Projects will be oriented around particular remediation approaches including chemical oxidation, chemical reduction, bioremediation, and thermal remediation, from which treatment trains will be developed. Initial treatment typically results in significant contaminant reduction but often does not meet regulatory requirements. Subsequent polishing steps are required to reduce contaminants to acceptable levels. This requires optimizing the selection and timing of each step and minimizing adverse effects of one technology on the next. Bench scale work and computer modelling will inform field tests conducted with our industrial partners. Diagnostic tools will be developed in the lab and applied to monitor field scale experiments.
Evaluation and development of tools to assess fate and degradation of contaminants
Effective tools to track and characterize subsurface microbial communities are finally accessible and affordable. These include large-scale sequencing, quantitative DNA and RNA extraction and amplification tools, and proteomic analyses applicable to complex mixtures and small sample sizes. Professor Elizabeth Edwards is responsible for this research topic.
The application of geophysical tools such as ground penetrating radar (GPR) and electrical resistivity tomography (ERT) as non-destructive diagnostic tools for environmental site assessment and mapping of the complexity of contaminant source zones in heterogeneous environments is the topic of interest of Professor Jason Gerhard. His team has demonstrated that GPR and ERT have the potential to map the location and volume of the subsurface remediated over time. Field validation and optimization will be achieved by mapping remediation on several sites in real time.
Evaluation of risks, potential exposure routes, and contaminant migration pathways from groundwater to surface waters are a major knowledge gap. Professors Clare Robinson and Denis O’Carroll are investigating subsurface contaminant mobility and fluxes at the groundwater-surface water interface.
In situ chemical oxidation (ISCO)
Professor Neil Thomson will lead research on ISCO, an aggressive technology involving the subsurface delivery of a chemical oxidant to destroy organic contaminants, and its potential for cost-effective remediation, including application in fractured rock. Combination of ISCO/bioremediation treatment trains, in granular media and in fractured rock—in collaboration with Kent Novakowski, Elizabeth Edwards and Barbara Sherwood Lollar—will also be investigated. Professor Denis O’Carroll will continue his research on oxidant delivery process through use of electrokinetics in collaboration with Dr. David Reynolds (Geosyntec).
In situ chemical reduction
Professors Denis O’Carroll, Brent Sleep, Jose Herrera, Kevin Mumford, and Edgar Acosta are studying the transport and reaction of nanoscale zero valent iron (nZVI) in porous media. RENEW trainees will develop new methods for maximizing nZVI mobility and reactivity in porous media and fractured rock. The potential for nZVI application to create conditions that stimulate biodegradation will also be investigated.
In situ bioremediation
Professor Elizabeth Edwards is widely recognized for leading-edge work on microbial community dynamics and characterization of degradation pathways associated with particular microbial species. Projects on bioremediation, using advanced molecular biology, and mass spectrometry will determine microbial degradation pathways and identify microbial species responsible for degradation of particular contaminants with a variety of terminal electron accepting processes. Professors Kent Novakowski and Brent Sleep will develop methods to predict the transport and activity of microbes in fractured rock related to bioaugmentation and biostimulation.
In situ thermal remediation
Professors Brent Sleep and Kevin Mumford will supervise students working to advance thermal remediation techniques. These include electrical resistance heating and thermal conductive heating, used to treat soil and groundwater contamination in heterogeneous environments, where rapid contaminant removal is required and permeability contrasts prevent the effective use of injection technologies.
A novel thermal technique that will be part of this research program is STAR (Self-sustaining Treatment for Active Remediation), invented by Professors Jason Gerhard and Jose Torero. Professor Jason Gerhard will supervise students in developing this promising technique for in situ source zone destruction. International collaborators Professors Jose Torero, Christine Switzer, and Guillermo Rein, who are experts in these areas, and will provide international exchanges for STAR trainees. Collaboration with Elizabeth Edwards and other PIs will look at treatment trains involving STAR, such as following with bioremediation as a polishing step.