چكيده لاتين
In this research, we explore the reduction of the pollution load in Shahin Shahr’s treated wastewater as it enters the Isfahan Refinery. Our investigation focuses on the efficacy of several advanced oxidation methods, including micro/nanobubble ozonation, Fenton, and Photofenton. Microbubbles play a crucial role in oxidizing pollutants and organic compounds by generating hydroxyl radicals within the sample environment. Initial tests on wastewater samples revealed varying Chemical Oxygen Demand (COD) levels, ranging from 50 to 80 mg/L. Using a micro/nanobubbler, we introduced gases (such as air, oxygen, and ozone) into the sample in the form of microbubbles. The COD reduction process was monitored at intervals of 15, 30, 45, and 60 minutes from the start of bubbling. We also investigated key factors affecting the process, including temperature, pH, and sample concentration. Notably, the maximum COD reduction up to 16% achieved using ozone gas occurred under alkaline conditions (pH = 9) and at a temperature of approximately 25°C. In addition to micro/nanobubble ozonation, we employed Fenton’s method to reduce COD in wastewater samples spiked with potassium hydrogen phthalate. Utilizing a central composite design (CCD) response procedure, we optimized the test conditions. Under the optimal parameters (pH = 2.50, hydrogen peroxide concentration of 0.017, catalyst concentration of 0.077, and initial COD value of 400 ppm), we achieved an impressive 86% reduction in COD. Building upon the Fenton approach, we introduced UV radiation to enhance the oxidation process (photofenton method). Remarkably, this modification led to a COD reduction of 99% under the optimal experimental conditions
