Degradation of carbamazepine from aqueous solutions via TiO2-assisted photo catalyze

Abstract

Photocatalytic degradation of carbamazepine (CBZ) from spiked aqueous solutions, via a UV/TiO2 system was investigated, and the optimum photocatalyst type (P25 Degussa) and dose (500 mg/L), as well as irradiation time (45 min), was established. The degradation process kinetics was studied, and a degradation rate constant of 3.14 × 10 −5 M min −1 was calculated for CBZ, using the Langmuir–Hinshelwood equation. Experiments performed in the presence of scavengers showed that the main reactive species involved in the degradation process are holes and free hydroxyl radicals; superoxide radicals also play a role in CBZ degradation. Eight transformation products of CBZ were identified, and a possible degradation pathway, consisting of four routes, was proposed. Toxicity and genotoxicity tests were also performed for both untreated and treated CBZ solutions, proving that the use of a UV/TiO2 system represents a suitable treatment approach for aqueous systems with CBZ content.