title: Electrochemical degradation of sulfonamides at BDD electrode: kinetics, reaction pathway and eco-toxicity evaluation.
abstract: The investigation dealt with electrochemical oxidation of five sulfonamides (SNs): sulfadiazine (SDZ), sulfathiazole (STZ), sulfamerazine (SMR), sulfamethazine (SMN) and sulfadimethoxine (SDM) in aqueous solution at boron-doped diamond (BDD) electrode. All studied sulfonamides were degraded according to a pseudo first order kinetics. The structure of SNs had no significant effect on the values of pseudo first order rate constants. Increased degradation efficiency was observed in higher temperature and in acidic pH. Due to the presence of chlorine and nitrate SNs were more effectively oxidized from municipal wastewater treatment plant (WWTP) effluents than from pure supporting electrolyte Na2SO4. The intermediates identified by LC-MS and GC-MS analysis suggested that the hydroxyl radicals attack mainly the SN bond, but also the aromatic ring systems (aniline, pyrimidine or triazole) of SNs. Finally, the toxicity of the SNs solutions and effluents after electrochemical treatment was assessed through the measurement of growth inhibition of green algae (Scenedesmus vacualatus) and duckweed (Lemna minor). Toxicity of SMR, STZ, SMN solutions before and after electrochemical oxidation and SDM solution after the process in L. minor test was observed. No significant toxicity of studied SNs was observed in algae test.
authors.affiliation: Faculty of Chemistry, University of Gdansk, ul. Wita Stwosza 63, 80-952 Gdansk, Poland.
authors.forename: Aleksandra
authors.initials: A
authors.lastname: Fabiańska
authors.affiliation: Faculty of Chemistry, University of Gdansk, ul. Wita Stwosza 63, 80-952 Gdansk, Poland.
authors.forename: Anna
authors.initials: A
authors.lastname: Białk-Bielińska
authors.affiliation: Faculty of Chemistry, University of Gdansk, ul. Wita Stwosza 63, 80-952 Gdansk, Poland.
authors.forename: Piotr
authors.initials: P
authors.lastname: Stepnowski
authors.affiliation: Faculty of Chemistry, University of Gdansk, ul. Wita Stwosza 63, 80-952 Gdansk, Poland; UFT-Centre of Environmental Research and Sustainable Technology, University of Bremen, Leobener Straße UFT, D-28359 Bremen, Germany.
authors.forename: Stefan
authors.initials: S
authors.lastname: Stolte
authors.affiliation: Faculty of Chemistry, University of Gdansk, ul. Wita Stwosza 63, 80-952 Gdansk, Poland. Electronic address: ewa.siedlecka@ug.edu.pl.
authors.forename: Ewa Maria
authors.initials: EM
authors.lastname: Siedlecka
mesh_terms: D001895:Boron / Q000737:chemistry*; D002851:Chromatography, High Pressure Liquid; D018130:Diamond; D055664:Electrochemical Techniques; D004566:Electrodes; D008401:Gas Chromatography-Mass Spectrometry; D019684:Magnoliopsida; D044444:Scenedesmus; D013449:Sulfonamides / Q000737:chemistry* / Q000633:toxicity; D014865:Waste Disposal, Fluid / Q000379:methods*; D014874:Water Pollutants, Chemical / Q000737:chemistry* / Q000633:toxicity
chemical_list: D013449:Sulfonamides; D014874:Water Pollutants, Chemical; D018130:Diamond; D001895:Boron
keywords: Eco-toxicity; Electrochemical oxidation; Intermediates; Sulfonamides