清华大学朱万诚团队报道了旋转水热法合成赤泥衍生的均匀分级多孔花状勃姆石（γ-AlOOH）微球——阴离子染料去除形成机理和优异吸附性能的驱动力分析。相关研究成果于2024年8月18日发表在《颗粒学报》。

针对铝工业释放的工业固体废赤泥（RM）在全球范围内日益严重的污染，在适当的尿素存在下，成功分离出有价元素Al，用于均匀分级多孔花状勃姆石（γ-AlOOH）微球的新型温和旋转水热合成（150°C，12 h，5 Hz），该微球具有明显较小的平均直径（1.52μm）和较窄的粒径分布（PSD:1.12-1.97μm），以及高比表面积（129.37 m² g^-1）。一方面，旋转水热合成促进了传质和传热，使γ-AlOOH微球在较低的温度下在较短的时间内实现。

另一方面，适度的旋转提供了主要的剪切力，使γ-AlOOH微球均匀，平均直径小，PSD窄。最佳AlOOH-U2M-R5Hz微球对刚果红（CR）和甲基蓝（MB）的吸附性能令人满意，最大吸附容量分别为602.4和1208.7 mg g^-1。利用Langmuir、Freundlich、Temkin和Dubinin-Radushkevich的各种等温线模型，分析了吸附动力学，揭示了基于氢键和静电吸引的吸附机理。

温度的升高或共存阳离子的存在促进了CR的吸附，而共存阴离子削弱了CR在AlOOH-U2M-R5Hz微球上的吸附。此外，AlOOH-U2M-R5Hz微球具有优异的恢复性能，特别是动态吸附（在1000分钟内保持约99.0%的去除效率）以及真实水体（如自来水和河水）模拟废水处理，这无疑表明，AlOOH-U2-R5Hz微球在清洁铝生产和经济高效的含阴离子染料废水可持续解决方案方面，具有巨大的实际应用价值。

附：英文原文

Title: Rotating hydrothermal route to red mud derived uniform hierarchical porous flowerlike boehmite (γ-AlOOH) microspheres: Force analysis on formation mechanism and superior adsorption performances for anionic dyes removal

Author: Heng Zhang, Wancheng Zhu

Issue&Volume: 2024/08/18

Abstract: Towards increasingly severe worldwide pollution of industrial solid waste red mud (RM) released from aluminum industry, constitutional valuable element Al has been successfully separated for a novel mild rotating hydrothermal synthesis (150 °C, 12 h, 5 Hz) of the uniform hierarchical porous flowerlike boehmite (γ-AlOOH) microspheres in the presence of appropriate urea, which exhibit distinctly small average diameter (1.52 μm) and narrow particle size distribution (PSD: 1.12-1.97 μm), as well as high specific surface area (129.37 m2 g-1). On the one hand, the rotating hydrothermal synthesis promotes the mass and heat transfer, enabling γ-AlOOH microspheres at a lower temperature within a shorter time. On the other hand, moderate rotation provides predominant shear force, rendering the uniform γ-AlOOH microspheres with small average diameter and narrow PSD. The optimal AlOOH-U2M-R5Hz microspheres demonstrate satisfactory adsorption performance for Congo Red (CR) and Methyl Blue (MB), with the maximum adsorption capacities of 602.4 and 1208.7 mg g-1, respectively. Various isotherm models of Langmuir, Freundlich, Temkin and Dubinin-Radushkevich are utilized, adsorption kinetics are analyzed, adsorption mechanism is uncovered based on hydrogen bonding and electrostatic attraction. The increase in the temperature or the presence of coexisting cations facilitates the adsorption of CR, whereas coexisting anions weaken the adsorption of CR on the AlOOH-U2M-R5Hz microspheres. Furthermore, the excellent recycling performances and especially dynamic adsorption (retainment of removal efficiency of approx. 99.0% within 1000 min) as well as authentic water bodies (e.g. tap water and river water) simulated wastewater treatment undoubtedly indicate great practical applications of the AlOOH-U2M-R5Hz microspheres, towards cleaner aluminum production and cost-effective sustainable solution to anionic dye-bearing wastewater.

DOI: 10.1016/j.partic.2024.08.006

Source: https://www.sciencedirect.com/science/article/abs/pii/S1674200124001615