Ultrasonically assisted adsorption of methyl orange dye using Aliquat-336 impregnated Amberlite XAD-4 in batch and recirculating flow vessel

Ultrasonically assisted adsorption of methyl orange (MO) dye from aqueous solution was performed using Amberlite XAD-4 resin wet-impregnated with Aliquat-336 (SIR) loaded in three different ratio (0.25/0.50/1 g per g of resin). To study the effect of different parameters like ultrasonication time (t(us): 0.5-10.5 min), adsorbent dosage (W: 0.05-0.25 g), (pH: 2-10) and concentration of MO dye in solution (C-dye(in): 5-65 mg/L), and their interaction on the dye removal efficiency, Central Composite Design of Response Surface Methodology was applied to obtain the optimized values of these parameters. At optimized condition (t(us) = 10.2 min, W=0.23 g, pH=9.5, and C-dye(in) = 35 mg/L), the percent removal of MO was found to be 97.14 +/- 0.5% which is very close to the predicted value (96.58%). Equilibrium and kinetic studies were also performed at optimized conditions. Freundlich and pseudo-second-order models best suited the experimental batch values. Time taken for the removal of dye by ultrasonication, water bath shaker, magnetic stirring and simple diffusion at optimized conditions were compared. The used resin was regenerated using 2 M HCl solution up to five cycles without any significant loss in the adsorption capacity of SIR. Finally, continuous study was performed in a recirculating flow vessel (RFV). Dye removal in RFV with ultrasonication saved 37.24% of energy and could process larger volume of dye containing water per unit of time effectively. (C) 2019 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.