Energy-saving photo-Fenton technology using solar energy and reusable zero-valent iron for degradation of aqueous rhodamine B

In this study, we examined the feasibility of employing zero-valent iron (ZVI) as a heterogeneous reactant in the photo-Fenton degradation of Rhodamine B (RhB) in water, utilizing solar energy. ZVI was implemented as a heterogeneous reactant for Fenton degradation of RhB in water, while solar energy-driven photo-Fenton degradation was carried out to assess the impacts of varying H2O2 and ZVI concentrations on these processes. Our experimental findings revealed that the photodegradation reaction rate of RhB, powered by solar energy at a light intensity of 1200-1400 W/m(2), was 1.7 times greater than that of the Fenton reaction, facilitating more rapid degradation of dye wastewater. Solar energy photo-Fenton necessitated merely 0.5 mM H2O2 and 8.92 mM ZVI to fully decompose RhB within 30 min, with the chemical oxygen demand (COD) removal efficiency being twice as high as the Fenton reaction. A cost analysis demonstrated that reusing ZVI for 33 times decreased the dose cost by 0.68 USD per ton in comparison with use of conventional homogeneous Fe2+ as a catalyst. The application of ZVI as a heterogeneous reactant for RhB degradation in water by solar energy photo-Fenton has significantly lower dose costs and offers potential for practical implementations. [GRAPHICS] .