Effective isolation of the residual anti-epidemic drugs from wastewater with an aluminum-based nano-flower adsorbent extracted from wasted aluminum polishing solution

Abstract

The present study aimed to prepare an aluminum-based nanoflower (Al-NF) adsorbent using wasted aluminum polishing solution as raw materials, which effectively isolated the residues of anti-epidemic related drugs (lopinavir (LPV) and ciprofloxacin (CIP)) from wastewater. A comprehensive characterization approach involving SEM, XRD, BET, TGA, FTIR, and XPS was employed to investigate the adsorption capacity and mechanism of Al-NF towards LPV and CIP. The results revealed that the adsorption process involved both homogeneous and non-homogeneous interactions between the LPV/CIP molecules and the Al-NF surface. According to the Langmuir model calculations, the maximum adsorption capacities of Al-NF for LPV and CIP at 293.15 K were determined to be 32.41 mg/g and 14.43 mg/g, respectively, while their adsorption kinetics followed a pseudo-second-order model more appropriately. Furthermore, the spontaneous exothermic nature of LPV/CIP adsorption on Al-NF was confirmed by thermodynamic analysis. The mechanism investigations indicated that hydrogen bonding, electrostatic interaction, π-π bonding interaction, as well as n-π EDA bonding collectively contributed to the overall adsorption process on the Al-NF surface for both LPV and CIP species. Additionally, the reusability demonstrated by Al-NF highlights its potential as a promising low-cost material for removing anti-epidemic related drug residues from wastewater utilizing industrial hazardous wastes.