This award is from the Environmental Chemical Sciences Program in the Division of Chemistry. Professor Mads P. Sulbaek Andersen of California State University, Northridge and his group investigate Far Ultra-Violet (FUV) photolysis of airborne pollutants. Volatile organic pollutants are emitted from domestic and industrial processes and impact the human and environmental health on local to global scales. This project investigates the chemistry behind gas-phase Advanced Oxidation Processes (AOPs), which can assist in purification of air directly in factory emission points or in building air-conditioning systems. The promise of AOP is that the technology can limit the high energy consumption associated with traditional filter-based air-cleaning systems. However, the FUV photolysis and processes utilized in AOPs may result in compounds more toxic than the parent pollutant. An accurate understanding of the fundamental kinetics and chemical reaction pathways associated with FUV degradation of the organic pollutants is crucial to determining the nature of the resulting compounds and their environmental fate and impact. The results of this research impact our understanding at a molecular level of photochemical processes that impact urban air quality. The project provides training opportunities for undergraduate students and supports a research-rich learning environment at a primarily undergraduate, minority-serving, institution.
Photolysis quantum yields and chemical oxidation mechanisms initiated at FUV wavelengths (~121-200 nm) are not well known for volatile organic compounds. This project uses a temperature-controlled advanced photochemical simulation chamber with in-situ excimer-radiation lamps and multi-pass analytical optics. Reactants and oxidation products are monitored using optical techniques including Fourier transform infra-red spectroscopy and high-resolution vacuum UV spectrophotometry. UV absorption cross sections are measured from 120-200 nm, as a function of temperature, for important, high-volume compounds emitted from industrial processes (aromatics, carbonyls, N-containing compounds). The 172-nm quantum yields of photolysis are measured and the photolysis mechanisms are investigated as a function of pressure, temperature and O2 partial pressure. This research provides new knowledge on fundamental photochemistry and is used for quantitative assessment of the fates and impact of the products formed during FUV photochemistry of organic gaseous pollutants. The research team is largely comprised of undergraduate researchers at this minority serving institution.
This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
