Chemistry Weekly Seminar - Dr. Tara Kahan, University of Saskatchewan
Tara Kahan, Associate Professor in the Department of Chemistry, University of Saskatchewan, will present a seminar at 1:30 pm in ARTS 146.
Title
Atmospheric Chemistry on Ice and in the House
Abstract
Chemistry in snowpacks and at ice surfaces can dramatically affect atmospheric composition and the fate of atmospheric pollutants. Including snow and ice as reaction media in coupled chemistry-atmospheric models is challenging because we generally do not understand how reactions occur there. There is not a lot of research in this area, and existing results are often conflicting. We combine measurements of reaction kinetics in laboratory-prepared snow and ice with microspectroscopic investigations of the physicochemical properties of ice surfaces in the presence of environmentally relevant solutes to link reactivity to physicochemical properties of the local environment. This work shows that reaction environments can be very different at ice surfaces compared to in liquid aqueous solution and provides mechanistic and kinetic insight that may help improve model parameterization.
Indoor air quality is as important as outdoor air quality, but it is less well understood. While the effects of emissions (e.g., from building materials) and intrusion of outdoor air have been studied for decades, the role of chemistry in indoor air composition and quality is less well-studied. Oxidation reactions drive chemistry in the outdoor atmosphere and largely control its composition. Indoors, oxidant levels are generally expected to be lower, leading to fewer chemical transformations. However, indoor oxidant levels can change dramatically due to human activities such as cooking, cleaning, and even opening windows. Our group has combined field measurements, chamber studies, and modelling to characterize the oxidizing capacity in residential and non-residential buildings. We have focused on the role of occupant activities on indoor air composition, with a recent emphasis on the effects of sanitizing and disinfecting surfaces. I will discuss the conditions under which oxidation reactions are likely to be important indoors and will highlight recent work from our group on the effects of cleaning and disinfecting surfaces on air composition in homes and non-residential buildings.
Date: Friday, September 9
Time: 1:30 pm
Place: Arts 146