Li Pan, Song Yuan, Wang Shuai, Tao Zheng, Yu Shuili, Liu Yanan
School of Environmental Science and Engineering, State Key Laboratory of Control and Resource Reuse, the Collaborative Innovation Center of Advanced Technology and Equipment for Water Pollution Control and the Collaborative Innovation Center for Regional Environmental Quality, Tongji University, 1239 Siping Road, Shanghai, PR China.
School of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai, PR China.
Ultrason Sonochem. 2015 Jan;22:132-8. doi: 10.1016/j.ultsonch.2014.05.025. Epub 2014 Jun 9.
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.
零价金属纳米颗粒的还原反应速率受其团聚作用的限制。本研究采用水力空化来克服这一缺点。在有无水力空化的水溶液中，进行了零价铜纳米颗粒对甲基橙偶氮染料脱色的实验。结果表明，水力空化极大地加速了甲基橙的脱色速率。水力空化处理后纳米颗粒尺寸减小。研究了诸如排放压力、初始溶液pH值和铜纳米颗粒浓度等重要操作参数对降解速率的影响。观察到存在一个最佳排放压力以获得最佳脱色性能。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呈线性增加。紫外可见光谱和傅里叶变换红外（FT-IR）分析证实形成了许多降解中间体。结果表明羟基自由基在脱色过程中起关键作用。因此，水力空化增强脱色可能是由于纳米颗粒的解团聚以及原位产生的羟基自由基的氧化作用。这些发现极大地提高了Cu(0)/水力空化技术在含危险物质废水处理领域应用的潜力。
