Abstract
Oil-contaminated wastewater generated in oil-producing regions requires effective treatment methods capable of degrading persistent petroleum hydrocarbons and reducing the overall organic load. This study investigated plasma–ozone treatment of model oil-contaminated water representative of Kumkol-associated wastewater, with emphasis on reactive oxygen species formation and pollutant degradation. Experiments were carried out in a dielectric barrier discharge plasma reactor operating at 8–15 kV, 10–30 kHz, and 100–300 W. The plasma process generated ozone in the range of 3–18 mg/L and hydrogen peroxide in the range of 4–25 mg/L. For model wastewater containing 100–500 mg/L petroleum hydrocarbons, plasma–ozone treatment for 30 min achieved 70–90% hydrocarbon degradation. At the same time, COD decreased from 180–600 to 60–180 mg O2/L, while TOC decreased from 60–250 to 20–90 mg/L. These results indicate that plasma–ozone treatment provides effective oxidation of petroleum hydrocarbons together with simultaneous reduction in key water quality indicators, demonstrating its potential for the treatment of oil-contaminated wastewater.