Comparative Performance of Ten Electrodes in Electro-Fenton Process for Removal of Organic Pollutants from Water

Electrochemical advanced oxidation processes (EAOPs), based on the in situ generation of the powerful oxidant, hydroxyl radical ((OH)-O-.), have been developed for effective destruction of recalcitrant organic pollutants. Electrode materials used both as anode and cathode constitute one of the key parameters affecting the process efficiency. The electro-Fenton (EF) process is one of the most powerful EAOPs in water/wastewater treatment. Inversely to other EAOPs, in the EF process, (OH)-O-. can be generated both in the bulk solution (from reagents formed at the cathode) and on anode surface. Therefore, the role of anode/cathode couple is of great importance for this process. This study focuses on the comparative performance of ten electrodes (5 anodes, 5 cathodes) through more than fifty combinations during removal of the antibiotic p-aminosalicylic acid (p-ASA), taken as target pollutant. The following parameters were chosen for performance assessment: oxidative degradation kinetics, the time needed for complete destruction of p-ASA, mineralization rate, mineralization current efficiency and energy consumption. The results obtained highlight the following sequence for the performance of anodes: BDD > PbO2 > Ti4O7 > Pt approximate to DSA, and that of cathodes: carbon sponge >= carbon felt > graphite > stainless steel approximate to titanium.