Ultrasonic-assisted synthesis of wood-aluminium-based sorbents: Comparison with conventional preparation and evaluation of chromium removal

An oak tree sawdust modified by aluminium was synthesized by a simple and facile one-stage sonochemical synthesis method. The synthesis reaction time decreases about 5 folds using ultrasonic energy compared to the conventional method without sonication. The obtained sorbents synthesized with and without sonication were characterized for their surface morphology, elemental composition, functionality, and crystallinity by SEM, EDX, FT-IR, and XRD, respectively. The performance of sorbents was evaluated using a time-dependent batch sorption protocol for the removal of Cr(VI) ions from aqueous media. The sorption mechanism was best described by the Langmuir isotherm followed pseudo-second-order kinetics. The maximal sorption capacity of sonicated sorbent for Cr(VI) ion removal was 104.2 mg/g. The obtained material was successfully applied to a real wastewater sample for the removal of Cr(VI) ions.