Preparation of Co–Ce–Ru/γ-Al2O3 catalyst for degradation rhodamine B in dye wastewater

Dye wastewater is a typical refractory organic wastewater. Advanced oxidation processes have been proven to be an effective way for treating high concentration dye wastewater. This method, which activates peroxymonosulfate (PMS) with cobalt-based catalysts and produces sulfate radicals, has garnered significant research interest. This study developed a highly efficient and environmentally friendly cobalt-based catalysts Co–Ce–Ru/γ-Al2O3 via an impregnation method for enhanced activation of PMS to degrade rhodamine B (RhB) in wastewater. The innovative incorporation of rare-earth metal Ce and precious metal Ru into Co/γ-Al2O3 significantly reduced cobalt loading while improving catalytic activity and stability. The decolorization rate of RhB in dye wastewater was used as the degradation performance index. Results showed that the decolorization rate of RhB using Co–Ce–Ru/γ-Al2O3 catalyst was close to 100% when the system temperature was 25 °C, the amount of catalyst was 0.5 g/L, the amount of PMS was 0.5 g/L, and the concentration of RhB was 50 mg/L. Importantly, the catalyst exhibited exceptional durability with minimal metal leaching (< 1.0 mg/L) over multiple cycles, complying with environmental standards. This work provides deep insights into the catalytic mechanism and kinetics of PMS activation, offering a practical and sustainable solution for the treatment of dye-contaminated wastewater.