Manganese oxide integrated catalytic ceramic membrane for degradation of organic pollutants using sulfate radicals

WATER RESEARCH

卷:167

Article

Wu, Hong¹  Xu, Xinyuan¹  Shi, Lei¹  Yin, Yu^1,2  Zhang, Lai-Chang¹  Wu, Zhentao³  Duan, Xiaoguang⁴  Wang, Shaobin⁴  Sun, Hongqi¹ 

[1] Edith Cowan Univ, Sch Engn, 270 Joondalup Dr, Joondalup, WA 6027, Australia

[2] Jiangsu Univ Sci & Technol, Sch Envirom & Chem Engn, Zhenjiang 212003, Jiangsu, Peoples R China

[3] Aston Univ, Sch Engn & Appl Sci, Aston Inst Mat Res, Birmingham B4 7ET, W Midlands, England

[4] Univ Adelaide, Sch Chem Engn, Adelaide, SA 5005, Australia

关键词: Manganese oxides;    Catalytic membrane;    Sulfate radicals;    4-Hydroxylbenzoic acid (HBA);    AOPs;   

DOI  :  10.1016/j.watres.2019.115110

来源: Elsevier

【 摘 要 】

Membrane separation and advanced oxidation processes (AOPs) have been respectively demonstrated to be effective for a variety of water and/or wastewater treatments. Innovative integration of membrane with catalytic oxidation is thus expected to be more competing for more versatile applications. In this study, ceramic membranes (CMs) integrated with manganese oxide (MnO2) were designed and fabricated via a simple one-step ball-milling method with a high temperature sintering. Functional membranes with different loadings of MnO2 (1.67%, 3.33% and 6.67% of the total membrane mass) were then fabricated. The micro-structures and compositions of the catalytic membranes were investigated by a number of advanced characterisations. It was found that the MnO2 nanocatalysts (10-20 nm) were distributed uniformly around the Al2O3 particles (500 nm) of the membrane basal material, and can provide a large amount of active sites for the peroxymonosulfate (PMS) activation which can be facilitated within the pores of the catalytic membrane. The catalytic degradation of 4-hydroxylbenzoic acid (HBA), which is induced by the sulfate radicals via PMS activation, was investigated in a cross-flow membrane unit. The degradation efficiency slightly increased with a higher MnO2 loading. Moreover, even with the lowest loading of MnO2 (1.67%), the effectiveness of HBA degradation was still prominent, shown by that a 98.9% HBA degradation was achieved at the permeated side within 30 min when the initial HBA concentration was 80 ppm. The stability and leaching tests revealed a good stability of the catalytic membrane even after the 6th run. Electron paramagnetic resonance (EPR) and quenching tests were used to investigate the mechanism of PMS activation and HBA degradation. Both sulfate radicals (SO4 center dot(-)) and hydroxyl radicals (center dot OH) were generated in the catalytic membrane process. Moreover, the contribution from non-radical process was also observed. This study provides a novel strategy for preparing a ceramic membrane with the function of catalytic degradation of organic pollutants, as well as outlining into future integration of separation and AOPs. (C) 2019 Elsevier Ltd. All rights reserved.

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