Synergies, radiation and kinetics in photo-Fenton process with UVA-LEDs

JOURNAL OF HAZARDOUS MATERIALS

卷:380

Article

Lopez-Vinent, N.¹  Cruz-Alcalde, A.¹  Romero, L. E.¹  Chavez, M. E.¹  Marco, P.¹  Gimenez, J.¹  Esplugas, S.¹ 

[1] Univ Barcelona, Fac Chem, Dept Chem Engn & Analyt Chem, C Marti i Franques 1, E-08028 Barcelona, Spain

关键词: Synergy wavelength;    UV-A LED;    Photo-Fenton;    Intermediates;    Kinetics;   

DOI  :  10.1016/j.jhazmat.2019.120882

来源: Elsevier

【 摘 要 】

The photo-Fenton process, with UV-A LED (lambda = 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 (Fe2+) and H2O2 were tested and monitored, and the best results in DPH removal were obtained for the highest concentrations of both iron (II) and H2O2 (10 mg Fe2+/L - 150 mg H2O2/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 Fe2+ 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.

【 授权许可】

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