Degradation ofMOandH2O2on Cu/γ-Al2O3pellets in a fixed bed reactor: Kinetics and transport characteristics

Pelletized Cu catalysts (Cu/gamma-Al2O3) with different diameters (d(p)= 1.1-4.2 mm) were prepared and examined kinetically for methyl orange (MO) degradation using a fixed bed reactor. A Cu/gamma-Al(2)O(3)catalyst (d(p)= 2.3 mm) exhibited high degradation activity (Conv.(MO) > 95%) and superior leaching resistance (Cu leaching <0.6 mg/L in 200 hr). Apparent kinetics showed that both MO degradation and H(2)O(2)decomposition were mainly controlled by internal mass transfer. A plug-flow reactor model with mass-transfer coefficients was developed, and a modified empirical correlation for external mass transfer (Sh = 1.5Re'Sc-1.10(0.42)) was proposed to accurately describe the species transport from/to the catalyst pellets in the low Reynolds number regime. The model was verified against conversions of pollutants degradation and H(2)O(2)decomposition separately in a fixed bed with relative errors <5% compared with experimental data; thus, it could be used as an effective tool for further design and optimization of reactor configuration and reaction conditions for the continuous catalytic wet peroxide oxidation process.