title: Carbamazepine degradation by photolysis and titanium dioxide photocatalysis.
abstract: We investigated the degradation of carbamazepine by photolysis/ultraviolet (UV)-C only and titanium dioxide photocatalysis. The degradation of carbamazepine by UV-only and titanium-dioxide-only (adsorption) reactions were inefficient, however, complete degradation of carbamazepine was observed by titanium dioxide photocatalysis within 30 min. The rate of degradation increased as initial carbamazepine concentration decreased, and the removal kinetics fit well with the Langmuir-Hinshelwood model. The addition of methanol, a radical scavenger, decreased carbamazepine removal, suggesting that the hydroxide radical played an important role during carbamazepine degradation. The addition of oxygen during titanium dioxide photocatalysis accelerated hydroxide radical production, thus improving mineralization activity. The photocatalytic degradation was more efficient at a higher pH, whereas the removal of carbamazepine and acridine (a major intermediate) were more efficient under aerobic conditions. The mineralization of carbamazepine during photocatalysis produced various ionic by-products such as ammonium and nitrate by way of nitrogen dioxide.
authors.affiliation: Department of Environmental Health, School of Public Health, Seoul National University, Seoul, Korea.
authors.forename: Jong-Kwon
authors.initials: JK
authors.lastname: Im
authors.forename: Hyun-Seok
authors.initials: HS
authors.lastname: Son
authors.forename: Young-Min
authors.initials: YM
authors.lastname: Kang
authors.forename: Kyung-Duk
authors.initials: KD
authors.lastname: Zoh
mesh_terms: D000927:Anticonvulsants / Q000737:chemistry*; D002220:Carbamazepine / Q000737:chemistry*; D002384:Catalysis; D006863:Hydrogen-Ion Concentration; D015394:Molecular Structure; D010782:Photolysis; D014025:Titanium / Q000737:chemistry*; D014865:Waste Disposal, Fluid / Q000379:methods; D014874:Water Pollutants, Chemical / Q000737:chemistry*; D018508:Water Purification / Q000379:methods
chemical_list: D000927:Anticonvulsants; D014874:Water Pollutants, Chemical; C009495:titanium dioxide; D002220:Carbamazepine; D014025:Titanium