Field trip to Stanford Foothills

March 2022

We went out to Stanford Foothills to collect samples for a new project. The photo shows Emily Lacroix (left) and myself (right) collecting soil aggregates. We are interested to see how the chemical environment and active microbial genes change across soil depth and between the inside and outside of soil aggregates. Now back to the lab... Photo credit: Maya Engel.

New publication in ES&T

January 2022

Groundwater quality in alluvial systems is controlled by biogeochemical and transport processes. We studied how exports across subsurface interfaces affect biogeochemical processes. Our work entitled Export of Organic Carbon from Reduced Fine-Grained Zones Governs Biogeochemical Reactivity in a Simulated Aquifer is now online on Environmental Science & Technology (ES&T). Using a simulated aquifer, we showed that organic substrates and live microorganisms were exported from fine-grained, reduced sediments and governed anaerobic activity in the downstream coarse-grained aquifer. More information is available on the Research page.

New publication in PNAS

January 2022

Various microorganisms use extracellular electron shuttles in anaerobic respiration. In our publication entitled Thermodynamic Controls on Rates of Iron Oxide Reduction by Extracellular Electron Shuttles in the Proceedings of the National Academy of Sciences of the United States of America (PNAS), we show that the thermodynamics of individual electron transfers from shuttles to iron oxides have to be considered when assessing rates of iron reduction and microbial respiration. Head over to the Research section or read the press release for more details and download the open access version of the article from the eawag repository.

AGU Fall Meeting 2021

December 2021

I am presenting my postdoctoral research on "Thermodynamic Limitations on Microbial Respiration Using Ferric Iron as Terminal Electron Acceptor" at the Fall Meeting of the American Geophysical Union.

Workshop on Carbon Cycle Modeling

May 2021

I took part in a two-week workshop on New Advances in Land Carbon Cycle Modeling led by Dr. Yiqi Luo's ECOLAB at the Northern Arizona University. Amongst other things, we looked into the structure of different models and used simulation and data-driven modeling (including data assimilation). The figure above illustrates the spatial distribution of carbon storage that we simulated using the Community Atmosphere-Biosphere-Land Exchange model (CABLE ) matrix model.

Soils from the Calhoun Critical Zone Observatory

January 2021

Aaron Thompson from the University of Georgia collected soils from the Calhoun Critical Zone Observatory that are now at Stanford and being characterized using mediated electrochemistry. We are interested in how the redox reactivity of iron minerals varies between soil horizons and usage. Head to the Research section to learn more.

Incubations of Lake Tahoe sediments

December 2020

The sediment cores that I collected from Lake Tahoe are incubating in our laboratory fridge. I mimic potential future changes in bottom water oxygen concentrations by incubating the cores in air-tight Mylar jars under various atmospheric oxygen levels. More details on this project can be found here.

Stanford Postdoc Teaching Certificate

October 2020

I finished my last teaching practice session and obtained the Stanford Postdoc Teaching Certificate! The certificate comprises teaching training, elective courses and workshops, teaching practice, and a teaching portfolio for a minimum in-class time of 100 h. I learned and applied a number of pedagogical practices, including strategies for active learning and creating inclusive learning environments.

SkillShare at Stanford Earth

October 2020

I led a workshop on Electronic Lab Notebooks at Stanford Earth. We discussed different types of Electronic Lab Notebooks and took a look at different softwares.

Field trip to Lake Tahoe

September 2020

I collected sediment and water samples from Lake Tahoe in collaboration with the UC Davis Tahoe Environmental Research Center. Find out more about the research project here. The photos show me holding a sediment core and preparing the box corer on the research boat John Le Conte .

Seminar talk at IUPUI

September 2020

I gave an invited talk in the Earth Science Seminar Series at Indiana University–Purdue University Indianapolis. It was a pleasure to get to talk with some of the students and faculty at IUPUI. A huge thanks to Greg Druschel for inviting me!

Column Experiment

July 2020

I started a series of column experiments with Kristin Boye, a staff scientist at the SLAC National Accelerator Laboratory. The columns (see photo above) are packed with ferrihydrite-coated sand and each contain a ball of reduced sediment from field sites in the Rocky Mountains. We want to find out what materials are exported from the reduced sediments into the sand and how these exports affect biogeochemical reactions in the sand. For more information, head to the Research Section.

Goldschmidt 2020

June 2020

Lots of firsts this year: At the first virtual Goldschmidt Conference, I am not only a presenter, but also a convener for Session 12b on the Coupled Redox Cycling of S, Mn, and Fe: Impacts on Nutrient and Contaminant Dynamics. It was also my first time delivering a presentation virtually!

Reactive Transport Modeling Workshop

June 2020

I learned about reactive transport modeling using The Geochemist's Workbench in a four-day workshop led by Craig Bethke, Brian Farrell, Qusheng Jin, and Jia Wang. The clip above shows the transport of lead in a contaminated aquifer. The highlight of the workshop was talking to Qusheng about thermodynamic controls on microbial respiration rates!

Infographic workshop

April 2020

I created an infographic on the role of soils in climate change in a workshop offered by Science Teaching Through Art at Stanford University. Unfortunately, our outreach events at high schools in the area were cancelled, but we instead presented our infographics on Twitter! Click on the image to see more.

ETH medal!

January 2020

I am honored to have been awarded the ETH Silver medal for "solving important knowledge gaps in the redox reactivity of iron using an interdisciplinary approach" in my doctoral research. ETH Zürich awards this medal to the top 8% of doctoral candidates.

Field trip to the Rocky Mountains

September 2019

I went on a field trip to the East River floodplain, near the town of Crested Butte in the Rocky Mountains, Colorado, to collect soil samples for my research. The photo shows an anoxic discharge into East River with orange iron-rich organic flocs.

Field trip to Sweden

June 2019

I went on a field trip to Sweden with members of my group at ETH Zürich. We studied redox processes in wetlands near Filipstad. The photo above shows one of our field sites. More details about our field work can be found in the article Waiting for Oxygen (p. 36 ff), which was published in the ETH Globe Magazine.