Advanced oxidation degradation kinetics as a function of ultraviolet LED duty cycle

作者：Duckworth Kelsey; Spencer Michael; Bates Christopher; Miller Michael E^*; Almquist Catherine; Grimaila Michael; Magnuson Matthew; Willison Stuart; Phillips Rebecca; Racz LeeAnn

来源：Water Science and Technology, 2015, 71(9): 1375-1381.

DOI：10.2166/wst.2015.108

• hydrogen peroxide
• light emitting diode
• methylene blue
• ultraviolet

Ultraviolet (UV) light emitting diodes (LEDs) may be a viable option as a UV light source for advanced oxidation processes (AOPs) utilizing photocatalysts or oxidizing agents such as hydrogen peroxide. The effect of UV-LED duty cycle, expressed as the percentage of time the LED is powered, was investigated in an AOP with hydrogen peroxide, using methylene blue (MB) to assess contaminant degradation. The UV-LED AOP degraded the MB at all duty cycles. However, adsorption of MB onto the LED emitting surface caused a linear decline in reactor performance over time. With regard to the effect of duty cycle, the observed rate constant of MB degradation, after being adjusted to account for the duty cycle, was greater for 5 and 10% duty cycles than higher duty cycles, providing a value approximately 160% higher at 5% duty cycle than continuous operation. This increase in adjusted rate constant at low duty cycles, as well as contaminant fouling of the LED surface, may impact design and operational considerations for pulsed UV-LED AOP systems.

• 出版日期2015
• 单位中国人民解放军空军电子技术研究所