Photocatalytic degradation of β-blockers by using immobilized titania/silica on glass slides

Photocatalytic degradation of five beta-blockers (acebutolol, atenolol, metoprolol, nadolol and propranolol) was investigated in aqueous media using immobilized TiO2 as a photocatalyst. The analyzed parameters were pharmaceutical removal and non purgeable organic carbon. Two different types of photocatalyst incorporated in sol-gel matrix were compared; P25 exhibited a higher photocatalytic activity compared to P90 (both from Evonik Degussa). Besides, optimal photocatalyst concentration and light intensity were determined. According to the results obtained, after 120 min of treatment a complete removal was achieved for all compounds (initial concentration 25 mg/L) using P25. After 240 min of irradiation a mineralization degree ranged froin 75% for acebutolol to 92% for propranolol. A longer illumination time was needed for complete removal of beta-blockers in river water. Main intermediate compounds were identified by high performance liquid chromatography coupled to mass spectrometry (HPLC-MS/MS) technique. (C) 2015 Elsevier B.V. All rights reserved.