Effect of drinking water ozone treatment on select pharmaceuticals and personal care products (PPCPs) and endocrine disrupting compounds (EDCs)

The effect of five process variables on the transformation of 16 selected PPCP/EDCs during drinking water ozonation was systematically studied through 25-1 fractional factorial designed experiments. Dissolved Organic Carbon (DOC) content, ozone dose, and their interaction were most significant for all 16 compounds, and accounted for 60--98% of the observed variability in the transformation efficiencies. Temperature was a significant factor for most of the fast-reacting compounds (kO3 >10 4 M-1s-1), accounting for up to 20% of the change in transformation efficiency, but was not significant for the slow-reacting compounds (kO3 <103 M -1s-1). Ozone exposure of > 1.0 mg L-1 min-1 resulted in > 80% transformation of all the 16 compounds at both low (5 °C) and high (23 °C) temperatures. However, this transformation is expected to be strongly dependent on the nature of the DOC for the slow-reacting compounds.