Kinetic Modeling of the Electro-Fenton Process: Quantification of Reactive Oxygen Species Generation

In this study, Electro-Fenton (E-Fenton) reactions at pH 3.0 were initiated by cathodic generation of H2O2, with subsequent production of (OH)-O-center dot following the addition of Fe(II) or Fe(III) ions into the system. The variation in concentrations of H2O2, Fe(II), total Fe and (OH)-O-center dot following addition of Fe ions into the E-Fenton system was investigated over a range of conditions. A kinetic model incorporating the key processes operating in the E-Fenton system was developed with particular attention given to (i) cathodic generation of H2O2 and anodic formation of (OH)-O-center dot, (ii) production of (OH)-O-center dot via homogeneous Fenton reactions, and (ii) surface reactions including electro-sorption of Fe ions and cathodic reduction of Fe(III) to Fe(II) species resulting in the enhancement of production of (OH)-O-center dot via surface-located Fenton reactions. (C) 2015 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY license.