Department of Civil and Environmental Engineering, University of South Carolina, Columbia, 300 Main Street, SC, 29208, USA.
Nanosystems Engineering Research Center for Nanotechnology-Enabled Water Treatment, School of Sustainable Engineering and the Built Environment, Arizona State University, Tempe, AZ, 85287, USA.
Chemosphere. 2020 Sep;254:126827. doi: 10.1016/j.chemosphere.2020.126827. Epub 2020 Apr 25.
Herein, ultrasonication (US)-assisted novel nanomaterial TiCT MXene was utilized as a selective adsorbent for treatment of synthetic dyes in model wastewater. Two types of US frequencies, 28 and 580 kHz, were applied to disperse MXene to evaluate the feasibility of US-assisted MXene for wastewater treatment. The physico-chemical properties of MXene after US were characterized by Fourier-transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), and zeta potential. According to FTIR and XPS, 28 kHz US-assisted MXene had a greater amount of oxygenated functional groups and dispersion compared to 580 kHz US-assisted and pristine MXene. Subsequently, US-assisted MXene was utilized as an adsorbent for the removal of positively charged methylene blue (MB) and negatively charged methyl orange. Both 28 and 580 kHz US-assisted MXene showed better adsorption performance for only MB compared to stirring-assisted MXene based on kinetics, isotherms, and several water chemistry factors including solution pH, temperature, ionic strength, and humic acid. Advantages of US-assisted MXene for water treatment are its fast kinetics at low dose and high selectivity for positively charged target compounds (i.e., MB). The main adsorption mechanism between MXene and MB was electrostatic interaction (attraction); however, physical properties (i.e., aggregation kinetics and hydrodynamic diameter), measured via dynamic light scattering, were also found to be critical factors in controlling the adsorption performance of the system. Lastly, US-assisted MXene exhibited a high regeneration property, based on 4th adsorption-desorption cycles.
在此，超声（US）辅助新型纳米材料 TiCT MXene 被用作模型废水中处理合成染料的选择性吸附剂。应用两种 US 频率，28 和 580 kHz，来分散 MXene，以评估 US 辅助 MXene 处理废水的可行性。超声后的 MXene 的物理化学性质通过傅里叶变换红外光谱（FTIR）、X 射线光电子能谱（XPS）和 ζ 电位进行表征。根据 FTIR 和 XPS，与 580 kHz US 辅助和原始 MXene 相比，28 kHz US 辅助 MXene 具有更多的含氧官能团和分散性。随后，将 US 辅助 MXene 用作吸附剂，用于去除带正电荷的亚甲基蓝（MB）和带负电荷的甲基橙。与搅拌辅助 MXene 相比，28 和 580 kHz US 辅助 MXene 仅对 MB 表现出更好的吸附性能，这基于动力学、等温线以及包括溶液 pH 值、温度、离子强度和腐殖酸在内的几种水化学因素。US 辅助 MXene 用于水处理的优势在于其在低剂量下的快速动力学和对带正电荷的目标化合物（即 MB）的高选择性。MXene 和 MB 之间的主要吸附机制是静电相互作用（吸引力）；然而，通过动态光散射测量的物理性质（即聚集动力学和水动力直径）也被发现是控制体系吸附性能的关键因素。最后，基于第 4 次吸附-解吸循环，US 辅助 MXene 表现出高的再生性能。
