Environmental Geochemistry Laboratory

Contact: David Decker

The chemical interaction of water with mineral surfaces and natural soils is studied in this laboratory. The processes of mineral dissolution, precipitation, sorption and aqueous complexation are examined.

Typical experiments include equilibrium and kinetic sorption studies of inorganic oxyanion and cation metal and metalloid species on sorbent minerals of environmental significance. Typical field collection capabilities include techniques and equipment for sampling ground and surface water for part-per-trillion levels of trace elements, dissolved CFC compounds, isotopes of H, O, C and N, and the standard water quality sampling approaches. These studies are essential for our increased understanding of the fate and transport of contaminants in surface and groundwaters. The laboratory is also used for the preparation of samples for investigations of the molecular level structure of sorbed complexes using X-ray Spectroscopy.

Facilities

The research facilities of the Environmental Geochemistry Laboratory include several laboratories for sample preparation and sample analysis.

Sample preparation labs include clean room facilities for sub part-per-trillion trace element analysis, field preparation laboratories, an arsenic oxyanion sorption laboratory, and a carbon-isotope laboratory.

Analytical laboratories are fully equipped with:

  • fume hoods
  • research grade quality water supply (NANOpure)
  • Orion model 720 pH meters
  • ovens
  • analytical balances
  • automated atomic absorption spectrometer (Perkin-Elmer, model 4110 ZL) with graphite furnace and Zeeman background correction
  • automated electric furnace absorption spectrometer (Varian 4400) with continuous pulse hydride generation for oxyanion analysis
  • computer-interfaced Hewlett-Packard (Model 5890 Series II) gas chromatograph with ELCD, FID, and PID detectors and a O-I-Analytical, Model 4460A Purge and Trap sample concentrator
  • Micromeritics (model ASAP 2010) fully automated and computer interfaced surface area and pore size distribution analyzer with low surface area Krypton gas adsorption option
  • Lauda constant temperature recirculating water bath
  • Marathon 21K/R high speed refrigerated centrifuge.
A Surface Science SSX-100 x-ray photoelectron spectrometer (XPS) is housed at DRI in Las Vegas and is capable of performing surface sensitive analyses down to approximately 100 micrometer spot size. A model 77530 6 L Labconco freeze drying system is used for XPS sample preparation of solid samples and cores used in water-rock interaction studies.