Highly efficient anodic oxidation of organic pollutants using Ti4O7 particle anode: Experimental and theoretical study of the operational and structural parameters influence

A new specially designed electrolysis cell with particle anode of sub-stoichiometric titanium oxide (Ti4O7) was implemented for the anodic oxidation of organic pollutants (hydroquinone and oxalic acid) in aqueous solutions. The degradation kinetics of oxalic acid and hydroquinone under different operating conditions (thickness of anode layer, current density and flow rate) was studied. High process efficiency with low energy consumption was observed over a wide range of current densities and concentrations of organics, indicating the applicability of the particle Ti4O7 electrode as an affordable alternative for microporous electrodes. A 2D reactive transport mathematical model was developed to simulate the anodic oxidation of organics in porous electrodes. The electrochemical reaction of organic oxidation by direct electron transfer were considered as well as oxygen evolution reaction. Good agreement between the simulation results and experimental data was obtained. Using the developed model, the influence of current density, solution flow rate, electrode thickness, conductivity and specific surface area on the anodic oxidation process efficiency was evaluated. It is shown that the obtained results are applicable to predict the anodic oxidation process with more complex organic compounds, using the example of hydroquinone degradation.