Department of Chemical and Materials Engineering, National Yunlin University of Science & Technology, Douliou, Yunlin, Taiwan.
Ultrason Sonochem. 2011 Sep;18(5):1232-40. doi: 10.1016/j.ultsonch.2010.11.014. Epub 2010 Dec 4.
Oxidative degradation of dinitrotoluenes (DNTs) and 2,4,6-trinitrotoluene (TNT) in wastewater was conducted using ultrasonic irradiation combined with titanium dioxide (TiO(2)). The batch-wise experiments were carried out to elucidate the influence of various operating parameters on the sonolytic behavior, including power intensity, TiO(2) dosage, acidity of wastewater, reaction temperature and oxygen dosage. It is worthy to note that the nitrotoluene contaminants could be almost completely eliminated by sonochemical oxidation enhanced significantly with the addition of TiO(2) due to the supply of adsorbent and/or excess nuclei. High destruction rate of nitrotoluenes could be achieved by increasing the acidity of wastewater and decreasing the reaction temperature. According to the result given by pyrolysis/gas chromatograph-mass spectrometer (Pyrolysis/GC-MS), it is postulated that DNTs adsorbed on TiO(2) preliminarily undergo denitration pathway to o-mononitrotoluene (MNT) or oxidation pathway to 1,3-dinitrobenzene (DNB), respectively. Further, based on the spectra obtained from GC-MS, it is proposed that DNTs dissolved in wastewater proceed with similar reaction pathways as those adsorbed on TiO(2). Besides, oxidative degradation of 2,4,6-TNT results in the formation of 1,3,5-trinitrobenzene (TNB). Apparently, the sonolytic technique established is promising for direct treatment of wastewater from TNT manufacturing process.
利用超声辐射与二氧化钛（TiO2）联合处理废水中的二硝基甲苯（DNTs）和 2,4,6-三硝基甲苯（TNT），进行了氧化降解实验。通过分批实验，研究了各种操作参数对超声行为的影响，包括功率强度、TiO2 用量、废水酸度、反应温度和氧气用量。值得注意的是，由于提供了吸附剂和/或过剩核，添加 TiO2 后，超声化学氧化显著增强，硝基甲苯污染物几乎可以完全消除。通过增加废水酸度和降低反应温度，可以实现更高的硝基甲苯破坏率。根据热解/气相色谱-质谱联用仪（Pyrolysis/GC-MS）的结果，推测 DNTs 首先在 TiO2 上通过脱硝途径转化为邻单硝基甲苯（MNT），或通过氧化途径转化为 1,3-二硝基苯（DNB）。此外，根据 GC-MS 获得的谱图，推测废水中溶解的 DNTs 也会经历类似的反应途径。此外，2,4,6-TNT 的氧化降解会生成 1,3,5-三硝基苯（TNB）。显然，所建立的超声技术有望直接处理 TNT 制造过程中的废水。
