A5082967159- Groundwater flow and contamination studies
- Environmental remediation with nanomaterials
- Microbial bioremediation and biosurfactants
- Electrokinetic Soil Remediation Techniques
- Soil and Unsaturated Flow
- Hydraulic Fracturing and Reservoir Analysis
- Toxic Organic Pollutants Impact
- Enhanced Oil Recovery Techniques
- Geophysical and Geoelectrical Methods
- CO2 Sequestration and Geologic Interactions
- Urban Heat Island Mitigation
- Groundwater and Isotope Geochemistry
- Landfill Environmental Impact Studies
- Water Treatment and Disinfection
- Atmospheric and Environmental Gas Dynamics
- Aerosol Filtration and Electrostatic Precipitation
- Methane Hydrates and Related Phenomena
- Plant Water Relations and Carbon Dynamics
- Radioactive element chemistry and processing
- Grouting, Rheology, and Soil Mechanics
- Nanopore and Nanochannel Transport Studies
- Microbial Community Ecology and Physiology
- Isotope Analysis in Ecology
- Electrochemical Analysis and Applications
- Reservoir Engineering and Simulation Methods
University of Toronto
2015-2024
Queen's University
2023
UNSW Sydney
2023
York University
2016
Geoscience BC
2016
Oregon Health & Science University
2011
Ministry of the Environment, Conservation and Parks
2006
Institute of Groundwater Ecology
2006
Washington State University
2000
University of Waterloo
1989-1999
The understanding of the processes dissolution, volatilization, and gas‐liquid partitioning in porous media is very limited. few models which attempt to characterize transport volatile organics variably saturated all assume that mass transfer are at equilibrium. In addition, gas phase advection neglected by assuming pressures uniformly atmospheric density gradients negligible. this study a model was developed solve for water flow dependent transport. Simple expressions partitioning,...
Area 6 at Dover Air Force Base (Dover, DE) has been the location of an in-depth study by RTDF (Remediation Technologies Development Forum Bioremediation Chlorinated Solvents Action Team) to evaluate effectiveness natural attenuation chlorinated ethene contamination in groundwater. Compound-specific stable carbon isotope measurements for dissolved PCE and TCE wells distributed throughout anaerobic portion plume confirm that values are isotopically enriched 13C consistent with effects...
Stable carbon isotopic analysis has the potential to assess biodegradation of chlorinated ethenes. Significant shifts, which can be described by Rayleigh enrichment factors, have been observed for trichloroethlyene (TCE), cis-dichloroethylene (cDCE), and vinyl chloride (VC). However, until this time, no systematic investigation fractionation during perchloroethylene (PCE) degradation undertaken. In addition, there comparison different microbial consortia, nor a consortia generated from same...
Nanoscale zerovalent iron (nZVI) particles were injected into a contaminated sandy subsurface area in Sarnia, Ontario. The nZVI was synthesized on site, creating slurry of 1 g/L nanoparticles using the chemical precipitation method with sodium borohydride (NaBH4) as reductant presence 0.8% wt. carboxymethylcellulose (CMC) polymer to form stable suspension. Individual formed during synthesis had transmission electron microscopy (TEM) quantified particle size 86.0 nm and dynamic light...
Nanoscale zerovalent iron (nZVI) is an emerging technology for the remediation of contaminated sites. However, there are concerns related to impact nZVI on in situ microbial communities. In this study, community composition at a site was monitored over two years following injection stabilized with carboxymethyl cellulose (nZVI–CMC). Enhanced dechlorination chlorinated ethenes nontoxic ethene observed long after expected oxidation. The abundance Dehalococcoides (Dhc) and vinyl chloride...
The effect of roughness on flow in fractures was investigated using lattice Boltzmann method (LBM). Simulations were conducted for both statistically generated hypothetical and a natural dolomite fracture. increasing effective hydraulic aperture, Izbash Forchheimer parameters with Reynolds number (Re) ranging from 0.01 to 500 examined. growth complex features, such as eddies arising near the fracture surface, directly associated changes surface roughness. Rapid eddy above Re values 1,...
ABSTRACT Compound-specific isotope analysis has the potential to distinguish physical from biological attenuation processes in subsurface. In this study, carbon and hydrogen isotopic fractionation effects during biodegradation of benzene under anaerobic conditions with different terminal-electron-accepting are reported for first time. Different enrichment factors (ε) (range −1.9 −3.6‰) −29 −79‰) were observed nitrate-reducing, sulfate-reducing, methanogenic conditions. These differences not...
A compositional simulator is developed for application to the analysis of contamination and remediation groundwater systems. Simultaneous flow three fluid phases (water, gas, organic) modeled. Interphase partitioning transport an arbitrary number organic inorganic components can be simulated. Phase densities are functions pressure phase composition. The model includes several numerical options, ranging from fully implicit with first‐order upstream weighting in pressure, explicit saturations...
To accurately interpret isotopic data obtained for volatile organic compounds (VOCs) dissolved in groundwater systems, the effects of subsurface processes must be understood. Previous work has demonstrated that volatilization and dissolution BTEX chlorinated ethene are not significantly isotopically fractionating. This study characterized carbon equilibrium sorption perchloroethylene, trichloroethylene, benzene, toluene to both graphite activated directly batch experiments over a range...
The temperature dependence of capillary pressure‐saturation relationships was measured for air‐water and perchloroethylene‐water systems in silica sand. Changes pressures, irreducible water phase saturations, residual nonwetting saturations with were determined. Relationships contact angle interfacial tension incorporated into the van Genuchten [1980] model fitted to data. Capillary pressures at constant degrees saturation decreased as increased. Hysteresis decreased, increased, magnitude...
A bench-scale study was performed to evaluate the enhancement of tetrachloroethene (PCE) dissolution from a dense nonaqueous phase liquid (DNAPL) source zone due reductive dechlorination. The conducted in pair two-dimensional aquifer systems using soil and groundwater Dover Air Force Base, DE. After establishment PCE zones each system, one biostimulated (addition electron donor) while other then bioaugmented with KB1 dechlorinating culture. Biostimulation resulted growth iron-reducing...
Nanoscale zerovalent iron (nZVI) particles have significant potential to remediate contaminated source zones. However, the transport of these through porous media is not well understood, especially at field scale. This paper describes simulation a injection carboxylmethyl cellulose (CMC) stabilized nZVI using 3D compositional simulator, modified include colloidal filtration theory (CFT). The model includes composition dependent viscosity and spatially temporally variable velocity,...
A pilot scale injection of nanoscale zerovalent iron (nZVI) stabilized with carboxymethyl cellulose (CMC) was performed at an active field site contaminated a range chlorinated volatile organic compounds (cVOC). The cVOC concentrations and microbial populations were monitored the before after nZVI injection. remedial successfully reduced parent compound on site. period abiotic degradation followed by enhanced biotic degradation. Results suggest that nZVI/CMC created conditions stimulated...
Carbon isotope fractionation produced by anaerobic biodegradation of toluene was evaluated in laboratory experiments under both methanogenic and sulfate-reducing conditions. A small (∼2‰) but highly reproducible 13C-enrichment the residual at advanced stages microbial transformation observed cultures. The maximum isotopic enrichment +2.0‰ +2.4‰ for cultures, respectively, corresponding to factors (ε) −0.5 −0.8. Because accuracy reproducibility associated with gas...