Phenol Degradation: Numerical Simulation in a Stirred Tank Electrochemical Reactor

In this work, phenol degradation of wastewater in a stirred tank chemical reactor was numerically simulated. The effect of the applied current density (I/A), changes in the concentration of dissolved O₂ and initial concentration of Fe²⁺ ions were studied. The operation conditions were 25°C, pH = 2.5, with 1000 mM phenol feed concentration at 1 atm of pressure. The results show that the phenol removal achieved was 78.97%, 84.2%, 97.0% and 99.8% for values of I/A of 0.3, 0.32, 0.37 and 0.4 mA cm^-2, respectively. For initial dissolved O₂ concentration values of 0.007, 0.01, 0.03, and 0.4 mM, degradation was achieved at 74.7%, 77.4%, 81.9% and 84.2%, respectively. Finally for values of initial Fe²⁺ ions concentration of 40, 9 and 2 mM, the phenol removal was achieved at 76.0%, 80.7% and 86.3%, respectively. After several simulations times, it was found [C_f]₀ = 1000 mM were the optimum operating conditions in which [O₂]₀ = 0.4 mM, [Fe²⁺]₀ = 2 mM and I/A = 0.4 mA cm^-2. With these values the phenol removal reached 99%, at dilution rate of 0.15 min^-1. A viable model for phenol degradations proposed.