Organic Pollutant Transformations in the Natural Environment and in Engineered Processes

Speaker:Inez Hua, Ph.D.,
Purdue University,
School of Civil Engineering,AbstractThis seminar will focus on two major themes: the abiotic, environmental transformation
of emerging contaminants, and the accelerated destruction of water pollutants via engineered
photochemical reactors. Photolysis and free-radical reaction mechanisms are the scientific basis
for each theme.The first research topic is part of a multi-disciplinary project focused on an emergingcategory of pollutants, the brominated flame retardants (BFRs). Certain BFRs have been widely detected in the environment, in wildlife, and in people. Photochemical reaction of BFRs provides an abiotic transformation mechanism in the environment, and the process occurs under a variety of conditions. Data will be presented which demonstrates the photolytic debromination of BFRs when the compounds are irradiated with either artificial or natural sunlight. The decomposition kinetics and products, and the quantum yield (for selected wavelengths of natural sunlight) will be discussed. The BFRs were either dissolved or adsorbed to mineral surfaces during irradiation. Complementing the research on environmental fate of BFRs is additional work that quantifies the inventory of BFRs in existing products (including electronics). We also investigate the potential pathways of BFRs to the environment from products and materials during their manufacture, use, recycle or disposal. The second research theme is focused on water pollution control. Critical infrastructure in the United States includes the water sector, and it is necessary to develop and optimize technologies that remove or destroy a range of known and potential water contaminants. The aim of this project is to explore the effectiveness of photochemical oxidation in destroying chemical threat agents. The destruction of nicotine and several organophosphate compounds has been investigated. The reaction kinetics and mechanism for each compound will be discussed. Also, the results of a process optimization study will be reported; a central composite Design of Experiments (DOE) was completed to provide quantitative information for optimizing the destruction of nicotine and phosphamidon.

Location: Kaprielian Hall (KAP) - rielian Hall, 203

Audiences: Everyone Is Invited

Contact: Evangeline Reyes