Catalytic ozonation of sulphamethoxazole in the presence of carbon materials: Catalytic performance and reaction pathways

• Type: Article in International Scientific Journal
• Date: 2012

Authors

Alexandra Gonçalves (Author) FEUP; José Melo Orfão (Author) FEUP; Manuel Fernando R Pereira (Author) FEUP

Journal

Title: Journal of Hazardous Materials

Vol. 239

Pages: 167-174

ISSN: 0304-3894

Publisher: Elsevier

Indexing

ISI Web of Knowledge - 84 Citations

ISI Web of Science

Scopus - 117 Citations

Scientific classification

FOS: Engineering and technology > Chemical engineering

Other information

Authenticus ID: P-002-3DY

DOI: 10.1016/j.jhazmat.2012.08.057

Abstract (EN): 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 center dot 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.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 8