title: Photocatalytic degradation of carbamazepine and three derivatives using TiO₂ and ZnO: effect of pH, ionic strength, and natural organic matter.
abstract: Removal of pharmaceuticals (PhCs) by photocatalysis is a promising avenue in water treatment. The efficiency of these treatments on PhC derivatives compared to their parent molecules remains poorly documented. The present study investigates the efficiency of photodegradation catalyzed by TiO₂ and ZnO nanoparticles on the removal of carbamazepine (CBZ) and three of its derivatives; carbamazepine epoxide (CBZ-E), acridine (AI), and acridone (AO). The effects of environmental parameters such as pH, ionic strength, and natural organic matter content on photodegradation efficiency (transformation after 6h and kinetics) were tested. We report that the efficiency of the catalysts (TiO2 and ZnO) can be very different when comparing CBZ and its derivatives (CBZ-E, AI and AO). TiO₂ was more efficient than ZnO at degrading CBZ and CBZ-E. For AI and AO, no significant differences were observed between the two catalysts. We also report that environmental parameters have contrasting effects on the efficiency of the photodegradation of CBZ compared to its derivatives. Changing pH and organic matter content had the most contrasted effects; the photodegradation of CBZ and CBZ-E was significantly affected by pH (especially in presence of TiO₂ NPs) and by the presence of natural organic matter. In contrast, the photodegradation of AI and AO was not affected by pH and organic matter. Only the photodegradation of CBZ was clearly affected by IS and solely at very high IS (1M). Overall, our results highlight that TiO₂ and ZnO catalysts present contrasted efficiency on the removal of CBZ when compared to its derivatives (CBZ-E, AI and AO). Our results also show that the effect of environmental parameters on the efficiency of the photodegradation of CBZ derivatives cannot be predicted based on the behavior of the parent molecule (CBZ).
authors.affiliation: Department of Chemistry, Université de Sherbrooke, 2500 Boul. de l'Université, Sherbrooke, (Qc) J1K 2R1, Canada.
authors.forename: Lounes
authors.initials: L
authors.lastname: Haroune
authors.affiliation: Department of Chemistry, Université de Sherbrooke, 2500 Boul. de l'Université, Sherbrooke, (Qc) J1K 2R1, Canada.
authors.forename: Maria
authors.initials: M
authors.lastname: Salaun
authors.affiliation: Department of Chemistry, Université de Sherbrooke, 2500 Boul. de l'Université, Sherbrooke, (Qc) J1K 2R1, Canada.
authors.forename: Alain
authors.initials: A
authors.lastname: Ménard
authors.affiliation: Department of Chemistry, Université de Sherbrooke, 2500 Boul. de l'Université, Sherbrooke, (Qc) J1K 2R1, Canada.
authors.forename: Claude Y
authors.initials: CY
authors.lastname: Legault
authors.affiliation: Department of Chemistry, Université de Sherbrooke, 2500 Boul. de l'Université, Sherbrooke, (Qc) J1K 2R1, Canada. Electronic address: Jean-Philippe.Bellenger@USherbrooke.ca.
authors.forename: Jean-Philippe
authors.initials: JP
authors.lastname: Bellenger
mesh_terms: D002220:Carbamazepine / Q000737:chemistry*; D009994:Osmolar Concentration; D010782:Photolysis; D014025:Titanium / Q000737:chemistry*; D014466:Ultraviolet Rays; D014874:Water Pollutants, Chemical / Q000737:chemistry*; D018508:Water Purification / Q000379:methods; D015034:Zinc Oxide / Q000737:chemistry*
chemical_list: D014874:Water Pollutants, Chemical; C009495:titanium dioxide; D002220:Carbamazepine; D014025:Titanium; D015034:Zinc Oxide
keywords: Carbamazepine; Derivatives; Environmental parameters; Nanoparticles; Photocatalysis