Chemist
Physiochemical Transformations
Chemist
Physiochemical Transformations

Biography

Odeta Qafoku is chemist with the Physiochemical Transformations team in PNNL’s Environmental Molecular Sciences Division and the Environmental Molecular Sciences Laboratory (EMSL) user program. Qafoku is an environmental soil scientist and geochemist with 20 years of research experience on a broad range of projects in the topics of soil science, geochemistry, geochemical and thermodynamic modeling, mineral synthesis, organic and contaminant interaction with soil minerals, CO2 sequestration, and mineral weathering. Her resent research interests are in studying organic mineral interactions using methods that extend from nano- to macroscale; studying iron mineral transformations induced by reductive reactions; studying mineral incipient weathering as function of biological inputs and environmental changes, and applying scanning electron microscopy to study reactivity and transformation at reaction boundaries.  

Research Interests 

  • Reactivity and transformation at reaction boundaries, with particular interest in investigating solid -fluid interfaces at microscopic scale 

  • Chemical processes that control and influence the behavior of nutrient and contaminants under a variety of (bio)geochemical conditions 

  • Early changes of mineral weathering at microscale, as a function of biological inputs in various humid environments 

Disciplines and Skills

  • Electron Microscopy
  • Environmental Chemistry
  • Geochemical Modeling
  • Geochemistry
  • Soil Chemistry
  • Soil Science
  • Thermodynamic Modeling

Education

  • MS in Soil Science, University of Georgia, 1998
  • BS in Chemistry, University of Tirana, 1988

Affiliations and Professional Service

  • American Geophysical Union 

  • Soil Science Society of America 

  • Microscopy Society of America 

Publications

2020 

McElroy, E., A. R. Lawter, D. Appriou, F. Smith, M. Bowden, O. Qafoku, L. Kovarik, J. E. Szecsody, M. J. Truex, and N. P. Qafoku. 2020. “Iodate Interactions with Calcite: Implications for Natural Attenuation.” Environmental Earth Sciences 79 (12). https://doi.org/10.1007/s12665-020-09023-1

Placencia-Gómez, E., S. N. Kerisit, H. S. Mehta, O. Qafoku, C. J. Thompson, T. R. Graham, E. S. Ilton, and J. S. Loring. 2020. “Critical Water Coverage During Forsterite Carbonation in Thin Water Films: Activating Dissolution and Mass Transport.” Environmental Science and Technology 54 (11): 6888-6899. https://doi.org/10.1021/acs.est.0c00897

Sheng, A., J. Liu, X. Li, O. Qafoku, R. N. Collins, A. M. Jones, C. I. Pearce, C. Wang, J. Ni, A. Lu, and K. M. Rosso. 2020. “Labile Fe(III) from Sorbed Fe(II) Oxidation Is the Key Intermediate in Fe(II)-Catalyzed Ferrihydrite Transformation.” Geochimica et Cosmochimica Acta 272: 105-120. https://doi.org/10.1016/j.gca.2019.12.028

Zhao, Q., S. J. Callister, A. M. Thompson, R. K. Kukkadapu, M. M. Tfaily, L. M. Bramer, N. P. Qafoku, S. L. Bell, S. E. Hobbie, E. W. Seabloom, E. T. Borer, and K. S. Hofmockel. 2020. “Strong Mineralogic Control of Soil Organic Matter Composition in Response to Nutrient Addition across Diverse Grassland Sites.” Science of the Total Environment 736. https://doi.org/10.1016/j.scitotenv.2020.137839

2019 

Huang, X., Y. Chen, E. Walter, M. Zong, Y. Wang, X. Zhang, O. Qafoku, Z. Wang, and K. M. Rosso. 2019. “Facet-Specific Photocatalytic Degradation of Organics by Heterogeneous Fenton Chemistry on Hematite Nanoparticles.” Environmental Science and Technology 53 (17): 10197-10207. https://doi.org/10.1021/acs.est.9b02946

Miller, Q. R. S., D. A. Dixon, S. D. Burton, E. D. Walter, D. W. Hoyt, A. S. McNeill, J. D. Moon, K. S. Thanthiriwatte, E. S. Ilton, O. Qafoku, C. J. Thompson, H. T. Schaef, K. M. Rosso, and J. S. Loring. 2019. “Surface-Catalyzed Oxygen Exchange During Mineral Carbonation in Nanoscale Water Films.” Journal of Physical Chemistry C 123 (20): 12871-12885. https://doi.org/10.1021/acs.jpcc.9b02215

Ohno, T., N. J. Hess, and N. P. Qafoku. 2019. “Current Understanding of the Use of Alkaline Extractions of Soils to Investigate Soil Organic Matter and Environmental Processes.” Journal of Environmental Quality 48 (6): 1561-1564. https://doi.org/10.2134/jeq2019.08.0292

Saslow, S. A., S. N. Kerisit, T. Varga, K. C. Johnson, N. M. Avalos, A. R. Lawter, and N. P. Qafoku. 2019. “Chromate Effect on Iodate Incorporation into Calcite.” ACS Earth and Space Chemistry 3 (8): 1624-1630. https://doi.org/10.1021/acsearthspacechem.9b00047

2018 

Asmussen, R. M., C. I. Pearce, B. W. Miller, A. R. Lawter, J. J. Neeway, W. W. Lukens, M. E. Bowden, M. A. Miller, E. C. Buck, R. J. Serne, and N. P. Qafoku. 2018. “Getters for Improved Technetium Containment in Cementitious Waste Forms.” Journal of Hazardous Materials 341: 238-247. https://doi.org/10.1016/j.jhazmat.2017.07.055

Lawter, A. R., W. L. Garcia, R. K. Kukkadapu, O. Qafoku, M. E. Bowden, S. A. Saslow, and N. P. Qafoku. 2018. “Technetium and Iodine Aqueous Species Immobilization and Transformations in the Presence of Strong Reductants and Calcite-Forming Solutions: Remedial Action Implications.” Science of the Total Environment 636: 588-595. https://doi.org/10.1016/j.scitotenv.2018.04.240

Lawter, A. R., N. P. Qafoku, R. M. Asmussen, R. K. Kukkadapu, O. Qafoku, D. H. Bacon, and C. F. Brown. 2018. “Element Mobilization and Immobilization from Carbonate Rocks between CO2 Storage Reservoirs and the Overlying Aquifers During a Potential CO2 Leakage.” Chemosphere 197: 399-410. https://doi.org/10.1016/j.chemosphere.2017.12.199

Popel, A. J., T. W. Wietsma, M. H. Engelhard, A. S. Lea, O. Qafoku, C. Grygiel, I. Monnet, E. S. Ilton, M. E. Bowden, and I. Farnan. 2018. “The Effect of Ion Irradiation on the Dissolution of UO2 and UO2-Based Simulant Fuel.” Journal of Alloys and Compounds 735: 1350-1356. https://doi.org/10.1016/j.jallcom.2017.11.216

Qafoku, O., E. S. Ilton, M. E. Bowden, L. Kovarik, X. Zhang, R. K. Kukkadapu, M. H. Engelhard, C. J. Thompson, H. T. Schaef, B. P. McGrail, K. M. Rosso, and J. S. Loring. 2018. “Synthesis of Nanometer-Sized Fayalite and Magnesium-Iron(II) Mixture Olivines.” Journal of Colloid and Interface Science 515: 129-138. https://doi.org/10.1016/j.jcis.2018.01.036

2017 

McBriarty, M. E., J. A. Soltis, S. Kerisit, O. Qafoku, M. E. Bowden, E. J. Bylaska, J. J. De Yoreo, and E. S. Ilton. 2017. “Trace Uranium Partitioning in a Multiphase Nano-FeOOH System.” Environmental Science and Technology 51 (9): 4970-4977. https://doi.org/10.1021/acs.est.7b00432

McGrail, B. P., H. T. Schaef, F. A. Spane, J. B. Cliff, O. Qafoku, J. A. Horner, C. J. Thompson, A. T. Owen, and C. E. Sullivan. 2017. “Field Validation of Supercritical CO2 Reactivity with Basalts.” Environmental Science and Technology Letters 4 (1): 6-10. https://doi.org/10.1021/acs.estlett.6b00387

McGrail, B. P., H. T. Schaef, F. A. Spane, J. A. Horner, A. T. Owen, J. B. Cliff, O. Qafoku, C. J. Thompson, and E. C. Sullivan. 2017. “Wallula Basalt Pilot Demonstration Project: Post-Injection Results and Conclusions.” https://doi.org/10.1016/j.egypro.2017.03.1716

Qafoku, O., C. I. Pearce, A. Neumann, L. Kovarik, M. Zhu, E. S. Ilton, M. E. Bowden, C. T. Resch, B. W. Arey, E. Arenholz, A. R. Felmy, and K. M. Rosso. 2017. “Tc(VII) and Cr(VI) Interaction with Naturally Reduced Ferruginous Smectite from a Redox Transition Zone.” Environmental Science and Technology 51 (16): 9042-9052. https://doi.org/10.1021/acs.est.7b02191

Xu, J., H. Veeramani, N. P. Qafoku, G. Singh, M. V. Riquelme, A. Pruden, R. K. Kukkadapu, B. N. Gartman, and M. F. Hochella, Jr. 2017. “Efficacy of Acetate-Amended Biostimulation for Uranium Sequestration: Combined Analysis of Sediment/Groundwater Geochemistry and Bacterial Community Structure.” Applied Geochemistry 78: 172-185. https://doi.org/10.1016/j.apgeochem.2016.12.024

Xu, M., S. L. Riechers, E. S. Ilton, Y. Du, L. Kovarik, T. Varga, B. W. Arey, O. Qafoku, and S. Kerisit. 2017. “Manganese-Calcium Intermixing Facilitates Heteroepitaxial Growth at the 101¯4 Calcite-Water Interface.” Chemical Geology 470: 152-163. https://doi.org/10.1016/j.chemgeo.2017.09.001

2016 

Andersen, A., P. N. Reardon, S. S. Chacon, N. P. Qafoku, N. M. Washton, and M. Kleber. 2016. “Protein-Mineral Interactions: Molecular Dynamics Simulations Capture Importance of Variations in Mineral Surface Composition and Structure.” Langmuir 32 (24): 6194-6209. https://doi.org/10.1021/acs.langmuir.6b01198

Byrne, J. M., G. Van Der Laan, A. I. Figueroa, O. Qafoku, C. Wang, C. I. Pearce, M. Jackson, J. Feinberg, K. M. Rosso, and A. Kappler. 2016. “Size Dependent Microbial Oxidation and Reduction of Magnetite Nano-and Micro-Particles.” Scientific Reports 6. https://doi.org/10.1038/srep30969

Neeway, J. J., R. M. Asmussen, A. R. Lawter, M. E. Bowden, W. W. Lukens, D. Sarma, B. J. Riley, M. G. Kanatzidis, and N. P. Qafoku. 2016. “Removal of TcO4- from Representative Nuclear Waste Streams with Layered Potassium Metal Sulfide Materials.” Chemistry of Materials 28 (11): 3976-3983. https://doi.org/10.1021/acs.chemmater.6b01296

Wang, G., N. P. Qafoku, A. R. Lawter, M. Bowden, O. Harvey, C. Sullivan, and C. F. Brown. 2016. “Geochemical Impacts of Leaking CO2 from Subsurface Storage Reservoirs to an Unconfined Oxidizing Carbonate Aquifer.” International Journal of Greenhouse Gas Control 44: 310-322. https://doi.org/10.1016/j.ijggc.2015.07.002

Williams, B. D., J. J. Neeway, M. M. V. Snyder, M. E. Bowden, J. E. Amonette, B. W. Arey, E. M. Pierce, C. F. Brown, and N. P. Qafoku. 2016. “Mineral Assemblage Transformation of a Metakaolin-Based Waste Form after Geopolymer Encapsulation.” Journal of Nuclear Materials 473: 320-332. https://doi.org/10.1016/j.jnucmat.2015.12.023

2015 

Felmy, A. R., O. Qafoku, B. W. Arey, L. Kovarik, J. Liu, D. Perea, and E. S. Ilton. 2015. “Enhancing Magnesite Formation at Low Temperature and High CO2 Pressure: The Impact of Seed Crystals and Minor Components.” Chemical Geology 395: 119-125. https://doi.org/10.1016/j.chemgeo.2014.12.003

Gartman, B. N., N. P. Qafoku, J. E. Szecsody, R. K. Kukkadapu, Z. Wang, D. M. Wellman, and M. J. Truex. 2015. “Uranium Fate in Hanford Sediment Altered by Simulated Acid Waste Solutions.” Applied Geochemistry 63: 1-9. https://doi.org/10.1016/j.apgeochem.2015.07.010

Qafoku, O., D. A. Dixon, K. M. Rosso, H. T. Schaef, M. E. Bowden, B. W. Arey, and A. R. Felmy. 2015. “Dynamics of Magnesite Formation at Low Temperature and High pCO2 in Aqueous Solution.” Environmental Science and Technology 49 (17): 10736-10744. https://doi.org/10.1021/acs.est.5b02588

Shao, H., N. P. Qafoku, A. R. Lawter, M. E. Bowden, and C. F. Brown. 2015. “Coupled Geochemical Impacts of Leaking Co2 and Contaminants from Subsurface Storage Reservoirs on Groundwater Quality.” Environmental Science and Technology 49 (13): 8202-8209. https://doi.org/10.1021/acs.est.5b01004

Xu, M., E. S. Ilton, M. H. Engelhard, O. Qafoku, A. R. Felmy, K. M. Rosso, and S. Kerisit. 2015. “Heterogeneous Growth of Cadmium and Cobalt Carbonate Phases at the 1014 Calcite Surface.” Chemical Geology 397: 24-36. https://doi.org/10.1016/j.chemgeo.2015.01.003

2014 

Arey, B. W., D. E. Perea, L. Kovarik, R. J. Colby, J. Liu, O. Qafoku, and A. R. Felmy. 2014. “Understanding Fayalite Chemistry Using Electron Microscopy and Atom Probe Tomography.”  20 (3): 998-999. https://doi.org/10.1017/S1431927614006710

Neeway, J. J., N. P. Qafoku, B. D. Williams, K. Rod, M. E. Bowden, C. F. Brown, and E. M. Pierce. 2014. “Performance of the Fluidized Bed Steam Reforming Product under Hydraulically Unsaturated Conditions.” Journal of Environmental Radioactivity 131: 119-128. https://doi.org/10.1016/j.jenvrad.2013.10.008

Pearce, C. I., J. Liu, D. R. Baer, O. Qafoku, S. M. Heald, E. Arenholz, A. E. Grosz, J. P. McKinley, C. T. Resch, M. E. Bowden, M. H. Engelhard, and K. M. Rosso. 2014. “Characterization of Natural Titanomagnetites (Fe3-xTixO4) for Studying Heterogeneous Electron Transfer to Tc(VII) in the Hanford Subsurface.” Geochimica et Cosmochimica Acta 128: 114-127. https://doi.org/10.1016/j.gca.2013.12.010

Qafoku, N. P., B. N. Gartman, R. K. Kukkadapu, B. W. Arey, K. H. Williams, P. J. Mouser, S. M. Heald, J. R. Bargar, N. Janot, S. Yabusaki, and P. E. Long. 2014. “Geochemical and Mineralogical Investigation of Uranium in Multi-Element Contaminated, Organic-Rich Subsurface Sediment.” Applied Geochemistry 42: 77-85. https://doi.org/10.1016/j.apgeochem.2013.12.001

Qafoku, O., J. Hu, N. J. Hess, M. Y. Hu, E. S. Ilton, J. Feng, B. W. Arey, and A. R. Felmy. 2014. “Formation of Submicron Magnesite During Reaction of Natural Forsterite in H2O-Saturated Supercritical CO2.” Geochimica et Cosmochimica Acta 134: 197-209. https://doi.org/10.1016/j.gca.2013.09.024

2013 

Arey, B. W., L. Kovarik, O. Qafoku, Z. Wang, N. J. Hess, and A. R. Felmy. 2013. “Identification of Fragile Microscopic Structures During Mineral Transformations in Wet Supercritical CO2.” Microscopy and Microanalysis 19 (2): 268-275. https://doi.org/10.1017/S1431927612014171

Veeramani, H., A. C. Scheinost, N. Monsegue, N. P. Qafoku, R. Kukkadapu, M. Newville, A. Lanzirotti, A. Pruden, M. Murayama, and M. F. Hochella. 2013. “Abiotic Reductive Immobilization of U(VI) by Biogenic Mackinawite.” Environmental Science and Technology 47 (5): 2361-2369. https://doi.org/10.1021/es304025x

2012 

Arey, B., D. Perera, L. Kovarik, O. Qafoku, A. Felmy, and B. Gorman. 2012. “Atom Probe and TEM Investigation of Natural Olivines.” Microscopy and Microanalysis 18 (S2): 658-659. https://doi.org/10.1017/S1431927612005144

Campbell, K. M., R. K. Kukkadapu, N. P. Qafoku, A. D. Peacock, E. Lesher, K. H. Williams, J. R. Bargar, M. J. Wilkins, L. Figueroa, J. Ranville, J. A. Davis, and P. E. Long. 2012. “Geochemical, Mineralogical and Microbiological Characteristics of Sediment from a Naturally Reduced Zone in a Uranium-Contaminated Aquifer.” Applied Geochemistry 27 (8): 1499-1511. https://doi.org/10.1016/j.apgeochem.2012.04.013

Felmy, A. R., O. Qafoku, B. W. Arey, J. Z. Hu, M. Hu, H. Todd Schaef, E. S. Ilton, N. J. Hess, C. I. Pearce, J. Feng, and K. M. Rosso. 2012. “Reaction of Water-Saturated Supercritical CO2 with Forsterite: Evidence for Magnesite Formation at Low Temperatures.” Geochimica et Cosmochimica Acta 91: 271-282. https://doi.org/10.1016/j.gca.2012.05.026

Loring, J. S., H. T. Schaef, R. V. F. Turcu, C. J. Thompson, Q. R. S. Miller, P. F. Martin, J. Hu, D. W. Hoyt, O. Qafoku, E. S. Ilton, A. R. Felmy, and K. M. Rosso. 2012. “In Situ Molecular Spectroscopic Evidence for CO2 Intercalation into Montmorillonite in Supercritical Carbon Dioxide.” Langmuir 28 (18): 7125-7128. https://doi.org/10.1021/la301136w

Pearce, C. I., O. Qafoku, J. Liu, E. Arenholz, S. M. Heald, R. K. Kukkadapu, C. A. Gorski, C. M. B. Henderson, and K. M. Rosso. 2012. “Synthesis and Properties of Titanomagnetite (Fe3-xTixO4) Nanoparticles: A Tunable Solid-State Fe(II/III) Redox System.” Journal of Colloid and Interface Science 387 (1): 24-38. https://doi.org/10.1016/j.jcis.2012.06.092

Qafoku, O., L. Kovarik, R. K. Kukkadapu, E. S. Ilton, B. W. Arey, J. Tucek, and A. R. Felmy. 2012. “Fayalite Dissolution and Siderite Formation in Water-Saturated Supercritical CO2.” Chemical Geology 332-333: 124-135. https://doi.org/10.1016/j.chemgeo.2012.09.028

Um, W., H. Chang, J. P. Icenhower, W. W. Lukens, R. Jeffrey Serne, N. Qafoku, R. K. Kukkadapu, and J. H. Westsik Jr. 2012. “Iron Oxide Waste Form for Stabilizing 99Tc.” Journal of Nuclear Materials 429 (1-3): 201-209. https://doi.org/10.1016/j.jnucmat.2012.06.004

2010 

Hixon, A. E., Y. J. Hu, D. I. Kaplan, R. K. Kukkadapu, H. Nitsche, O. Qafoku, and B. A. Powell. 2010. “Influence of Iron Redox Transformations on Plutonium Sorption to Sediments.” Radiochimica Acta 98 (9-11): 685-692. https://doi.org/10.1524/ract.2010.1769

2009 

Qafoku, N. P., R. K. Kukkadapu, J. P. McKinley, B. W. Arey, S. D. Kelly, C. Wang, C. T. Resch, and P. E. Long. 2009. “Uranium in Framboidal Pyrite from a Naturally Bioreduced Alluvial Sediment.” Environmental Science and Technology 43 (22): 8528-8534. https://doi.org/10.1021/es9017333

2008 

Hess, N. J., O. Qafoku, Y. Xia, D. A. Moore, and A. R. Felmy. 2008. “Thermodynamic Model for the Solubility of TcO2·xH2O in Aqueous Oxalate Systems.” Journal of Solution Chemistry 37 (11): 1471-1487. https://doi.org/10.1007/s10953-008-9328-5

2007 

Qafoku, N. P., O. Qafoku, C. C. Ainsworth, A. Dohnalkova, and S. G. McKinley. 2007. “Fe-Solid Phase Transformations under Highly Basic Conditions.” Applied Geochemistry 22 (9): 2054-2064. https://doi.org/10.1016/j.apgeochem.2007.04.023