Degradation of typical environmental pollutants (ciprofloxacin, carbamazepine and 17-β estradiol) on supported TiO2 photocatalysts: Identification of degradation products and in silico toxicity assessment

Abstract

The study describes a few significant aspects of photocatalytic studies: (i) the methodology for finding optimal support for TiO2 photocatalytic films with possible environmental application and (ii) degradation of pollutants of widespread concern including detailed kinetic study and identification of degradation products with respective in silico toxicity assessment. Different cotton textiles and glass fiber mesh were studied as flexible supports for TiO2. Preliminary experiments were done with an aqueous solution of 2-HBA in a rectangular open channel reactor under UVA light, due to known kinetics and photocatalytic degradation pathway of 2-HBA. Further environmental application of the photocatalytic film on the most appropriate support was studied in the same reactor using ciprofloxacin (CIPRO), carbamazepine (CARBA) and 17β-estradiol (E2) as model environmental pollutants under UVA and artificial solar irradiation. A detailed kinetic study, including photon absorption effects, was performed using recently published models. Degradation products were identified by means of high-resolution mass spectrometry (UHPLC-QTOF MS system) with electrospray ionization analysis of the water samples. The environmental impact of photocatalytic oxidation of CIPRO, CARBA and E2 was addressed via in silico toxicity assessment of initial pollutants and respective degradation products.