Skip to Main Content U.S. Department of Energy
Fundamental and Computational Sciences Directorate

Staff information

Thomas Wietsma

Molecular Plant Phenotyping
Earth Scientist
Pacific Northwest National Laboratory
PO Box 999
MSIN: K8-96
Richland, WA 99352

PNNL Publications

2025

2024

  • Velickovic D., T.E. Winkler, V. Balasubramanian, T.W. Wietsma, C.R. Anderton, A. Ahkami, and K. Zemaitis. 2024. "RhizoMAP: a comprehensive, nondestructive, and sensitive platform for metabolic imaging of the rhizosphere." Plant Methods 20, no. _:Art. No. 117. PNNL-SA-199579. doi:10.1186/s13007-024-01249-5
  • Ward N.D., M.K. Bowe, K.A. Muller, X. Chen, Q. Zhao, R.K. Chu, and Z. Cheng, et al. 2024. "Interactive effects of salinity, redox, and colloids on greenhouse gas production and carbon mobility in coastal wetland soils." PLoS One 19, no. 12:Art. No. : e0316341. PNNL-SA-192847. doi:10.1371/journal.pone.0316341

2020

  • Bhattacharjee A., D. Velickovic, T.W. Wietsma, S.L. Bell, J.K. Jansson, K.S. Hofmockel, and C.R. Anderton. 2020. "Visualizing Microbial Community Dynamics Via a Controllable Soil Environment." mSystems 5, no. 1:Article No. e00645-19. PNNL-SA-147223. doi:10.1128/mSystems.00645-19
  • Boiteau R.M., R.K. Kukkadapu, J.B. Cliff, C.R. Smallwood, L. Kovarik, M.G. Wirth, and M.H. Engelhard, et al. 2020. "Calcareous organic matter coatings sequester siderophores in alkaline soils." Science of the Total Environment 724. PNNL-SA-147851. doi:10.1016/j.scitotenv.2020.138250
  • Ogden A.J., T.W. Wietsma, T.E. Winkler, Y. Farris, G.L. Myers, and A. Ahkami. 2020. "Dynamics of Global Gene Expression and Regulatory Elements in Growing Brachypodium Root System." Scientific Reports 10. PNNL-SA-145907. doi:10.1038/s41598-020-63224-z

2019

  • Ahkami A., W. Wang, T.W. Wietsma, T.E. Winkler, I. Lange, G.C. Jansson, and M.D. Lange, et al. 2019. "Metabolic shifts associated with drought-induced senescence in Brachypodium." Plant Science 289. PNNL-SA-145496. doi:10.1016/j.plantsci.2019.110278

2018

  • Popel A., T.W. Wietsma, M.H. Engelhard, A. Lea, O. Qafoku, C. Grygiel, and I. Monnet, et al. 2018. "The Effect of Ion Irradiation on the Dissolution of UO2 and UO2-based Simulant Fuel." Journal of Alloys and Compounds 735. PNNL-SA-129551. doi:10.1016/j.jallcom.2017.11.216
  • Wang Y., N. Wei, C. Zhang, T.W. Wietsma, A.H. Bonneville, X. Li, and M. Li, et al. 2018. "Experimental study of drying effects during supercritical CO2 displacement in a pore network." Microfluidics and Nanofluidics 22, no. 9:101. PNNL-SA-137617. doi:10.1007/s10404-018-2122-9

2017

  • Childers M.I., M. Nguyen, K.A. Rod, P.K. Koech, W. Um, J. Chun, and V. Glezakou, et al. 2017. "Polymer-Cement Composites with Self-Healing Ability for Geothermal and Fossil Energy Applications." Chemistry of Materials 29, no. 11:4708-4718. PNNL-SA-127162. doi:10.1021/acs.chemmater.7b00344
  • Childers M.I., M.C. Endres, C.A. Burns, B.J. Garcia, J. Liu, T.W. Wietsma, and A.H. Bonneville, et al. 2017. "Novel Highly Dispersible, Thermally Stable Core/Shell Proppants for Geothermal Applications." Geothermics 70. PNNL-SA-121506. doi:10.1016/j.geothermics.2017.05.013
  • Maddi B., E.A. Panisko, T.W. Wietsma, T.L. Lemmon, M.S. Swita, K.O. Albrecht, and D.T. Howe. 2017. "Quantitative Characterization of Aqueous Byproducts from Hydrothermal Liquefaction of Municipal Wastes, Food Industry Wastes, and Biomass Grown on Waste." ACS Sustainable Chemistry & Engineering 5, no. 3:2205-2214. PNNL-SA-121413. doi:10.1021/acssuschemeng.6b02367

2016

  • Chang C., Q. Zhou, T.J. Kneafsey, M. Oostrom, T.W. Wietsma, and Q. Yu. 2016. "Pore-Scale Supercritical CO2 Dissolution and Mass Transfer under Imbibition Conditions." Advances in Water Resources 92. PNNL-SA-117137. doi:10.1016/j.advwatres.2016.03.015
  • Maddi B., E.A. Panisko, T.W. Wietsma, T.L. Lemmon, M.S. Swita, K.O. Albrecht, and D.T. Howe. 2016. "Quantitative Characterization of the Aqueous Fraction from Hydrothermal Liquefaction of Algae." Biomass & Bioenergy 93. PNNL-SA-113775. doi:10.1016/j.biombioe.2016.07.010
  • Moore J.S., S.S. Xantheas, J.W. Grate, T.W. Wietsma, E. Gratton, and A. Vasdekis. 2016. "Modular Polymer Biosensors by Solvent Immersion Imprint Lithography." Journal of Polymer Science. Part B, Polymer Physics 54, no. 1:98-103. PNNL-SA-112121. doi:10.1002/polb.23961
  • Oostrom M., Y. Mehmani, P. Romero Gomez, Y. Tang, H. Liu, H. Yoon, and Q. Kang, et al. 2016. "Pore-scale and Continuum Simulations of Solute Transport Micromodel Benchmark Experiments." Computational Geosciences 20, no. 4:857-879. PNNL-SA-100394. doi:10.1007/s10596-014-9424-0

2015

  • Panisko E.A., T.W. Wietsma, T.L. Lemmon, K.O. Albrecht, and D.T. Howe. 2015. "Characterization of the Aqueous Fractions from Hydrotreatment and Hydrothermal Liquefaction of Lignocellulosic Feedstocks." Biomass & Bioenergy 74. PNNL-SA-105768. doi:10.1016/j.biombioe.2015.01.011
  • Scheibe T.D., W.A. Perkins, M.C. Richmond, M.I. McKinley, P. Romero Gomez, M. Oostrom, and T.W. Wietsma, et al. 2015. "Pore-Scale and Multiscale Numerical Simulation of Flow and Transport in a Laboratory-Scale Column." Water Resources Research 51, no. 2:1023-1035. PNNL-SA-103382. doi:10.1002/2014WR015959
  • Truex M.J., V.R. Vermeul, D. Adamson, M. Oostrom, L. Zhong, R.D. Mackley, and B.G. Fritz, et al. 2015. "Field Test of Enhanced Remedial Amendment Delivery Using a Shear-Thinning Fluid." Groundwater Monitoring and Remediation 35, no. 3:34-45. PNNL-SA-101736. doi:10.1111/gwmr.12101

2014

  • Oostrom M., M.J. Truex, T.W. Wietsma, and G.D. Tartakovsky. 2014. "Pore-Water Extraction from Unsaturated Porous Media: Intermediate-Scale Laboratory." Vadose Zone Journal 13, no. 8. PNNL-SA-102165. doi:10.2136/vzj2014.04.0044
  • Oostrom M., M.J. Truex, V.R. Vermeul, L. Zhong, G.D. Tartakovsky, and T.W. Wietsma. 2014. "Remedial Amendment Delivery near the Water Table Using Shear Thinning Fluids: Experiments and Numerical Simulations." Environmental Processes 1, no. 4:331-351. PNNL-SA-103590. doi:10.1007/s40710-014-0031-9
  • Wunschel D.S., H.E. Engelmann, K.D. Victry, B.H. Clowers, C.M. Sorensen, N.B. Valentine, and C.M. Mahoney Fahey, et al. 2014. "Protein markers for identification of Yersinia pestis and their variation related to culture." Molecular and Cellular Probes 28, no. 2-3:65-72. PNNL-SA-96155. doi:10.1016/j.mcp.2013.12.001

2013

  • Fanizza M.F., H. Yoon, C. Zhang, M. Oostrom, T.W. Wietsma, N.J. Hess, and M.E. Bowden, et al. 2013. "Pore-Scale Evaluation of Uranyl Phosphate Precipitation in a Model Groundwater System." Water Resources Research 49, no. 2:874-890. PNNL-SA-91344. doi:10.1002/wrcr.20088
  • Grate J.W., M.G. Warner, J.W. Pittman, K.J. Dehoff, T.W. Wietsma, C. Zhang, and M. Oostrom. 2013. "Silane Modification of Glass and Silica Surfaces to Obtain Equally Oil-Wet Surfaces in Glass-Covered Silicon Micromodel Applications." Water Resources Research 49, no. 8:4724-4729. PNNL-SA-90520. doi:10.1002/wrcr.20367
  • Johnson T.C., M. Oostrom, M.J. Truex, J.N. Thomle, and T.W. Wietsma. 2013. "Determination of water saturation using gas phase partitioning tracers and time-lapse electrical conductivity measurements." Vadose Zone Journal 12, no. 2. PNNL-SA-91015. doi:10.2136/vzj2012.0142
  • Wang Y., C. Zhang, N. Wei, M. Oostrom, T.W. Wietsma, X. Li, and A. Bonneville. 2013. "Experimental study of crossover from capillary to viscous fingering for supercritical CO2 - water displacement in a homogeneous pore network." Environmental Science & Technology 47, no. 1:212-218. PNNL-SA-87244. doi:10.1021/es3014503

2012

  • Grate J.W., K.J. Dehoff, M.G. Warner, J.W. Pittman, T.W. Wietsma, C. Zhang, and M. Oostrom. 2012. "Correlation of Oil-Water and Air-Water Contact Angles of Diverse Silanized Surfaces and Relationship to Fluid Interfacial Tensions." Langmuir 28, no. 18:7182-7188. PNNL-SA-83545. doi:10.1021/la204322k
  • Oostrom M., K.V. Smoot, T.W. Wietsma, M.J. Truex, M.W. Benecke, and G.B. Chronister. 2012. "Vadose Zone Soil Moisture Wicking Using Super Absorbent Polymers." Vadose Zone Journal 11, no. 4. PNNL-SA-84832. doi:10.2136/vzj2011.0200
  • Oostrom M., T.W. Wietsma, C.E. Strickland, V.L. Freedman, and M.J. Truex. 2012. "Sensor and numerical simulator evaluation for porous medium desiccation and rewetting at the intermediate laboratory scale." Vadose Zone Journal 11, no. 1:Article No. 0089. PNNL-SA-83396. doi:10.2136/vzj2011.0089
  • Oostrom M., V.L. Freedman, T.W. Wietsma, J.H. Dane, and M.J. Truex. 2012. "Effects of Porous Medium Heterogeneity on Vadose Zone Desiccation: Intermediate-scale Laboratory Experiments and Simulations." Vadose Zone Journal 11, no. 4. PNNL-SA-84135. doi:10.2136/vzj2011.0168

2011

  • Oostrom M., G.D. Tartakovsky, T.W. Wietsma, M.J. Truex, and J.H. Dane. 2011. "Determination of Water Saturation in Relatively Dry Porous Media Using Gas-phase Tracer Tests." Vadose Zone Journal 10, no. 2:634-641. PNNL-SA-74637.
  • Truex M.J., T. Macbeth, V.R. Vermeul, B.G. Fritz, D.P. Mendoza, R.D. Mackley, and T.W. Wietsma, et al. 2011. "Demonstration of Combined Zero-Valent Iron and Electrical Resistance Heating for In Situ Trichloroethene Remediation." Environmental Science & Technology 45, no. 12:5346-5351. PNNL-SA-76701. doi:10.1021/es104266a
  • Truex M.J., V.R. Vermeul, D.P. Mendoza, B.G. Fritz, R.D. Mackley, M. Oostrom, and T.W. Wietsma, et al. 2011. "Injection of Zero Valent Iron into an Unconfined Aquifer Using Shear-Thinning Fluids." Groundwater Monitoring and Remediation 31, no. 1:50-58. PNNL-SA-70324.
  • Zhang C., M. Oostrom, J.W. Grate, T.W. Wietsma, and M.G. Warner. 2011. "Liquid CO2 Displacement of Water in a Dual-Permeability Pore Network Micromodel." Environmental Science & Technology 45, no. 17:7581-7588. PNNL-SA-81215. doi:10.1021/es201858r
  • Zhang C., M. Oostrom, T.W. Wietsma, J.W. Grate, and M.G. Warner. 2011. "Influence of Viscous and Capillary Forces on Immiscible Fluid Displacement: Pore-Scale Experimental Study in a Water-Wet Micromodel Demonstrating Viscous and Capillary Fingering." Energy and Fuels 25, no. 8:3493-3505. PNNL-SA-79115. doi:10.1021/ef101732k

2010

  • Grate J.W., C. Zhang, T.W. Wietsma, M.G. Warner, N.C. Anheier, B.E. Bernacki, and G. Orr, et al. 2010. "A note on the visualization of wetting film structures and a nonwetting immiscible fluid in a pore network micromodel using a solvatochromic dye." Water Resources Research 46. PNNL-SA-71572. doi:10.1029/2010WR009419
  • Oostrom M., M.J. Truex, G.D. Tartakovsky, and T.W. Wietsma. 2010. "Three-Dimensional Simulation of Volatile Organic Compound Mass Flux from the Vadose Zone to Groundwater." Ground Water Monitoring and Remediation 30, no. 3:45-56. PNNL-SA-68431. doi:10.1111/j.1745-6592.2010.01285.x
  • Oostrom M., M.J. Truex, G.D. Tartakovsky, and T.W. Wietsma. 2010. "Three-Dimensional Simulation of Volatile Organic Compound Mass Flux from the Vadose Zone to Groundwater." Groundwater Monitoring and Remediation 30, no. 3:45-56. PNNL-SA-70865.
  • Willingham T.W., C. Zhang, C.J. Werth, A.J. Valocchi, M. Oostrom, and T.W. Wietsma. 2010. "Using Dispersivity Values to Quantify the Effects of Pore-Scale Flow Focusing on Enhanced Reaction along a Transverse Mixing Zone." Advances in Water Resources 33, no. 4:525-535. PNNL-SA-70933. doi:10.1016/j.advwatres.2010.02.004
  • Zhang C., K.J. Dehoff, N.J. Hess, M. Oostrom, T.W. Wietsma, A.J. Valocchi, and B.W. Fouke, et al. 2010. "Pore-Scale Study of Transverse Mixing Induced CaCO3 Precipitation and Permeability Reduction in a Model Subsurface Sedimentary System." Environmental Science & Technology 44, no. 20:7833-7838. PNNL-SA-73959. doi:10.1021/es1019788

2009

  • Oostrom M., T.W. Wietsma, J.H. Dane, M.J. Truex, and A.L. Ward. 2009. "Desiccation of unsaturated porous media: Intermediate-scale experiments and numerical simulation." Vadose Zone Journal 8, no. 3:643-650. PNNL-SA-64019.
  • Wietsma T.W., M. Oostrom, M.A. Covert, T.E. Queen, and M.J. Fayer. 2009. "An automated tool for three types of saturated hydraulic conductivity laboratory measurements." Soil Science Society of America Journal 73, no. 2:466-470. PNNL-SA-59658.
  • Yoon H., M. Oostrom, T.W. Wietsma, C.J. Werth, and A.J. Valocchi. 2009. "Numerical and experimental investigation of DNAPL removal mechanisms in a layered porous medium by means of soil vapor extraction." Journal of Contaminant Hydrology 109, no. 1-4:1-13. PNNL-SA-64091. doi:10.1016/j.jconhyd.2009.07.001

2008

  • Zhong L., M. Oostrom, T.W. Wietsma, and M.A. Covert. 2008. "Enhanced Remedial Amendment Delivery through Fluid Viscosity Modifications: Experiments and numerical simulations." Journal of Contaminant Hydrology 101, no. 1-4:29-41. PNNL-SA-59438. doi:10.1016/j.jconhyd.2008.07.007

2007

  • Istok J.D., M.M. Park, A.D. Peacock, M. Oostrom, and T.W. Wietsma. 2007. "An experimental investigation of nitrogen gas produced during denitrification." Ground Water 45, no. 4:461-467. PNNL-SA-53488.
  • Oostrom M., J.H. Dane, and T.W. Wietsma. 2007. "A Review of Multidimensional, Multifluid Intermediate-scale Experiments: Flow Behavior, Saturation Imaging, and Tracer Detection and Quantification." Vadose Zone Journal 6, no. 3:610-637. PNNL-SA-55643. doi:10.2136/vzj2006.0178
  • Oostrom M., M.J. Truex, P.D. Thorne, and T.W. Wietsma. 2007. "Three-Dimensional Multifluid Flow and Transport at the Brooklawn Site near Baton Rouge, LA: A Case Study." Soil & Sediment Contamination 16, no. 2:109-141. PNWD-SA-7319.
  • Oostrom M., T.W. Wietsma, M.A. Covert, and V.R. Vermeul. 2007. "Zero-valent Iron Emplacement in Permeable Porous Media Using Polymer Additions." Ground Water Monitoring and Remediation 27, no. 1:122-130. PNNL-SA-52567.

2006

  • Oostrom M., C. Hofstee, and T.W. Wietsma. 2006. "Behavior of a Viscous LNAPL under Variable Water Table Conditions." Soil & Sediment Contamination 15, no. 6:543 - 564. PNNL-SA-46807. doi:10.1080/15320380600958976
  • Oostrom M., C. Hofstee, and T.W. Wietsma. 2006. "LNAPLs do not Always Float: An Example Case of a Viscous LNAPL under Variable Water Table Conditions." In 26th Annual American Geophysical Union Hydrology Days, March 20-22, 2006, edited by J.A. Ramirez, 119-130. Fort Collins, Colorado:Colorado State University. PNNL-SA-48870. LNAPLs do not Always Float: An Example Case of a Viscous LNAPL under Variable Water Table Conditions
  • Oostrom M., J.H. Dane, and T.W. Wietsma. 2006. "A Review of Multidimensional, Multifluid Intermediate-scale Experiments: Nonaqueous Phase Liquid Dissolution and Enhanced Remediation." Vadose Zone Journal 5. PNNL-SA-47245. doi:10.2136/vzj2005.0125
  • Oostrom M., T.W. Wietsma, M.A. Covert, and V.R. Vermeul. 2006. "Micron-Size Zero-Valent Iron Emplacement in Porous Media Using Polymer Additives: Column and Flow Cell Ex-periments." In 26th Annual American Geophysical Union Hydrology Days Conference Proceedings, March 20-22, 2006, Colorado State University, edited by J.A. Ramirez, 131-139. Fort Collins, Colorado:Colorado State University. PNNL-SA-48855. Micron-Size Zero-Valent Iron Emplacement in Porous Media Using Polymer Additives: Column and Flow Cell Ex-periments

2005

  • Laskin A., T.W. Wietsma, B.J. Krueger, and V.H. Grassian. 2005. "Heterogeneous Chemistry of Individual Mineral Dust Particles with Nitric Acid. A Combined CCSEM/EDX, ESEM AND ICP-MS Study." Journal of Geophysical Research. D. (Atmospheres) 110, no. D10:D10208. PNNL-SA-42393.
  • Oostrom M., J.H. Dane, and T.W. Wietsma. 2005. "Removal of Carbon Tetrachloride from a Layered Porous Medium by Means of Soil Vapor Extraction Enhanced by Desiccation and Water Table Reduction." Vadose Zone Journal 4, no. 4:1170-1182. PNNL-SA-43627. doi:10.2136/vzj2004.0173
  • Oostrom M., J.H. Dane, and T.W. Wietsma. 2005. "Removal of carbon tetrachloride from a layered porous medium by means of soil vapor extraction enhanced by desiccation and water table reduction." Vadose Zone Journal 4. PNNL-SA-44539. doi:10.2136/vzj2004.0173
  • Oostrom M., M.D. White, R.J. Lenhard, P. Van Geel, and T.W. Wietsma. 2005. "A comparison of models describing residual NAPL formation in the vadose zone." Vadose Zone Journal 4, no. 1:163-174. PNNL-SA-44538.

2004

2003

  • Oostrom M., C. Hofstee, R.J. Lenhard, and T.W. Wietsma. 2003. "Flow Behavior and Residual Saturation Formation of Liquid Carbon Tetrachloride in Unsaturated Heterogeneous Porous Media." Journal of Contaminant Hydrology 64, no. 1-2:93-112. PNNL-SA-36286.
  • Oostrom M., P.D. Thorne, M.D. White, M.J. Truex, and T.W. Wietsma. 2003. "Numerical Modeling to Assess DNAPL Movement and Removal at the Scenic Site Operable Unit Near Baton Rouge, Louisiana: A Case Study." Soil & Sediment Contamination 12, no. 6:901 - 926. PNNL-SA-38784.

2001

  • Schroth M.H., M. Oostrom, T.W. Wietsma, and J.D. Istok. 2001. "In-situ oxidation of trichloroethene by permanganate: effects on porous medium hydraulic properties." Journal of Contaminant Hydrology 50, no. 1-2:79-98. PNNL-SA-31670.

2000

  • Brusseau M., N.T. Nelson, M. Oostrom, Z. Zhang, G.R. Johnson, and T.W. Wietsma. 2000. "Influence of Heterogeneity and Sampling Method on Aqueous Concentrations Associated with NAPL Dissolution." Environmental Science & Technology 34, no. 17:3657-3664. PNWD-SA-5144.
  • Oostrom M., J.H. Dane, and T.W. Wietsma. 2000. "Gamma radiation techniques in subsurface multifluid flow and transport studies." In Proceedings of the 2000 ASME Fluids Engineering Division Summer Meeting : presented at the 2000 ASME Fluids Engineering Division Summer Meeting, June 11-15, 2000, Boston, Massachusetts, edited by David E. Stock, 2, 417-424. New York, New York:American Society of Mechanical Engineers. PNNL-SA-31754.
  • Schroth M.H., M. Oostrom, T.W. Wietsma, and J.D. Istok. 2000. "In Situ Oxidation of Liquid Trichloroethylene by Permanganate Solutions: Preliminary Results of Column Studies." In Proceedings of the 19th American Geophysical Union Hydrology Days, edited by H.J. Morel-Seytoux, 411-420. Atherton, California:Hydrology Days Pub. PNNL-SA-32593.
  • Zachara J.M., N.S. Foster, J.E. Amonette, E.J. Bylaska, A.R. Felmy, P.L. Gassman, and S.M. Heald, et al. 2000. Annual Report 1999 Environmental Dynamics & Simulation. PNNL-13206. Richland, WA: Pacific Northwest National Laboratory. Annual Report 1999 Environmental Dynamics & Simulation

1999

  • Nelson N.T., M. Oostrom, T.W. Wietsma, and M.L. Brusseau. 1999. "An Experimental Investigation of the Partitioning Tracer Method to Detect and Quantify Dense Nonaqueous Phase Liquids in a Heterogeneous System." In American Geophysical Union Hydrology Days. Held August, 1999 in Fort Collins, CO., edited by H.J. Morel-Seytoux, Ed., 307-318. Atherton, California:Hydrology Days. PNWD-SA-5034.
  • Nelson N.T., M. Oostrom, T.W. Wietsma, and M.L. Brusseau. 1999. "Partitioning tracer method for the in situ measurement of DNAPL saturation: influence of heterogeneity and sampling method." Environmental Science & Technology 33, no. 22:4046-4053. PNWD-SA-5037.
  • Williams M.D., V.R. Vermeul, M. Oostrom, J.C. Evans, J.S. Fruchter, J.D. Istok, and M.D. Humphrey, et al. 1999. Anoxic Plume Attenuation in a Fluctuating Water Table System: Impact of 100-D Area In Situ Redox Manipulation on Downgradient Dissolved Oxygen Concentrations. PNNL-12192. Richland, WA: Pacific Northwest National Laboratory. Anoxic Plume Attenuation in a Fluctuating Water Table System: Impact of 100-D Area In Situ Redox Manipulation on Downgradient Dissolved Oxygen Concentrations

1994

  • Murphy E.M., J.M. Zachara, S.C. Smith, J.L. Phillips, and T.W. Wietsma. 1994. "Interaction of Hydrophobic Organic Compounds with Mineral-Bound Humic Substances." Environmental Science & Technology 28, no. 7:1291-1299. PNL-SA-20396. doi:10.1021/es00056a017

Science at PNNL

Core Research Areas

User Facilities

Centers & Institutes

Research Highlights

View All Research Highlights & Staff Accomplishments

RSS Feed

Contacts