An amino-functionalized magnetic mesoporous silica nano-adsorbent for removing antibiotics from aqueous environments

This study developed a novel amino-functionalized magnetic mesoporous silica nano-adsorbent (Fe3O4@mSiO2/ NH2) employing a hydrothermal technique coupled with an encapsulation approach to address antibiotics pollution caused by ciprofloxacin (CIP), norfloxacin (NOR), and doxycycline hydrochloride (DOX). The nano- adsorbent exhibited homogeneous spherical morphology with an average diameter of 200 nm, specific surface area of 308.93 m2 center dot g-1, total pore volume of 0.179 cm3 center dot g-1, and magnetic saturation intensity of 2.24 x 107A center dot m- 1. Adsorption experiments revealed that Fe3O4@mSiO2/NH2 could efficiently eliminate CIP, NOR, and DOX. Notably, the removal efficiency for NOR increased with temperature, whereas that of CIP and DOX presented the opposite trend. The maximum adsorption capacities reached 142.96, 190.03, and 138.92 mg center dot g- 1 for CIP, NOR, and DOX, respectively. The adsorption dynamics, predominantly governed by chemical interactions, achieved equilibrium within 300 min, optimally described by the pseudo-second-order kinetic model. CIP adsorption aligned with the Freundlich model, while NOR and DOX were closer to the Langmuir model. Additionally, Fe3O4@mSiO2/NH2 demonstrated remarkable stability and reusability, maintaining the removal efficiency of antibiotics above 80 % after five consecutive cycles. These findings highlight the potential of Fe3O4@mSiO2/NH2 as an effective, stable, and reusable nano-cleaning material for removing antibiotic pollutants, with significant implications for water purification and environment remediation.