Langmuir-Freundlich model had the best adjustment, obtaining maximum adsorption capacity of 21.00 ± 2.11 mg g−1 and 55.43 ± 6.82 mg g−1 of phenol and Cd2+, respectively. The binary component, meanwhile, behaved in a constant manner between the adsorption quantity and the adsorbate and adjusted well to the experimental data with the modified Langmuir model. According to these results, the activated carbon analysed was considered a good adsorbent for the removal of phenol and Cd2+, as it is derived from a renewable residue, thus contributing to more environmentally friendly processes.