Fenton and Photo-Fenton Oxidation of Petroleum Aromatic Hydrocarbons Using Nanoscale Zero-Valent Iron

This study investigated the feasibility of nanoscale zero-valent iron(nZVI) as the source of catalytic ferrous iron for Fenton and photo-Fenton oxidation of petroleum aromatic hydrocarbons. The oxidation processes were able to degrade more than 99% of benzene, toluene, ethylbenzene, and xylene (BTEX) within 15min at pH 3.0, which the initial concentrations of BTEX, nZVI, and were , 9mM, and , respectively. The average pseudo-first-order constants for BTEX degradation were 0.309 and at pH 3.0 for Fenton and photo-Fenton processes, respectively. Experiments revealed that by increasing pH, solubility of nZVI decreased significantly, while ultraviolet (UV) irradiation improved nZVI solubility and subsequently BTEX degradation. Cations and anions were found to reduce oxidation efficiencies of BTEX; among anions, and had the most negative effect on the removal efficiencies. On the other hand, and played a considerable inhibitor role among cations. The removal efficiencies of both systems declined when treating real polluted groundwater collected from the city of Tehran, Iran. (C) 2013 American Society of Civil Engineers.