화학공학소재연구정보센터
Journal of Hazardous Materials, Vol.356, 53-60, 2018
Efficient removal of organic and bacterial pollutants by Ag-La(0.8)Ca(0.2)Fe(0.94)O(3-delta )perovskite via catalytic peroxymonosulfate activation
Removal of toxic organics and bacterial disinfection are important tasks in wastewater treatment. Most heavy metal-based catalysts for degradation of aqueous organic pollutants in heterogeneous Fenton-like processes suffer from the toxicity of leached metals. The present work reports environmentally benign systems for both degradation of organics and bacterial disinfection. Calcium substituted LaFeO3-delta perovskite was demonstrated as an efficient catalyst to activate peroxymonosulfate (PMS) for degradation of phenol, methylene blue and rhodamine 6 G. Compared to LaFeO3-delta and nanocrystal Fe3O4, the lattice oxygen vacancies in B-site cation-deficient perovskite of La0.8Ca0.2Fe0.94O3-delta (LaCaFeO3-delta) particles renders this material a greatly improved catalytic performance. Electron paramagnetic resonance (EPR) suggested that both sulfate (SO4 center dot-) and hydroxyl radicals (center dot OH) played critical roles in the advanced oxidation processes. Moreover, silver doped perovskite (Ag-LaCaFeO3-delta)/PMS successfully inhibited the growth of waterborne pathogen Escherichia colt and Methicillin-resistant Staphylococcus aureus (MRSA) at a lower dose than silver ions, proving a synergetic effect between free radicals and Ag+ in killing the bacteria. Therefore, Ag-LaCaFeO3-delta /PMS would be promising for practical wastewater treatment.