Chen Hua-Wei, Ku Young, Irawan Agus
Department of Chemical Engineering, National Taiwan University of Science and Technology, 43, Keelung Road, Section 4, Taipei 106, Taiwan.
Chemosphere. 2007 Sep;69(2):184-90. doi: 10.1016/j.chemosphere.2007.04.051. Epub 2007 Jun 4.
This study investigated the effect of controlled periodic illumination on the photonic efficiency and temporal decomposition behavior of o-cresol by UV/TiO2 process in a slurry reactor using light emitting diodes as the light source. Based on the same UV light intensity of 6.7 W m(-2), the calculated photonic efficiencies increased from 1.5% to 6.3% with the decreasing duty cycle from 1.0 to 0.1 possibly ascribed to the decreasing electron-hole recombination. Actually, the calculated photonic efficiency under periodic illumination at sufficiently intermittence was inferior to, but approached, those under continuous illumination at equivalent average UV light intensity. The calculated electric energy per order increased from 32 to 37 k W h m(-3)order(-1) for experiments conducted with the increasing duty cycle from 0.1 to 1.0, and the electric energy consumption decreased significantly due to the lower duty cycle and average UV light intensity. The photocatalytic decomposition of o-cresol with the UV-light emitting diodes light could be well modeled by the Langmuir-Hinshelwood kinetic equation.
本研究在以发光二极管为光源的浆态反应器中，通过紫外光/二氧化钛工艺，研究了可控周期性光照对邻甲酚光子效率和时间分解行为的影响。基于6.7 W m(-2)的相同紫外光强度，随着占空比从1.0降至0.1，计算得到的光子效率从1.5%提高到6.3%，这可能归因于电子-空穴复合的减少。实际上，在足够间歇的周期性光照下计算得到的光子效率低于但接近在等效平均紫外光强度下连续光照时的光子效率。对于占空比从0.1增加到1.0的实验，每级计算得到的电能从32增加到37 k W h m(-3)order(-1)，并且由于较低的占空比和平均紫外光强度，电能消耗显著降低。用紫外发光二极管光进行邻甲酚的光催化分解可以用Langmuir-Hinshelwood动力学方程很好地模拟。
