Transformation in Bulk and Trace Organics during Ozonation of Wastewater

The aim of this paper is to determine the ozone dosages needed to oxidize bulk and trace organics. Treated effluent from eight full-scale wastewater treatment plants was collected and subjected to lab-scale ozonation. Because both organics and inorganics exert ozone demand, an approach was developed to calculate only the ozone demand associated with organics. This method allowed normalization of dosing parameters to correlate with removal of color, UV absorbance, plus oxidation of trace organics and nitrosamine precursors. We also showed that ozonation effectively reduces the fraction of organic matter characterized as "colloidal organic matter," thereby reducing the potential for membrane fouling.