Waste control by waste: Fenton-like oxidation of phenol over Cu modified ZSM-5 from coal gangue

Coal gangue and phenol are two main pollutants in coal mining and processing. Using coal gangue as raw material, a series of Cu modified ZSM-5 (Cu/ZSM-5) catalysts were developed to remove phenol through heterogeneous Fenton-like reaction. This procedure implies the concept of waste control by waste. The characterization results showed that Cumodification had no obvious impact on theMFI (Mobile Five) structure of ZSM-5. Copper ions were presented as doping element (substitution of Na and Al ions) and copper oxides on ZSM-5 surface. The XPS spectra suggested the co-existence of Cu2+ and Cu+. As a consequence ofwell-defined experimental parameters, 7% Cu/ZSM-5 performed excellent activity and stability for the degradation and mineralization of phenol pollutant, which could degrade phenol completely within 30 min and the TOC removal efficiency could reach 63% within 60 min and 92% within 8 h. ESR and radicals capturing experiments demonstrated that center dot OH and O-1(2) played the dominant roles in the Fenton-like reaction. In combination with XPS, ESR and catalytic tests, it's found that the redox cycling of Cu+/Cu2+ played critical roles in accelerating the active radical generation in this Fenton-like system. (C) 2019 Elsevier B.V. All rights reserved.