DEGRADATION OF EMERGING CONTAMINANTS IN AQUEOUS MATRIXES BY PHOTOCATALYSIS WITH W10O324-

Contaminants of emerging concern (CECs), including pharmaceuticals, are frequently detected at low concentrations in natural waters and, even if some of them have not been established as causes of human illness, they can cause adverse effect on biota such as antibiotic resistance [1, 2]. Therefore, it is important to reduce their introduction in the environment by increasing the efficiency of wastewaters treatment plants [3]. This study aims to evaluate the photocatalytic action of decatungstate anion (W10O324-), both in solution and immobilized on modified silica particles, to degrade some pharmaceuticals in aqueous matrix. The target molecules, differing in chemical structure and physico-chemical characteristics, belong to β-blockers (atenolol and propranolol), antibiotics (sulfamethoxazole, trimethoprim, levofloxacin) and antiepileptic (carbamazepine) drugs. The characteristics of the heterogenized photocatalyst favor the interaction between photoactive sites and the drug molecule. Finally, the heterogeneous photocatalyst can be recycled without a significant loss of efficiency. This is an important finding because the heterogenization of a soluble photo-catalyst has some advantages such as increase of stability, easiness of recover and handling. The degradation process has been studied at ambient temperature, atmospheric pressure and at pH values similar to that of natural waters. Stability and reuse of the employed heterogeneous photocatalyst were also examined. EPR spin trapping technique and HPLC-MS analyses gave evidence that the degradation is mediated by OH• radicals. [1] Arroyo 2013; Water Resources Research Center, College of Agriculture and Life Sciences, The University of Arizona [2] O. A. Jones, J. N. Lester, N Voulvoulis, Trends Biotechnol., 2005, 23 (4), 163-167 [3] Pacific Institute (Editor) World Water Quality Facts and Statistics. Oakland: Pacific Institute. 2010