Ultraviolet Light-Emitting Diodes and Peroxydisulfate for Degradation of Basic Red 46 from Contaminated Water

Abstract

In this article, a novel batch reactor of ultraviolet (UV) light-emitting diodes (LEDs) and peroxydisulfate has been studied for the degradation of Basic Red 46 (BR46) as a model organic pollutant in water. Almost no dye degradation was achieved with UV LED alone, whereas 43% of destruction was obtained in the presence of peroxydisulfate. More than 90% of the dye content was eliminated using UV LED and peroxydisulfate simultaneously in 30 min. Effects of different parameters such as UV LED irradiation, peroxydisulfate concentration, dye concentration, pH, and current on the removal of BR46 were investigated. Satisfactory degradation of BR46 was observed for tested pH range of 2–9.8, with peak at pH 6.43. Electrical energy per order (EEO) for degradation values of BR46 using both UV LEDs and traditional UV lamps in different concentrations of peroxydisulfate were calculated. Our results show that using LEDs reduces EEO significantly. On increasing the current from 360 to 2,000 mA, the decolorization rate increased. Hence, 720 mA of current intensity was preferred to avoid consumption of energy. A novel and effective cooling system was installed to increase the lifespan of LEDs and make the system economically more feasible for water and wastewater treatment.