WRRI Research Projects - 2012 Research Project: Aria Amirbahman
Photocatalytic Degradation of Pharmaceuticals and Personal Care Products (PPCPs) in Natural Water using Silver-Doped Zeolites
Pharmaceuticals and personal care products (PPCPs) are a diverse group of organic contaminants of emerging concern in U.S. water supplies. Despite minute quantities of individual compounds, the sheer number of a variety of PPCPs found is quite large. Their continued input and occurrence in natural waters from human and animal excretions, industrial use, incomplete treatment at wastewater facilities, as well as improper disposal of unused or expired medicine, affect water quality and generate adverse impact on drinking water supplies, ecosystems and human health.
The most widely used processes to remove these and other micropollutants at water treatment plants involve enhanced coagulation, membrane and granular-activated carbon (GAC) adsorption, ion exchange and oxidation. Due to the wide array of chemical structures and properties associated with PPCPs, no one single treatment can remove them all. Given the relative little research on the removal of PPCPs under natural environmental conditions, there is an evident need for effective and practical water remediation techniques to remove PPCPs in natural waters. Additionally, the effect of ubiquitous dissolved organic carbon (DOC) in natural waters on the fate and degradation of these organic micropollutants is not completely understood, and as such, it is important that any degradation strategy should consider the presence of DOC. Enhanced photolytic techniques can be a significant destructive pathway for the PPCPs.
This study tests a novel zeolite doped with silver ions to photocatalytically degrade a list of PPCPs contaminants in the presence of DOC. Several individual PPCPs and their mixtures will be photodecomposed using the silver-zeolite system to investigate their degradation and removal capacity by this novel technology. The decomposition rate will be monitored using fluorescence spectroscopy and analyzed using parallel factor analysis (PARAFAC). The effect of DOC on the removal of PPCPs as well as the photodecomposition products will be evaluated using gas chromatograph-mass spectroscopy (GC-MS).