Petrochemical Wastewater Treatment by Photo-Fenton Process

In recent decades, the rise in the generation of extremely toxic and refractory wastewaters, as petroleum refinery plant effluents, is demanding increasingly efficient treatment technologies, among which photo-Fenton advanced oxidation processes are highlighted due to their rapid and effective petroleum-derived pollutant degradation. However, these systems are costly for their application at industrial scale, especially due to the associated electric energy and reagent costs. Several strategies have been adapted for overcoming these limitations, including the use of ferricarboxylate complexes or heterogeneous iron catalysts, the automated dosing of the oxidant, and even the combination of different AOPs, such as photo-electro-Fenton or sono-photo-Fenton hybrid methods. Nonetheless, the reduction of energy costs is not successfully accomplished. In this sense, further studies are required for minimizing operational costs by taking profit of solar light and coupling photo-Fenton-derived processes to biological treatments so industries can afford to implement these degradation systems and thus meet environmental legislation.