Influence of preoxidizing treatments on the preparation of iron-containing activated carbons for catalytic wet peroxide oxidation of phenol

摘要

Iron species were heterogeneously supported over activated carbons (AC) after different oxidizing pre-treatments. The influence of the oxidizing method on the iron yield and the physicochemical properties of the iron-containing activated carbons (Fe/AC) were studied. Thereafter, the activity and stability of Fe/AC catalysts for the wet peroxide oxidation of phenol as model pollutant was evaluated. Results: The pre-oxidizing treatment with HNO _3 was the most appropriate for iron incorporation, providing a Fe/AC catalyst with the highest TOC removal and oxidant efficiency. A high stability of the catalysts was observed with low values of iron leaching (below 1.5% of their initial iron contents). The best Fe/AC catalyst was studied at different reaction temperatures and initial phenol concentrations. Conclusion: The promising results for the Fe/AC catalyst using HNO _3 pre-oxidizing treatment lay in the remarkable adsorption capacity of the carbon matrix and the potential activity of the iron species as Fenton-like catalyst for the generation of oxidizing hydroxyl radicals.