title: Degradation of triclosan by an integrated nano-bio redox process.
abstract: In this study, a sequential reduction-oxidation method was developed for complete degradation of triclosan (2,4,4'-trichloro-2'-hydroxydiphenyl ether, TCS) in aqueous solution. Rapid reductive dechlorination of TCS was achieved with palladized zero-valent iron nanoparticles (Pd/nFe), under anaerobic conditions, with generation of 2-phenoxyphenol as the sole dechlorination product. Sequentially, 2-phenoxyphenol was transformed into a non-toxic polymer using laccase (EC:1.10.3.2) derived from Trametes versicolor in the presence of natural redox mediator syringaldehyde (SYD). High performance liquid chromatography combined with electrospray ionization mass spectroscopy (HPLC-ESI-MS) revealed the formation of dimer and trimer products during the laccase-mediated transformation process. The efficiency of the integrated method is critically dependent on the Fe(2+) concentration, which was effectively controlled by optimizing the solution pH. To the best of our knowledge, this is the first report of a redox two-step hybrid system for the complete transformation of TCS into non-toxic products.
authors.affiliation: School of Environmental Science and Engineering, Pohang University of Science and Technology (POSTECH), Pohang, South Korea.
authors.forename: Varima
authors.initials: V
authors.lastname: Bokare
authors.forename: Kumarasamy
authors.initials: K
authors.lastname: Murugesan
authors.forename: Young-Mo
authors.initials: YM
authors.lastname: Kim
authors.forename: Jong-Rok
authors.initials: JR
authors.lastname: Jeon
authors.forename: Eun-Ju
authors.initials: EJ
authors.lastname: Kim
authors.forename: Yoon Seok
authors.initials: YS
authors.lastname: Chang
mesh_terms: D000332:Aerobiosis; D000891:Anti-Infective Agents, Local / Q000378:metabolism*; D002851:Chromatography, High Pressure Liquid; D006863:Hydrogen-Ion Concentration; D053768:Metal Nanoparticles; D036103:Nanotechnology; D010084:Oxidation-Reduction; D021241:Spectrometry, Mass, Electrospray Ionization; D014260:Triclosan / Q000378:metabolism*
chemical_list: D000891:Anti-Infective Agents, Local; D014260:Triclosan