Co2+ ion adsorption behavior on plum stone carbon prepared by a solid-combustion process

Abstract

A B S T R A C TCo 2+ ion adsorption behavior on plum stone (Spondias purpurea) carbon (PSC) prepared by a solid-combustion process in batch mode was studied. The effects of various important adsorption parameters, such as the contact time, cobalt concentration, pH, and temperature were investigated. The as-prepared powders were characterized using X-ray diffraction, scanning electron microscopy, and N 2 physisorption measurements. Porous and amorphous PSC was obtained with a BET-surface area of 286.06 m 2 /g and a maximum Co 2+ ion adsorption capacity of 4.23 mg/g. The kinetic data, analyzed by non-linear regression, obeyed a pseudo-second-order model with intra-particle diffusion as one of the rate determining steps and showed that the equilibrium behavior can be well described by a Langmuir isotherm. The obtained thermodynamics parameters indicate that the adsorption process is endothermic, spontaneous, and has a chemical adsorption mechanism. The present study revealed that the PSC material can be used as an alternative to more costly adsorbents and that the outcome of this study may be helpful in the design of treatment plants for treatment of Co 2+ -rich effluents.