Preparation of Fe-Cu catalysts and treatment of a wastewater mixture by microwave-assisted UV catalytic oxidation processes

Microwave-assisted UV catalytic oxidation (MW/UV) is a potential method to treat organic pollutants that have non-biological degradability and high toxicity. To achieve high treatment efficiency, it is crucial to prepare heterogeneous photocatalysts with a high activity. Iron-copper catalysts were prepared by four different methods. Synthetic wastewater containing aniline and nitrophenol (TOC = 1000 mg/L) was treated. The key parameters including the proportion of Fe2O3 and CuO and the total content of the active components are discussed. The optimum catalyst dosage and the whole catalytic oxidation process were investigated, and different catalytic oxidation systems were also compared. The catalyst prepared by impregnation was best: the highest TOC removal efficiency reached 78%. The optimum proportion of Fe2O3 and CuO and the content of the total active composition were 4:1 and 30%, respectively. The catalyst preparation method had a greater influence on the MW/UV system than on the microwave (MW) system, and the synergistic effect between MW and UV was verified. The MW/UV system was more susceptible to catalyst dosage than was the MW system, and the optimum catalyst dosage was 5 g/L. The catalyst and H2O2 had a synergistic effect. The presence of a possible non-thermal microwave effect could be expected.