Dr. D.M. O'Carroll - Research Interests

Improved Understanding of Water and Energy Transport in Unsaturated and Saturated Systems

My interests in water and energy transport has application to green roofs, contaminated site remediation, CO2 sequestration and agriculture. These interests, in part, lie in the development of capillary pressure/relative permeability/saturation constitutive relationships that are used in numerical models for the prediction of water and energy transport in permeable media. One of my studies evaluated the capabilities of a numerical model to predict observed non isothermal behavior. The computer model was then used to simulate field scale scenarios of non isothermal removal of a viscous NAPL.

Assessment of Nanoparticle (Colloid) Transport in the Environment

Nanotechnology is an emerging industry in Canada and throughout the world. This new area is met with both excitement and skepticism. The risks of nanoparticles in subsurface environments are as yet unknown, limited by a lack of basic scientific understanding of nanoparticle transport in water bearing soils . My work in this area involved assessing carbon nanotube and silver nanoparticl transport in column experiments and modeling nanoparticle transport at the field scale. For more information about this project please click here.

Nanotechnology for Contaminated Site Remediation

Nanoparticles have tremendous potential in the development of innovative groundwater remediation technologies. I supervises a number of graduate students and postdoctoral fellows investigating the utility of nanoiron and bimetallic nanoparticles at sites contaminated with chlorinated solvents and heavy metals. This work has generated significant industry and consulting company interest with key partnerships in place (e.g., Dow Chemical, CH2MHill, Geosyntec, AMEC) to transfer the developed technologies to the field. As an example of this a field trial took place in Sarnia in early Nov. 2010 to test methodologies and technologies developed in the laboratory to degrade contaminants in the field. A second field trial that took place in Feb. 2011 was the focus of a Oct. 2011 CBC The Nature of Things special. For more information about this project please click here.

Green roofs for storm water management and reduced heat island effect

Although popular and arguably successful, green roofs have not received systematic assessment and scientific characterization. The difficulties of assessment are compounded by the multiple benefits of green roofs that make their evaluation more complex than those of ‘cool’ (high-albedo) roofs. To date, relatively little work has been completed for the development of green roof design guidelines in Australia although there is considerable interest in both the academic community and the construction community.

The current research project that I lead involves quantification of green roof performance at a variety of field sites where performance is quantified as the extent that green roofs attenuate and reduce storm water runoff as well as reduce building energy consumption. In additional to significant field components this theme also includes detailed characterization of plant survival, in collaboration with an ecologist colleague, detailed characterization of growth media, numerical modelling of water and energy transport in the green roof as well as urban scale modelling of green roof performance at the larger urban scale, in collaboration with a geography colleague. Coupling of water and atmospheric flows with the energy balance is enabling our group to make significant advances in the engineering design of green roofs. To learn more about green roof research at Western click here.