Pharmaceutical industries generate significant amounts of aromatic and chemical compounds that cause many environmental problems. Relevant contaminants include various drugs such as painkillers, antibiotics, cardiovascular drugs that most of them can be degraded by advanced oxidation process. In this study, the removal of the recalcitrant oxycodone pollutant, an industrially derived from opium compounds, was investigated using persulfate oxidizer under visible light. A vortex spiral reactor with a 150 watt visible lamp was used in this project. Sampling was performed every 10 minutes and was measured using UV spectrophotometer [1]. The effect of various factors in degradation process, including persulfate concentration, initial pH of the solution and reaction temperature was investigated. The oxycodone degradation efficiency could reach to 84.4%, during 60 min treatment, under the found optimal conditions of 150 mg/L persulfate, normal pH and temperature of 35 °C. In this process, 86.2% degradation was accomplished with hydroxyl radical and 13.8% with sulfate anion radical. The presence of conventionally found carbonate, bicarbonate and chlorine anions in water caused diminishing the oxycodone degradation. Further, presence of cations of intermediate metals caused stability and resistance of the contaminant against degradation. Kinetic study showed that oxycodon deletion followed a pseudo first-order reaction with the rate constat of 0.0299 min-1. To determine the mechanism of degradation and identify the produced intermediates, liquid chromatography-mass spectrometry (LC-MS) analysis was performed [2]. Active radicals in the environment react with the pollutant and destroy its structure.
