Single and mixture adsorption of clofibric acid, tetracycline and paracetamol onto Activated carbon developed from cotton cloth residue

Abstract

Abstract The aim of this work is to investigate the feasibility of the preparation of adsorbent materials from waste textiles (cotton) for the removal of pharmaceutical products such as clofibric acid (AC), tetracycline (TC) and paracetamol (PC). Our results showed that the adsorbents prepared by chemical activation in the presence of phosphoric acid and pyrolysis at 600 °C lead to microporous materials with high surface areas. The adsorbents exhibit acid and basic groups at their porous surface and the acid character overrides the basic character. Kinetic data for AC and PC adsorption are found to follow a pseudo-second order kinetic equation with the exception of adsorption of TC which is well described by the pseudo-first-order model. The equilibrium data for the adsorption of pharmaceuticals compounds onto Activated Carbon Cloths (ACCs) were analyzed by testing different models. Additionally, the Langmuir model provided a good description of the experimental isotherms for PC and TC, whereas AC isotherm rather follows the Freundlich model. On the basis of the Langmuir analysis, the maximum adsorption capacities were determined to be 109, 105 mg g−1 for TC and PC, respectively. The activated carbon cloth also showed high efficiency for the removal of a mixture of 3 pharmaceuticals, except for AC. This study highlights that activated carbon prepared from the cotton cloths waste using phosphoric acid at 50% (ACC 50%) is a promising adsorbent because of its relatively high efficiency and potential of reuse.