Prof. Arthur Chan
- Atmospheric chemistry, air pollution and health impacts
- Developing analytical methods for complex mixtures
- Chemical characterization of semivolatile and particle-phase emissions
- Atmospheric oxidation chemistry of organic compounds
Developing analytical methods for complex mixtures
Chemically complex mixtures, such as crude oil and its derivatives, biofuels and biomaterials, are prevalent in the environment. Their sources and environmental fates are often poorly understood, owing to the complexity in their composition. Our research group focuses on developing analytical techniques to characterize these environmental mixtures. We develop techniques to speciate organic compounds in atmospheric aerosol by carbon number, branching and cyclization on a laboratory scale. Through understanding the molecular characteristics of these mixtures, we can better constrain their sources, properties, and environmental fates.
Chemical characterization of semivolatile and particle-phase emissions
Organic aerosol is a major fraction of particulate matter, and has important effects on global climate change and local air quality. It can be directly emitted from sources (primary) or formed from oxidation of volatile or semivolatile emissions (secondary). One major focus of the research group is speciating in urban emissions of semivolatile and particle-phase compounds. Specific compounds unique to various sources are used to estimate the overall contribution to atmospheric organic aerosol.
Atmospheric oxidation chemistry of organic compounds
Most organic aerosol is secondary, formed from atmospheric oxidation of gas-phase and semivolatile emissions. We simulate the oxidation of primarily emitted compounds to form secondary products in a laboratory reactor. This allows us to control important environmental variables, such as temperature, oxidants and humidity. With detailed knowledge of the composition, we can probe the effect of molecular structures on aerosol formation mechanisms. The oxidative capacity of laboratory-generated aerosol is also linked to the effect of particulate matter on human health.
Prof. Frank Gu
- Nanotechnologies with real-world applications
- Ocular delivery of nanomedicines
- Nano-enabled photocatalyst for water remediation
- Nanoparticles for soil remediation
- Nanomaterials for pathogen detection
Our laboratory specializes in the development of self-assembled polymeric nanoparticles for the delivery of conventional small molecule therapeutic agents. Our technology aims to improve the therapeutic index of currently available drugs by optimizing their efficacy and toxicity, and to improve the solubility and stability of drug entities that have been stalled in preclinical trials because of suboptimal biochemical properties.
- Development of biomaterials for nanomedicine and biopharmecuticals
- Targeted nanoparticles for differential delivery and controlled release of drugs
The central challenge in administering polymeric nanoparticles in vivo lies in the rapid particle clearance from the systemic circulation by the liver and spleen. As a result, only a small fraction of the administered nanoparticle dose is able to reach the targeted diseased cells and tissues. The nanoparticle clearance process is initiated when blood plasma proteins bind to the particle surface, making them visible to macrophages.
We propose that the rate of nanoparticle clearance by macrophages can be substantially decreased by systematically optimizing the surface properties of polymeric nanoparticles. We are developing a high-throughput combinatorial screening technique for studying the nanoparticle physicochemical properties to minimize blood protein adsorption on the particle surface.
Our lab also specializes in designing and optimizing the processes in nanoparticle manufacturing, which include particle formation, collection, drying and sterilization.
Prof. Vladimiros Papangelakis
- Aqueous and Environmental Process Engineering
- Water purification by forward osmosis
- Bio-hydrometallurgy of sulphidic wastes for base metal recovery, and remediation
- Aqueous chemistry and recovery of rare earth elements
Aqueous and Environmental Process Engineering
The mining and metals industry is facing the need to develop novel technology that addresses the requirements for sustainability in the extraction and processing of natural mineral resources. The Aqueous Process Engineering and Chemistry (APEC) group is providing solutions in the processing of complex mineral resources by studying the fundamentals of aqueous process chemistry and engineering to recover and produce metals or metallic products by hydrometallurgical routes. The research focuses on developing novel chemical processing ideas to:
- Treat increasingly complex mineral deposits with low metal content including wastes, for the recovery and separation of base, precious and critical rare earth metals;
- Reduce the environmental impact (on water, land, and air), as well as minimize the use of energy and chemicals including water;
Specific project examples are:
- Water purification by forward osmosis: Removal of soluble salts by lower energy consuming technologies compared to reverse osmosis and evaporation. Introduces low-cost bleed of salts and process water recycling to minimise fresh water intakes.
- Bio-hydrometallurgy of sulphidic wastes for base metal recovery, and remediation:Bioleaching of sulphidic wastes to recover pay metals and discharge the acid-mine-drainage toxicity of tailings.
- Aqueous chemistry and recovery of rare earth elements: Ion exchange leaching of ionic clays and production of a mixed oxide product by novel process configurations.
- Recovery of metals by molten salt hydrate systems: Development of new chemistry that uses very little water and moderate energy input to extract metals from raw materials.
- Pressure oxidation of metallurgical wastes (slags) for base metal recovery and remediation: Total remediation and cleanup of waste slags with simultaneous recovery of base metals by POX technology.
- Development of sensors for acid and redox monitoring in aqueous streams at high temperatures: In situ monitoring by robust sensors in a variety of slurry streams in temperatures ranging from room to those in autoclaves
- Chemical modeling of complex aqueous electrolyte solutions: Development of dedicated databases for modeling the chemistry (i.e., speciation, solubility, vapor-liquid equilibria) of salts and other compounds in complex multicomponent process solutions within very wide temperature ranges.
Prof. Elodie Passeport
- Removal of contaminants in natural and engineered environments
- Passive water treatment systems
- Stable and radio isotope tracing
To protect water quality from adverse effects due to these and other emerging contaminants, the research of our group is driven by three main objectives:
(1) to track the behavior of specific emerging contaminants in surface waters;
(2) to develop and evaluate novel cost-effective water treatment technologies based on ecological engineering principles;
(3) to develop a new application for stable isotope techniques to quantify trace levels of emerging contaminants in surface waters.
This information is vital for the development of appropriate policies and engineering solutions for use, disposal, and sustainable removal of these chemicals.
Prof. Barbara Sherwood Lollar
- Compound specific isotope analysis Innovations in contaminant hydrogeology
- Ancient waters and deep subsurface biosphere
Dr. Sherwood Lollar’s research in groundwater quality and remediation – specifically investigations of degradation of toxic organic compounds using stable isotopes – led the field of stable carbon isotope analysis in environmental geochemistry of organic contaminants in groundwater. Her research established the scientific principles involved in using compound specific stable carbon isotope signatures, rather than just concentration levels of contaminants, to determine the source of contaminants in groundwater and to track their movement, fate, and particularly, the effectiveness of proposed environmental clean-up strategies. A second important aspect and corollary of these results is that the degree of fractionation observed during transformation of a compound is controlled by the specifics of the reaction mechanisms, or which bonds are broken. This second important feature of Sherwood Lollar’s research was explored in a series of impactful publications that demonstrated the ability to use CSIA to identify different reaction mechanisms at work at field sites. In situ degradation remediation schemes involving both biotic and abiotic processes are a major focus of R&D on site remediation for organic contaminants.
Prof. Brent Sleep
- Biological and geochemical processes for the remediation of soils and water
- Computational methods for modelling environmental processes
- Waste disposal and groundwater pollution modelling and remediation
- Multiphase flow and transport in soils
Professor Sleep’s research interests are in the remediation of ground water contamination. Approaches include experimental studies and numerical modelling with a focus on bioremediation and thermal remediation. Experimental studies range from microcosms to pilot scale. Current projects include laboratory studies of anaerobic biodegradation of DNAPL source zones, in situ chemical oxidation and biodegradation of DNAPL source zones, biodegradation of mixtures of halogenated organic compounds, isotopic fractionation associated with biological processes, biofilm growth in fractures, biofouling of wells, and biological processes in low permeability media. Research funding is from a variety of government and industrial (Canadian and U.S.) sources.