Novel phenylalanine-modified magnetic ferroferric oxide nanoparticles for ciprofloxacin removal from aqueous solution

The pollution of natural water bodies by pharmaceutical compounds has led to serious concerns regard-ing ecological and public health safety. In this study, novel recyclable phenylalanine (Phe)-modified mag-netic ferroferric oxide nanoparticles (Fe3O4@Phe NPs) were successfully synthesized for the first time using a simple one-pot method to remove ciprofloxacin (CIP) from aqueous solutions. Fe3O4 and Fe3O4@Phe NPs were characterized using different techniques, such as scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared (FTIR), X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET), Turbiscan analysis and vibrating-sample magnetometry (VSM). The results show that Fe3O4 NPs are fully encapsulated by Phe, exhibiting an average diameter of 200 nm, a high specific surface area (35.79 m2 g-1), good dispersion and superparamagnetic properties. The effects of Phe content, initial pH and ionic strength on CIP adsorption onto Fe3O4 and Fe3O4@Phe NPs are investigated. The maximal adsorption capacity of CIP onto Fe3O4@Phe NPs is determined to be 49.27 mg g-1. The adsorption kinetics and isotherms show that the adsorption process follows the pseudo-second-order-kinetic and Langmuir isotherm models, respectively. This indicates that the adsorption involves a rate-controlled monolayer chemisorption process. The regeneration experiments show that Fe3O4 and Fe3O4@Phe NPs exhibit good reusability for CIP adsorption. Adsorption mechanisms include electrostatic interactions, hydrogen bonding, hydrophobicity and 7C -7C interactions. This study presents a promising strategy for the design and preparation of multifunctional nanoparticles to remove contaminants from the environment. & COPY; 2022 Elsevier Inc. All rights reserved.