Adsorption profiles of rhodamine B and reactive orange 16 onto pharmaceutical-based activated charcoals

Abstract

The present study was aimed to characterize the adsorptive properties of pharmaceutical-based activated charcoals (Biocarbon and Dyna) for the adsorption of reactive orange 16 (RO16) and rhodamine B (Rh B). A commercial activated (CAC) was employed for comparison. The materials were characterized for textural properties and functional groups. Batch adsorption was evaluated at different concentrations of dyes and contact times. The adsorption data were analyzed using isotherm and kinetics models. Result shows that the specific surface area is in the order of CAC > Biocarbon > Dyna. The surface area of CAC is 909 m2/g, renders a higher removal of RO16 of 69.4 mg/g, while Biocarbon displays a higher removal of Rh B of 54.5 mg/g, despite a lower surface area of 172 m2/g. The adsorption data fitted well with Langmuir model and pseudo-kinetics models. The adsorption mechanisms of pharmaceutical-based activated charcoals are unique and may not necessarily dependent on surface area alone. The charcoals demonstrate a promising attribute as dyes adsorbent for wastewater treatment.