Degradation of emerging concern contaminants in water by heterogeneous photocatalysis with Na4W10O32

Contaminants of emerging concern (CECs), including pharmaceuticals, are frequently detected at low concentrations in natural water and can cause adverse effect in biota, such as antibiotic resistance. Therefore, it is important to reduce their introduction in the environment by increasing their removal efficiency from wastewaters. In this work, a new photocatalytic method for removal of three CECs target molecules (i.e. atenolol, levofloxacin, trimethoprim) from water is proposed. The photoactive species is decatungstate anion both in solution and immobilized on modified silica particles. The degradation process is studied at ambient temperature, atmospheric pressure and at pH values similar to that of natural waters. EPR spin trapping technique and HPLC–MS analysis give evidence that degradation is mediated by OH[rad] radicals. The heterogeneous catalyst is stable and can be recycled without a significant loss of efficiency thus opening the possibility of developing new solid materials with interesting photocatalytic performance.