Comparison between Fenton oxidation process and electrochemical oxidation for PAH removal from an amphoteric surfactant solution

The decomposition of polycyclic aromatic hydrocarbons in a creosote oily solution and in synthetic solutions containing naphthalene and pyrene was investigated in the presence of an amphoteric surfactant using electrooxidation by comparison to Fenton oxidation process. Electrolysis was carried out using a parallelepipedic electrolytic 1.5-L cell containing five anodes (expanded titanium covered with ruthenium) and five cathodes (stainless steel) alternated in the electrode pack, whereas Fenton oxidation process was carried out in 500 mL Erlenmeyer glass-flasks in which H₂O₂ and Fe²⁺ were added. Using electrochemical oxidation, the sum concentration of 16 polycyclic aromatic hydrocarbons investigated could be optimally diminished by up to 80–82% by applying a current density of 9.23 mA cm⁻² and a pH of 4.0 or 7.0 for 90-min reaction period. By comparison, the best yield (46%) of Fenton oxidation process for polycyclic aromatic hydrocarbons degradation was recorded by using H₂O₂/Fe²⁺ molar ratio of 11.0 and a pH of 4.0.