Highly stable Fe/γ‐Al 2 O 3 catalyst for catalytic wet peroxide oxidation

BACKGROUND: A highly stable Fe/γ‐Al 2 O 3 catalyst for catalytic wet peroxide oxidation has been studied using phenol as target pollutant. The catalyst was prepared by incipient wetness impregnation of γ‐Al 2 O 3 with an aqueous solution of Fe(NO 3 ) 3 · 9H 2 O. The influence of pH, temperature, catalyst and H 2 O 2 doses, as well as the initial phenol concentration has been analyzed. RESULTS: The reaction temperature and initial pH significantly affect both phenol conversion and total organic carbon removal. Working at 50 °C, an initial pH of 3, 100 mg L −1 of phenol, a dose of H 2 O 2 corresponding to the stoichiometric amount and 1250 mg L −1 of catalyst, complete phenol conversion and a total organic carbon removal efficiency close to 80% were achieved. When the initial phenol concentration was increased to 1500 mg L −1 , a decreased efficiency in total organic carbon removal was observed with increased leaching of iron that can be related to a higher concentration of oxalic acid, as by‐product from catalytic wet peroxide oxidation of phenol. CONCLUSION: A laboratory synthesized γ‐Al 2 O 3 supported Fe has shown potential application in catalytic wet peroxide oxidation of phenolic wastewaters. The catalyst showed remarkable stability in long‐term continuous experiments with limited Fe leaching, < 3% of the initial loading. Copyright © 2010 Society of Chemical Industry