Enhanced decolorization of methyl orange using zero-valent copper nanoparticles under assistance of hydrodynamic cavitation
Enhanced decolorization of methyl orange using zero-valent copper nanoparticles under assistance of hydrodynamic cavitation
复制标题
水动力空化辅助下零价铜纳米颗粒增强甲基橙脱色
DOI：
10.1016/j.ultsonch.2014.05.025
复制
发表时间：
2015-01-01
影响因子：
8.4
通讯作者：
Liu, Yanan
中科院分区：
文献类型：
--
作者：
Li, Pan;Song, Yuan;Liu, Yanan
零价金属纳米颗粒的团聚限制了其还原反应的速度。为了克服这一缺点，本研究采用水力空化技术。在水溶液中进行了零价纳米铜对甲基橙偶氮染料的脱色实验。结果表明，水力空化大大加快了甲基橙的脱色速率。经水力空化处理后，纳米颗粒的尺寸减小。考察了放电压力、初始溶液pH值、纳米铜颗粒浓度等重要操作参数对降解率的影响。实验发现，存在一个最佳的放电压力，以获得最佳的脱色性能。较低的溶液pH值有利于脱色。甲基橙降解的准一级动力学常数随铜剂量的增加而线性增加。UV-Vis光谱和傅里叶变换红外光谱(FT-IR)分析证实了降解中间产物的形成。结果表明，羟基自由基在脱色过程中起着关键作用。因此，水力空化对脱色的强化可能是由于纳米颗粒的解聚以及原位生成的羟基自由基的氧化。这些发现极大地提高了铜-0/水力空化技术在含危险物质废水处理领域的应用潜力。(C)2014爱思唯尔B.V.保留所有权利。
The rate of reduction reactions of zero-valent metal nanoparticles is restricted by their agglomeration. Hydrodynamic cavitation was used to overcome the disadvantage in this study. Experiments for decolorization of methyl orange azo dye by zero-valent copper nanoparticles were carried out in aqueous solution with and without hydrodynamic cavitation. The results showed that hydrodynamic cavitation greatly accelerated the decolorization rate of methyl orange. The size of nanoparticles was decreased after hydrodynamic cavitation treatment. The effects of important operating parameters such as discharge pressure, initial solution pH, and copper nanoparticle concentration on the degradation rates were studied. It was observed that there was an optimum discharge pressure to get best decolorization performance. Lower solution pH were favorable for the decolorization. The pseudo-first-order kinetic constant for the degradation of methyl orange increased linearly with the copper dose. UV-vis spectroscopic and Fourier transform infrared (FT-IR) analyses confirmed that many degradation intermediates were formed. The results indicated hydroxyl radicals played a key role in the decolorization process. Therefore, the enhancement of decolorization by hydrodynamic cavitation could due to the deagglomeration of nanoparticles as well as the oxidation by the in situ generated hydroxyl radicals. These findings greatly increase the potential of the Cu-0/hydrodynamic cavitation technique for use in the field of treatment of wastewater containing hazardous materials. (C) 2014 Elsevier B.V. All rights reserved.