Research Interests
Dr. Mumford is interested in the movement of multiple fluid phases (water, oil, gases) in porous media, and the mass transfer between those phases. These processes are relevant to many important environmental systems. For example, soil and groundwater can be significantly contaminated by the accidental release or improper disposal of non-aqueous phase liquids (NAPLs). These hazardous chemicals include petroleum fuels (gasoline, diesel fuel), chlorinated solvents (dry cleaning chemicals, degreasers), and coal tar. Contamination can jeopardize drinking water sources and limit the redevelopment of brownfield sites, which are critical to the sustainable development of urban areas. The remediation of sites contaminated by these chemicals is a significant scientific and engineering challenge. An understanding of how these chemicals are distributed, and how they are transferred to the surrounding groundwater, is required to assess potential risk and design appropriate remediation strategies. Of particular interest to Dr. Mumford is how the presence of gas bubbles, which can be generated by physical trapping mechanisms or produced by remediation-related reactions, can affect these processes. Dr. Mumford’s current research focuses on the impact of gas generation during in situ remediation, including oxidation, reduction, and thermal treatment technologies.
Graduate Students and Postdoctoral Researchers
Paul Hegele
Hometown: Vancouver, British Columbia
Email: 6ph13@queensu.ca
Education: B.Sc. (Eng) Civil Engineering, Queen’s University (2011)
Master’s research: Assessing and enhancing gas production and connectivity during Electrical Resistance Heating (ERH), a thermal remediation technology that targets contaminated soils and groundwater. Other research interests include modelling discontinuous gas flow with macroscopic invasion-percolation techniques and using light transmission methods to quantify local saturations in experimental flow cells.
Eric Martin
Hometown: Richmond Hill, Ontario
Email: emartin@ce.queensu.ca
Education: B.Sc. (Eng) Chemical Engineering, Queen’s University (2003); B.A. English Literature, Queen’s University (2003); M.Sc. (Eng) Civil Engineering, Queen’s University (2009)
Co-supervisor: Dr. Bernard Kueper (Queen’s University)
Ph.D. research: Research centered on laboratory experimentation using electrical resistance heating (ERH) as a groundwater remediation method. Contaminants of interest are dense, non-aqueous phase liquids (DNAPLs), which are often toxic and considered carcinogenic. Special concerns include gas production and transport, and the effect that changes in geological and hydraulic conditions have on this process.
Nizar Mustafa
Hometown: West Bank, Palestinian Authority
Email: nmustaf@uwo.ca
Education: Ph.D. Environmental Engineering, Oregon State University (2009); M.S. Water and Environmental Engineering, An-Najah National University, West- Bank, Palestinian Authority (1996); B.S. Chemical Engineering, Jordan University of Science and Technology, Jordan (1989)
Co-supervisors: Dr. Jason Gerhard (Western University) and Dr. Denis O’Carroll (Western University); member of RESTORE group (http://www.eng.uwo.ca/research/restore/)
Postdoctoral research: Risk assessment at key receptors surrounding contaminated sites based on the evaluation of the fate, transport, and transformation of industrial contaminants at the scale of a site versus a community. Monte Carlo suites of simulations are used to investigate the influence of heterogeneity in subsurface physical, chemical and biological properties on the risk to groundwater, surface water, and indoor air receptors in a three-dimensional aquifer, and assess the implications for risk-based decision making.
Cindy Zhao
Hometown: Henan, China
Email: cindy.zhao@ce.queensu.ca
Education: B.Sc. Earth Sciences, University of Waterloo (2010)
Co-supervisor: Dr. Bernard Kueper (Queen’s University)
Master’s research: Performing laboratory experiments using Time Domain Reflectometry (TDR) to quantify the gas generation rate by heating of multi-component NAPL. Multi-component NAPL partitioning between NAPL-Aqueous-Gas phases during heating are studied by gas and soil sampling and VOCs analysis. The examination of co-boiling plateau of heating Multi-component NAPL and water is also part of my research.
Undergraduate Students
Jonah Munholland
Hometown: Martensville, Saskatchewan
Email: 6jm47@queensu.ca
Education: B.Sc. (Eng) Civil Engineering, Queen’s University (Expected Date: April 2012)
Undergraduate research: Develop a visualization technique to assess non-wetting phase dissolution in saturated porous media using trapped, disconnected gas as a surrogate for dense non-aqueous phase liquid (DNAPL). The residual gas and dissolved plume are imaged to quantify dissolution and aqueous transport at small scales.
Lee-Ann Sills
Hometown: Bannockburn, Ontario
Email: leeann.sills@queensu.ca
Education: B.Sc. (Eng) Civil Engineering, Queen’s University (Expected Date: April 2012)
Co-supervisor: Dr. Greg Siemens (Royal Military College of Canada)
Undergraduate research: Investigating discontinuous gas flow mechanisms in a heterogeneous system of transparent soil, instead of a translucent system such as glass beads and water. Transient gas saturations are quantified by image processing techniques and matched to numerical simulations.
Kirill Stepanov
Hometown: Ithaca, New York
Email: 7ks48@queensu.ca
Education: B.Sc. (Eng) Civil Engineering, Queen’s University (Expected Date: April 2012)
Undergraduate research: Visual observation of gas formation and transport in porous media using a light transmission technique. Study of gas production applicable to groundwater remediation technologies, including phase change during in situ thermal treatment and hydrogen production from nanoscale zero valent iron (nZVI) injection.