Process Intensification in the CWPO of Phenol Solutions

N. INCHAURRONDO; J. CECHINI; J. FONT; P. HAURE

Río de Janeiro

Congreso; VI Encontro sobre Aplicações Ambientais de Processos Oxidativos Avançados (EPOA); 2011

Heterogeneous catalysts based on low-valence transition metals appear as a promising alternative for CWPO of organics pollutants. In the last few years, a great variety of solid catalysts containing Fe, Cu or other transition metal precursors supported on different materials were tested for CWPO of phenol compounds (1). Copper has a similar role as iron in catalyzing hydrogen peroxide to produce hydroxyl radical, with the advantage that this reaction still retains a high efficiency at a higher pH range (2). However, catalyst deactivation by leaching of the active phase is a serious drawback. CWPO strongly depends on the concentration of hydroxyl radicals (•OH) produced through a redox process once the H2O2 is contacted with the catalyst. For a given H2O2 concentration and pH, the production of hydroxyl radicals mainly depends on catalyst concentration and reaction temperature. However, once the radicals are formed, they can efficiently react with the organics or they can undergo parasitic or scavenging reactions. Therefore, the efficient use of the •OH radicals is a challenge. In this study we investigate the performance of a commercial CuO/alumina catalyst in the CWPO of phenol solutions. Experiments were performed addressing the effect of catalyst concentration, temperature and hydrogen peroxide concentration and dosification strategies on phenol conversion and mineralization. Studies were conducted to achieve Process Intensification in terms of efficient use of reagents and/or reduced reaction times and catalyst stability.