Department of Chemical Engineering and Analytical Chemistry, Faculty of Chemistry, Universitat de Barcelona, C/Martí i Franqués 1, 08028, Barcelona, Spain.
Department of Chemical Engineering and Analytical Chemistry, Faculty of Chemistry, Universitat de Barcelona, C/Martí i Franqués 1, 08028, Barcelona, Spain.
J Hazard Mater. 2019 Dec 15;380:120882. doi: 10.1016/j.jhazmat.2019.120882. Epub 2019 Jul 13.
The photo-Fenton process, with UV-A LED (λ = 380-390, 390-400 and 380-400 nm) has demonstrated to be effective in the abatement of a target micropollutant, such as diphenhydramine hydrochloride (DPH). Different concentrations of iron (Fe) and HO were tested and monitored, and the best results in DPH removal were obtained for the highest concentrations of both iron (II) and HO (10 mg Fe/L - 150 mg HO/L). The evolution of iron and peroxide concentration was also monitored. Kinetic studies showed that dark Fenton process prevails at the beginning of the experiment, when Fe concentration is higher. However, after these initial moments, the prevailing process is photo-Fenton and, in addition, wavelength radiation plays an important role. Concerning the effect of radiation, four LEDs (4.2 W total power) were used, emitting radiation in the wavelength range between 380-390 or 390-400 nm. Similar results were obtained in both cases in DPH removal by photo-Fenton (30 min for total elimination). However, a synergistic effect was observed when two LEDs of 380-390 nm and two LEDs of 390-400 nm were used. Total power was the same (4.2 W) in each experimental condition, but the increase in the wavelength range to 20 nm (380-400 nm) produces an increase in the rate of DPH removal, achieving its total elimination at 15 min. This fact, with the use of a simple radiation model, reveals the important role that radiation plays in the photo-Fenton process. Finally, the formed intermediates were determined and some reaction pathways were proposed.
光-Fenton 过程采用 UV-A LED（λ=380-390、390-400 和 380-400nm），已被证明可有效去除目标微量污染物，如盐酸苯海拉明（DPH）。测试和监测了不同浓度的铁（Fe）和 HO，在铁（II）和 HO 的最高浓度下（10mg Fe/L-150mg HO/L），DPH 的去除效果最佳。还监测了铁和过氧化物浓度的演变。动力学研究表明，在实验初期，当 Fe 浓度较高时，暗 Fenton 过程占主导地位。然而，在这些初始时刻之后，占主导地位的过程是光-Fenton，此外，辐射波长也起着重要作用。关于辐射的影响，使用了四个 LED（总功率为 4.2W），在 380-390nm 或 390-400nm 波长范围内辐射。在光-Fenton 去除 DPH 方面，两种情况下都得到了相似的结果（30 分钟即可完全消除）。然而，当使用两个 380-390nm 的 LED 和两个 390-400nm 的 LED 时，观察到协同效应。在每种实验条件下，总功率均为 4.2W，但波长范围增加到 20nm（380-400nm）会增加 DPH 去除率，在 15 分钟内即可完全消除。这一事实，结合使用简单的辐射模型，揭示了辐射在光-Fenton 过程中所起的重要作用。最后，确定了形成的中间体，并提出了一些反应途径。
