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.

采用简便易行的一步法声化学合成策略，制备了铝改性橡木锯末吸附材料。相较于未施加超声辅助的传统合成工艺，超声辅助可将合成反应时间缩短至原时长的1/5。分别采用扫描电子显微镜（SEM）、能量色散X射线光谱（EDX）、傅里叶变换红外光谱（FT-IR）及X射线衍射（XRD），对有无超声辅助合成的吸附剂的表面形貌、元素组成、表面官能团及晶体结构进行了表征。采用时间依赖性批量吸附实验方案，评估了吸附剂从水介质中去除六价铬（Cr(VI)）离子的吸附性能。吸附机制最符合朗缪尔等温吸附模型，且遵循准二级动力学规律。超声辅助制备的吸附剂对Cr(VI)离子的最大吸附容量可达104.2 mg/g。所制备的材料已成功应用于实际废水样品的Cr(VI)离子去除实验。