Comparison of Acid Red 114 Dye Adsorption by Fe3O4 and Fe3O4 Impregnated Rice Husk Ash

Abstract

The removal of Acid Red 114 (AR114) dye by adsorption process, using the magnetic nanoparticle (RHA-MNP) which is produced from rice husk ash burned at 300 degrees C and the magnetic nanoparticle (MNP, Fe3O4), was studied. Batch processes were used under different test parameters: pH (2, 4, 6, and 10) and without pH, initial dye concentration (20, 40, 60, 80, and 100 mg/L), and contact time (0, 1, 5, 10, 15, 30, 45, 60, 90, and 150 min). Optimum conditions for AR114 removal were found to be at natural pH (pH without correction) for both adsorbents. Freundlich isotherm was found to be more consistent for MNP and Langmuir isotherm was found to be more consistent for RHA-MNP. The maximum adsorption capacities of MNP and RHA-MNP adsorbents for AR114 dye were equal to 111 mg/g. The kinetic experimental data fitted the pseudo-second-order model for both MNP and RHA-MNP. It can be concluded that RHA-MNP which is a waste could be used as low-cost adsorbent to remove AR114 from aqueous solution.