Summer of Research 2022 on Coal Mine Drainage Remediation: by Ella Dorman ’24, Alicia Nguyen ’23, Sarah Teagle ’23 (Originally written for our Geo Dept Alumni Newsletter)

This summer, we had the amazing opportunity to work with Professor Hinkle on a geochemistry project to help mitigate metal contamination in coal mine drainage. Coal Mine Drainage (CMD) is runoff from abandoned coal mines that enters watersheds and contaminates them with metals that are difficult to remediate like Mn. This is a pervasive issue across Appalachia where there are thousands of abandoned coal mines that pollute watersheds and contaminate human drinking water. Current treatments for Mn remediation from CMD are kinetically unfavorable and leave significant amounts of Mn(II) in solution. This research aims to find a fast and long-term solution to Mn contamination from CMD through the use of Mn-oxidizing microbes and liner rocks like limestone and zeolites. To be more specific, our project examines improvements to current coal mine drainage (CMD) passive bioremediation systems. We are exploring the impacts of increased acidity, competitive sorption of copper, and different ratios of limestone and zeolite liner rocks impact the Mn(II) remediation from CMD.

Last summer, we analyzed systems of fungi and limestone and fungi and zeolites respectively and determined that a myco-zeolite system could remove over 95% of Mn(II) from solution in just 24 hours. The fungal-limestone system removed just 11% of Mn(II) in the same amount of time but removed over 99% of Mn(II) by the conclusion of the 16-day experiments. Building upon that work, this summer, we created systems with both limestone and zeolites in varying ratios, hoping to combine the catalytic properties of zeolites with the effectiveness of limestone to arrive at the ideal bioremediation system for Mn from CMD.

Another side of this summer research project is to study how changes in pH and copper concentrations could impact the fungi and liner rocks’ ability to oxidize and remediate Mn from the solution. We hypothesize that increased acidity level and copper concentration can undermine our Mn bioremediation system. Acidity can impact our remediation processes because fungi thrive in neutral to alkaline environments so if we create an environment with a lower pH, fungal growth will be hampered and the remediation of soluble Mn(II) could be slowed down. Increased copper concentration, on the other hand, affect our remediation systems because liner rocks preferentially bind to copper instead of Mn so we hypothesize that as more copper is added into our system, the already oxidized Mn would be released back into the solution as copper would be bound to the rocks instead. If these two hypotheses are supported, further research should be done on how to make up for these systematic disadvantages to guarantee maximal effectiveness of our Mn bioremediation systems.

An essential skill set we acquired from this work is the use of sterile techniques. To ensure that all microbial processes were the result of our oxidizing microbes and not affected by unwanted bacteria (especially Mn-oxidizing bacteria), systems and materials had to be sterile at all times. These skills were not only useful for future lab work but also helped enhance our attention to detail. We also utilized techniques like Scanning Electron Microscopy paired with Energy Dispersive X-ray Spectroscopy, or SEM-EDS, to determine the composition and analyze the structure of our liner rocks and fungi. We additionally prepared samples for Ion Chromatography (IC) to track the anions and cations present and Inductively Coupled Plasma Mass Spectroscopy (ICP-MS) to track levels of trace metal contaminants in our systems. These techniques allowed us to gain valuable experience in sample preparation and analysis and conduct meaningful and in-depth analysis of our data and support our hypothesis.

Beside lab techniques, we also got to learn how to read and analyze scientific papers to write an abstract according to the specific guidelines of the Geological Society of America (GSA). During the 10-week research process, we learned to use Box, Excel, Excel Online to store, backup and manipulate data and create graphs necessary for our GSA poster. As we have over 50 samples in total, each with 20 data entries for 16 days, we needed to figure out a consistent naming and graphic aesthetics scheme for both sub-experiments. Through this process, we understood how even the smallest detail such as the shape of the marker for each line on the graph must be consistent in order to make a good scientific poster. As far as the writing up of the results and discussion sections, we were able to get started with it during Week 10 and will be able to work during the Fall Term to finish it up before the GSA conference in October!

Keck Geology Advanced Project 2021-2022: Haley Culbertson (C'22), Written For Our Geo Dept Alumni Newsletter

This summer I’ve had the fantastic opportunity to work with Dr. Margaret Anne Hinkle and Dr. Eva Lyon as they led a Keck Geology Consortium Advanced Summer Research project on manganese (Mn) contamination in soils and waters of the surrounding area. Beginning in Spring Term, preparations were made for the arrival of seven students from visiting universities, as well as two more of our own. In the wake of COVID, which we’re getting used to living with and working around, preparations included stocking up on KN95 masks and personal lab goggles, reserving all of the vans, and LOTS of hand sanitizer. After the common experience of anticipated summer projects being canceled last year, health and safety was the number one priority, which allowed us to successfully see the program to completion!

In the Shenandoah Valley region of Virginia, 21% of groundwater wells are plagued by Mn contamination at levels which have been found to cause adverse health effects if chronically consumed (McMahon et al. 2018; Langley et al. 2015). Nine fourth-year students from across the country and I spent four weeks travelling around the region collecting soil and water samples in and around springs to determine the origin, behaviors, and controls of any Mn found. Springs were of specific interest to us because of the interface they create between the water table, a saturated, typically less oxygen rich environment, and the surface. Because of the immense differences in dissolved oxygen between the groundwater and surface water, the stage is set for interesting and meaningful redox reactions which can transform metals from harmless oxides to potentially deadly aqueous constituents. Such is the case for Mn, which in its oxide form (Mn[III/IV]) is an essential part of humans’ diets, yet as an aqueous ion can cause brain development issues and even hallucinations (Agency for Toxic Substances and Disease Registry 2012).

By analyzing the collected samples with a suite of instruments (ICP, XRD, SEM/EDS, XRF, and XAFS), we have the ability to determine the chemistry of the samples and whether they include any concerning constituents. Any identified contaminants, Mn specifically, can be analyzed with respect to their neighboring particles to determine the phase which the contaminant is in and the relationship between it and surrounding elements. This allows us to understand if the Mn is in a state which is harmful for human consumption, how it exists in the system, and gives us the best ideas for remediation if necessary. Once these have been assessed, we may correlate the presence and phase of contaminants with surface water quality, underlying geology, proximity to surface water, and potentiometric maps to understand why the constituents are behaving the way they are. This understanding can be applied to assess risk of contamination to drinking sources, including springs and new or existing groundwater wells.

All members of the team will continue to focus on this project for the extent of our senior year, as this research is the foundation for our senior theses. We will be presenting a poster with an update of our progress during the 2021 Geological Society of America Meeting in Portland, Oregon and aim to publish our findings so that they may be accessible to the public.

The whole Keck gang (minus Prof Margaret Anne Hinkle, as she took the photo) collecting samples along the Maury River.

Keck Geology Advanced Project 2021-2022: Ani (Marina) Croy (C'22), Written for our Geo Dept Alumni Newsletter

This summer I spent about three months participating in summer research with the Keck Geology Advanced Project for 2021 and Dr. Hinkle in the Washington and Lee Geology Department. Essentially working a nine to five, hands-on job was a big change from studying abstract topics in the classroom setting. Thanks to the Keck program, I received practical experience of working in the field and the lab. Field work consisted of visiting various locations over the summer to collect water and soil samples. We visited lakes, streams, dams and springs across the Shenandoah Valley to create a thorough hydrological and geochemical profile of the area. These samples were then brought back to the lab where they were tested via ion chromatography to identify their chemical makeup. Lab work introduced me to many new experiences. Working with dangerous chemicals and acids took some getting used to. On the other hand, learning to use new equipment and instruments was exciting as it felt like I was learning crucial skills I would need in my professional career. Data analysis made up a huge portion of the lab work, as many of the samples turned out raw data which was up to my interpretation. Learning when to maintain the scientific integrity of a sample set was another huge learning experience for me personally. A massive amount of thought, planning, and caution goes into managing a dataset so that it is both reliable and tells a story about the geochemistry of the area. The Advanced Project for 2021 focused on water quality in the Shenandoah Valley, with a particular emphasis on concentrations of manganese in water. Over the course of the project, I learned about how manganese precipitates and the different forms it can take in soil and water (in very very very great detail). Aqueous manganese can have a plethora of nasty effects on human health, so learning where manganese is located, and how much of it there is in said location, was a big focus for the project. The broader impact of this project is that our findings can hopefully be combined with other datasets to help determine the quality and the geochemical make-up of drinking water throughout Virginia and West Virginia.

Field work consisted of visiting various locations over the summer to collect water and soil samples. We visited lakes, streams, dams and springs across the Shenandoah valley to create a thorough hydrological and geochemical profile of the area. These samples were then brought back to the lab where they were tested via ion chromatography to identify their chemical makeup. Lab work introduced me to many new experiences. Working with dangerous chemicals and acids took some getting used to. On the other hand, learning to use new equipment and instruments was exciting as it felt like I was learning crucial skills I would need in my professional career. Data analysis made up a huge portion of the lab work, as many of the samples turned out raw data which was up to my interpretation. Learning when to maintain the scientific integrity of a sample set was another huge learning experience for me personally. A massive amount of thought, planning, and caution goes into managing a dataset so that it is both reliable and tells a story about the geochemistry of the area.

The Advanced Project for 2021 focused on water quality in the Shenandoah Valley, with a particular emphasis on concentrations of manganese in water. Over the course of the project, I learned about how manganese precipitates and the different forms it can take in soil and water (in very very very great detail). Aqueous manganese can have a plethora of nasty effects on human health, so learning where manganese is located, and how much of it there is in said location, was a big focus for the project. The broader impact of this project is that our findings can hopefully be combined with other datasets to help determine the quality and the geochemical make-up of drinking water throughout Virginia and West Virginia.

Lake Merriweather, one of the dams / reservoirs where we collected water and lake sediment samples.

Spring Term 2021: Environmental Field Methods Madness! by Jessie Ogden (C'23), Written for the Geo Dept Alumni Newsletter

I took 231 Environmental Field Methods with Margaret Anne in the spring term of 2021 as a sophomore. Throughout the course my twelve classmates and I learned about field work, environmentalism, water resources, pollution, stream health, and so much more. We stayed in Lexington for the full four weeks and went outside every day, sometimes staying on campus to do work in Woods Creek, and other times traveling to locations near town or in the surrounding Blue Ridge. Over the four weeks Margaret Anne taught us many types of field work, including how to take soil cores, measure tree throws, assess stream health, analyze water samples, and test for dissolved ions both in the lab and in the field. One of my favorite things we did was study the ben-thic macroinvertebrates of Woods Creek. It was fascinating to learn about how these little “bugs” can tell us so much about stream conditions, and then getting to collect and study them for our stream health analyses was so much fun. During the second two weeks, our class created a project to work on together. We used the methods and techniques that we’d been taught to analyze the impact of fertilizers on Woods Creek. It was great to get to research it together, and Margaret Anne was there every step of the way to help us find ways to answer our questions and reinforce our new skills. I really loved this course because I got outside, learned a lot about the environment and geolo-gy in and around Lexington, and made great connections with my peers. It was a lot of work, 30 hours of class a week is no joke, but the knowledge and experience I got out of it was definitely worth it. Now I feel confident when I do field work in my other classes, and I can apply the things I learned about environmentalism to other topics in geology. Overall, it was an awesome experience and I’m so glad I took the class.

Hinkle’s GEOL 231: Environmental Field Methods students conducting their final student-proposed and selected project assessing the health of Woods Creek via stream water geochemistry and benthic macroinvertebrate analyses

Jessie Ogden’s bunny, Daisy, was an honorary member of our class, visiting on occasion!

Jessie Ogden (C’23) collects depth measurements along a transect of the Maury River while teammate AJ Mabaka (C’22) supports from the canoe.

Keck Geology Advanced Team Heads to GSA to Present their Work!

GSA 2021: The first conference back in person since the start of the pandemic for many, including our 10 undergraduate students working on the Keck Advanced Project! While getting there was a bit of a challenge (delayed flights, with Co-PIs Margaret Anne & Eva Lyon carrying the Keck posters for everyone making everyone a bit worried about whether or not we’d make it there in time!), it all worked out in the end. Margaret Anne had an absolute blast catching up with colleagues and seeing her students present their work (and maybe writing abstracts for the upcoming spring ACS meeting). Most of the undergraduates had their first conference experience, and spent time getting back together as a Keck group - the first time the team had seen each other since the summer. We all came away jazzed about our research and ready to work on individual theses to help us tackle the bigger project together.

The list of presentations we gave at GSA include:

(*denotes presenting authors, ‡denotes undergraduate student)

1.     ‡Croy A., ‡Culbertson H., ‡Goldmann C., ‡Willis N., ‡Roquemore M.G., Lyon E., *Hinkle M.A.G. (2021) “Assessing manganese concentrations in spring and groundwater across the Shenandoah Valley, VA.” Poster presentation by all students at the 2021 Geological Society of America National Meeting, Oct 2021. doi: 10.1130/abs/2021AM-370401

2.     ‡*Larkin K., ‡Iosso C., Harbor D., Hinkle M.A.G., Lyon E. (2021) “Channel morphology change and legacy sediment mobilization following dam removal on the Maury River, VA” Poster presentation by Larkin at the 2021 Geological Society of America National Meeting, Oct 2021. doi: 10.1130/abs/2021AM-370963

3.     ‡Groff M., ‡Holicky M.G., ‡Larkin K., ‡Pulido M., ‡Wilde K., Hinkle M.A.G., Lyon E. “Characterizing land use history and assessing potential geochemical contaminants from legacy sediments and impounded water in Rockbridge County, VA.” Poster presentation by all students at the 2021 Geological Society of America National Meeting, Oct 2021. doi: 10.1130/abs/2021AM-371052

Guest Post from Javier Peralta, Summer Research Scholar

Note from MAGH: This post is a guest post from Javier Peralta, who wrote up the following for the W&L Geo Department website to share his research experience. Any undergraduate W&L student who wants to work with me or any other Geo Department faculty member - reach out! There are many opportunities, and all of us are engaged in exciting research projects and would love to work alongside motivated engaged students on our research projects.

Link to original post is here

Link to Geo Department’s Guide on Research Opportunities for Students here

Guest Post on Being a Summer Research Scholar

by Javier Peralta, W&L Geology C’21

This summer, I had the opportunity to work under the supervisor of Professor Hinkle in W&L's geochemistry lab. My research focused on fungal bioremediation of manganese oxidizes from coal mine drainage (CMD) and how various buffers can impact the biogeochemical process.

As with any mining operation, coal mining creates a significant amount of wastewater, which is then treated for heavy metal contamination. Manganese is usually the final heavy metal that is remediated from the wastewater. It is typically dissolved into the water as a Mn (II), making it soluble and difficult to remove. To facilitate its removal, the manganese is typically oxidized to Mn (IV) through abiotic processes, allowing it to bond with oxygen and create minerals such as δ-MnO2. This mineral can then be used for scavenging other toxic heavy metals present in the water given its layered/tunnel atomic structure.

Although abiotic processes are usually employed to oxidize the manganese, bioremediation has drawn a lot of attention given the speed at which it occurs. Studies that have looked at the rate of biogenic formation of δ-MnO2 claim that microorganisms can accelerate oxidation by five orders of magnitude over abiotic oxidation. Moreover, a shift to bioremediation of manganese can prove to be more cost effective and is less likely to form by-products. Despite the potential benefits, there is still a great lack of knowledge when it comes to understanding how microorganisms, such as bacteria and fungi, are capable of oxidizing manganese is such an effective way.

In an effort to add to the body of knowledge of geomycology, my research looked into how employing distinct buffers impacted the fungi's oxidative capacities, with the hope of finding a buffer that has the least effect on the process. We did this by culturing six different sample sets of Paraconiothyrium Sporulosum in AY media with designated buffer in each set, as well as a Mn-free sample set and a buffer-free control. Once the sample sets were made, the fungi were stored and allowed to grow for about two weeks. The pH was checked and recorded every day, a small amount of media was collected each day for UV-VIS analysis, and pictures were taken to track changes in fungal growth. After two weeks, the fungi were prepared for SEM-EDS analysis, the remaining filtrate was collected, and the pH and Mn (II) data was compiled for spreadsheet analysis.

Spending my summer in Professor Hinkle's lab was an incredible experience for me. Her lab environment allowed for me to both learn from her guidance and experience but also required me to be independent and free thinking when it came to my work and my research. I learned valuable skills in general research protocol as well as gained a variety lab skills and techniques. I was exposed to the literature behind my project, gaining an insight on how scholars seek to understand the natural world and its overwhelming intricacies. Overall, I came to realize how little we know as fact, which sparked within me a desire to further pursue research opportunities in geology.

Guest Post from Briyana Mondesir, Advanced Research Cohort

Note from MAGH: This post is a guest post from Briyana Mondesir, who wrote up the following for the W&L Geo Department website to share her research experience as an Advanced Research Cohort member (now Advanced Immersion and Mentoring, or AIM), a program designed for incoming first years interested in research to work part time in the lab with a professor (who will also serve as their incoming academic advisor) the summer before they matriculate. Any undergraduate W&L student who wants to work with me or any other Geo Department faculty member - reach out! There are many opportunities, and all of us are engaged in exciting research projects and would love to work alongside motivated engaged students on our research projects.

Link to original post is here: https://my.wlu.edu/geology-department/resource-guide-for-majors/junior-and-senior-years/briyana-mondesir-22

Link to Geo Department’s Guide on Research Opportunities for Students here

Link to more information on the AIM program (previously ARC program) here: https://my.wlu.edu/provosts-office/for-students/aim-program

Guest Post on Research in the Advanced Research Cohort

by Briyana Mondesir, W&L Environmental Studies & Spanish C’22

I was an incoming freshman at Washington and Lee, beginning to come to terms with the homesickness blues and the new college environment I would be living in. When I had previously visited W&L, I was struck by its natural beauty and its standing within the academic community. I was looking forward to entering the school in the fall with my other peers and begin the newest chapter of my life. I never imagined that I would have the opportunity to spend five weeks before the fall semester began doing research.

From mid-June to early July, I worked in Professor Margret Anne Hinkle's geochemistry lab primarily synthesizing minerals. The research was focused around biomineralizing fungi called Manganese. Over the course of a couple weeks, I attempted to create synthetic Manganese on which we would be able to test a variety of buffers. During this process, I learned, among other things, how to use a pipette, centrifuge, and analyze an XRD pattern. Although I struggled with always understanding the different components of the research, this invaluable experience allowed me to acclimate to college life and develop new research and laboratory skills. I would have never thought that as an inexperienced, fresh out of high school student I could have been able to do this. Yet, with the help of Professor Hinkle and my lab partners, I did it!

Last beamtime for the postdoc years

Last week I had my final beamtime for my postdoc work at the APS at Argonne Nat'l Labs. It was a really fun one with Liz Roepke & Josh Torgeson joining from Cara Santelli's group at U of MN. We got some beautiful XAFS spectra from 12-BM and as I start processing & comparing the data I'm getting more & more excited about this research (as if I weren't excited about it already). 

In other news, summer if flying by WAY too quickly. So much to do & so little time! At the same time, though, I can't wait to move to Lexington -- for a lot of reasons, but one of the main reasons is that I've convinced the family we need to get goats. To be honest, it didn't take much convincing. This blog may become overrun with goat pictures once we get them, and for that I apologize (sorry not sorry) in advance.

Sunset at the APS (apologies for the blurry upper right hand corner -- my phone case is annoying)

New signage on the sidewalk at the APS. Applies to life in general. It may or may not be my new computer background...

Post-all-nighter trike ride at beamtime! More effective than coffee, but not as delicious.

New Position in 2017!

I am really excited to be sharing the news that I will be starting as an Assistant Professor in Geology at Washington & Lee University this coming fall (2017). I cannot wait to start teaching again and get my lab up and running! The W&L community is an incredible one and I am beyond thrilled to be joining it. 

All PhD work is officially published!

So big news... all the papers from my PhD are now out. The last one, looking at Ni & Zn binding to abiotic manganese oxides when reacted with Mn(II), just came out in ES&T. I loved the research involved in this paper -- a lot of beamtime, a lot of syntheses, a lot of samples (a LOT of conical centrifuge tubes -- 263 samples, each one requiring 3 test tubes for experiment, filtrate, dilution = 789 test tubes), a lot of fun times in the lab, and a lot of coffee. Now that is done, I get to really focus on my little fungi & the structures of manganese oxides they end up making!

Hinkle M.A.G., Becker K.G., Catalano J.G. “Impact of Mn(II)-Manganese oxide reactions on Ni and Zn speciation.” Environmental Science & Technology 51(6), 3187-3196. [link]

DOI: 10.1021/acs.est.6b04347

A day in PA at a Coal Mine Drainage Remediation Site

I had a really grand time up in PA doing some field work and collecting samples at a coal mine drainage remediation site. The site has several active Mn remediation beds, comprised of dolomite/limestone lined trenches. A lot of microbial life here, with algal mats abounding in most of the beds. Since it was a day trip, we only had a couple hours available at the site, so we disbanded to be as efficient as possible. Won't say much more, because lots of data left to process, except to say it was really neat to see Mn remediation in action! Also, I'd forgotten how good Pringles and powdered mini doughnuts are on road trips... 

New paper accepted

Quick news update --new paper from my PhD work now has its very own doi, & the link is live! 

Hinkle M.A.G., Flynn E.D., & Catalano J.G. "Structural Response of Phyllomanganates to Wet Aging and Aqueous Mn(II)" Geochimica et Cosmochimica Acta (2016) doi: 10.1016/j.gca.2016.07.035

Click here for a free download for the next 30 days -- 

http://authors.elsevier.com/a/1TZPI3p4Z4wNy

Beamtime = super fun time

Last week I had a really great beamtime at the APS with Flo Ling. We collected Mn K-edge XAFS spectra on natural Mn oxides for Flo's work and some fungal Mn oxides. For the mycogenic Mn oxides we were testing to see if we could collect the spectra in transmission mode instead of relying on fluorescence-yield measurements. We've had some issues with self absorption in the past, so we were really hoping we could get transmission to work on these fungal samples-- and we did! Success! This was my first beamtime where I was actually able to fiddle with the samples -- all of my previous beamtimes involved experiments with anoxic samples that were heat sealed in bags. With these anoxic samples, I always had to rely on calculations for absorption lengths and estimates of packing densities, hoping it would work out, or bringing multiple samples with different loadings for each experiment. With this beamtime, it took a bit too much time to fiddle with the samples to get things just right (these samples are fungi + Mn oxides, so not as homogenous as I would like), but in the end we worked it out. Hooray data! And congratulations to Flo, who passed her PhD defense just a couple days after we got back from beamtime!

Set up inside the hutch for collecting fluorescence-yield Mn K-edge XAFS spectra!