Environmental Science: Processes & Impacts blog

Ryan Sullivan is an Associate Professor at Carnegie Mellon University, with a joint appointment in the Departments of Chemistry and Mechanical Engineering, and a courtesy appointment in the Department of Civil and Environmental Engineering. He is also a faculty member in the Center for Atmospheric Particle Studies, and the Associate Director of CMU’s Institute for Green Science. His primary interest is understanding the sources and chemical evolution of atmospheric aerosol particles, and how this evolution in turn alters the particle’s ability to nucleate clouds and thus alter climate. His research group at CMU develops analytical techniques for real-time analysis of individual aerosol particle composition used in his research. These include laser ablation single-particle mass spectrometry, aerosol optical tweezers, and microfluidic devices for ice nucleation measurements. The multi-phase chemical evolution of biomass burning aerosol from wood smoke is a major current focus. Ongoing experimental investigations include the alteration of the ice nucleation properties of smoke particles induced by chemical aging; and the activation of photo-labile chlorinated gases from heterogeneous reactions of nitrogen oxides with chloride salts emitted in the smoke. He has recently started new initiatives to develop and rigorously test advanced oxidation methods for the biosafe removal of micropollutants from wastewater.

Ryan obtained his Hon.B.Sc. in chemistry from the University of Toronto, and his M.Sc. and Ph.D. in chemistry from the University of California, San Diego. Before moving to Carnegie Mellon University in 2012, he completed his postdoctoral research in atmospheric chemistry at Colorado State University. Ryan is the recipient of a Faculty Early Career Development (CAREER) award from the National Science Foundation, and the National Academy of Science’s Cozzarelli Prize.

Read his Emerging Investigator Series article “Determination of biphasic core–shell droplet properties using aerosol optical tweezers” and find out more about him in the interview below:

Your recent Emerging Investigator Series paper focuses on the determination of biphasic core–shell droplet properties using aerosol optical tweezers . How has your research evolved from your first article to this most recent article?

The aerosol optical tweezers technique is a powerful approach to studying individual levitated particles. I started using optical tweezers six years ago, and we built two custom systems in my lab. One is for low temperature work to study ice nucleation, and the other has better controlled mixing and flow regimes for studying organic aerosol particles; that is the system used here. We recently reported the first aerosol optical tweezers experiments on complex secondary organic aerosol (SOA) that was produced and condensed onto a droplet directly in the tweezing chamber. We found that most of the SOA phase separated from the original droplet, be it a hydrophobic or aqueous phase, to form a core-shell morphology. We also observed strong evidence for a stable emulsified state of small SOA particles circulating in an aqueous droplet core. To more deeply investigate the chemical properties of these core-shell particle morphologies required us to develop the sophisticated analysis algorithm that we report here. This allows us to determine the properties of both the core and shell phases by analyzing the whispering gallery modes present in the Raman spectrum that form a standing wave around the droplet’s core and shell phases. It was Kyle Gorkowski who advanced upon the existing WGM analysis algorithms, drawing on his aerosol optics background to improve the accuracy and computational efficiency of this fitting algorithm.  I have never worked on spectral analysis algorithms before and this research is a nice example of how new scientific discoveries drive the creation of advanced data analysis methods, allowing us to probe environmental chemical systems more deeply.

What aspect of your work are you most excited about at the moment?

There has been a lot of interest in atmospheric chemistry recently in the role that particle morphology plays in determining how particles interact with and affect their surrounding environment. This changes how particles interact with radiation, with water vapor and clouds, and with trace gases that can react heterogeneously with particle surfaces, and the partitioning of gases into organic or aqueous particle phases. As each particle’s composition and morphology can be quite different from one and other, it is important to determine these properties at the individual particle level. Determining particle morphology is quite difficult, but aerosol optical tweezers provides a powerful way to do this in a direct manner on single levitated particles. The analysis algorithm we reported here allows us to better and more quickly determine the properties of core-shell morphologies. I’m excited to continue to use optical tweezers as a powerful physical chemistry experiment to investigate complex and realistic atmospheric particle systems. We’re now starting to use our core-shell analysis algorithm to investigate the interplay between a particle’s morphology and how it reacts heterogeneously with trace reactant gases.

In your opinion, what are the biggest advantages of the new algorithm presented in your paper over previous methods of analysing data from core-shell biphasic droplets?

When we first started analyzing core-shell droplets it would take hours just to fit one Raman spectral frame. We acquire a new droplet spectrum every 2 seconds, and often conduct experiments on a single droplet for hours, so this analysis was completely impractical. Thanks to the clever approaches that Kyle worked out, our new algorithm is much more efficient and can fit each spectrum in much less than a minute. We’re now able to analyze hours-long experiments and observe the properties of core-shell droplets evolve during these long experiments that simulate how particles might evolve during atmospheric transport. We now also have a much deeper understanding of the accuracy of our algorithm’s analysis of core-shell droplets and how this accuracy changes with the quality of the spectral data and number of whispering gallery modes present. This gives us much more confidence in the accuracy of any properties that we determine from biphasic droplets.

What do you find most challenging about your research?

Aerosol particles are really tough to do experiments on. This makes this research a fun challenge, but it can be very challenging indeed. A whole suite of expensive instruments is often required to determine all the different aerosol properties you need to know to understand their chemistry. As the submicron particles are so small and have very little mass, they are difficult to study at the individual particle level, and prone to change during analysis. If you just look at the particles they will change; they are constantly evolving. So you have to design your experiments very carefully, and always be open to unexpected surprises. That’s what makes the aerosol optical tweezers approach so powerful. We are constantly determining the properties of an individual particle as it continues to evolve so we know its entire life history. That allows us to answer important questions in a unique way, such as how do particles evolve as they move through the atmosphere and interact with light, water, other particles, and condensible or reactive gases?

In which upcoming conferences or events may our readers meet you?

This summer I’m helping to run a Workshop on “Aerosols and Clouds: Connections from the Laboratory to the Field to the Globe” at the Telluride Science Research Center in Colorado. Then in September I’ll be attending the International Aerosol Conference in St. Louis, Missouri. There I’m organizing a Special Symposium on “Unraveling the Many Facets of Ice Nucleating Particles and Their Interactions with Clouds”, and I’m the Chair of the working group on Instrumentation & Methods and helped organize more than 150 abstracts submitted to that topic. The International Aerosol Conference only takes place every 4 years, and comes to North America every 12 years, so it’s a great opportunity to interact with a wide range of international scholars who are all advancing our understanding of these complex, tiny, airborne particles.

How do you spend your spare time?

These days I play a lot of volleyball (indoor, on grass, and beach). Playing sand volleyball is the closest we get to going to the beach in Pittsburgh! Being 6’3” is a slight advantage in volleyball, but less so for the olympic lifting I also do. I also like to go hiking on the many trails we have in Appalachia.

Which profession would you choose if you were not a scientist?

I had to think about this one for awhile. I would probably work more on developing technology to help tackle important environmental problems, such as improved methods to remove pollutants from our air and water, and to prevent them from being produced in the first place. I suppose that still sounds like science though… A career working with environmental advocacy groups and NGOs to help raise awareness of environmental issues and educate young students and the general public about the environment would also be very satisfying.

Can you share one piece of career-related advice or wisdom with other early career scientists?

It’s really important to find research questions and topics that greatly speak to you. All research is hard to complete, especially when you’re starting your own lab, so why work on science that doesn’t really excite you? That passion will help propel you through the challenging parts. It’s also important to carve out your niche in research – what will you become known for? That doesn’t mean you have to try doing completely different new-to-you research from the start. Having a good balance of safer close-to-home and riskier but more innovative research projects is a good approach.

We are delighted to introduce our latest Environmental Science: Processes and Impacts Emerging Investigator, Ning Dai!

Dr. Ning Dai is an Assistant Professor in the Department of Civil, Structural and Environmental Engineering at the University at Buffalo. Her research areas include disinfection processes for wastewater reuse and the fate of agrochemicals in natural systems. Ning received her B.S in Environmental Science and Engineering from Tsinghua University in China, M.S. in Civil and Environmental Engineering from Stanford University, and Ph.D. in Chemical and Environmental Engineering from Yale University. She joined the University at Buffalo in 2014 after a brief postdoctoral training in Stanford University. Dr. Dai is a recipient of the National Science Foundation CAREER Award.

Read her Emerging Investigator Series article: ‘Sunlight photolysis of 2,4-D herbicides in systems simulating leaf surfaces’ and find out more about her in the interview below:

Your recent Emerging Investigator Series paper focuses on sunlight photolysis of herbicides in systems simulating leaf surfaces. How has your research evolved from your first article to this most recent article?

This is actually my first article on photochemistry in natural systems. My past research mainly focused on engineering systems such as amine scrubbers for carbon capture and disinfection and oxidation processes for water reuse. As a PhD student, I only had a short project on tetracycline photolysis in my first semester; however, I was continuously exposed to photochemistry from group meeting presentations and from the discussions with one of my lab mates, who is an excellent photochemist. After I started my own group at University at Buffalo, I thought it would be interesting to pursue some projects in this topic. I still have a lot to learn in photochemistry, but I think that is the exciting part to be in academia – there are always new things to learn and discover!

What aspect of your work are you most excited about at the moment?

I am generally excited about learning. My students and I are learning new methods and analytical tools to try to answer new research questions. I find that a rewarding experience.

In your opinion, what is the biggest environmental impact presented by the photolysis of herbicides on leaf surfaces?

I believe further understanding of herbicide photolysis on leaf surface can improve the environmental fate model for pesticides. Currently, pesticide transformation on plant surface is not considered in the fate model, but it can be important for some pesticides. For example, we showed in this study that the photolysis of 2,4-D herbicides on surface can proceed at comparable rates as their biodegradation. This is noteworthy because biodegradation is considered to be the most important degradation pathway in the current fate model.

What do you find most challenging about your research?

To study photochemistry on plant surface, it is challenging to create well-controlled and yet environmentally relevant experimental conditions. This, I believe, also applies to any research involving heterogeneous systems.

In which upcoming conferences or events may our readers meet you?

I will be attending the American Chemical Society Fall Meeting in Boston this August. My student Lei Su (first author of this paper) will be presenting at the ARGO division.

How do you spend your spare time?

I enjoy swing dance, although I don’t get to dance as frequently as I did in graduate school. I guess it is somewhat busy to be a new faculty!

Which profession would you choose if you were not a scientist?

I believe I would be a full-time teacher (that is part of the university faculty job description as well). I enjoy the process of sharing knowledge.

Can you share one piece of career-related advice or wisdom with other early career scientists?

In my own experience as a PhD student, I learned a lot from my research group; not only on my dissertation projects, but also on the research topics I was not involved in. Similarly, I also learned from friends in other research groups and even other departments. The benefits extend beyond scientific knowledge, and include many great advices on career development. I consider peer learning a crucial component of the graduate school experience, and I would recommend everyone to fully engage in it.

We are delighted to introduce our latest Environmental Science: Processes and Impacts Emerging Investigator, Raoul-Marie Couture!

Raoul-Marie Couture is an aquatic geochemist studying coupled elementary cycles in lakes, waterlogged soils and freshwater sediment, with a focus on such systems within the boreal zone. He holds a BSc in Chemistry (2004) from Laval University and a PhD in Water Sciences (2010) from the University of Quebec, Canada. After his graduate studies he held a post-doctoral fellowship at the Georgia Institute of Technology and a Research Assistant Professor position in the Ecohydrology Group at the University of Waterloo. From 2013 to 2018, he was researcher, then head of the section for Catchment Processes at the Norwegian Institute for Water Research (NIVA) in Oslo, Norway. Form March 1^st 2018 onward he is Associate Professor in the Chemistry department at Laval University. His research aims to understand how the biogeochemical cycling of key elements responds to human activities and climatic factors, with the overarching goal of improving water quality. To acheve his research goals, he combines field work, instrumental analysis and process-oriented computer modelling. His publications have touched on the modelling of biogeochemical processes controlling seasonal anoxia and algae blooms in lakes, the speciation and fate of contaminant metals and metalloids, and the modelling of sediment-water interactions during early diagenesis. He lives in Quebec city with his spouse and two daughters.

Read his Emerging Investigators series article: “Geochemistry of trace elements associated with Fe and Mn nodules in the sediment of limed boreal lakes“ and find out more about him in the interview below:

Your recent Emerging Investigator Series paper focuses on the geochemistry of trace elements in the sediment of limed boreal lakes. How has your research evolved from your first article to this most recent article?

This article reflects my continuous interest in sediment redox processes and in metal and metalloid diagenesis. Since my first article in 2008, my research has evolved to consider multiple lake systems at once, and how they respond to multiple pressures such as atmospheric deposition, long-term changes in land use and climate, and to geoengineering measures.

What aspect of your work are you most excited about at the moment?

I am just about to start a new position as a professor in the chemistry department at Laval University. I am looking forward to building a research group in aquatic geochemistry to work the impact of current environmental changes on water quality. I am particularly excited about the opportunity to work on a wide range of water quality issues in various settings, from populated agricultural catchments to boreal and arctic landscapes.

In your opinion, what is the biggest environmental impact posed by the release of trace elements into the water column?

The release of trace elements – especially those that are potentially toxic – to the water column can have a significant environmental impact. In the natural environment, it is a threat to aquatic ecosystems, with often severe impact on the food web from phytoplankton to fish. In drinking water reservoirs, it is a direct threat to water quality and to human health.  Understanding on how trace elements can remain sequestered in the sediment contributes to reducing their environmental impacts.

What do you find most challenging about your research?

The most challenging aspect of my research is the combination of field work, laboratory experiments and computer-based modelling. Understanding the coupled cycling of major and trace elements in the aquatic environment requires balancing project resources along these three axes.

In which upcoming conferences or events may our readers meet you?

I can be found at the upcoming workshop on Restoration of Eutrophic Lakes in Lahti, Finland, June 4-5 2018 (https://lahtilakes2018.fi/) and at the upcoming Goldschmidt 2018 conference in Boston, USA, Aug. 17-18, 2018.

How do you spend your spare time?

I enjoy spending time with my spouse and two young daughters. These days I am also learning the ins and outs of improving the old house that we recently bought in Quebec City.

Which profession would you choose if you were not a scientist?

Choosing between art and natural sciences was a difficult decision when the time came to select an undergraduate program – my other choice would have been architecture.

Can you share one piece of career-related advice or wisdom with other early career scientists?

I have experienced that the demands on the time of young researchers is hard to balance, especially with the needs of a young family. Learning early to manage our time efficiently strikes me as an important skill.  For instance, knowing in advance the criteria for advancement has helped me to seize the right opportunities.

We are delighted to introduce our latest Environmental Science: Processes and Impacts Emerging Investigator, Andrew Graham! 

Andrew Graham is an environmental geochemist specializing in the fate of trace elements in aquatic environments.  Andrew received his BA in Geology from Earlham College (2003) and a Ph.D. from the Johns Hopkins University Department of Geography and Environmental Engineering (with Ed Bouwer).  From 2010-2012, Andrew was a postdoctoral fellow at the Smithsonian Environmental Research Center (with Cindy Gilmour), and began his career at Grinnell College (Grinnell, IA) as an assistant professor of chemistry in 2012.  At Grinnell, Andrew teaches courses in earth system science, inorganic and environmental chemistry, geochemistry, and water resources, and maintains an active undergraduate research group.

Read his Emerging Investigators series  article: “Methylmercury speciation and dimethylmercury production in sulfidic solutions” and find out more about him in the interview below:

Your recent Emerging Investigator Series paper focuses on methylmercury speciation and dimethylmercury production in sulfidic solutions. How has your research evolved from your first article to this most recent article?

The first publication from my Ph.D. work was on chromium speciation in anoxic sediments, with an emphasis on the role that acid volatile sulfides (composed of aqueous sulfide and mineral phases such as FeS) play in reducing Cr(VI) to Cr(III).  Most of my work now centers on Hg biogeochemistry, but a common thread to my work has been in understanding the intersection of the biogeochemical cycles of sulfur and trace elements.

What aspect of your work are you most excited about at the moment?

I teach at a small liberal arts college, and my laboratory consists entirely of undergraduate students.  Three undergraduate students (Kanzler, Leverich Trainer, and Yang) were co-authors on the paper published in ESPI.  Getting to share in the process of scientific discovery with my students and mentoring them at this early stage of their scientific careers is the most exciting and rewarding part of my job.   I’ve been pretty much a strict experimentalist throughout my career, and the opportunity to collaborate with computational chemist colleagues at ORNL (Lian and Parks) and PNNL (Govind) on this paper was also really exciting.

In your opinion, what is the biggest environmental concern presented by methylmercury speciation and dimethylmercury production?

Methylmercury is a potent neurotoxin that bioaccumulates and biomagnifies in aquatic foodwebs.  Most of human exposure to mercury comes from eating methylmercury-contaminated fish, especially pelagic fish like tuna.  In the oceans, a significant portion of the organic mercury is dimethylmercury (DMeHg), but we know relatively little about the origin and fate of DMeHg.

What do you find most challenging about your research?

Most of my energy right now is aimed at understanding element cycling in real natural systems.  For example, my group is working on understanding Hg cycling in alluvial groundwaters in the Upper Mississippi River Basin. Scaling findings from controlled laboratory experiments to real systems is a challenging task.

In which upcoming conferences or events may our readers meet you?

I usually attend one or two meetings per year – the American Chemical Society National Meeting and the International Conference on Mercury as a Global Pollutant (which meets every other year).

How do you spend your spare time?

I spend most of my time outside of work with my family.  My wife Lauren and I enjoy helping our twin four-year old sons explore the world.

Which profession would you choose if you were not a scientist?

If I had more discipline and more talent, I’d write literary nonfiction, in the mold of one of my favorite authors, John McPhee.

Can you share one piece of career-related advice or wisdom with other early career scientists?

My most significant scientific discoveries have occurred when I’ve asked good questions about “failed” experiments.  These experiences are frustrating at the time, to be sure, but remaining open to what the data are telling you allows you to better define the limits of your knowledge or underlying assumptions.

We are delighted to introduce our latest Environmental Science: Processes & Impacts Emerging Investigator, Ami Riscassi!

Ami received her B.S. in Mathematics from Wake Forest University (1996) and worked in Yosemite National Park for the next year where she decided to pursue a career which would allowed her to apply her analytical skills to supporting air and water resource management in National Parks. She returned to graduate school in 1997 for an M.S. in Environmental Engineering at the University of Virginia (UVA). After graduating in 1999, she worked as a fish/water quality research assistant with the National Park Service/USGS in Lake Clark National Park and as a physical science technician in Yosemite National Park. Ami spent the next 6 years (2000-2006) as a physical scientist within the USGS National Research Program, Water Resources Division, measuring and modeling the complex hydrologic system within Everglades National Park.

Knowing she wanted to work in forested/mountain systems as well as in her local environment, she returned to UVA to pursue her PhD in Environmental Sciences (2006-2011) conducting research within Shenandoah National Park, followed by 3-yrs as a post-doctoral researcher at Oak Ridge National Laboratory (2011-2014). In both PhD and post-doc positions, her research focused on determining the controls on mercury mobilization from the watershed to the stream ecosystem. Ami returned to UVA in 2014 to be a research scientists and Projects Coordinator for the Shenandoah Watershed Study. In this position, she maintains the long-term water quality monitoring program while pursuing additional research questions relevant to water resources in the western Virginia mountains.

Read her Emerging Investigators series article: “The effect of wildfire on streamwater mercury and organic carbon in a forested watershed in the southeastern United States” and find out more about her research in the interview below:

Your recent Emerging Investigator Series paper focuses on the effect of wildfires on streamwater mercury and organic carbon content. How has your research evolved from your first article to this most recent article?

One of my first articles as a graduate student assessed the instrumentation and methodology necessary to conduct automated high-flow stream sampling for trace-level mercury analysis. I then used those methods to evaluate the hydrologic and chemical controls on mercury transport in forested mountain streams. From those remote systems, contaminated from atmospheric Hg deposition, I moved to assessing controls on stream Hg transport in an industrially contaminated urban system and expanded on the prior work to evaluate organic (methyl mercury) as well as inorganic mercury. This most recent article was an application of what I had learned about stream Hg transport, but within the context of a large scale disturbance, fire. I was ‘lucky’ to be working within Shenandoah National Park when a relatively rare wildfire (for the Eastern U.S.) burned one of our study watersheds. It didn’t take long to search the literature and conclude that the impact of forest fire on streamwater Hg had not been assessed and we were in a unique position to quickly mobilize and conduct this study. I applied the methods developed in that first paper to this most recent study; it’s a nice feeling to continue citing one of your first papers throughout your career.

What aspect of your work are you most excited about at the moment?

I put some research on hold for the time sensitive post-fire Hg study that I am excited to return to now. I am evaluating the response/recovery of streams in Shenandoah National Park from historical acid deposition, within the context of different flow regimes. It’s a very unique data set (collecting high flow data in headwater streams for decades is labor intensive and not frequently done!) and I’m excited to finish up the analysis, write the manuscript and get this new piece of information out to the research and resource management community.

In your opinion, what is the biggest impact to aquatic ecosystems caused by elevated mercury and organic carbon?

Elevated inorganic mercury concentrations (what we measured in this featured study) have the potential to result in increased methylmercury concentrations, given the right environmental conditions and microbial community. Methylmercury is a neurotoxin that bioaccumulates in higher order predators, like fish, that humans eat. The global community is making efforts to reduce mercury in the environment due to the negative health implications, including the U.S. (see MATS standards, https://www.epa.gov/mats). Quantifying the contribution of Hg to streamwater from unregulated sources, such as wildfire, is important to accurately assess global budgets as well as the potential for changes in methylmercury in local streams.

What do you find most challenging about your research?

Communicating research findings succinctly in papers. I tend to want to write about every detail of the methods, analysis, and all my ideas of what the results may mean. I always end up writing way too much initially, but then take a few steps back, and return to it (many, many times) from the perspective of a fellow scientist not involved in the project. With that approach, I am ultimately able to sculpt it down to something that is more useful and relatively concise.

In which upcoming conferences or events may our readers meet you?

You’ll have to come to the University of Virginia or Shenandoah National Park!  I was just at the International Conference on Mercury as a Global Pollutant this past summer and will hopefully be attending the fall AGU meeting in 2018.

How do you spend your spare time?

Trail running, dog walking, reading (just finished Lab Girl by Hope Jahren, wonderful book), and volunteering with the local collie rescue. Vacations are usually backpacking adventures with my former grad school lab-mates.

Which profession would you choose if you were not a scientist?

Can I just pick another type of scientist? I think being a wildlife biologist or entomologist would be pretty spectacular. If pressed, perhaps I could be a Resource Manager with a National Park or National Forest.

Can you share one piece of career-related advice or wisdom with other early career scientists?

From my personal experience (see my bio), I would point out that there is no one path to becoming a scientist. Pursue the ideas/places/environments/collaborations that interest you from the start and you’ll be led down a path where you enjoy your work and your life.

We are delighted to introduce our latest Environmental Science: Processes & Impacts Emerging Investigator, Andres Martinez!

Andres Martinez is a Researcher Scientist and Adjunct Assistant Professor at the University of Iowa, USA. He has 10 years of scientific research experience, during which he has developed expertise in the areas of field sampling, development of analytical method and analysis of hydrophobic organic compounds in complex environmental matrices, environmental modeling, and data analysis. Distribution, transport, and fate of polychlorinated biphenyls (PCBs) in air, water and sediment/soil have been his main areas of interest, where he has already published more than twenty peer review papers in high impact scientific journals. His research has included collaboration with other researchers in the Iowa Superfund Research Program, IIHR-Hydroscience & Engineering, department of Occupational and Environmental Health, the Center for Global and Regional Environmental Research (CGRER), and Lucille A. Carver Mississippi Riverside Environmental Research Station (LACMRERS), at the University of Iowa. He has also collaborated with researchers in the department of Civil, Architectural and Environmental Engineering, the University of Texas at Austin and researchers from the Department of Environmental Health, Boston University

Read his Emerging Investigators series article “Development and application of polymeric electrospun nanofiber mats as equilibrium-passive sampler media for organic compounds” and find out more about his research in the interview below:

Your recent Emerging Investigator Series paper focuses on the role of the use of polymeric electrospun nanofiber mats for monitoring environmental organic compounds. How has your research evolved from your first article to this most recent article?

It is quite different. Most of my research focus on measuring and modelling PCBs and other POPs in the environment (air, water, sediment) using already tested active and passive sampling methods. Here, we developed “from scratch” a novel passive method to measure more polar organic compounds in water and sediment systems.

What aspect of your work are you most excited about at the moment?

Exploring new research ideas.

In your opinion, what is the biggest advantage of using nanofiber mats over traditional organic compound sampling mediums?

As we emphasize in the paper, the idea of fabricating electrospun nanofiber mats (ENM) that sample during the equilibrium stage, which minimizes the uncertainty when calculating the environmental concentration. It is very promising (i.e., shorter field deployments and easier analytical detection). In addition to the ENM high surface area-to-volume ratios (S/V), that is a faster sampler, we can improve their uptake performance through surface chemical functionalization and addition of nanoparticles.

What do you find most challenging about your research?

Generate interesting research questions that can be funded.

In which upcoming conferences or events may our readers meet you?

SETAC Minneapolis.

How do you spend your spare time?

With my family.

Which profession would you choose if you were not a scientist?

Good question. Outdoor photographer…

Can you share one piece of career-related advice or wisdom with other early career scientists?

Develop new collaborations

We are delighted to introduce our latest Environmental Science: Processes & Impacts Emerging Investigator, Anke Neumann!

Anke Neumann is an environmental chemist (MSc in Chemistry from ETH Zurich, 2004) and received her PhD from ETH Zurich (2009). She carried out postdoctoral research in Bangladesh (freelance, 2009-2011) and at the University of Iowa (fellowships, 2011-2013). In 2014, Anke joined Newcastle University as a Lecturer in Environmental Engineering.

Her research focuses on redox processes at the mineral-water interface and how these processes affect the fate of organic and inorganic compounds in the environment. For more details, visit her research group’s website

Read her Emerging Investigators series article “As(V) in magnetite: incorporation and redistribution” and find out more about her research in the interview below:

Your recent Emerging Investigator Series paper focuses on sorbed and incorporated As on magnetite and the effect of Fe minerals on As mobility in natural systems. How has your research evolved from your first article to this most recent article?

My first article was based on my MSc work on the redox reactivity of Fe(II) species associated with Fe-bearing clay minerals and I have worked on redox reactions of Fe minerals and their effect on contaminant fate ever since. I started working on the interactions between Fe minerals and As after my PhD, when I led and conducted a long-term field project investigating As removal from drinking water with zero-valent iron-based filters in Bangladesh. It was then lucky coincidence that I arrived in Michelle Scherer’s lab as a postdoc just as Brittany Huhmann was beginning her MSc project on As-magnetite interactions, which provided the data for this most recent article.

What aspect of your work are you most excited about at the moment?

I am actually excited about two projects. On the one hand, my PhD students have been producing very interesting results from their work on contaminant degradation with Fe-bearing clay minerals that they reduced with dissolved Fe(II). On the other hand, I am also interested in oxygenation reactions of Fe(II)-bearing clay minerals, which have long been overlooked and are now – finally – enjoying increasing attention. So, this new field is expanding and quickly gaining momentum, and I am excited to contribute to further developing this field.

In your opinion, what is the potential impact of your findings on groundwater quality?

I do not think that our findings will change groundwater quality per se but rather increase our understanding of how and where As is sequestered in the environment, for example an aquifer. The new insights will also help us to design and engineer sequestration pathways, be it in situ in the aquifer or once the water has been pumped to the surface. This will be particularly important when we think about water management for the future, which will likely include approaches such as managed aquifer recharge or aquifer storage and recovery and produce conditions under which As sequestration into magnetite could occur.

What do you find most challenging about your research?

Most of my research focuses on understanding reactions mechanisms and how things work at a very fundamental level. I find it sometimes difficult to convince others of the significance and relevance of my research to environmental issues and ‘real-world’ problems.

In which upcoming conferences or events may our readers meet you?

I usually attend one or two conferences a year, such as Goldschmidt, ACS National Meetings, or the Clay Minerals Society Annual Meeting. My ‘conference season’ has just ended with the start of the new semester and so far, the only set event this year is the biennially held Iron Biogeochemistry workshop.

How do you spend your spare time?

I spend most of my free time with my family. Seeing my daughter (4) grow up, exploring the world, and, just recently, starting school is my reality check and spending time with her makes me realize the (other) really important things in life.

Which profession would you choose if you were not a scientist?

This is one of the most difficult questions for me – I never really considered any other profession. I think that if I had to quit being a scientist, I would need to do something really different but I also enjoy creating ‘TOC art’ and similar, although I am not sure that I am sufficiently artistic to make this a profession.

Can you share one piece of career-related advice or wisdom with other early career scientists?

As a scientist, your work is constantly being judged: prepare yourself for harsh criticism and also failure to convince, for example reviewers of your papers or grant applications. When I am faced with rejection, I find it important to be able to tap into a broad variety of support: from my colleagues who have been in the same situation and cheer me on; from my friends who engage me in a life outside of academia; and, most importantly, from my family who so naturally confront me with a totally different perspective on things.

Yu (Frank) Yang is an Assistant Professor at the University of Nevada, Reno, working in the Civil and Engineering Department. Prior to this, he completed both his undergraduate studies and PhD at Peking University, China. His current research interests include: the impact of global climate change on the fate of critical pollutants; the response of organic matter geochemistry to the temperature increases; and the colloid-facilitated reactive transport of insoluble radionuclides.

Read his Emerging Investigators article “Dual role of organic matter in the anaerobic degradation of triclosan” and find ourmore about Frank and his research in the interview below:

Are you within 10 years of receiving your PhD? Do you have an independent research career? Then you could be eligible for our Emerging Investigator Series! find out more at rsc.li/emerging-espi

Your recent Emerging Investigator Series paper focuses on the role of organic matter in the anaerobic degradation of triclosan. How has your research evolved from your first article to this most recent article?

My first research paper is about the human exposure to legacy pesticides (e.g. DDT) and their health risk. My Ph.D. studies and postdoctoral projects are mainly focused on the organic matter-mediated fate and transport of organic and inorganic pollutants. In this paper, we have found an interesting novel dual role of organic matter in the degradation of an emerging organohalide compound.

What aspect of your work are you most excited about at the moment?

In my research group, we are mainly working on the important environmental redox reactions, focusing on the degradation of organohalides, microbial assimilation and plant uptake of carbon nanomaterials, and stability of soil organic carbon. We are currently using lots of state-of-the-art technologies to study the transformation of organohalides and natural organic carbon, which is really exciting to us.

In your opinion, what is the biggest impact to the environment presented by antimicrobial agents?

Release of antimicrobial agents can induce the development of antimicrobial resistance, which is one of the biggest environmental problems.

What do you find most challenging about your research?

I would like to fully understand the degradation pathways of emerging organohalides and work out cost-effective removal strategies. Both are challenging tasks.

In which upcoming conferences or events may our readers meet you?

My group and I will present our work (6 talks and 3 posters) at American Chemical Society 2017 Spring Meeting (April 2-6, 2017, San Francisco). I am also chairing two symposia with my colleagues, with one for redox reactions and the other for nanomaterials.

How do you spend your spare time?

When I have spare time, I enjoy watching movies, playing chess, and spending time with my family.

Which profession would you choose if you were not a scientist?

Without science, probably I would become a high-school teacher.

Can you share one piece of career-related advice or wisdom with other early career scientists?

Have a good balance and be persistent. Balance between the crazy ideas and relatively “low-risk” projects, balance between pursuing grants and publishing papers, balance between research and teaching, and many others