School of Resources and Environment, University of Jinan, Jinan 250022, China.
Ultrason Sonochem. 2014 Mar;21(2):572-5. doi: 10.1016/j.ultsonch.2013.10.015. Epub 2013 Oct 24.
Degradation of azo dye Acid Orange 7 (AO7) by zero-valent aluminum (ZVAl) in combination with ultrasonic irradiation was investigated. The preliminary studies of optimal degradation methodology were conducted with sole ultrasonic, sole ZVAl/air system, ultrasonication + ZVAl/air system (US-ZVAl). In ZVAl/air system, the degradation of AO7 could almost not be observed within 30 min. The degradation of AO7 by ZVAl/air system was obviously enhanced under ultrasound irradiation, and the enhancement is mainly attributed to that the production of hydroxyl radicals in ultrasound-ZVAl process was much higher than that in sole ultrasonic or in sole ZVAl/air system. The variables considered for the effect of degradation were the power of ultrasound, the initial concentration of AO7, as well as the initial pH value and the dosage of zero-valent aluminum. The results showed that the decolorization rate increased with the increase of power density and the dosage of ZVAl, but decreased with the increase of initial pH value and initial concentration of AO7. More than 96% of AO7 removal was achieved within 30 min under optimum operational conditions (AO7: 20 mg/L, ZVAl: 2 g/L, pH: 2.5, ultrasound: 20 kHz, 300 W). This study demonstrates that ultrasound-ZVAl process can effectively decolorize the azo dye AO7 in wastewater.
零价铝（ZVAl）与超声波辐射联合降解偶氮染料酸性橙 7（AO7）的研究。采用单独超声、单独 ZVAl/空气体系、超声+ZVAl/空气体系（US-ZVAl）对最佳降解方法进行了初步研究。在 ZVAl/空气体系中，30 分钟内几乎观察不到 AO7 的降解。在超声波辐射下，ZVAl/空气体系中 AO7 的降解明显增强，这种增强主要归因于超声-ZVAl 过程中羟基自由基的产生明显高于单独超声或单独 ZVAl/空气体系。考察了降解效果的变量有超声功率、AO7 的初始浓度以及初始 pH 值和零价铝的用量。结果表明，随着功率密度和 ZVAl 用量的增加，脱色率增加，但随着初始 pH 值和 AO7 初始浓度的增加而降低。在最佳操作条件下（AO7：20mg/L，ZVAl：2g/L，pH：2.5，超声：20kHz，300W），30 分钟内可去除 96%以上的 AO7。本研究表明，超声-ZVAl 工艺可有效去除废水中的偶氮染料 AO7。
