Chlorphenamine Adsorption on Commercial Activated Carbons: Effect of Operating Conditions and Surface Chemistry

Abstract

Abstract Chlorphenamine (CPA) adsorption onto three activated carbons (ACs), namely, Megapol M (MM), Micro 10 (M10), and GAMA B (GB), was studied in this work. The textural properties, concentrations of active sites, surface charge and point of zero charge of the ACs were assessed. The surface areas (SBET) of MM, GB and M10 were 1107, 812 and 766 m2/g, respectively. The MM surface character was acidic, whereas the surfaces of M10 and GB presented a basic character. The adsorption capacity of MM, M10, and GB towards CPA was studied at pH 7 and 11, and the adsorption capacity decreased in the order MM > M10 ≈ GB, and this trend was ascribed to the magnitude of SBET and the concentration of acidic sites. The solution pH significantly increased the CPA adsorption capacity of MM by raising the solution pH from 5 to 9, and this behavior was attributed to the electrostatic attraction between the negatively charged surface of MM and the cationic species of CPA. The maximum uptake of CPA adsorbed on MM was 574.6 mg/g at pH = 11 and T = 25°C. The adsorption capacity of MM was slightly raised by incrementing the temperature. Lastly, the zeta potential measurements of pristine MM and MM saturated with CPA confirmed that the electrostatic attraction predominated in the pH range of 5–9, and the π-π stacking interactions were the principal mechanism of CPA adsorption on MM at pH 11.