A review on the degradation of organic pollutants in waters by UV photoelectro-Fenton and solar photoelectro-Fenton

摘要

This paper presents a review on emerging electrochemical advanced oxidation processes (EAOPs) such as UV photoelectro-Fenton (PEF) and solar photoelectro-Fenton (SPEF) in which the irradiation of the effluent with UV light and sunlight, respectively, causes a synergistic effect on the degradation process of organic pollutants by the formation of more ?OH and/or the photolysis of complexes of Fe(III) with generated carboxylic acids. Fundamentals of these EAOPs are explained to clarify their performance in the removal of industrial chemicals, pesticides, dyes and pharmaceuticals. Examples with bench-scaled stirred tank reactors equipped with Pt or boron-doped diamond (BDD) anodes and gas-diffusion, carbon-felt or activated carbon fiber cathodes are discussed. Treatments with a recirculation pre-pilot plant coupled to a solar photoreactor are also examined. A combined method involving PEF and photocatalysis is described. The influence of experimental parameters on the mineralization rate, mineralization current efficiency and energy cost of the PEF and SPEF methods is detailed. The decay kinetics of contaminants and the evolution of their intermediates and final inorganic ions are discussed. The SPEF process resulted more efficient and less expensive than other EAOPs like anodic oxidation with electrogenerated H2O2, electro-Fenton and PEF.