Li Yao, Meng Xiangyu, Pang Yin, Zhao Cong, Peng Daoping, Wei Yu, Xiang Bayongzhong
Faculty of Geosciences and Environmental Engineering, Southwest Jiaotong University, Chengdu 610031, People's Republic of China.
State Key Laboratory of Materials Processing and Die and Mould Technology, School of Materials Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, People's Republic of China.
R Soc Open Sci. 2022 Nov 30;9(11):220466. doi: 10.1098/rsos.220466. eCollection 2022 Nov.
In this study, red mud (RM) was used as a support for LaFeO to prepare LaFeO-RM via the ultrasonic-assisted sol-gel method for the removal of methylene blue (MB) assisted with bisulfite (BS) in the aqueous solution. Characterization by scanning electron microscopy and the Brunauer-Emmett-Teller method indicated that LaFeO-RM exhibited a large surface area and porous structure with a higher pore volume (i.e. 10 times) compared with the bulk LaFeO. The XRD, XPS and FTIR results revealed that the support of porous RM not only dispersed LaFeO particles but also increased Fe oxidation capability, oxygen-containing functional groups and chemically adsorbed oxygen (from 44.3% to 90.3%) of LaFeO-RM, which improved the catalytic performance in structure and chemical composition. MB was removed through the synergistic effect of adsorption and catalysis, with MB molecules first absorbed on the surface and then degraded. The removal efficiency was 88.19% in the LaFeO-RM/BS system under neutral conditions but only 27.09% in the LaFeO/BS system. The pseudo-first-order kinetic constant of LaFeO-RM was six times higher than that of LaFeO. Fe(III) in LaFeO-RM played a key role in the activation of BS to produce by the redox cycle of Fe(III)/Fe(II). Dissolved oxygen was an essential factor for the generation of . This work provides both a new approach for using porous industrial waste to improve the catalytic performance of LaFeO and guidance for resource utilization of RM in wastewater treatment.
在本研究中，赤泥（RM）被用作LaFeO的载体，通过超声辅助溶胶-凝胶法制备LaFeO-RM，用于在亚硫酸氢盐（BS）辅助下去除水溶液中的亚甲基蓝（MB）。扫描电子显微镜和布鲁诺尔-埃米特-泰勒方法表征表明，与块状LaFeO相比，LaFeO-RM具有较大的表面积和多孔结构，孔体积更高（即10倍）。XRD、XPS和FTIR结果表明，多孔RM载体不仅分散了LaFeO颗粒，还提高了LaFeO-RM的铁氧化能力、含氧官能团和化学吸附氧（从44.3%提高到90.3%），从而在结构和化学成分上改善了催化性能。MB通过吸附和催化的协同作用被去除，MB分子首先吸附在表面，然后被降解。在中性条件下，LaFeO-RM/BS体系中的去除效率为88.19%，而在LaFeO/BS体系中仅为27.09%。LaFeO-RM的准一级动力学常数比LaFeO高六倍。LaFeO-RM中的Fe(III)在通过Fe(III)/Fe(II)的氧化还原循环激活BS以产生 方面起关键作用。溶解氧是产生 的重要因素。这项工作既为利用多孔工业废料提高LaFeO的催化性能提供了新方法，也为赤泥在废水处理中的资源利用提供了指导。
