Polyaniline-coated magnetic nanoparticles to enhance removal of diclofenac from aqueous media

Abstract

This study presents a straightforward and cost-effective synthesis method for producing magnetic nanoparticles coated with polyaniline. These nanoparticles are utilized for the efficient removal of diclofenac from aqueous solutions. The synthesized material underwent thorough characterization through various techniques. Additionally, the adsorbent's properties were investigated, and adsorption experiments were conducted to explore the effects of pH, contact time, and diclofenac concentration. The most favorable outcomes were achieved at pH 4, using 25 mg of adsorbent, and with a stirring time of 10 min. Under these optimized conditions, the material exhibited a diclofenac removal efficiency of approximately 90 %. The adsorption process was comprehensively studied employing the pseudo-second-order kinetic model and the isothermal Langmuir-Freundlich dual-site model. Furthermore, the adsorbent displayed exceptional regenerative capabilities, allowing for multiple reuse cycles without a noticeable decline in efficiency. Theoretical investigations suggested that the interaction between diclofenac and the polyaniline surface predominantly involves the nucleophilic groups of diclofenac (-CO, -OH, and -NH) as well as the electrophilic group of polyaniline (-NH-). Overall, these findings underscore the high potential of this adsorbent material for effectively extracting diclofenac from water sources.