Screening of Trace PhACs from Drinking Water and Removal of Gemfibrozil by Catalytic Ozonation at Pilot Scale

Trace pharmaceutical active compounds (PhACs) in drinking water have been attracting wide attention due to their hazardous impacts and negative effects on human health and ecology, and their removal from drinking water has been becoming a priority. Here, we used the methods of UPLC-triple-TOF/MS to screen PhACs in the Shangxi Drinking Water Treatment Plant (DWTP) in Zhejiang, East China, and found the occurrence of ibuprofen, propranolol, and gemfibrozil. The current processes of DWTP cannot remove PhACs effectively. Gemfibrozil has the highest average concentrations among PhACs with 0.464, 1.292, and 0.583 ng/L at the units of sand filtration, ozonation-biological aerated filter (ozonation-BAF), and clean water pool, respectively. In a pilot-scale test, the ozonation removes 21.1–67.9% of gemfibrozil, while the catalytic ozonation with ceramic catalyst achieves removal efficiencies of 55.6–85.2% in 3.6 min. Gemfibrozil is degraded by catalytic ozonation through two pathways: initiated by ·OH reaction with aromatic ring C2 or started with ·OH attacking aromatic ring C3. This study reveals the existence of PhACs in DWTP and validates a feasible way of catalytic ozonation with a ceramic catalyst to remove them quickly.