Laboratório de Catálise e Materiais (LCM), Departamento de Engenharia Química, Faculdade de Engenharia, Universidade do Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal.
J Hazard Mater. 2012 Nov 15;239-240:167-74. doi: 10.1016/j.jhazmat.2012.08.057. Epub 2012 Sep 1.
Two carbon materials (multi-walled carbon nanotubes, MWCNTs, and activated carbon) were investigated as ozonation catalysts for the mineralization of the antibiotic sulphamethoxazole (SMX). MWCNTs presented a higher catalytic performance than activated carbons, which was justified by their differences in surface chemistry and by the higher internal mass transfer resistances expected for activated carbons. 3-Amino-5-methylisoxazole and p-benzoquinone were detected as primary products of single and catalytic ozonation of SMX, whereas oxamic, oxalic, pyruvic and maleic acids were identified as refractory final oxidation products. The original sulphur of the SMX was almost completely converted to sulphate and part of the nitrogen was converted to NH4+ and NO3-. The presence of the radical scavenger tert-butanol during catalytic and single ozonation evidenced the participation of HO radicals in the oxidation mechanisms of SMX, especially in the mineralization of several intermediates. Microtox tests revealed that simultaneous use of ozone and MWCNTs originated lower acute toxicity. The time course of all detected compounds was studied and the transformation pathway for the complete mineralization of SMX by single and catalytic ozonation in the presence of the selected materials was elucidated.
两种碳材料（多壁碳纳米管（MWCNTs）和活性炭）被研究为臭氧化催化剂，以实现抗生素磺胺甲恶唑（SMX）的矿化。MWCNTs 表现出比活性炭更高的催化性能，这可以通过它们在表面化学方面的差异以及活性炭预期的更高的内部传质阻力来解释。3-氨基-5-甲基异恶唑和对苯醌被检测为 SMX 的单臭氧化和催化臭氧化的主要产物，而草酸、草酰、丙酮酸和马来酸则被鉴定为难氧化的最终氧化产物。SMX 的原始硫几乎完全转化为硫酸盐，部分氮转化为 NH4+和 NO3-。在催化臭氧化和单臭氧化过程中加入自由基清除剂叔丁醇，证明了 HO 自由基参与了 SMX 的氧化机制，特别是在几种中间产物的矿化过程中。微毒测试表明，臭氧和 MWCNTs 的同时使用会降低急性毒性。研究了所有检测到的化合物的时间过程，并阐明了在选定材料存在下，通过单臭氧化和催化臭氧化实现 SMX 完全矿化的转化途径。
