Optimization Study on Synergistic System of Photocatalytic Degradation of AR 26 and UV-LED Heat Dissipation

Abstract

In this work, a novel UV-LED/TiO2 photocatalytic system, having a single layer with ten LED beads, was designed to simultaneously achieve UV-LED cooling and wastewater degradation, to deal with heat dissipation problems of high-power UV-LEDs. To gain more insight into this system, the parameters affecting both cooling and photocatalytic performance were first optimized using AR 26 as a basis. With respect to sewage, sewage with a flow rate of 80 mL/min and a temperature of 20 °C helped to keep a lower temperature of UV-LED, which benefits the long-term operation stability of LED beads. For parameters affecting the photocatalytic performance only, the experiments showed that TiO2 with moderate dosing (0.75 g/L) under strong acid conditions (pH = 2) helped to further improve photocatalytic activity when the initial concentration of AR 26 was 45 mg/L. Lastly, to illustrate the advantages of this novel system, the performance of the synergistic system was compared with a conventional photocatalytic reactor with respect to degradation performance, optical quantum efficiency, and energy consumption. The results showed that the degradation efficiency and light source utilization ratio of this coupled system were, respectively, 2.1 times and 1.5 times as much as those of a conventional reactor. As the unit power consumption of the synergistic system was only 0.18-fold more than that of a conventional reactor, our work suggests that this synergistic system with the advantage of LED lamp beads has a bright future in dealing with refractory organic pollutants of sewage.