Biosorption of anionic dyes from aqueous solutions using a novel magnetic nanocomposite adsorbent based on rice husk ash

This study investigated the potential use of an agricultural waste, rice husk ash, for the removal of methyl orange. The adsorbent was prepared via a simple one-pot synthesis of magnetic iron oxide nanoparticles (MIONs). The prepared magnetic nanocomposites were characterized using Fourier transform infrared, scanning electron microscopy, transmission electron microscopy, X-ray diffraction, and vibrating sample magnetometer techniques. Bach adsorption experiments were carried out to evaluate the effects of initial dye concentration, pH and contact time as well as MION content on adsorption capacity. The mechanism of dye adsorption was well fitted to a pseudo-second-order kinetic model. Moreover, the equilibrium data fitted well with the Langmuir isotherm model.