Physical Sciences Division
Pacific Northwest National Laboratory
PO Box 999
Richland, WA 99352
Dr. John Zachara has performed extensive experimental research on various geochemical and biogeochemical processes that control the concentrations, fate, and transport of organic, metal and radionuclide contaminants in subsurface environments. The research has ranged from fundamental surface chemical and spectroscopic studies of mineral suspensions in the laboratory, to comprehensive studies of solute mobilization and transport in the field. He has been active in evaluating complex co-contaminant interactions that occur in contaminant mixtures and in applying multi-component adsorption models to contaminant binding in mineralogically complex natural materials. He has made important contributions to understanding how microorganisms interact with mineral surfaces through his long-term collaboration with microbiologist Dr. Jim Fredrickson.
Dr. Zachara's current research is focused on the geochemical behavior of metals and radionuclides with emphasis on the Hanford site, the influence of subsurface microbial processes on mineral surface chemistry and mineralization, and reactive transport chemistry. His research is assisted by applications of electron microscopy, scanning probe microscopy, Mössbauer spectroscopy, laser-induced fluorescence spectroscopy, and x-ray absorption spectroscopy. Dr. Zachara has been committed to identifying and performing fundamental research that provides basis for remedial action and closure decisions at the Hanford site.
Dr. Zachara received the prestigious E.O. Lawrence Award for Environmental Science and Technology in 2007 from the U.S. Department of Energy. He is a former coordinator of the DOE/OBER co-contaminant chemistry research subprogram, former associate director of the William R. Wiley Environmental Molecular Sciences Laboratory at PNNL, current chief scientist for Hanford's Science and Technology program, and co-coordinator of the PNNL/EMSL Biogeochemistry Grand Challenge along with Dr. Jim Fredrickson.
Dr. Zachara has over 125 peer-reviewed publications in leading environmental/geochemical journals on contaminant environmental geochemistry.
- Biogeochemical processes influencing the fate and transport of metals & radionuclides in subsurface environments.
- Biogeochemical electron transfer mechanisms at the microbial cell-mineral interface and resulting impacts on mineral surface chemistry.
- Linking phenomena at the molecular and microscopic scales to contaminant behavior in the field.
- Mineral transformations, including chemical and microbiological weathering and mineralization reactions, and their impact on contaminant reactive transport.
- Mineral surface chemistry including adsorption, surface precipitation, and heterogeneous electron transfer, and their linkage with other environmental processes.
- Solving DOE’s complex legacy waste management problems through the application of targeted, fundamental science.
Education and Credentials
- Ph.D., Soil Chemistry, Washington State University
- M.S., Soil/Watershed Chemistry, University of Washington
- B.S., Chemistry, Bucknell University
Affiliations and Professional Service
- American Geophysical Union
- American Chemical Society
- American Association for the Advancement of Science
- Soil Science Society of America
- Clay Minerals Society
- Geochemical Society of America
Awards and Recognitions
- Battelle Fellow, 2010
- E.O. Lawrence Award, 2007
- Fellow, American Association for the Advancement of Science
- Fellow, Pacific Northwest National Laboratory
- One of ISI’s (Institute of Scientific Information) most cited environmental scientists