Green synthesized superparamagnetic iron oxide nanoparticles for water treatment with alternative recyclability

Widely used water treatment methods are based on chemicals that leave residual unwanted impurities, instigating long-term health impacts. Hence, functionalized magnetic nanoparticles (MNPs) have been used to fill those gabs and are commonly used for metallic adsorption in contaminated waters. High surface to volume ratio of those MNPs allows for a larger capacity of pollutant adsorption. In this study, functionalized iron oxide MNPs are synthesized by a novel green approach using plant phytochemicals with the capability of absorbing multiple organic pollutants. Herein, we studied synthesis of iron oxide MNPs with crude plant extracts using a simple maceration technique. The reaction was supported further by heat treatments at the supercritical condition of ethanol to complete the reduction process to superparamagnetic iron oxide nanoparticles. Our XRD result shows formation of spherical and cubic goethite (be-fore treatment-Y0PL), magnetite (after treatment-Y0PR) and magnetite (after treatment and functionalization-Y0PRP) with an average crystalline size 277, 29, 45 nm respectively. Phytochemicals increased the size and altered texture of nanoparticles. The magnetic properties were measured for magnetization dependence on external magnetic field to show superparamagnetic behavior with Ms = 44 (Hc = 123 Oe), 36 (Hc = 133 Oe) and 13 (Hc = 44 Oe) emu/g for Y0PR, Y0PRP and Y0PL, respectively. Absorption/reduction efficiency of nanoparticles was studied against MB (10-140 mg/L) and 4-NA (0.5-1 mM). As synthesized green nanoparticles absorbed the model dyes above 80% efficiency under a wide range of conditions in a very short time and 94% under optimum conditions. Moreover, this work introduces successful alternative recyclability in particular for weakly magnetic nanoparticles by growing them on the surface of polyvinyl alcohol solid support. Therefore, the green synthesized superparamagnetic iron oxide nanoparticles prepared in this study are easy to synthesize and cost-effective and enviro-friendly water treatment agents. (C)& nbsp;2022 Elsevier B.V. All rights reserved.