Abstract

Ozonation, TiO2 photocatalytic ozonation (PCO) and WO3 PCO were used to demonstrate the removal of carbamazepine (CBZ), an antiepileptic drug commonly found in water bodies. The experiment was carried out in a lab-scale reactor (500 mL) at pH 7, CBZ concentration 1 mg/L and 0.25 g/L catalyst dose. The mixture was stirred in the dark for 30 minutes to achieve adsorption equilibrium. A UV and visible light source of 8 watt was used to photoactivate TiO2 and WO3. Ozonation alone using an ozone dose of 10 mg/hour was found to be very effective for CBZ removal. In all the processes investigated, CBZ was easily removed while the removal of by-products varied depending on the reaction pathway. The mineralization efficiencies (TOC removal) for complete by-products removal using ozonation, TiO2 PCO and WO3 PCO were 95, 73 and 62% respectively. TiO2 PCO performed better than WO3 PCO in achieving complete mineralization, but it would not be a sustainable solution considering the costs of UV lamps, harmful UV rays and toxicity of TiO2. The removal efficiency of WO3 PCO can be increased by increasing the ozone dose and duration of treatment.

Graphical Abstract

Graphical Abstract
Graphical Abstract
You do not currently have access to this content.