Ozonation of bezafibrate over ceria and ceria supported on carbon materials

• Published in: Environmental technology 2015-03, Vol.36 (6), p.776-785
• Main Authors: Gonçalves, Alexandra G, Órfão, José J.M, Pereira, Manuel Fernando R
• Format: Article
• Language: English
• Subjects: Activated carbon; acute toxicity; Aliivibrio fischeri; bezafibrate; Bezafibrate - chemistry; carbon nanotubes; catalysts; catalytic ozonation; ceric oxide; Cerium - chemistry; cerium oxide; chlorine; environmental technology; Free radicals; Mineralization; multi-walled carbon nanotubes; Nanotechnology; nitrogen; oxidation; ozonation; Ozone; Ozone - chemistry; Toxicity Tests; Water Pollutants, Chemical - chemistry; Water Pollutants, Chemical - toxicity
• ISSN: 1479-487X; 0959-3330; 1479-487X
• DOI: 10.1080/09593330.2014.961563

Two catalysts containing ceria dispersed on the surface of multi-walled carbon nanotubes and activated carbon were investigated as ozonation catalysts for the mineralization of bezafibrate (BZF). The results were compared with those obtained in the absence of the catalyst and in the presence of the parent carbon materials, as well as in the presence of ceria (CeO ₂). Carbon materials containing ceria showed an interesting catalytic effect. Both materials enhanced the mineralization of BZF relatively to single ozonation and ozonation catalysed by the corresponding carbon materials. In the catalytic ozonation with these materials, both surface and bulk reactions are supposed to occur. The BZF ozonation catalysed by CeO ₂ leaded to the highest mineralization degrees, indicating that the reaction mechanism followed in the presence of CeO ₂ (free radical oxidation in solution) leads to the formation of intermediates more easily degradable, mainly after 120 min of reaction. Some primary products and refractory final oxidation compounds in single and catalytic ozonation of BZF were followed. The original chlorine present on the BZF molecule is completely converted to chloride anion and part of the nitrogen is mainly converted to along with smaller amounts of and . Microtox tests revealed that simultaneous use of ozone and CeO ₂ originated lower acute toxicity.