Synergistic mechanisms for efficient and safe antibiotic removal: Effective adsorption and photocatalytic degradation using aerogels

Abstract

To tackle the issues of low adsorption capacity, poor regeneration efficiency, and limited recoverability in wastewater treatment adsorbents, we innovatively developed a low-cost Fe(III)-SA gel ball aerogel (FA) through a simple chemical crosslinking method. FA aerogel exhibits exceptional adsorption performance for a wide range of antibiotics, including norfloxacin (NOR), ciprofloxacin (CIP), and tetracycline hydrochloride (TC), showcasing its broad applicability. Remarkably, FA achieved a maximum NOR adsorption capacity of 338.4 mg/g (Langmuir isotherm model, pH 7.0, 298 K, m/V=0.1 g/L). Furthermore, under the synergistic effect of photocatalysis, FA demonstrated a breakthrough by removing 97 % of NOR (30 mg/L, 50 mL) within just 150 min. Notably, FA displayed innovative regeneration capabilities, successfully completing 10 continuous and stable NOR removal cycles without loss of performance. The DFT calculations alongside experimental evidence were employed to elucidate the NOR degradation pathway, while electron density distribution and Fukui function analysis confirming the proposed degradation pathways through HPLC-MS results. Moreover, plant stress and zone of inhibition tests verified that the degradation intermediates were significantly less toxic, ensuring the safety of the regeneration process. This research introduces an innovative approach for designing superior adsorbents and provides critical insights into efficient and sustainable adsorbent regeneration.