Development of novel advanced oxidation system using combined UV/H₂O₂ technique and kinetic analysis for decomposition of dye solutions

A novel advanced oxidation system using a combined UV/H₂O₂ technique was constructed for application to wastewater treatment. In this system, wastewater containing H₂O₂ flows along a channel with a flat surface in a thin film, onto which surface UV rays with a wavelength of 253.7 nm are irradiated. As a model wastewater, we used various dye solutions and investigated decoloration rates under various conditions differing in H₂O₂ concentration, temperature, UV illuminance, and so on. Based on the model, which takes into consideration the formation as well as the disappearance rate of hydroxyl radical (·OH), distribution of UV illuminance along the depth of the flow, and the rate of reaction between dye and ·OH, we could simulate the course of dye decomposition. Furthermore, we showed the existence of an optimum H₂O₂ concentration for decomposition on the basis of this model.