Martín de Vidales María J, Rua Jaime, Montero de Juan José Luis, Fernández-Martínez Francisco, Dos Santos-García Antonio J
Mechanical, Chemical and Industrial Design Engineering Department, ETSIDI, Universidad Politécnica de Madrid (UPM), Ronda de Valencia 3, 28012 Madrid, Spain.
Materials (Basel). 2020 Dec 5;13(23):5551. doi: 10.3390/ma13235551.
In this work, we study the electrochemical oxidation of methyl red, a dye present in textile industrial effluents, which is selected as the model for the degradation of Contaminants of Emerging Concern. The influence of the initial pollutant concentration (1-5 mg dm), applied current density (2-15 mA cm), and the coupling of ultraviolet or ultrasound radiation have been studied using a titanium plate as anode. The results show that electrochemical oxidation is able to efficiently remove methyl red, and the process efficiency decreases with the initial pollutant concentration. At high applied current densities, efficiency drastically decreases due to a less effective mass transfer of the pollutant on the anodic surface. On one hand, the coupling of ultrasound entails an antagonistic effect on the process efficiency, which is probably due to a massive formation of oxidant radicals followed by a fast recombination process. On the other hand, the coupling of ultraviolet radiation increases the process efficiency. Concomitantly to the oxidation processes, titanium electrode produces rising TiO-anatase nanoparticles, boosting the mineralization process. This new finding sets up a significant improvement over conventional photocatalysis treatments using TiO-anatase as a catalyst due to synergistic effects coming from the coupling of the electrochemical oxidation and photocatalysis process with Ti anode.
在本研究中，我们研究了甲基红的电化学氧化过程。甲基红是纺织工业废水中存在的一种染料，被选作新兴关注污染物降解的模型。以钛板为阳极，研究了初始污染物浓度（1 - 5 mg dm）、施加电流密度（2 - 15 mA cm）以及紫外线或超声波辐射耦合的影响。结果表明，电化学氧化能够有效去除甲基红，且该过程效率随初始污染物浓度降低。在高施加电流密度下，由于污染物在阳极表面的传质效率降低，效率急剧下降。一方面，超声波耦合对过程效率产生拮抗作用，这可能是由于大量氧化剂自由基的形成以及随后快速的复合过程。另一方面，紫外线辐射耦合提高了过程效率。与氧化过程同时发生的是，钛电极产生了不断增加的TiO - 锐钛矿纳米颗粒，促进了矿化过程。由于电化学氧化与光催化过程和钛阳极耦合产生的协同效应，这一新发现相对于使用TiO - 锐钛矿作为催化剂的传统光催化处理有了显著改进。
