Degradation of Phenol in Aqueous Solution by Advanced Oxidation Process

Abstract

Advanced oxidation processes (UV, UV/H₂O₂, UV/H₂O₂/ Fe(II) and UV/H₂O₂/Fe(III)) were investigated in lab-scale experiments for degradation of phenol in aqueous solution. The study shows that the Photo-Fenton process, (a mixture of hydrogen peroxide and ferrous or ferric ion), was the most effective treatment process under acidic conditions and produced a higher rate of degradation of phenol at a very short radiation time. It accelerates the oxidation rate by 5-8 times the rate of the UV/H₂O₂ process. The reaction was influenced by pH, the input concentration of H₂O₂ and the amount of the iron catalyst and the type of iron salt. The experimental results show that the optimum conditions were obtained at a pH value of 3, with 6 mmol/L H₂O₂ and 0.5 mmol/L Fe(II) for the UV/ H₂O₂/Fe(II) system and 6 mmol/L H₂O₂ and, 0.4 mmol/L Fe(III) for the UV/H₂O₂/Fe(III) system. As for the UV processes, UV/H₂O₂/Fe(III) showed the highest degradation rate.