Pharmaceuticals and personal care products removal from aqueous solution by nitrogen-functionalized carbon adsorbent derived from pomelo peel waste

Abstract

The aim of this work is to investigate the feasibility of the preparation of nitrogen-functionalized adsorbent material from waste pomelo peel by using diammonium hydrogen orthophosphate (DAP) activation for the removal of Pharmaceuticals and personal care products (PPCPs) such as carbamazepine (CBZ), clofibric acid (CFA) and oxytetracycline (OTC). Our results showed that the adsorbent prepared by chemical activation in the presence of DAP lead to mesoporous material. The adsorbent exhibits acid and basic groups at its porous surface. The kinetic data are found to follow a pseudo-second order kinetic model. The Langmuir model provided a good description of the experimental isotherms for CBZ, whereas CFA and OTC adsorption behavior rather follow the Freundlich model. Moreover, the PPCPs adsorption was found to be strongly dependent on the pH of solution as well as the pKa of both adsorbents and PPCPs. The strong adsorptive interaction between PPCPs and P-DAP was mainly attributed to the combination interactions of electrostatic interaction, hydrogen bonding and π-π interactions.