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Peggy O'Day

(209) 228-4338
S&E 1 Bldg., RM 216
S&E 1 Bldg., RM 225
  • Ph.D., 1992 — Stanford University
  • M.S., 1984 — Cornell University
  • B.S., 1981 — University of California, Davis
Research Interests: 

O'Day's research is in the area of mineral-aqueous interface geochemistry as it relates to the chemistry and mobility of inorganic chemical species in the environment. She applies a variety of spectroscopic and microscopic techniques, in particular synchrotron X-ray methods, to studies of contaminant cycling, bioavailability, and remediation in natural systems.

Current research projects include:

  • Arsenic speciation, cycling and bioavailability
  • Environmental influences on mercury speciation and methylation
  • Novel methods for remediation of soils and sediments through application of reactive amendments
  • Strontium and cesium uptake and release by weathering products related to radionuclide contamination at Hanford, WA
  • Mechanisms and rates of abiotic and biotic uranium oxidation linked to nitrogen and iron cycling
Media Contact: 

Society has become increasingly concerned with the presence and potentially harmful effects of certain chemical elements in the environment. What happens to heavy metals that wind up in landfills? Do pesticides break down and become harmless, or do they just change form? How do chemical contaminants interact with the environment? What effects can be predicted as contaminants find their way into waterways?

O'Day's research and expertise focus on understanding the behavior and movement of chemicals in aqueous media, such as underground aquifers. A geochemist, she uses a variety of state-of-the-art scientific techniques to study contaminant cycling, remediation and related issues. Her research includes field and experimental studies with arsenic, metals and radionucleides in various forms and in various environments. She is particularly interested in what might control uptake or sequestration in solid phases – holding the substances in question – versus letting them move through water.

O’Day holds a B.S. in geology from UC Davis, an M.S. in geological sciences from Cornell University and a Ph. D. in applied earth sciences from Stanford University. Prior to joining the faculty at UC Merced in 2003, she taught and conducted research in her field at Arizona State University.