Research on the application of LED light source in photocatalytic wastewater treatment technology

Photocatalytic dye wastewater treatment has the advantages of being green and free from secondary pollution. However, the low processing rate in visible light and the high electric energy cost of artificial light sources limit its implementation in industry. With the continuous development of light-emitting diode (LED) technology in recent years, the photoelectric conversion efficiency of LEDs has been constantly improved. Therefore, using LED as the light source for photocatalytic wastewater treatment may be an effective method to improve the efficiency of wastewater treatment. Compared to traditional light sources, LED technology has advantages such as smaller volume, longer service life, lower energy consumption and greater adjustability. By combining LED light sources with photosensitive catalysts, efficient and environmentally friendly photocatalytic reactions can be achieved. In this study, several common photocatalysts were tested for their photocatalytic rates using a parallel light reactor. The effects of LED wavelength, irradiance intensity and mode on photocatalytic rates were also investigated. The results showed that TiO₂ had the highest first-order reaction rate constant under 365 nm LED irradiation, while g-C₃N₄ exhibited relatively high first-order reaction rate constants in the 365-420 nm wavelength range. Increasing irradiance intensity and the changes of irradiance mode were found to be conducive to improving the photocatalytic rate.