Earth Scientist
Earth Scientist

Biography

Dr. Ravi Kukkadapu is an Earth scientist with the Biogeochemical Transformations team in PNNL’s Environmental Molecular Sciences Division and the Environmental Molecular Sciences Laboratory (EMSL) user program. He has brought international recognition to PNNL and EMSL, and its 57Fe-Mössbauer spectroscopy laboratory, as a premier capability for biogeochemical sciences involving Fe-oxides and Fe-containing clays that are ubiquitous in the subsurface. His expertise in the application of Mössbauer spectroscopy, coupled with electron microscopy, X-ray diffraction, and absorption techniques has resulted in many fruitful collaborations and numerous publications. He has applied these techniques to better understand the (bio)transformation of primary Fe(II)/(III)-oxides into secondary Fe(II)/(III)-minerals (carbonates, phosphates, and sulfides) and redox transformations of Fe-clays under various biological, geochemical, and hydrological conditions on attenuation or long-term stability of redox-sensitive contaminants. 

Currently, Kukkadapu is extensively involved in programmatic research funded by the U.S. Department of Energy’s (DOE) Biological and Environmental Research program’s Subsurface Biogeochemical Research and the Geosciences Division of DOE's Basic Energy Science program. He collaborates with numerous universities and other DOE laboratory investigators in subsurface biogeochemical research through EMSL user proposals. His research has direct implications to DOE's primary environmental mission, assisting in developing predictive biogeochemical transport models to better understand the fate and transport of radioactive and hazardous metal contaminants, such as uranium (U), technetium (Tc), plutonium (Pu), and mercury (Hg) in aquifers. 

Research Interest

Dr. Kukkadapu is recognized in the area of soil Fe minerals' role on soluble radionuclide attenuation in the subsurface. His current interests are: 

  • The interplay of organic matter-mineral-bacteria interactions in subsurface and floodplain/terrestrial-aquatic interfaces on stability of soil organic matter (effect on greenhouse gases), nutrient cycling, and metal contaminant remediation 

  • The role of (bio)transformation/redox cycling of Fe-(oxyhydr)oxides/Fe-clays/Fe-sulfides (and Mn-oxides and zero-valent Fe) in subsurface/floodplain/lake sediments on remediation of soluble metal contaminants( e.g., radionuclides), such as U, Tc, and Pu, and hazardous metals, such as, As, Cr, and Hg, and nitrate and phosphate nutrient cycling (water quality) 

  • The effect of soil organic matter on interfacial electron transfer between sorbed Fe(II) and clay Fe(III)/Fe-oxides 

  • The development of stable materials for safe disposal of nuclear materials (e.g., garnets) with large amounts of U loading 

  • Geological CO2 sequestration 

  • Reactive nano Fe phases 

  • Fe containing NH3-SCR catalysts 

  • The application of 57Fe (and 119Sn) Mössbauer spectroscopy in geosciences, material synthesis, and catalysis areas 

Education

  • PhD in Chemistry, Indian Institutes of Technology 

  • MS in Chemistry, Osmania University 

Affiliations and Professional Service

  • American Chemistry Society 

  • American Geophysical Union 

  • The Clay Minerals Society 

  • Soil Science Society of America 

Awards and Recognitions

  • Co-Organizer, “Stability of Mineral-Organic Matter Interactions Under Varying Biogeochemical Conditions,” 2020 Clay Mineral Society, PNNL 

  • Co-Organizer, “Clays and Climate Change,” 2020 Clay Mineral Society, PNNL

  • Co-Organizer, “Emerging Methods in Soil Science,” 2020 Clay Mineral Society, PNNL 

  • Member, PhD Thesis Committee for Li Zhang, Miami University (2019) 

  • Member, PhD Thesis Committee for Elizabeth Wu, University of Delaware (2014) 

  • Member, PhD Thesis Committee for Wu Tao, University of Wisconsin (2014) 

  • Co-Organizer, The Sixth Nassau-Argonne International Mössbauer Symposium, Garden City (2011) 

  • Rising Star, Cover of Mössbauer Effect Reference and Data Journal (2010) 

  • Cover, Clays and Clay Minerals (2010) 

  • Associate Editor, Clays and Clay Minerals (2010) 

  • Keynote Speaker, Annual Meeting, Clay Minerals Group of the Mineralogical Society of United Kingdom, FuturoClay Symposium (2009) 

  • Outstanding Performance Award for bringing external visibility to EMSL’s Mössbauer capability, PNNL (2009) 

  • Emerging Scientist in the Mössbauer Spectroscopy Field, International Conference on the Applications of the Mössbauer Effect Conference (2009) 

  • Editor's Choice, "Reduction of Hg(II) to Hg(0) by Magnetite” in Environmental Science and Technology, Science Magazine (July 2009) 

  • Co-Organizer, Magnetic Resonance Spectroscopic Studies of Clay Minerals Session, 41st Annual Meeting of the Clay Minerals Society (2004) 

  • Best Poster Award, International Symposium on the Industrial Applications of Mössbauer Effect (2000) 

  • Postdoctoral Research Fellowship, Robert R. Welch Foundation, University of Houston (1987 – 1990)  

Patents

R. K. Kukkadapu and S. A. Boyd. 1996, 1997, 1998. “Method of Removing Organic Contaminants from Air and Water with Organophilic, Quaternary Phosphonium Ion-exchanged Smectite Clays.” 5,587,084 (1996), 5,630,075 (1997), and 5,747,403 (1998). 

Publications

2020 

Kenton AR, A. P Smith, Weinan Leng, Sean Colby, Ravi K. Kukkadapu, Mark Bowden, Odeta Qafoku, Wooyong Um, Michael F. Hochella, Jr, Vanessa L. Bailey, Ryan S. Renslow (2020) "Water dispersible nano-colloids and higher temperatures promote the release of carbon from riparian soil" Vadose Zone Journal  19 (1) doi.org/10.1002/vzj2.20077 

Boglaienko, D., J. A. Soltis, R. K. Kukkadapu, Y. Du, L. E. Sweet, V. E. Holfeltz, G. B. Hall, E. C. Buck, C. U. Segre, H. P. Emerson, Y. Katsenovich, and T. G. Levitskaia. 2020. “Spontaneous Redox Continuum Reveals Sequestered Technetium Clusters and Retarded Mineral Transformation of Iron.” Communications Chemistry 3 (1). https://doi.org/10.1038/s42004-020-0334-x

Boiteau, R. M., R. Kukkadapu, J. B. Cliff, C. R. Smallwood, L. Kovarik, M. G. Wirth, M. H. Engelhard, T. Varga, A. Dohnalkova, D. E. Perea, T. Wietsma, J. J. Moran, and K. S. Hofmockel. 2020. “Calcareous Organic Matter Coatings Sequester Siderophores in Alkaline Soils.” Science of the Total Environment 724. https://doi.org/10.1016/j.scitotenv.2020.138250

O'Connell, D. W., N. Ansems, R. K. Kukkadapu, D. Jaisi, D. M. Orihel, B. J. Cade-Menun, Y. Hu, J. Wiklund, R. I. Hall, H. Chessell, T. Behrends, and P. Van Cappellen. 2020. “Changes in Sedimentary Phosphorus Burial Following Artificial Eutrophication of Lake 227, Experimental Lakes Area, Ontario, Canada.” Journal of Geophysical Research: Biogeosciences 125 (8). https://doi.org/10.1029/2020JG005713

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

Zuo, H., R. Kukkadapu, Z. Zhu, S. Ni, L. Huang, Q. Zeng, C. Liu, and H. Dong. 2020. “Role of Clay-Associated Humic Substances in Catalyzing Bioreduction of Structural Fe(III) in Nontronite by Shewanella putrefaciens CN32.” Science of the Total Environment 741. https://doi.org/10.1016/j.scitotenv.2020.140213

2019 

Garcia Arredondo, M., C. R. Lawrence, M. S. Schulz, M. M. Tfaily, R. Kukkadapu, M. E. Jones, K. Boye, and M. Keiluweit. 2019. “Root-Driven Weathering Impacts on Mineral-Organic Associations in Deep Soils over Pedogenic Time Scales.” Geochimica et Cosmochimica Acta 263: 68-84. https://doi.org/10.1016/j.gca.2019.07.030

Ilgen, A. G., R. K. Kukkadapu, K. Leung, and R. E. Washington. 2019. “"Switching on" Iron in Clay Minerals.” Environmental Science: Nano 6 (6): 1704-1715. https://doi.org/10.1039/c9en00228f

Noël, V., K. Boye, R. K. Kukkadapu, Q. Li, and J. R. Bargar. 2019. “Uranium Storage Mechanisms in Wet-Dry Redox Cycled Sediments.” Water Research 152: 251-263. https://doi.org/10.1016/j.watres.2018.12.040

Yuan, H., Q. Li, R. K. Kukkadapu, E. Liu, J. Yu, H. Fang, H. Li, and D. P. Jaisi. 2019. “Identifying Sources and Cycling of Phosphorus in the Sediment of a Shallow Freshwater Lake in China Using Phosphate Oxygen Isotopes.” Science of the Total Environment 676: 823-833. https://doi.org/10.1016/j.scitotenv.2019.04.322

Zhang, L., H. Dong, R. K. Kukkadapu, Q. Jin, and L. Kovarik. 2019. “Electron Transfer between Sorbed Fe(II) and Structural Fe(III) in Smectites and Its Effect on Nitrate-Dependent Iron Oxidation by Pseudogulbenkiania sp. Strain 2002.” Geochimica et Cosmochimica Acta 265: 132-147. https://doi.org/10.1016/j.gca.2019.08.042

2018 

Bhattacharyya, A., A. N. Campbell, M. M. Tfaily, Y. Lin, R. K. Kukkadapu, W. L. Silver, P. S. Nico, and J. Pett-Ridge. 2018. “Redox Fluctuations Control the Coupled Cycling of Iron and Carbon in Tropical Forest Soils.” Environmental Science and Technology 52 (24): 14129-14139. https://doi.org/10.1021/acs.est.8b03408

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

Overman, N. R., X. Jiang, R. K. Kukkadapu, T. Clark, T. J. Roosendaal, G. Coffey, J. E. Shield, and S. N. Mathaudhu. 2018. “Physical and Electrical Properties of Melt-Spun Fe-Si (3–8 Wt.%) Soft Magnetic Ribbons.” Materials Characterization 136: 212-220. https://doi.org/10.1016/j.matchar.2017.12.019

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

Wang, A., Y. Wang, E. D. Walter, R. K. Kukkadapu, Y. Guo, G. Lu, R. S. Weber, Y. Wang, C. H. F. Peden, and F. Gao. 2018. “Catalytic N2O Decomposition and Reduction by NH3 over Fe/Beta and Fe/SSZ-13 Catalysts.” Journal of Catalysis 358: 199-210. https://doi.org/10.1016/j.jcat.2017.12.011

Wu, Y., R. K. Kukkadapu, K. J. T. Livi, W. Xu, W. Li, and D. L. Sparks. 2018. “Iron and Arsenic Speciation During As(III) Oxidation by Manganese Oxides in the Presence of Fe(II): Molecular-Level Characterization Using XAFS, Mössbauer, and TEM Analysis.” ACS Earth and Space Chemistry 2 (3): 256-268. https://doi.org/10.1021/acsearthspacechem.7b00119

2017 

Chen, C., R. K. Kukkadapu, O. Lazareva, and D. L. Sparks. 2017. “Solid-Phase Fe Speciation Along the Vertical Redox Gradients in Floodplains Using XAS and Mössbauer Spectroscopies.” Environmental Science and Technology 51 (14): 7903-7912. https://doi.org/10.1021/acs.est.7b00700

Elsaidi, S. K., M. A. Sinnwell, D. Banerjee, A. Devaraj, R. K. Kukkadapu, T. C. Droubay, Z. Nie, L. Kovarik, M. Vijayakumar, S. Manandhar, M. Nandasiri, B. P. McGrail, and P. K. Thallapally. 2017. “Reduced Magnetism in Core-Shell Magnetite@MOF Composites.” Nano Letters 17 (11): 6968-6973. https://doi.org/10.1021/acs.nanolett.7b03451

Ilgen, A. G., R. K. Kukkadapu, D. R. Dunphy, K. Artyushkova, J. M. Cerrato, J. N. Kruichak, M. T. Janish, C. J. Sun, J. M. Argo, and R. E. Washington. 2017. “Synthesis and Characterization of Redox-Active Ferric Nontronite.” Chemical Geology 470: 1-12. https://doi.org/10.1016/j.chemgeo.2017.07.010

Kaur, M., J. S. McCloy, R. Kukkadapu, C. Pearce, J. Tucek, M. Bowden, M. Engelhard, E. Arenholz, and Y. Qiang. 2017. “Tetragonal-Like Phase in Core-Shell Iron Iron-Oxide Nanoclusters.” Journal of Physical Chemistry C 121 (21): 11794-11803. https://doi.org/10.1021/acs.jpcc.7b01469

Kovarik, L., N. M. Washton, R. Kukkadapu, A. Devaraj, A. Wang, Y. Wang, J. Szanyi, C. H. F. Peden, and F. Gao. 2017. “Transformation of Active Sites in Fe/Ssz-13 SCR Catalysts During Hydrothermal Aging: A Spectroscopic, Microscopic, and Kinetics Study.” ACS Catalysis 7 (4): 2458-2470. https://doi.org/10.1021/acscatal.6b03679

Noël, V., K. Boye, R. K. Kukkadapu, S. Bone, J. S. Lezama Pacheco, E. Cardarelli, N. Janot, S. Fendorf, K. H. Williams, and J. R. Bargar. 2017. “Understanding Controls on Redox Processes in Floodplain Sediments of the Upper Colorado River Basin.” Science of the Total Environment 603-604: 663-675. https://doi.org/10.1016/j.scitotenv.2017.01.109

Wu, T., A. M. Griffin, C. A. Gorski, E. S. Shelobolina, H. Xu, R. K. Kukkadapu, and E. E. Roden. 2017. “Interactions between Fe(III)-Oxides and Fe(III)-Phyllosilicates During Microbial Reduction 2: Natural Subsurface Sediments.” Geomicrobiology Journal 34 (3): 231-241. https://doi.org/10.1080/01490451.2016.1174758

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

2016 

Gao, F., Y. Zheng, R. K. Kukkadapu, Y. Wang, E. D. Walter, B. Schwenzer, J. Szanyi, and C. H. F. Peden. 2016. “Iron Loading Effects in Fe/SSZ-13 NH3-SCR Catalysts: Nature of the Fe Ions and Structure-Function Relationships.” ACS Catalysis 6 (5): 2939-2954. https://doi.org/10.1021/acscatal.6b00647

Guo, X., A. Navrotsky, R. K. Kukkadapu, M. H. Engelhard, A. Lanzirotti, M. Newville, E. S. Ilton, S. R. Sutton, and H. Xu. 2016. “Structure and Thermodynamics of Uranium-Containing Iron Garnets.” Geochimica et Cosmochimica Acta 189: 269-281. https://doi.org/10.1016/j.gca.2016.05.043

Guo, X., E. Tiferet, L. Qi, J. M. Solomon, A. Lanzirotti, M. Newville, M. H. Engelhard, R. K. Kukkadapu, D. Wu, E. S. Ilton, M. Asta, S. R. Sutton, H. Xu, and A. Navrotsky. 2016. “U(V) in Metal Uranates: A Combined Experimental and Theoretical Study of MgUO4, CrUO4, and FeUO4.” Dalton Transactions 45 (11): 4622-4632. https://doi.org/10.1039/c6dt00066e

Kaplan, D. I., R. Kukkadapu, J. C. Seaman, B. W. Arey, A. C. Dohnalkova, S. Buettner, D. Li, T. Varga, K. G. Scheckel, and P. R. Jaffé. 2016. “Iron Mineralogy and Uranium-Binding Environment in the Rhizosphere of a Wetland Soil.” Science of the Total Environment 569-570: 53-64. https://doi.org/10.1016/j.scitotenv.2016.06.120

Long, G. J., F. Grandjean, X. Guo, A. Navrotsky, and R. K. Kukkadapu. 2016. “Mössbauer Spectral Properties of Yttrium Iron Garnet, Y3Fe5O12, and Its Isovalent and Nonisovalent Yttrium-Substituted Solid Solutions.” Inorganic Chemistry 55 (7): 3413-3418. https://doi.org/10.1021/acs.inorgchem.5b02769

Nune, S. K., D. B. Lao, D. J. Heldebrant, J. Liu, M. J. Olszta, R. K. Kukkadapu, L. M. Gordon, M. I. Nandasiri, G. Whyatt, C. Clayton, D. W. Gotthold, M. H. Engelhard, and H. T. Schaef. 2016. “Anomalous Water Expulsion from Carbon-Based Rods at High Humidity.” Nature Nanotechnology 11 (9): 791-797. https://doi.org/10.1038/nnano.2016.91

Ruby C, Naille S, Ona-Nguema G, Morin G, Mallet M, Guerbois D, Barthelemy K, Etique M, Zegeye A, Zhang Y, Boumaiza H, Renard A, Noel V, Binda P, Hanna K, Despas C, Abdelmoula M, Kukkadapu R, Sarrias J, Albignac M, Rocklin P, Nauleau F, Hyvard N, and Genin JMR (2016) “Use of ferrihydrite-coated pouzzolana and biogenic green rust to purify waste water containing phosphate and nitrate” Green Rust and Related Iron Containing Compounds: Structure, Redox Properties and Environmental Applications” in Current Inorganic Chemistry, 6(2), 100-118. doi:10.2174/1877944106999160603125459 

Lao D, Kukkadapu RK, Kovarik L, Bruce W Arey, Heldebrant DJ, and Nune SK (2016) “Switchable Ionic Liquids: An Environmentally-friendly Medium to Synthesize Nanoparticulate Green Rust” Green Rust and Related Iron Containing Compounds: Structure, Redox Properties and Environmental Applications” in Current Inorganic Chemistry,  6(2), 92-99. 

Starcher, A. N., W. Li, R. K. Kukkadapu, E. J. Elzinga, and D. L. Sparks. 2016. “Fe(II) Sorption on Pyrophyllite: Effect of Structural Fe(III) (Impurity) in Pyrophyllite on Nature of Layered Double Hydroxide (LDH) Secondary Mineral Formation.” Chemical Geology 439: 152-160. https://doi.org/10.1016/j.chemgeo.2016.06.017

Wu, T., R. K. Kukkadapu, A. M. Griffin, C. A. Gorski, H. Konishi, H. Xu, and E. E. Roden. 2016. “Interactions between Fe(III)-Oxides and Fe(III)-Phyllosilicates During Microbial Reduction 1: Synthetic Sediments.” Geomicrobiology Journal 33 (9): 793-806. https://doi.org/10.1080/01490451.2015.1117546

Zhang, W., D. Banerjee, J. Liu, H. T. Schaef, J. V. Crum, C. A. Fernandez, R. K. Kukkadapu, Z. Nie, S. K. Nune, R. K. Motkuri, K. W. Chapman, M. H. Engelhard, J. C. Hayes, K. L. Silvers, R. Krishna, B. P. McGrail, J. Liu, and P. K. Thallapally. 2016. “Redox-Active Metal-Organic Composites for Highly Selective Oxygen Separation Applications.” Advanced Materials 28 (18): 3572-3577. https://doi.org/10.1002/adma.201600259

2015 

Abrecht, D. G., J. M. Schwantes, R. K. Kukkadapu, B. S. McDonald, G. C. Eiden, and L. E. Sweet. 2015. “Real-Time Noise Reduction for Mössbauer Spectroscopy through Online Implementation of a Modified Kalman Filter.” Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment 773: 66-71. https://doi.org/10.1016/j.nima.2014.10.053

Chen, C., R. Kukkadapu, and D. L. Sparks. 2015. “Influence of Coprecipitated Organic Matter on Fe2+(aq)-Catalyzed Transformation of Ferrihydrite: Implications for Carbon Dynamics.” Environmental Science and Technology 49 (18): 10927-10936. https://doi.org/10.1021/acs.est.5b02448

Gao, F., M. Kollár, R. K. Kukkadapu, N. M. Washton, Y. Wang, J. Szanyi, and C. H. Peden. 2015. “Fe/SSZ-13 as an NH3-SCR Catalyst: A Reaction Kinetics and FTIR/Mössbauer Spectroscopic Study.” Applied Catalysis B: Environmental 164: 407-419. https://doi.org/10.1016/j.apcatb.2014.09.031

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

Guo, X., R. K. Kukkadapu, A. Lanzirotti, M. Newville, M. H. Engelhard, S. R. Sutton, and A. Navrotsky. 2015. “Charge-Coupled Substituted Garnets (Y3-xCa0.5xM0.5x)Fe5O12 (M = Ce, Th): Structure and Stability as Crystalline Nuclear Waste Forms.” Inorganic Chemistry 54 (8): 4156-4166. https://doi.org/10.1021/acs.inorgchem.5b00444

Joshi, S. R., R. K. Kukkadapu, D. J. Burdige, M. E. Bowden, D. L. Sparks, and D. P. Jaisi. 2015. “Organic Matter Remineralization Predominates Phosphorus Cycling in the Mid-Bay Sediments in the Chesapeake Bay.” Environmental Science and Technology 49 (10): 5887-5896. https://doi.org/10.1021/es5059617

Liu, Y., C. Liu, R. K. Kukkadapu, J. P. McKinley, J. Zachara, A. E. Plymale, M. D. Miller, T. Varga, and C. T. Resch. 2015. “99Tc(VII) Retardation, Reduction, and Redox Rate Scaling in Naturally Reduced Sediments.” Environmental Science and Technology 49 (22): 13403-13412. https://doi.org/10.1021/acs.est.5b03273

McCloy, J., N. Washton, P. Gassman, J. Marcial, J. Weaver, and R. Kukkadapu. 2015. “Nepheline Crystallization in Boron-Rich Alumino-Silicate Glasses as Investigated by Multi-Nuclear NMR, Raman, & Mössbauer Spectroscopies.” Journal of Non-Crystalline Solids 409: 149-165. https://doi.org/10.1016/j.jnoncrysol.2014.11.013

Zhao, L., H. Dong, R. K. Kukkadapu, Q. Zeng, R. E. Edelmann, M. Pentrák, and A. Agrawal. 2015. “Biological Redox Cycling of Iron in Nontronite and Its Potential Application in Nitrate Removal.” Environmental Science and Technology 49 (9): 5493-5501. https://doi.org/10.1021/acs.est.5b00131

2014 

Fan, D., R. P. Anitori, B. M. Tebo, P. G. Tratnyek, J. S. Lezama Pacheco, R. K. Kukkadapu, L. Kovarik, M. H. Engelhard, and M. E. Bowden. 2014. “Oxidative Remobilization of Technetium Sequestered by Sulfide-Transformed Nano Zerovalent Iron.” Environmental Science and Technology 48 (13): 7409-7417. https://doi.org/10.1021/es501607s

Felmy, A. R., D. A. Moore, E. Buck, S. D. Conradson, R. Kukkadapu, L. Sweet, D. Abrecht, and E. S. Ilton. 2014. “The Solubility of 242PuO2 in the Presence of Aqueous Fe(II): The Impact of Precipitate Preparation.” Radiochimica Acta 102 (10): 861-874. https://doi.org/10.1515/ract-2013-2187

Guo, X., A. H. Tavakoli, S. Sutton, R. K. Kukkadapu, L. Qi, A. Lanzirotti, M. Newville, M. Asta, and A. Navrotsky. 2014. “Cerium Substitution in Yttrium Iron Garnet: Valence State, Structure, and Energetics.” Chemistry of Materials 26 (2): 1133-1143. https://doi.org/10.1021/cm403444f

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

Shah, M., C. C. Lin, R. Kukkadapu, M. H. Engelhard, X. Zhao, Y. Wang, T. Barkay, and N. Yee. 2014. “Syntrophic Effects in a Subsurface Clostridial Consortium on Fe(III)-(Oxyhydr)Oxide Reduction and Secondary Mineralization.” Geomicrobiology Journal 31 (2): 101-115. https://doi.org/10.1080/01490451.2013.806610

Shao, H., R. K. Kukkadapu, E. J. Krogstad, M. K. Newburn, and K. J. Cantrell. 2014. “Mobilization of Metals from Eau Claire Siltstone and the Impact of Oxygen under Geological Carbon Dioxide Sequestration Conditions.” Geochimica et Cosmochimica Acta 141: 62-82. https://doi.org/10.1016/j.gca.2014.06.011

2013 

Bi, Y., S. P. Hyun, R. Kukkadapu, and K. F. Hayes. 2013. “Oxidative Dissolution of UO2 in a Simulated Groundwater Containing Synthetic Nanocrystalline Mackinawite.” Geochimica et Cosmochimica Acta 102: 175-190. https://doi.org/10.1016/j.gca.2012.10.032

Fan, D., R. P. Anitori, B. M. Tebo, P. G. Tratnyek, J. S. L. Pacheco, R. K. Kukkadapu, M. H. Engelhard, M. E. Bowden, L. Kovarik, and B. W. Arey. 2013. “Reductive Sequestration of Pertechnetate (99TcO4-) by Nano Zerovalent Iron (nZVI) Transformed by Abiotic Sulfide.” Environmental Science and Technology 47 (10): 5302-5310. https://doi.org/10.1021/es304829z

Fox, P. M., J. A. Davis, R. Kukkadapu, D. M. Singer, J. Bargar, and K. H. Williams. 2013. “Abiotic U(VI) Reduction by Sorbed Fe(II) on Natural Sediments.” Geochimica et Cosmochimica Acta 117: 266-282. https://doi.org/10.1016/j.gca.2013.05.003

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

Zhao, L., H. Dong, R. Kukkadapu, A. Agrawal, D. Liu, J. Zhang, and R. E. Edelmann. 2013. “Biological Oxidation of Fe(II) in Reduced Nontronite Coupled with Nitrate Reduction by Pseudogulbenkiania sp. Strain 2002.” Geochimica et Cosmochimica Acta 119: 231-247. https://doi.org/10.1016/j.gca.2013.05.033

2012 

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

Lee, J. H., J. K. Fredrickson, R. K. Kukkadapu, M. I. Boyanov, K. M. Kemner, X. Lin, D. W. Kennedy, B. N. Bjornstad, A. E. Konopka, D. A. Moore, C. T. Resch, and J. L. Phillips. 2012. “Microbial Reductive Transformation of Phyllosilicate Fe(III) and U(VI) in Fluvial Subsurface Sediments.” Environmental Science and Technology 46 (7): 3721-3730. https://doi.org/10.1021/es204528m

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

Peretyazhko, T. S., J. M. Zachara, R. K. Kukkadapu, S. M. Heald, I. V. Kutnyakov, C. T. Resch, B. W. Arey, C. M. Wang, L. Kovarik, J. L. Phillips, and D. A. Moore. 2012. “Pertechnetate (TcO4-) Reduction by Reactive Ferrous Iron Forms in Naturally Anoxic, Redox Transition Zone Sediments from the Hanford Site, USA.” Geochimica et Cosmochimica Acta 92: 48-66. https://doi.org/10.1016/j.gca.2012.05.041

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

Shelobolina, E., H. Xu, H. Konishi, R. Kukkadapu, T. Wu, M. Blöthe, and E. Roden. 2012. “Microbial Lithotrophic Oxidation of Structural Fe(II) in Biotite.” Applied and Environmental Microbiology 78 (16): 5746-5752. https://doi.org/10.1128/AEM.01034-12

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

Wu, T., E. Shelobolina, H. Xu, H. Konishi, R. Kukkadapu, and E. E. Roden. 2012. “Isolation and Microbial Reduction of Fe(III) Phyllosilicates from Subsurface Sediments.” Environmental Science and Technology 46 (21): 11618-11626. https://doi.org/10.1021/es302639n

Yang, J., R. K. Kukkadapu, H. Dong, E. S. Shelobolina, J. Zhang, and J. Kim. 2012. “Effects of Redox Cycling of Iron in Nontronite on Reduction of Technetium.” Chemical Geology 291: 206-216. https://doi.org/10.1016/j.chemgeo.2011.10.013

2011 

Bishop, M. E., H. Dong, R. K. Kukkadapu, C. Liu, and R. E. Edelmann. 2011. “Bioreduction of Fe-Bearing Clay Minerals and Their Reactivity toward Pertechnetate (Tc-99).” Geochimica et Cosmochimica Acta 75 (18): 5229-5246. https://doi.org/10.1016/j.gca.2011.06.034

Campbell, K. M., J. A. Davis, J. Bargar, D. Giammar, R. Bernier-Latmani, R. Kukkadapu, K. H. Williams, H. Veramani, K. U. Ulrich, J. Stubbs, S. Yabusaki, L. Figueroa, E. Lesher, M. J. Wilkins, A. Peacock, and P. E. Long. 2011. “Composition, Stability, and Measurement of Reduced Uranium Phases for Groundwater Bioremediation at Old Rifle, CO.” Applied Geochemistry 26 (SUPPL.): S167-S169. https://doi.org/10.1016/j.apgeochem.2011.03.094

Jaisi, D. P., R. K. Kukkadapu, L. M. Stout, T. Varga, and R. E. Blake. 2011. “Biotic and Abiotic Pathways of Phosphorus Cycling in Minerals and Sediments: Insights from Oxygen Isotope Ratios in Phosphate.” Environmental Science and Technology 45 (15): 6254-6261. https://doi.org/10.1021/es200456e

McCloy, J., R. Kukkadapu, J. Crum, B. Johnson, and T. Droubay. 2011. “Size Effects on Gamma Radiation Response of Magnetic Properties of Barium Hexaferrite Powders.” Journal of Applied Physics 110 (11). https://doi.org/10.1063/1.3665769

Zachara, J. M., R. K. Kukkadapu, T. Peretyazhko, M. Bowden, C. Wang, D. W. Kennedy, D. Moore, and B. Arey. 2011. “The Mineralogic Transformation of Ferrihydrite Induced by Heterogeneous Reaction with Bioreduced Anthraquinone Disulfonate (AQDS) and the Role of Phosphate.” Geochimica et Cosmochimica Acta 75 (21): 6330-6349. https://doi.org/10.1016/j.gca.2011.06.030

2010 

Bishop, M. E., D. P. Jaisi, H. Dong, R. K. Kukkadapu, and J. Ji. 2010. “Bioavailability of Fe(III) in Loess Sediments: An Important Source of Electron Acceptors.” Clays and Clay Minerals 58 (4): 542-557. https://doi.org/10.1346/CCMN.2010.0580409

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

Hu, Y. J., L. K. Schwaiger, C. H. Booth, R. K. Kukkadapu, E. Cristiano, D. Kaplan, and H. Nitsche. 2010. “Molecular Interactions of Plutonium(VI) with Synthetic Manganese- Substituted Goethite.” Radiochimica Acta 98 (9-11): 655-663. https://doi.org/10.1524/ract.2010.1766

Jaisi, D. P., R. E. Blake, and R. K. Kukkadapu. 2010. “Fractionation of Oxygen Isotopes in Phosphate During Its Interactions with Iron Oxides.” Geochimica et Cosmochimica Acta 74 (4): 1309-1319. https://doi.org/10.1016/j.gca.2009.11.010

Moon, H. S., L. McGuinness, R. K. Kukkadapu, A. D. Peacock, J. Komlos, L. J. Kerkhof, P. E. Long, and P. R. Jaffé. 2010. “Microbial Reduction of Uranium under Iron- and Sulfate-Reducing Conditions: Effect of Amended Goethite on Microbial Community Composition and Dynamics.” Water Research 44 (14): 4015-4028. https://doi.org/10.1016/j.watres.2010.05.003

Rastogi, G., S. Osman, R. Kukkadapu, M. Engelhard, P. A. Vaishampayan, G. L. Andersen, and R. K. Sani. 2010. “Microbial and Mineralogical Characterizations of Soils Collected from the Deep Biosphere of the Former Homestake Gold Mine, South Dakota.” Microbial Ecology 60 (3): 539-550. https://doi.org/10.1007/s00248-010-9657-y

2009 

Arey, B., R. K. Kukkadapu, J. P. McKinley, and C. Wang. 2009. “Microscopic Evidence of U Association with Fe-Minerals (Pyrite and Magnetite-Like Phases) in Naturally Bioreduced Sediment Cores Obtained from a U-Contaminated Aquifer.” Microscopy and Microanalysis 15 (SUPPL. 2): 912-913. https://doi.org/10.1017/S1431927609097402

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

Smith, S. C., M. Douglas, D. A. Moore, R. K. Kukkadapu, and B. W. Arey. 2009. “Uranium Extraction from Laboratory-Synthesized, Uranium-Doped Hydrous Ferric Oxides.” Environmental Science and Technology 43 (7): 2341-2347. https://doi.org/10.1021/es802621t

Wiatrowski, H. A., S. Das, R. Kukkadapu, E. S. Ilton, T. Barkay, and N. Yee. 2009. “Reduction of Hg(II) to Hg(0) by Magnetite.” Environmental Science and Technology 43 (14): 5307-5313. https://doi.org/10.1021/es9003608

Zhang, G., H. Dong, H. Jiang, R. K. Kukkadapu, J. Kim, D. Eberl, and Z. Xu. 2009. “Biomineralization Associated with Microbial Reduction of Fe3+ and Oxidation of Fe2+ in Solid Minerals.” American Mineralogist 94 (7): 1049-1058. https://doi.org/10.2138/am.2009.3136

2008 

Bank, T. L., R. K. Kukkadapu, A. S. Madden, M. A. Ginder-Vogel, M. E. Baldwin, and P. M. Jardine. 2008. “Effects of Gamma-Sterilization on the Physico-Chemical Properties of Natural Sediments.” Chemical Geology 251 (1-4): 1-7. https://doi.org/10.1016/j.chemgeo.2008.01.003

Komlos, J., A. Peacock, R. K. Kukkadapu, and P. R. Jaffé. 2008. “Long-Term Dynamics of Uranium Reduction/Reoxidation under Low Sulfate Conditions.” Geochimica et Cosmochimica Acta 72 (15): 3603-3615. https://doi.org/10.1016/j.gca.2008.05.040

Mohanty, S. R., B. Kollah, D. B. Hedrick, A. D. Peacock, R. K. Kukkadapu, and E. E. Roden. 2008. “Biogeochemical Processes in Ethanol Stimulated Uranium-Contaminated Subsurface Sediments.” Environmental Science and Technology 42 (12): 4384-4390. https://doi.org/10.1021/es703082v

Peretyazhko, T., J. M. Zachara, S. M. Heald, B. H. Jeon, R. K. Kukkadapu, C. Liu, D. Moore, and C. T. Resch. 2008. “Heterogeneous Reduction of Tc(VII) by Fe(II) at the Solid-Water Interface.” Geochimica et Cosmochimica Acta 72 (6): 1521-1539. https://doi.org/10.1016/j.gca.2008.01.004

Peretyazhko, T., J. M. Zachara, S. M. Heald, R. K. Kukkadapu, C. Liu, A. E. Plymale, and C. T. Resch. 2008. “Reduction of Tc(VII) by Fe(II) Sorbed on Al (Hydr)Oxides.” Environmental Science and Technology 42 (15): 5499-5506. https://doi.org/10.1021/es8003156

2007 

Borch, T., Y. Masue, R. K. Kukkadapu, and S. Fendorf. 2007. “Phosphate Imposed Limitations on Biological Reduction and Alteration of Ferrihydrite.” Environmental Science and Technology 41 (1): 166-172. https://doi.org/10.1021/es060695p

Komlos, J., R. K. Kukkadapu, J. M. Zachara, and P. R. Jaffé. 2007. “Biostimulation of Iron Reduction and Subsequent Oxidation of Sediment Containing Fe-Silicates and Fe-Oxides: Effect of Redox Cycling on Fe(III) Bioreduction.” Water Research 41 (13): 2996-3004. https://doi.org/10.1016/j.watres.2007.03.019

Zachara, J. M., S. M. Heald, B. H. Jeon, R. K. Kukkadapu, C. Liu, J. P. McKinley, A. C. Dohnalkova, and D. A. Moore. 2007. “Reduction of Pertechnetate [Tc(VII)] by Aqueous Fe(II) and the Nature of Solid Phase Redox Products.” Geochimica et Cosmochimica Acta 71 (9): 2137-2157. https://doi.org/10.1016/j.gca.2006.10.025

2006 

Kukkadapu, R. K., J. M. Zachara, J. K. Fredrickson, J. P. McKinley, D. W. Kennedy, S. C. Smith, and H. Dong. 2006. “Reductive Biotransformation of Fe in Shale-Limestone Saprolite Containing Fe(III) Oxides and Fe(II)/Fe(III) Phyllosilicates.” Geochimica et Cosmochimica Acta 70 (14): 3662-3676. https://doi.org/10.1016/j.gca.2006.05.004

Seabaugh, J. L., H. Dong, R. K. Kukkadapu, D. D. Eberl, J. P. Morton, and J. Kim. 2006. “Microbial Reduction of Fe(III) in the Fifthian and Muloorina Illites: Contrasting Extents and Rates of Bioreduction.” Clays and Clay Minerals 54 (1): 67-79. https://doi.org/10.1346/CCMN.2006.0540109

Weber, K. A., M. M. Urrutia, P. F. Churchill, R. K. Kukkadapu, and E. E. Roden. 2006. “Anaerobic Redox Cycling of Iron by Freshwater Sediment Microorganisms.” Environmental Microbiology 8 (1): 100-113. https://doi.org/10.1111/j.1462-2920.2005.00873.x

2005 

Cooper, D. C., A. L. Neal, R. K. Kukkadapu, D. Brewe, A. Coby, and F. W. Picardal. 2005. “Effects of Sediment Iron Mineral Composition on Microbially Mediated Changes in Divalent Metal Speciation: Importance of Ferrihydrite.” Geochimica et Cosmochimica Acta 69 (7): 1739-1754. https://doi.org/10.1016/j.gca.2004.09.013

Jaisi, D. P., R. K. Kukkadapu, D. D. Eberl, and H. Dong. 2005. “Control of Fe(III) Site Occupancy on the Rate and Extent of Microbial Reduction of Fe(III) in Nontronite.” Geochimica et Cosmochimica Acta 69 (23): 5429-5440. https://doi.org/10.1016/j.gca.2005.07.008

Kukkadapu, R. K., J. M. Zachara, J. K. Fredrickson, D. W. Kennedy, A. C. Dohnalkova, and D. E. McCready. 2005. “Ferrous Hydroxy Carbonate Is a Stable Transformation Product of Biogenic Magnetite.” American Mineralogist 90 (2-3): 510-515. https://doi.org/10.2138/am.2005.1727

Liu, C., J. M. Zachara, L. Zhong, R. Kukkadupa, J. E. Szecsody, and D. W. Kennedy. 2005. “Influence of Sediment Bioreduction and Reoxidation on Uranium Sorption.” Environmental Science and Technology 39 (11): 4125-4133. https://doi.org/10.1021/es048501y

Punnoose, A., J. Hays, A. Thurber, M. H. Engelhard, R. K. Kukkadapu, C. Wang, V. Shutthanandan, and S. Thevuthasan. 2005. “Development of High-Temperature Ferromagnetism in SnO2 and Paramagnetism in SnO by Fe Doping.” Physical Review B - Condensed Matter and Materials Physics 72 (5). https://doi.org/10.1103/PhysRevB.72.054402

2004 

Fredrickson, J. K., J. M. Zachara, D. W. Kennedy, R. K. Kukkadapu, J. P. McKinley, S. M. Heald, C. Liu, and A. E. Plymale. 2004. “Reduction of TcO4- by Sediment-Associated Biogenic Fe(II).” Geochimica et Cosmochimica Acta 68 (15): 3171-3187. https://doi.org/10.1016/j.gca.2003.10.024

Kukkadapu, R. K., J. M. Zachara, J. K. Fredrickson, and D. W. Kennedy. 2004. “Biotransformation of Two-Line Silica-Ferrihydrite by a Dissimilatory Fe(III)-Reducing Bacterium: Formation of Carbonate Green Rust in the Presence of Phosphate.” Geochimica et Cosmochimica Acta 68 (13): 2799-2814. https://doi.org/10.1016/j.gca.2003.12.024

Norberg, N. S., K. R. Kittilstved, J. E. Amonette, R. K. Kukkadapu, D. A. Schwartz, and D. R. Gamelin. 2004. “Synthesis of Colloidal Mn2+:ZnO Quantum Dots and High-TC Ferromagnetic Nanocrystalline Thin Films.” Journal of the American Chemical Society 126 (30): 9387-9398. https://doi.org/10.1021/ja048427j

Strawn, D. G., N. E. Palmer, L. J. Furnare, C. Goodell, J. E. Amonette, and R. K. Kukkadapu. 2004. “Copper Sorption Mechanisms on Smectites.” Clays and Clay Minerals 52 (3): 321-333. https://doi.org/10.1346/CCMN.2004.0520307

Zachara, J. M., R. K. Kukkadapu, P. L. Gassman, A. Dohnalkova, J. K. Fredrickson, and T. Anderson. 2004. “Biogeochemical Transformation of Fe Minerals in a Petroleum-Contaminated Aquifer.” Geochimica et Cosmochimica Acta 68 (8): 1791-1805. https://doi.org/10.1016/j.gca.2003.09.022

2003 

Amonette, J. E., R. K. Kukkadapu, E. E. Alp, W. Sturhahn, and T. S. Toellner. 2003. “Heterogeneous Electron-Transfer Kinetics with Synchrotron 57Fe Mössbauer Spectroscopy.” Geochimica et Cosmochimica Acta 67 (12): 2109-2116. https://doi.org/10.1016/S0016-7037(02)01346-7

Dong, H., R. K. Kukkadapu, J. K. Fredrickson, J. M. Zachara, D. W. Kennedy, and H. M. Kostandarithes. 2003. “Microbial Reduction of Structural Fe(III) in Illite and Goethite.” Environmental Science and Technology 37 (7): 1268-1276. https://doi.org/10.1021/es020919d

Fredrickson, J. K., S. Kota, R. K. Kukkadapu, C. Liu, and J. M. Zachara. 2003. “Influence of Electron Donor/Acceptor Concentrations on Hydrous Ferric Oxide (HFO) Bioreduction.” Biodegradation 14 (2): 91-103. https://doi.org/10.1023/A:1024001207574

Hansel, C. M., S. G. Benner, J. Neiss, A. Dohnalkova, R. K. Kukkadapu, and S. Fendorf. 2003. “Secondary Mineralization Pathways Induced by Dissimilatory Iron Reduction of Ferrihydrite under Advective Flow.” Geochimica et Cosmochimica Acta 67 (16): 2977-2992. https://doi.org/10.1016/S0016-7037(03)00276-X

Kukkadapu, R. K., H. Li, G. L. Smith, J. D. Crum, J. S. Jeoung, W. H. Poisl, and M. C. Weinberg. 2003. “Mössbauer and Optical Spectroscopic Study of Temperature and Redox Effects on Iron Local Environments in a Fe-Doped (0.5 Mol% Fe2O3) 18Na2O-72SiO2 Glass.” Journal of Non-Crystalline Solids 317 (3): 301-318. https://doi.org/10.1016/S0022-3093(02)01815-X

Kukkadapu, R. K., J. M. Zachara, J. K. Fredrickson, S. C. Smith, A. C. Dohnalkova, and C. K. Russell. 2003. “Transformation of 2-Line Ferrihydrite to 6-Line Ferrihydrite under Oxic and Anoxic Conditions.” American Mineralogist 88 (11-12 PART 2): 1903-1914. https://doi.org/10.2138/am-2003-11-1233

2002 

Zachara, J. M., R. K. Kukkadapu, J. K. Fredrickson, Y. A. Gorby, and S. C. Smith. 2002. “Biomineralization of Poorly Crystalline Fe(III) Oxides by Dissimilatory Metal Reducing Bacteria (DMRB).” Geomicrobiology Journal 19 (2): 179-207. https://doi.org/10.1080/01490450252864271

2001 

Fredrickson, J. K., J. M. Zachara, R. K. Kukkadapu, Y. A. Gorby, S. C. Smith, and C. F. Brown. 2001. “Biotransformation of Ni-Substituted Hydrous Ferric Oxide by an Fe(III)-Reducing Bacterium.” Environmental Science and Technology 35 (4): 703-712. https://doi.org/10.1021/es001500v

Kukkadapu, R. K., J. M. Zachara, S. C. Smith, J. K. Fredrickson, and C. Liu. 2001. “Dissimilatory Bacterial Reduction of Al-Substituted Geothite in Subsurface Sediments.” Geochimica et Cosmochimica Acta 65 (17): 2913-2924. https://doi.org/10.1016/S0016-7037(01)00656-1

Matocha, C. J., D. L. Sparks, J. E. Amonette, and R. K. Kukkadapu. 2001. “Kinetics and Mechanism of Birnessite Reduction by Catechol.” Soil Science Society of America Journal 65 (1): 58-66. https://doi.org/10.2136/sssaj2001.65158x

Wang, Z., R. C. Moore, A. R. Felmy, M. J. Mason, and R. K. Kukkadapu. 2001. “A Study of the Corrosion Products of Mild Steel in High Ionic Strength Brines.” Waste Management 21 (4): 335-341. https://doi.org/10.1016/S0956-053X(00)00058-1

2000 

Dong, H., J. K. Fredrickson, D. W. Kennedy, J. M. Zachara, R. K. Kukkadapu, and T. C. Onstott. 2000. “Mineral Transformation Associated with the Microbial Reduction of Magnetite.” Chemical Geology 169 (3-4): 299-318. https://doi.org/10.1016/S0009-2541(00)00210-2

1999 

Maxwell, R. S., R. K. Kukkadapu, J. E. Amonette, and H. Cho. 1999. “2H Solid-State NMR Investigation of Terephthalate Dynamics and Orientation in Mixed-Anion Hydrotalcite-Like Compounds.” Journal of Physical Chemistry B 103 (25): 5197-5203. https://doi.org/10.1021/jp990459j

1998 

Lawrence, M. A. M., R. K. Kukkadapu, and S. A. Boyd. 1998. “Adsorption of Phenol and Chlorinated Phenols from Aqueous Solution by Tetramethylammonium- and Tetramethylphosphonium-Exchanged Montmorillonite.” Applied Clay Science 13 (1): 13-20. https://doi.org/10.1016/S0169-1317(98)00009-X

1997 

Kukkadapu, R. K., M. S. Witkowski, and J. E. Amonette. 1997. “Synthesis of a Low-Carbonate High-Charge Hydrotalcite-Like Compound at Ambient Pressure and Atmosphere.” Chemistry of Materials 9 (2): 417-419. https://doi.org/10.1021/cm960536c

1995 

Kukkadapu, R. K., and S. A. Boyd. 1995. “Tetramethylphosphonium- and Tetramethylammonium-Smectites as Adsorbents of Aromatic and Chlorinated Hydrocarbons: Effect of Water on Adsorption Efficiency.” Clays and Clay Minerals 43 (3): 318-323. https://doi.org/10.1346/CCMN.1995.0430306.