Assessing Hydrocarbon Removal from Petroleum Hydrocarbon-containing Effluent using UV/O3 Advanced Oxidation

The purpose of this study was to experimentally investigate the treatment of petroleum hydrocarbons-contaminated wastewater using UV/O3 method. To predict the degree of pollutant destruction, the initial concentrations of O3 and pollutant, pH, solution temperature, reaction time and UV intensity were designed. For this purpose, 1-liter cylindrical glass reactor was used. The radiation source was a low-pressure mercury UV lamp with 254-nanometer wavelength (30 W UV-C) placed on the top of the batch photoreactor in order to perform UV/O3 experiments. Different concentrations of O3 (5, 10, 15, 20, 25, and 30 mg/l) were tested. In a concentration of 15 mg/l petroleum and contact time of 5, 10, 30, 20, 40, 50, 60, 100, and 120 minutes, the removal rate of hydrocarbons in the UV/O3 system was 15, 28, 31, 36, 42, 52, 56, 73, and 59.5%, wheras, the COD removal efficiency at the same contact times was 22, 38, 45, 61.5, 67.5, 70, 80, 88.5, 76.5% respectively. When the initial pH was 3, 4, 5, 6, 9, 10, and 12, the approximately efficiency of hydrocarbon removal was 75, 8, 62, 63, 4, 58, 44, 8, 35, 8, and 30% respectively. The results of this study showed that 20 mg/l O3 dose at pH = 3 and UV intensity of 2.8 W/cm (254 nm), the optimal utilization conditions for mineralization of hydrocarbon provide 73% removal after