Shape-controllable synthesis of MnO 2 nanostructures from manganese-contained wastewater for phenol degradation by activating peroxymonosulphate: performance and mechanism

• Published in: Environmental technology 2020-07, Vol.41 (16), p.2037-2048
• Main Authors: Xiao, Yaxiong, Wang, Yabo, Xie, Yi, Ni, Haixiang, Li, Xiang, Zhang, Yongkui, Xie, Tonghui
• Format: Article
• Language: English
• Subjects: Manganese; Manganese Compounds; Nanostructures; Oxides; Peroxides; Phenols; Waste Water
• ISSN: 0959-3330; 1479-487X
• DOI: 10.1080/09593330.2018.1554708

Nanostructured manganese oxide materials were prepared from manganese-contained wastewater (MW) using a facile hydrothermal method and adopted as a catalyst to degrade phenol via activation of peroxymonosulphate (PMS). In the WM environment, δ-MnO (flower-like Mn-2 with nanosheets) was transformed to α-MnO (needle-like Mn-4 with nanowires). Catalytic evaluation experiments demonstrated that the needle-like MnO was highly efficient for phenol removal, with a degradation efficiency of 100% within 15 min at the optimal conditions of catalyst dosage 0.2 g/L, PMS dosage 1.5 g/L, initial phenol concentration 0.025 g/L, initial pH 3 and temperature 25°C. Moreover, the needle-like MnO catalyst could be recycled and the regenerated material after calcination remained excellent catalytic activity. On the surface of catalysts, PMS was activated by Mn to generate [Formula: see text] which was the major reactive species attacking phenol. Overall, the needle-like MnO prepared from MW was an efficient catalyst with low cost for organic wastewater treatment, realizing both Mn resource recycle and organic wastewater treatment.