Conferences - Seminars
EESS talk on "Chemically-informed monitoring of atmospheric particulate matter"
By Prof. Satoshi Takahama, Assistant Tenure Track, Atmospheric Particles Research Laboratory, APRL Short biography: Satoshi Takahama has been a tenure-track assistant professor at EPFL and head of the Atmospheric Particle Research Laboratory (APRL) since 2012. He received his BS in civil engineering from the University of Texas at Austin and PhD in chemical engineering from Carnegie Mellon University, and spent six years at the Scripps Institution of Oceanography as a postdoc and scientist before coming to EPFL. The research of APRL encompasses various domains of atmospheric aerosol characterization through numerical simulation, statistical modeling, and hardware development, with recent work focusing on chemical characterization of the carbonaceous fraction of particulate matter in monitoring networks.
The World Health Organization (WHO) lists air pollution as the world's "largest single environmental health risk". Particulate matter less than 2.5 micrometers in diameter, or PM2.5, is a pervasive pollutant emitted or formed from a multitude of sources and contains thousands of different types of compounds. Its total mass is regulated out of concerns for their impact on cardiovascular and respiratory health of the human population, but it is estimated that 84\% of the world's population is exposed to conditions that exceed recommended atmospheric concentration limits set forth by the WHO.
Continuous monitoring of PM2.5 is therefore necessary to understand the local air quality, emission control strategies, and impacts regulations have on their concentrations. In this effort, chemical speciation must accompany mass concentration measurements to understand their source contributions, how they change over time, and evaluate our capability to simulate their emission, transport, and photochemistry in air quality models. In this talk, I describe the current state-of-the-art for PM2.5 chemical speciation monitoring, and introduce a low-cost, chemically informative technique based on Fourier Infrared Transform (FTIR) spectroscopy that can augment current practices in PM2.5 measurement.
FTIR characterizes the chemical composition of PM2.5 based on absorption of mid-infrared radiation by its constituent molecules, which reveals the underlying functional group structures present. While FTIR has enjoyed a long history for measurement of atmospheric gas composition, interpretation of condensed-phase spectra poses significant challenges that we overcome through judicious selection of calibration samples and mathematical algorithms. I describe our technical efforts to make FTIR useful toward the monitoring community and other endeavors, coupled with a means for improving our evaluation of chemical simulations using functional group representations that can be obtained by FTIR. Finally, I describe a novel finding that results from our work in applying FTIR to a large data set consisting of monitoring network measurements in the US, Switzerland, and other field campaigns, which potentially simplifies our understanding of the complex organic fraction in atmospheric particulate matter.
Organization EESS - IIE
Contact Prof. D. Andrew Barry, IIE director
Accessibility General public
This event is internal