Characteristics of Fe2+/H2O2/UV Oxidization Process

Abstract

The characteristics of a Fe²⁺/H₂O₂/UV system, which was constructed by introducing UV irradiation (wave length 253.7 nm) into a Fenton oxidization system, were evaluated on decomposition of pyridine and other organics. The effect of oxygen on organic decomposition was also examined by feeding air into the reactor. The optimum Fe²⁺ concentrations for pyridine and acetic acid were found to be 45.6 and 9.1 mg l⁻¹, respectively, under the conditions of 250 mgTOC l⁻¹, 2450 mgH₂O₂ l⁻¹, and 35°C. On the other hand, there existed no optimum H₂O₂ concentration for pyridine decomposition in the range of 550 mg l⁻¹ to 2450 mg l⁻¹. Aeration was found to be an effective method to increase the TOC removal efficiency. The reaction rate was increased by increasing the reaction temperature. Of the 15 compounds investigated in this study, organics with high electron density, such as aromatic and heterocyclic compounds were relatively easy to decompose, compared with the aliphatic compounds such as alcohols, ketones, and organic acids. The relatively low decomposition rates of alcohols and ketones were originated from the formation of acetic acid. Nitromethane was difficult to be completely decomposed by the Fe²⁺/H₂O₂/UV system.

Keywords:

• Chemical treatment
• Fenton reaction
• oxidation
• photo-enhanced Fenton reaction
• wastewater treatment