Bio


Joey Nelson is a Teaching and Research Fellow in Thinking Matters, Stanford Introductory Studies. He holds a BS in Environmental Sciences and a BA in Mathematics from the University of Virginia. He received a PhD in Geological and Environmental Sciences at Stanford University, where he was a Diversifying Academia, Recruiting Excellence (DARE) Fellow and a National Science Foundation (NSF) Graduate Research Fellow. His environmental science research broadly examines how reactions between aqueous solutions and Earth materials alter the environment around us and beneath our feet. More specifically, his hydrogeochemical research projects focus on how mineral-fluid reactions, nanoscale confinement, and surface disorder govern transition metal adsorption, isotopic fractionation, redox reactions, and release and storage of natural and anthropogenic contaminants. Along with teaching critical thinking in an interdisciplinary context to undergraduates, he greatly enjoys mentoring and advising students in their academic and personal pursuits. Joey also served as president of the Stanford Chapter of Out in Science, Technology, Engineering, and Mathematics, and is passionate about helping create welcoming spaces for a diversity of identities.

Academic Appointments


  • Lecturer, Stanford Introductory Studies - Thinking Matters

Honors & Awards


  • Best Paper Award, Geochemistry Division, American Chemical Society (2017)
  • James W. Lyons Award for Service, Stanford University (2017)
  • Academic Achievement Award for the Stanford LGBT Community Resource Center, Vice Provost for Graduate Education, Stanford University (2016)
  • Outstanding Student Paper Award, American Geophysical Union (2016)
  • DARE (Diversifying Academia, Recruiting Excellence) Doctoral Fellowship, Stanford University (2015-Present)
  • Certificate of Achievement in Mentoring, School of Earth, Energy & Environmental Sciences, Stanford University (2015)
  • Distinguished Student Lecturer, Global Climate and Energy Project, Stanford University (2013)
  • NSF Graduate Research Fellowship, National Science Foundation (2012-2015)

Professional Education


  • PhD, Stanford University, Geological and Environmental Sciences (2017)
  • BS, University of Virginia, Environmental Sciences (2011)
  • BA, University of Virginia, Mathematics (2011)

Current Research and Scholarly Interests


I investigate how reactions between aqueous solutions and Earth materials alter the environment around us and beneath our feet. Mineral surfaces comprise most of the area available for chemical reactions with water in soils and aquifers. Although there is a finite set of reaction types that can occur between minerals and below-ground fluids containing metals and organic molecules, large discrepancies are commonly observed between lab-based experiments and field measurements of concentrations and reaction rates. To eliminate such field-lab discrepancies, a deeper understanding of fundamentals governing groundwater transport and geochemical reactions between mineral surfaces and subsurface fluids is needed, especially at the nanoscale and disordered surfaces. My research probes environmentally- and societally-relevant geochemical reactions that occur at the fluid-mineral interface, with unique attention to the 3-dimensional region surrounding reaction components at this interface. I employ bench-top experiments, spectroscopy, isotope geochemistry, and geochemical and hydrological modeling to elucidate how fluid transport and surface properties affect transition metal adsorption, isotopic fractionation, redox reactions, and release and storage of natural and anthropogenic contaminants. Such research provides insight into complex hydrogeochemical networks and data for constructing increasingly accurate models of contaminant remediation, climatic and hydrogeologic processes, nutrient transport, and natural resource formation.

All Publications


  • Cr(VI) reduction by Fe(II) sorbed to silica surfaces. Chemosphere Nelson, J., Joe-Wong, C., Maher, K. 2019; 234: 98–107

    Abstract

    The reaction kinetics of groundwater contaminants are integral to evaluating the fate and transport of toxic metals in the environment. For redox sensitive contaminants, such as chromium, the kinetics of different reaction pathways can vary by orders of magnitude. Species-specific rate constants for iron-chromium oxidation-reduction reactions are unknown for many systems, especially in the presence of sorbing surfaces. We investigate the role of quartz and amorphous silica (SiO2(am)) surfaces in mediating abiotic reduction of Cr(VI)aq by aqueous and sorbed Fe(II) using batch sorption and redox experiments. Sorption edges indicate outer-sphere (Fe(II)ads,OS) and inner-sphere (Fe(II)ads,IS) complexes are present on both silica surfaces, and their abundance depends on pH, ionic strength, and surface disorder. The rate constants for Cr(VI)aq reduction by Fe(II) species increase in the following order: kaq ≪ kads,OS,quartz < kads,OS,SiO2(am) < kads,IS,quartz < kads,IS,SiO2(am), suggesting that increasing proximity of Fe(II) to the negatively charged silica surface enhances the rate of reduction of Cr(VI)aq. However, we observe that experiments with larger amounts of sorbed Fe(II) reduce less total Cr(VI)aq over time, which we attribute to a portion of the sorbed Fe(II) being sequestered into the Cr(III)-Fe(III)-oxyhydroxide precipitates forming on the silica surface. Therefore, the balance between increases in the rate and decreases in the total amount of Cr(VI)aq reduction by various sorbed Fe(II) species must be considered when devising remediation strategies.

    View details for DOI 10.1016/j.chemosphere.2019.06.039

    View details for PubMedID 31203046

  • Effects of nano-confinement on Zn(II) adsorption to nanoporous silica Geochimica et Cosmochimica Acta Nelson, J., Bargar, J. R., Wasylenki, L., Brown Jr., G. E., Maher, K. 2018; 240: 80-97
  • Inter-calibration of a proposed new primary reference standard AA-ETH Zn for zinc isotopic analysis JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY Archer, C., Andersen, M. B., Cloquet, C., Conway, T. M., Dong, S., Ellwood, M., Moore, R., Nelson, J., Rehkamper, M., Rouxel, O., Samanta, M., Shin, K., Sohrin, Y., Takano, S., Wasylenki, L. 2017; 32 (2): 415-419

    View details for DOI 10.1039/c6ja00282j

    View details for Web of Science ID 000395529800019

  • Effects of surface structural disorder and surface coverage on isotopic fractionation during Zn(II) adsorption onto quartz and amorphous silica surfaces Geochimica et Cosmochimica Acta Nelson, J., Wasylenki, L., Bargar, J. R., Brown Jr., G. E., Maher, K. 2017; 215: 354-376
  • Uranium Incorporation into Amorphous Silica ENVIRONMENTAL SCIENCE & TECHNOLOGY Massey, M. S., Lezama-Pacheco, J. S., Nelson, J. M., Fendor, S., Maher, K. 2014; 48 (15): 8636-8644

    Abstract

    High concentrations of uranium are commonly observed in naturally occurring amorphous silica (including opal) deposits, suggesting that incorporation of U into amorphous silica may represent a natural attenuation mechanism and promising strategy for U remediation. However, the stability of uranium in opaline silicates, determined in part by the binding mechanism for U, is an important factor in its long-term fate. U may bind directly to the opaline silicate matrix, or to materials such as iron (hydr)oxides that are subsequently occluded within the opal. Here, we examine the coordination environment of U within opaline silica to elucidate incorporation mechanisms. Precipitates (with and without ferrihydrite inclusions) were synthesized from U-bearing sodium metasilicate solutions, buffered at pH ∼ 5.6. Natural and synthetic solids were analyzed with X-ray absorption spectroscopy and a suite of other techniques. In synthetic amorphous silica, U was coordinated by silicate in a double corner-sharing coordination geometry (Si at ∼ 3.8-3.9 Å) and a small amount of uranyl and silicate in a bidentate, mononuclear (edge-sharing) coordination (Si at ∼ 3.1-3.2 Å, U at ∼ 3.8-3.9 Å). In iron-bearing synthetic solids, U was adsorbed to iron (hydr)oxide, but the coordination environment also contained silicate in both edge-sharing and corner-sharing coordination. Uranium local coordination in synthetic solids is similar to that of natural U-bearing opals that retain U for millions of years. The stability and extent of U incorporation into opaline and amorphous silica represents a long-term repository for U that may provide an alternative strategy for remediation of U contamination.

    View details for DOI 10.1021/es501064m

    View details for Web of Science ID 000340080600039

    View details for PubMedID 24984107

  • Effects of Antennule Morphology and Flicking Kinematics on Flow and Odor Sampling by the Freshwater Crayfish, Procambarus clarkii CHEMICAL SENSES Nelson, J. M., Mellon, D., Reidenbach, M. A. 2013; 38 (8): 729-741

    Abstract

    The flow structure around the lateral antennular flagellum of the freshwater crayfish, Procambarus clarkii, was quantified to determine how antennule morphology and flicking kinematics affect fine-scale flow surrounding their chemosensory sensilla, called aesthetascs. Particle image velocimetry was used to measure velocity and vorticity of flow between aesthetascs of dynamically scaled physical models of P. clarkii antennules. Results revealed that the spacing between aesthetascs and antennule flicking speed induces substantial changes in fluid flow near aesthetascs. The downstroke flicking motion of the antennule occurs at a peak speed of 2.7cm/s. The returnstroke occurs at approximately 70% of this speed, but the fluid velocity between aesthetascs during the returnstroke is approximately 15% compared with the downstroke. The significant decrease in fluid flow near aesthetascs results from the reduced antennule speed and from the coupled interaction of boundary layers of the aesthetascs and antennule during the returnstroke. Odorant-laden fluid captured during the downstroke is retained between the aesthetascs during the slower returnstroke, and sufficient time occurs for odorant molecules to molecularly diffuse to aesthetasc surfaces. In addition, locally generated vorticity was observed near the tip of the aesthetascs, which may induce odorant transport to aesthetasc surfaces and enhance olfactory response times to odors.

    View details for DOI 10.1093/chemse/bjt041

    View details for Web of Science ID 000324776600007

    View details for PubMedID 23978687