Effect of UV/H2O2 advanced oxidation processes for the removal of naphthalene from the water

Naphthalene is a polyaromatic hydrocarbon (PAH) present in many sediment-water systems. The aim of This study evaluated the performance of UV/H2O2 reaction to decompose naphthalene in the aqueous solution. A 1 L cylindrical glass reactor was used for performing all degradation experiments. The radiation source was a low pressure mercury UV lamp emitting at 254 nm (30 W، UV-C، manufactured by Philips، Holland) which was placed above a batch photoreactorfor UV/H2O2 experiments and different concentrations of H2O2 (5، 10، 15، 20، 25 and 30 mg/L) were tested. At naphthalene = 15 mg/L and reaction time = 5، 10، 20، 30، 40، 50، 60، 100 and 120 min، 15، 28، 31، 36، 42، 52، 56، 73 and 59. 5%naphthaleneremoval efficiencies were observed in UV/H2O2 system and COD removal efficiencies in reaction time = 5، 10، 20، 30، 40، 50، 60، 100 and 120 min، 22، 38، 45، 61. 5، 67. 5، 70، 80، 88. 5 and 76 % were observed. When the initial pH values were 3، 4، 5، 6، 7،9، 10 and 12 the naphthalene removal efficiency were approximately 75. 8، 63. 4، 62، 58. 5، 44. 8، 35. 8 and 30%، respectively، with UV/H2O2 system. The experimental results of this study suggested that the dosages with 20 mg/L H2O2 at pH 3 with 2. 8 W/cm2UV intensity (254 nm) provided the optimal operation conditions for the mineralization of naphthalene yielding a 73% mineralizationefficiency after 100min of reaction time.