Efficiency comparison of advanced photochemical oxidation technologies in phenol removal from aqueous solution in Iran

Abstract

In this study, advanced oxidation processes (UV, UV/H 2 O 2 , UV/H 2 O 2 /Fe(II) and UV/H 2 O 2 /Fe(III)) were investigated in lab-scale experiments for degradation of phenol or benzene hydroxy in aqueous solution. The study showed 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 accelerated the oxidation rate by 4-5 times the rate for the UV/H 2 O 2 process. The reaction was influenced by the pH, the input concentration of H 2 O 2 and the amount of the iron catalyst and the type of iron salt. The experimental results showed that the optimum conditions were obtained at a pH value of 3, with 6 mmol/1 H 2 O 2 , and 0.5 mmol/1 Fe(II) for the UV/H 2 O 2 /Fe(II) system and 6 mmol/l H 2 O 2 and, 0.4 mmol/1 Fe(III) for the UV/H 2 O 2 /Fe(III) system. As for the UV processes, UV/H 2 O 2 /Fe(III) showed the highest degradation rate.