Performance of electrochemical oxidation and photocatalysis in terms of kinetics and energy consumption. New insights into the p-cresol degradation

Abstract

This work reports the comparative performance of two Advanced Oxidation Processes (AOPs), electrochemical oxidation and photocatalysis, as individual technological alternatives for the treatment of effluents containing p-cresol. First, the influence of operating parameters in the oxidation and mineralization yield was carried out together with kinetic analysis. Boron Doped Diamond (BDD), RuO₂ and Pt as anodic materials, Na₂SO₄ and NaCl as supporting electrolytes and different current densities were evaluated in electrochemical oxidation whereas the effect of TiO₂ concentration and radiation was studied in the photocatalytic degradation. Then, the parameter Electrical Energy per Order (E_EO) was calculated to compare the energy consumption in both AOPs, concluding that under the studied conditions the electrochemical treatment with BDD, Na₂SO₄ and 125 A m^-2 showed the best energy efficiency, with an E_EO of 5.83 kW h m^-3 order^-1 for p-cresol and 58.05 kW h m^-3 order^-1 for DOC removal, respectively.

Keywords: Electrical Energy per Order (E(EO)); Electrochemical oxidation; Energy consumption; Light Emitting Diodes (LED); Photocatalysis; p-Cresol.