Magnetic nickel ferrite nanoparticles for removal of dipyrone from aqueous solutions

Abstract

Magnetic nickel ferrite nanoparticles with a size of 20 ± 3 nm have been synthesized by a co-precipitation method at room temperature. Crystalline structured particles with ferromagnetic properties were obtained by calcination at 600 °C. These nanoparticles were characterized in order to determine the particle size distribution, morphology, surface charge and adsorption properties. Nickel ferrite nanoparticles were tested as potential adsorbent for removal of dipyrone from aqueous solution by evaluating adsorption kinetics and isotherms. The maximum adsorption capacities at 20 °C were 30.4 mg g-1 (pH 6) and 25.0 mg g-1 (pH 4). Additionally, analytical solution of the Langmuir adsorption kinetic equation was successfully applied. Desorption experiments were conducted at lab scale by using a flow through system aiming to study the release of dipyrone from the proposed material at different experimental conditions. A 55% of desorption for pre-sorbed DIP is achieved by performing several extraction cycles with an aqueous solution (pH 2.5) at 50 °C. Also, 43% desorption was obtained by adding 0.2 M phosphate, and 48% by adding 0.2 M sulfate. With the advantages of low cost and rapid processing, these magnetic nanoparticles could gain a promising application in the removal of pharmaceutical compound residues during treatment of water samples on a large scale.