investigating the performance of the photo-fenton process of the naphthalene removal from petroleum wastewater

The present research investigated the photo-fenton process’s effect on naphthalene’s decomposition in petroleum wastewater. the research was conducted on a laboratory scale and in a discontinuous manner. the effect of ph (2, 4.5, 7), fe2+(5, 42.5, 80 mg/l), h2o2(50, 425, 800mg/l), uv (8, 16, 24 w in the wavelength 254 nm), and time (10, 65, 120 min) on the removal of naphthalene       (10, 40, 70 µg/l) in synthetic wastewater was investigated. all the experiments were done continuously in 1-liter erlenmeyer flasks at a constant speed of 300 rpm and at room temperature. to investigate the effect of independent variables on the efficiency of naphthalene removal, the response surface method was used on the box-behnken design and based on a 6-variable in three levels with three central points, 54 experiments were designed and executed. the research results showed an increase in the initial concentration of h2o2, and the removal efficiency of naphthalene from the wastewater also increased. at the concentration of 750 mg/l, the decomposition and removal of naphthalene increased up to 93.6%. the optimal limit of fe2+ concentration in removing naphthalene from wastewater was also determined at 42.5 mg/l. the removal process of naphthalene from wastewater was also improved in acidic ph (3). the removal of naphthalene has also increased in the 24w light range and has reached 91.4%. the results of investigating the effect of reaction time showed that the percentage of naphthalene decomposition and removal has also increased, and the best efficiency was reached in 80 to 100 minutes. notably, a negative correlation was observed between fe2+ concentration  and uv radiation on removing naphthalene. finally, in optimal conditions, the removal efficiency of naphthalene using the photo-fenton method is estimated to be more than 98%. the present research results show the optimal efficiency of the photo-fenton process in the decomposition of naphthalene.