COMPARISON OF PHENOL PHOTODEGRADATION BY UV/H2O2 AND PHOTO-FENTON PROCESSES

In this study, advanced photochemical oxidation processes, UV/H 2 O 2 and photo-Fenton systems were investigated for phenol degradation in wastewater with low-pressure mercury vapor lamp.The results indicated that in the UV/H 2 O 2 system, a sufficient amount of H 2 O 2 was necessary, but a very high H 2 O 2 concentration inhibited the photolysis rate.The optimum H 2 O 2 concentration was achieved in the range of 0.05-0.1 mol/L at phenol concentration of 100 mg/L.No pH effects were observed in the range of 4-10.The results of study showed that the UV/H 2 O 2 /Fe(II) system was the most effective treatment process under acidic condition and generated a higher rate of phenol degradation at a very short time.It enhanced the oxidation rate by 3 times the rate for the UV/H 2 O 2 process.For all these reactions, the degradation rates are evaluated by determining their first-order rate constants and half-life times.At the optimum condition, phenol completely disappeared with UV/H 2 O 2 and UV/H 2 O 2 /Fe(II) systems in less than 50 min and 20 min, respectively.