Groundwater Geochemistry and Remediation Research Group

1. Group Profile

The GGR Research Group at the University of Waterloo, led by David Blowes and Carol Ptacek, is committed to advancing the understanding of the fate, transport, and remediation of contaminants, including metals, metalloids, pathogens, nutrients, and emerging contaminants in groundwater. This research includes detailed field investigations, laboratory studies, development of reactive barriers and other passive remediation solutions, application of non-traditional stable isotope techniques, and development of mathematical models to predict the complex geochemical behaviour of these systems.

We have conducted studies at mine sites, mine-waste disposal facilities, wetlands, on-site sewage disposal systems, and other industrial sites. Laboratory studies often focus on reaction mechanisms utilizing batch, column, and flow-through cell experiments. Remediation research is focused on the development of passive, in situ methods, including permeable reactive barriers. Mathematical modelling has focused on the development of fully-coupled reactive transport codes that can account for thermodynamic and kinetic controls on geochemical reactions between groundwater and the aquifer material.

2. Infrastructure

The GGR Research Group is equipped with a comprehensive suite of analytical and field instrumentation.

Analytical capabilities housed within our clean room include:

  • Inductively-Coupled Plasma – Optical Emission Spectroscopy (ICP-OES)
  • Inductively-Coupled Plasma – Mass Spectrometry (ICP-MS)
  • High Resolution-ICP-MS (HR-ICP-MS)
  • Laser Ablation (LA-HR-ICP-MS)
  • Multi-Collector-ICP-MS (MC-ICP-MS)
  • Liquid Chromatography-Electrospray Triple Quadrupole Mass Spectrometer
  • Reagent-Free Ion Chromatography (RFIC)
  • Total Mercury Analyzer

Additional analytical capabilities include:

  • Carbon/sulfur Analyzer
  • Gas Chromatography Single Quadropole Mass Spectrometer
  • Ion Chromatography
  • Liquid Chromatography-Electrospray Triple Quadrupole Mass Spectrometer
  • Methylmercury Analyzer
  • Scanning Electron Microscopy
  • X-ray Fluorescence

Additional equipment for sample preparation and preservation, and experimental setup:

  • Acid purification still
  • Anaerobic chambers
  • Auto-diluters
  • Balances
  • Ball mill
  • Centrifuges
  • Cold room storage
  • Core presses
  • Fume hoods
  • HEPA-filtered clean air bench
  • Incubator
  • Laminar flow hood
  • Lyophilizer/freeze dryer
  • Mercury distillation system
  • Milli-Q water purification systems
  • Ovens
  • Pan sieves
  • pH, Eh, EC, DO, and temperature meters and probes
  • Portable spectrophotometers
  • Riffle sample splitter
  • Shaker tables
  • Wide variety of columns, humidity cells, and flow-through cells

3. Opportunities

The GGR Research Group welcomes applications for research exchanges from qualified individuals currently registered as graduate students or postdoctoral researchers at accredited Canadian universities. Interested candidates are invited to contact Steve Holland to discuss available opportunities. Ongoing research projects include investigations of: the hydrogeochemical and biogeochemical evolution of diamond, gold, and base metal mine waste-rock and tailings; the development and environmental application of novel analytical techniques for determining ratios of non-traditional stable isotopes; mercury cycling and mobilization from riverine sediments at legacy industrial sites; environmental fate of artificial sweeteners and pharmaceuticals; permeable reactive barrier development and optimization; and the environmental fate of nanoparticles and perfluorinated compounds. Many of these research projects utilize a wide variety of field-based characterization techniques, in addition to laboratory analyses and experimentation, as well as numerical modelling methods.