FORMATION OF OZONATION DBPs IN TERTIARY WASTEWATER

Ozonation has been used for disinfection in wastewater treatment since the 1970s. Recently, ozonation has gained more attention for advanced wastewater treatment during water reuse applications for destruction of endocrine disrupting compounds and pharmaceuticals. In this study, the disinfection byproduct formation was investigated at dosages common for wastewater disinfection and trace contaminant removal. Tertiary treated wastewater was collected for pilot scale studies with ozonation and advanced oxidation with ozone and hydrogen peroxide. Several ozone dosages (2.1-8.7 mg/L) were applied to examine the coliform inactivation. Kinetic data was collected to examine the ozone demand, ozone decay, and hydroxyl radical formation. Ozone disinfection byproducts were monitored including bromate, assimilable organic carbon (AOC), carboxylic acids, and aldehydes. Results showed that ozone provided optimal disinfection of total and fecal coliforms while minimizing the DBP formation versus advanced oxidation with ozone and hydrogen peroxide.