Efficient degradation of fulvic acids in water by catalytic ozonation with CeO2/AC

BACKGROUND: Fulvic acids (FA), the main organic compounds in landfill leachate, are toxic and bio-resistant organic compounds. Ozonation is effective in removing non-biodegradable components and the addition of catalysts can improve the removal rates. The objective of this study is to prepare and improve CeO2/AC catalyst for catalytic ozonation of FA. RESULTS: The cerium precursor, calcination atmosphere and calcination temperature changed the percentage of Ce3+ on the surface, thus affecting the catalytic performance of CeO2/AC catalyst. A linear relationship was established between the correcting apparent rate constant of FA degradation (k(app)/S-BET) and the percentage of Ce3+ on the surface. The CeO2/AC with 5% of Ce loading and calcined under hydrogen atmosphere at 450 degrees C showed the highest catalytic activity, allowing a FA removal efficiency of 83%. The FA removal efficiency and ozone utilization efficiency were enhanced in O-3/CeO2/AC compared with ozonation alone. CONCLUSION: Ce3+ on the CeO2/AC surface is the active site for ozonation, indicating a feasible way to improve the catalytic performance of CeO2/AC. The O-3/CeO2/AC process may be applied as a promising treatment method for landfill leachate. (C) 2013 Society of Chemical Industry