Ozonation of sulfamethoxazole promoted by MWCNT

Multi-walled carbon nanotubes (MWCNTs) with different surface chemical properties were prepared by oxidative and thermal treatments. Samples were characterized by nitrogen adsorption, temperature programmed desorption and pH at the point of zero charge. These catalysts were tested in the ozonation of sulfamethoxazole. Complete conversion of this compound was achieved after approximately 30 min. MWCNTs significantly enhanced the mineralization degree compared to single ozonation. Some oxidation products were quantified. The catalytic process is favored by MWCNTs with basic or neutral properties. Successive experimental runs of SMX degradation show that the catalysts suffer some deactivation.

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► MWCNT with different surface chemical properties were prepared and characterized.
► These materials were tested as catalysts in the ozonation of sulfamethoxazole (SMX).
► Surface chemistry of MWCNTs plays an important role in the catalytic ozonation of SMX.
► Samples with basic or neutral properties and high surface areas favored the process.
► Successive catalytic runs showed some deactivation due to carbon surface oxidation.