Re ECF Project: 2011-24

Project Title: Probing the environmental fate of UV filters: occurrence, bioaccumulation and degradation

Applicant: Dr. Kelvin Sze-Yin Leung of Hong Kong Baptist University

Total Approved Grant: $868,320.00

Duration: 1/11/2012 to 31/10/2014

Project Status/Remarks: Completed

The project seeks to develop analytical LC-MS/MS and GC-MS/MS methods to identify and quantify 12 UV filters in water and sediment. Based on the developed methods, occurrence of target UV filters in Hong Kong aquatic environments, including regions related to recreational activities, water treatment facilities and aquaculture ponds would be studied. The study would be extended to the water supply resources in the Pearl River Delta region as a guide to the quality of the raw water supply to Hong Kong.

Summary of the Findings/Outcomes:
As a widely studied advanced oxidative process for wastewater treatment, ozonation provided higher removal efficiency with lower power consumption compared with the treatment of photocatalysis with visible light and UV-irradiation. According to their research, ozonation is also able to detoxify the treated wastewater with no toxic by-products detected. Therefore, the complete mineralization of twelve target UV filters was investigated by simulative ozonation in lab-scale. At the concentration of 0.5 µg•mL-1 in 100 mL milliQ water with 1% (v/v) of methanol, complete mineralization of twelve target UV filters were achieved with the O3 flow rate of 1.2 mg•min-1. Except for OC, the other eleven UV filters were completed mineralized within 2-5 min, while it took about 30 min to reach the endpoint of ozonation treatment for OC. Consistent results were also reported as the removal efficiency over 95% for EHMC and BP-3 within 15 min, over 99% for 4-MBC and 92% for OC. As a result, ozonation performed a good efficiency and fast in mineralization of UV filters.