Gallo-Cordova Alvaro, Veintemillas-Verdaguer Sabino, Tartaj Pedro, Mazarío Eva, Morales María Del Puerto, Ovejero Jesús G
Instituto de Ciencia de Materiales de Madrid, ICMM/CSIC, C/Sor Juana Inés de la Cruz 3, 28049 Madrid, Spain.
Departamento de Química Física Aplicada, Facultad de Ciencias, Universidad Autónoma de Madrid, C/Francisco Tomás y Valiente, 7, Cantoblanco, 28049 Madrid, Spain.
Nanomaterials (Basel). 2021 Apr 20;11(4):1052. doi: 10.3390/nano11041052.
Advanced oxidation processes constitute a promising alternative for the treatment of wastewater containing organic pollutants. Still, the lack of cost-effective processes has hampered the widespread use of these methodologies. Iron oxide magnetic nanoparticles stand as a great alternative since they can be engineered by different reproducible and scalable methods. The present study consists of the synthesis of single-core and multicore magnetic iron oxide nanoparticles by the microwave-assisted polyol method and their use as self-heating catalysts for the degradation of an anionic (acid orange 8) and a cationic dye (methylene blue). Decolorization of these dyes was successfully improved by subjecting the catalyst to an alternating magnetic field (AMF, 16 kA/m, 200 kHz). The sudden temperature increase at the surface of the catalyst led to an intensification of 10% in the decolorization yields using 1 g/L of catalyst, 0.3 M HO and 500 ppm of dye. Full decolorization was achieved at 90 °C, but iron leaching (40 ppm) was detected at this temperature leading to a homogeneous Fenton process. Multicore nanoparticles showed higher degradation rates and 100% efficiencies in four reusability cycles under the AMF. The improvement of this process with AMF is a step forward into more sustainable remediation techniques.
高级氧化工艺是处理含有机污染物废水的一种很有前景的替代方法。然而，缺乏具有成本效益的工艺阻碍了这些方法的广泛应用。氧化铁磁性纳米颗粒是一种很好的替代物，因为它们可以通过不同的可重复和可扩展的方法来制备。本研究包括通过微波辅助多元醇法合成单核和多核磁性氧化铁纳米颗粒，并将其用作自热催化剂来降解阴离子染料（酸性橙8）和阳离子染料（亚甲基蓝）。通过使催化剂受到交变磁场（AMF，16 kA/m，200 kHz）作用，这些染料的脱色效果得到了成功改善。使用1 g/L的催化剂、0.3 M的过氧化氢和500 ppm的染料时，催化剂表面温度的突然升高导致脱色率提高了10%。在90°C时实现了完全脱色，但在此温度下检测到铁浸出（40 ppm），导致了均相芬顿过程。多核纳米颗粒在AMF作用下的四个可重复使用循环中表现出更高的降解速率和100%的效率。利用AMF改进此工艺是朝着更可持续的修复技术迈出的一步。
