USE OF SILVER-DOPED ZEOLITE TO ENHANCE THE PHOTODEGRADATION OF PPCPS IN THE PRESENCE OF DISSOLVED ORGANIC CARBON

USE OF SILVER-DOPED ZEOLITE TO ENHANCE THE PHOTODEGRADATION OF PPCPS IN THE PRESENCE OF DISSOLVED ORGANIC CARBON

By William R. Laliberte

A Lay Abstract of the Thesis Presented In Partial Fulfillment of the Requirements for the Degree of Master of Science (in Chemistry) August, 2012

Keywords: Zeolite, Photodegradation, DOC, Pharmaceutical, Binding

Pharmaceuticals and personal care products (PPCPs) contain a variety of chemicals that enter natural waters after use. The impact of these compounds on aquatic life as well as on humans has not been well studied, and wastewater treatment processes are not completely successful in removing PPCPs. Photodegradation by sunlight is a useful technique for reducing PPCP concentrations, but is inhibited by dissolved organic carbon (DOC) ubiquitously found in natural waters. To better understand the relationship with DOC and PPCPs and to find a way to enhance photodegradation, the binding behavior of several PPCPs was studied with various DOC sources under natural, low, and high pH. Silver-doped zeolite was introduced as way of increasing photodegradation by binding the PPCPs before the DOC could interact with them. Solutions were treated in the dark and under UV light conditions to observe overall effect that each component of the mixture had on photodegradation. Results were monitored using synchronous luminescence spectroscopy and high-performance liquid chromatography to observe the decrease of PPCP concentration over time. Binding of PPCPs with DOC was shown to influence overall photodegradation. The extent of this influence was shown to be related to how strongly the PPCP bound with DOC. Silver-doped zeolite appeared to increase the overall photodegradation of PPCPs with DOC present, especially when irradiated with UV light. The increase was postulated to be caused by the formation of a complex of DOC, the zeolite, and the PPCP.