2013 – NSERC Engage Grants Program- Removal of Emerging Pollutants from Drinking Water by the Combined Photolytic Ozonation and Ultrafiltration Processes
This pilot-scale project investigated the expansion in the capacity of the Dagua drinking water treatment technology that uses a combination of ozonation and membrane ultrafiltration processes, enabling it to remove a wide range of emerging pollutants including pharmaceutical compounds, hormones and antibiotics that are commonly found in surface waters and resist degradation by the conventional biological and physical-chemical processes. The advanced treatment technology developed in this project results from the incorporation of a photolytic ozonation (ozone/UV) process downstream of the ultrafiltration membranes to generate free radicals which are potent chemical agents, particularly efficient in disintegration of emerging pollutants. The Dagua technology uses ozone to degrade dissolved organic compounds and disinfect water by killing the pathogenic substances. The membrane ultrafiltration further removes the suspended particles and precipitated matter and improves the turbidity and color of water. In addition, the ozone microbubbles, generated by a proprietary process, eliminate the need for frequent backwashing or use of chemicals to clean the membranes while preventing their clogging, thus supporting long-term operation of the membranes and preventing the generation of chemical waste sludge. The addition of O3/UV process to the existing Dagua technology produces an advanced treatment technology by generating hydroxyl (OH) radicals which are more powerful oxidants than ozone, considerably increasing the efficiency of treatment and expanding the application of this technology for the removal of a large group of pollutants that are refractory to ozonation and resist degradation.