Systematic investigation of parameters affecting ozonation oxidation of emerging contaminants.

The effect of five process variables—pH, dissolved organic matter (DOM), ozone concentration, contact time, and temperature— on the removal efficiency of 14 selected pharmaceutically active compounds and bisphenol A was studied through fractional factorial- designed experiments. Results showed that DOM content and ozone dose had the most significant effect, accounting for 60-99% of the observed variability in oxidation efficiencies for compounds with both fast and slower reaction rates with ozone. Oxidation efficiency of > 90% is expected for the fast-reacting compounds at ozone exposures > 1.3 mg/L × min, over the wide range of operating conditions used in the study. For compounds with a slower reaction rate with ozone, the oxidation efficiency is expected to be variable and strongly dependent on the characteristics of the raw water, particularly the concentration and nature of the DOM. [ABSTRACT FROM AUTHOR]