Campus
- Scarborough (UTSC)
Fields of Study
- Environmental Chemistry
Areas of Interest
Our research is concerned with understanding and quantifying the fate and behaviour of chemicals in the environment. The focus is on phase partitioning and transport of organic contaminants.
The Global Fate of Persistent Contaminants
The presence of persistent, anthropogenic compounds in remote areas such as the Arctic has resulted in considerable interest in their global transport and accumulation behaviour. Our work aims at an improved conceptual understanding and quantification of the processes involved in the global dispersion of these chemicals. In 1993, we put forward the hypothesis of global fractionation and cold condensation for semi-volatile organic compounds, which states that certain characteristics make chemicals prone to preferential deposition and accumulation in cold areas. We are presently developing and testing a passive air sampling technique to probe this hypothesis by mapping the large scale dispersion behaviour of persistent contaminants across Canada. We are further developing and using zonally averaged global computer models to simulate the long term fate of persistent organic chemicals.
The Air-Surface Exchange of Semi-Volatile Organic Compounds
Compounds that readily exchange between the vapor and the sorbed state under environmental conditions are often referred to as semi-volatile. Atmospheric deposition of such chemicals is reversible and this two-directional exchange between the atmosphere and the Earth's surface is the key to the understanding of their complex environmental behaviour. We are interested in various aspects of the atmosphere-surface exchange of such chemicals, including the influence of temperature and the role of vegetation, specifically forests.
Measurements and Estimation Methods of Physical-Chemical Properties and Phase Equilibria
A prerequisite for virtually all investigations in environmental chemistry is the availability of data on a chemical's basic physical-chemical properties such as vapour pressure, solubility in water, octanol-water partition coefficient KOW, and Henry's law constant. Our focus in this area is on the development and use of simple and fast chromatography-based estimation techniques of these physical chemical properties, as well as the measurement of environmentally relevant phase equilibria and their prediction from basic physical-chemical properties.