Environmental Science: Water Research & Technology blog

John-David R. Rocha is an Assistant Professor in the School of Chemistry and Materials Science at the Rochester Institute of Technology. His research focus is in the area of nanotechnology as a physical / analytical / materials chemist, more specifically, in the use of nanomaterials in energy, electronics, and environmental science. He utilizes his expertise in the areas of carbon nanomaterials characterization to expand areas of fundamental understanding in carbon nanotubes and graphenes, keenly working to tie the acquired knowledge to the application needs of the chemical and engineering industries. He received his BS and MS degrees in Chemistry from the University of North Texas in 1995 and 2002, respectively. Following his PhD in 2008 from Rice University, he was a Postdoctoral Researcher at the National Renewable Energy Laboratory. Prior to arriving at RIT, Dr. Rocha was a Research Scientist at SouthWest NanoTechnologies Inc. where, among other responsibilities, he led a $1.1M joint collaboration between SWeNT and a major electronics corporation to develop semiconducting SWCNT inks for thin film transistor applications. His doctoral and postdoctoral research focused on optical spectroscopic characterization of carbon-based nanomaterials including carbon nanotubes and metal organic frameworks. Rocha’s chemical research experience also includes work in gas-phase chemical kinetics of atmospheric and combustion chemistry and computational chemistry studies of organometallics. He is a member of the American Chemical Society and also participates regularly in activities with the MRS, AAAS, and the Society for the Advancement of Chicano and Native Americans in Science (SACNAS). Prior to returning to full-time chemical research in 2003, Rocha taught secondary Mathematics and Chemistry in the large urban school district of Dallas, TX, his hometown.

Reginald Rogers is an Assistant Professor in Chemical Engineering at the Rochester Institute of Technology.  He is head of the Nanoscale Energy and Separation Materials Laboratory (NESML).  Dr. Rogers and his group have been involved in a variety of projects investigating the separation of organic and inorganic compounds from aqueous environments using carbon-based nanomaterials.  Dr. Rogers also has projects focused on the development of cathode materials for sodium ion batteries.  He has served as a co-author on over 20 research papers and has presented at many national conferences.  Dr. Rogers recently received several awards, including the 2015 Joseph N. Cannon Award in Chemical Engineering from the National Organization for the Professional Advancement of Black Chemists and Chemical Engineers, and the 2016 Richard and Virginia Eisenhart Provost’s Award for Excellence in Teaching from RIT.

Read their Emerging Investigators article “Highly Effective Adsorption of Organic Aromatic Molecules from Aqueous Environments by Electronically Sorted SingleWalled Carbon Nanotubes“ and find out more about their work in the interview below:

Your recent Emerging Investigator Series paper in Environmental Science: Water Research & Technology focuses on single-walled carbon nanotubes, and the influence of chirality on their performance for water remediation applications. How has your research evolved from your first article to this most recent article?

Reginald: In 2011, we had a premise that carbon nanotubes could be used in water treatment applications, but never had a complete picture on their promise.  The initial results, published in Chemical Engineering Journal, laid the foundation for further expansion on the subject.  In 2013, we reported on a novel technique for using hybrid structures, which significantly improved the adsorption uptake capacity.  With this knowledge, my group published 5 other publications to further develop and clarify the adsorption behavior in batch and fixed bed systems.  This new paper on using sorted carbon nanotubes by chirality provides another stepping stone towards the development of 3-D adsorption architectures for filtration systems.  The hope is to take this knowledge and continue the growth of this fairly new adsorbent in water treatment applications. 

John-David: My work with single-walled carbon nanotubes began back in 2003 with my primary expertise developed in the use of novel optical spectroscopic techniques for characterization. Following the establishment of new spectrofluorimetric analytical methods, I demonstrated the application of the techniques to study chirality specific reactivities to solve important early questions of single-walled carbon nanotube chemistry. Interestingly, these studies illustrated how early cursory studies of carbon nanotubes can be impacted by material variability and control of experimental conditions. It was with these studies between 2003 to 2008, followed by my growth of research experience in SWCNT separations work, that I developed the knowledge to partner with Dr. Rogers in broadening his exciting research in applying carbon nanotubes to water treatment applications.

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

Reginald: I am most excited about the opportunity for translating our results from the past research efforts into actual systems (e.g. mocked up water filtration system) to see what an end user would see from an engineered product solution standpoint.  This will calibrate us to other focus areas that may be needed to further enhance this particular type of adsorbent.

John-David: The most exciting aspects of my carbon nanomaterials research at the moment are seeing the growth opportunities in novel, unexplored application areas like environmental science and water remediation.

In your opinion, what is the biggest challenge in using nanotubes as an adsorbent in environmental systems?

Reginald: I would say that biggest challenge in using nanotubes as an adsorbent in environmental systems is being able to demonstrate their reusability on the long-range scale.  One of the biggest debates around nanomaterials is their end of life attributes.  It is my belief that we can overcome the fears of increasing toxicity levels from nanomaterials by continually exploring how to recycle these materials for reuse by the end user. 

John-David: This question dovetails into the next, but essentially the biggest challenge is the intrinsic variability of carbon nanotube materials, both single- and multi-walled. These variations arise from the different large-scale production and processing techniques. Ultimately, determining how the variations can affect results in applications like adsorption of environmental pollutants can sometimes be more difficult relative to the potential advantages gained.

What do you find most challenging about your research?

Reginald: The most challenging thing about my research is focusing on how to drive down the costs associated with material development of these carbon nanotube-based adsorbents.  A major hurdle in the rapid expansion of this type of adsorbent is driven by scale-up.  Given the wide variability in carbon nanotube synthesis and purification techniques, it is not as straightforward as one might expect to simply produce bulk quantities of this type of adsorbent with a small degree in variation from one batch to another.  As my group continues to develop these adsorbents, we are constantly looking for ways to minimize variability in synthesis techniques.

John-David: I would strongly concur with Dr. Rogers in his summary of the challenging aspects with respect to carbon nanomaterials research. More broadly, it is extremely difficult to demonstrate the ability to scale bench-top research results to actual real-world application level results. Quite often the disconnect between published results to the production level end-user application goals is too great to overcome. The challenge is to continually find ways to answer the important questions that can help close or reduce these gaps.

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

Reginald: I will be attending the 2017 Gordon Research Conference on Environmental Nanotechnology in Stowe, VT June 18^th-23^rd.  I will also be at the 2017 American Institute of Chemical Engineers Annual Meeting in Minneapolis, MN October 29^th-November 3^rd.

John-David: I will be attending the 254^th American Chemical Society National Meeting in Washington, DC August 20 – 24 and the ACS Northeast Regional Meeting in October 2017.

How do you spend your spare time?

Reginald: I am typically spending my time traveling to new locations, reading books, or staying in shape at the gym.

John-David: I enjoy spending time with my family, volunteering in the community, participating in church activities, reading books, and exercising.

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

Reginald: Since I love to travel, I would say I would choose to be travel agent or food connoisseur.

John-David: I was a high school chemistry teacher for a number of years, so it’s hard to speak of a profession that doesn’t fall within the broad context of the STEM fields. Potential non-chemistry related professions might be medical doctor/surgeon or a computer programmer.

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

Reginald: Find balance in how your handle your workload.  Don’t go overboard with trying to do everything at one time.  Be willing to say “no” when the going gets tough.  This will help you maintain sanity as you navigate all of your responsibilities.

John-David: Find like-minded colleagues to communicate with regarding all aspects of life, not exclusive to, but in particular those areas outside of research and teaching, including family life, recreation, and social areas. Also don’t sacrifice your personal life, particularly family, for your career.

Joseph Kasprzyk, Assistant Professor of Civil and Architectural Engineering.

Joseph Kasprzyk is an assistant professor in the Civil Environmental and Architectural Engineering Department at the University of Colorado Boulder.  His research focuses on advancing multi-objective decision making and model diagnostics for water resources and environmental engineering problems.  Recent research projects in his group include stakeholder engagement for water resources management in the Front Range of Colorado, creating a framework for improved water quality under extreme climate events, and analysing the air quality and public health impacts of unconventional oil and gas development.  He is the recipient of the Universities Council on Water Resources dissertation award and the Early Career Research Excellence award from the International Environmental Modelling and Software Society.  Kasprzyk earned his PhD from the Pennsylvania State University.

Read Joseph’s Emerging Investigators review of “Decision support systems for water treatment: making the case for incorporating climate change and climate extremes“ and find out more about his work in the interview below:

How has your research evolved from your first to your most recent article?

When I started my research career, my research adviser Prof. Pat Reed and I started a productive collaboration with Prof. Greg Characklis at the University of North Carolina.  Greg had some innovative ideas on risk-based decision making for water resources systems, such as using thresholds and probabilistic modelling to inform utilities on how to make their water supply have a higher reliability (i.e. meeting demands and maintaining supply levels).  In my own research I worked on new methods for multi-objective decision making for these systems.  Later, we would also collaborate with researchers at RAND corporation on how to bring robust decision making techniques to bear on these problems, coupling them with multi-objective optimization.

In my more recent papers, we have worked on a diverse set of problems with these techniques including a multi-reservoir water resources system in Texas and groundwater contamination remediation.  I’ve also worked on a set of projects that seeks to continue advancing the methodology of multi-objective optimization, such as exploring the impact of problem formulation on the solutions generated from optimization (e.g., what is the influence of constraints on the solutions from decision support).  Of course, we are quite excited about the work published in Environmental Science: Water Research and Technology, where we have provided a critical review of how some of the water resources research that we have done can inform and advance the study of source water quality and water treatment.

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

There are many reasons to be excited when studying environmental engineering and decision making these days!

There is a growing community working on these problems, as evidenced by a new Society for Decision Making Under Deep Uncertainty, as well as a burgeoning community in Water and Society at the American Geophysical Union.  It is exciting to have more people joining the conversation and bringing in new ideas.

The proliferation of scientific tools, programming languages, and technologies is making it easier to share decision support systems with students, analysts, as well as decision makers and stakeholders themselves.  However, this opportunity also means that we need to keep educating people as to how to properly use scientific and engineering techniques to come to the proper conclusion about their systems.  For example, in the past, it might have been possible to only run a small number of computer simulations to understand the performance of a system, but with high performance computing systems as well as cloud services, the possibilities are now being greatly expanded.

I’m excited to continue pursuing work directly with stakeholders and decision makers, which helps us learn how to improve our tools to have greater applicability, as well as disseminate our scientific findings within the community to guide their activities.  My work in this area has been greatly aided by Western Water Assessment at the University of Colorado Boulder and the Water Research Foundation, an organization that has a great relationship with water utilities around the country.

In your opinion, what is the most concerning impact associated with your work?

Our critical review paper suggests that although scientists are gaining a good understanding of how climate change impacts the quantity of water in our supply systems, the relationship between climate change and water quality is more complex and not as well understood.  The complexity of decision support for water treatment, as well as the wide variety of models and techniques used within the field, is exciting, but potentially overwhelming for stakeholders and users in the field.  So we are happy that we were able to share our findings in the journal so that our review can be a resource for researchers to continue their important work in the future.

What do you find most challenging about your research?

The project team on this paper is an interesting mix of hydrologists, environmental chemists, and water resources engineers.  The terminology used within these fields is not always consistent, but what was even more challenging was that the terminology within the research articles that we reviewed was even less consistent.  This is one of the main reasons why one of the recommendations we made is for a standardization of terminology in order to improve communication in this important field.  The lead author of the paper, William Raseman, did a great job in culling all the information and I hope it came through in the final manuscript.

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

My group typically attends the American Geophysical Union fall meeting (in December of every year) and the American Society of Civil Engineers Environmental Water Resources Institute meeting (in May or June every year).  I am also proud to be a member of the Association of Environmental Engineering and Science Professors, and I look forward to their conference in June 2017.

How do you spend your spare time?

Boulder, Colorado is a great place to do outdoor activities, and I enjoy hiking, jogging, and horseback riding.  Music is also an important part of my life, and I enjoy going to concerts as well as playing several instruments such as the guitar and piano.  Ben Livneh, one of my co-authors on this paper, is also an avid guitarist himself, and we have made music together in addition to publishing.

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

One of my favourite parts about being a professor is in interacting with students, other researchers, and the general public.  So, if I were to choose another profession I would want it to be one that includes a lot of communication and public outreach!

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

The most rewarding part of my career so far has been in working with smart people with diverse interests, that allow us to expand our approaches into new areas.  For example, I am beginning a new US National Science Foundation-funded project this year that seeks to advance the design of sustainable building materials, in collaboration with Profs. Wil Srubar and Leah Sprain at the University of Colorado Boulder.  So, when starting your career, don’t be afraid to pursue new lines of inquiry and get out of your comfort zone.  In addition to opening up new research opportunities, it might teach you something about your own area at the same time.  Also, make sure that you are enjoying your work and having fun.  Being able to enjoy the research that you are doing comes through in the quality of the finished product.

Dr Haizhou Liu, University of California, Riverside

Dr Haizhou Liu is an Assistant Professor of Chemical and Environmental Engineering at the University of California, Riverside. He received his Ph.D. in Environmental Engineering from University of Washington in 2010, and has a M.S. in Civil Engineering from University of Washington and B.S. in Environmental Engineering from Sichuan University, China. Prior to joining UC Riverside, he worked as a postdoctoral researcher at UC Berkeley for two years on soil remediation projects. Haizhou’s research interests include water chemistry, colloidal metal behavior and redox chemistry in drinking water, water reuse and treatment, environmental remediation, electrochemistry and catalysis. Haizhou’s current research focuses on the applications of aquatic chemistry principles to our benefits in engineered applications such as water purification and wastewater reclamation, as well as to understand how various redox and interfacial chemical processes influence natural systems such as estuarine, surface and groundwater.

Read Haizhou’s Emerging Investigators review on the “Occurrence and speciation of chromium in drinking water distribution systems” and find out more about his work  in the interview below:

How has your research evolved from your first to your most recent article?

My first research experience dates back to my freshman year. I participated in an undergraduate research to develop desulfurization technologies to treat flue gas. It was an exciting opportunity to learn how to design an experiment, collect and analyze the data, and come up with a hypothesis to test it. From my first research experience, I became very interested in environmental chemistry and have been working in this area since then. My most recent research is focused on water chemistry, especially the fate of metal and metalloids in water distribution system.

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

I am most excited about the complex interfacial and redox-driven chemical processes in the water distribution system. Our ongoing work shows that the water distribution system has many reactive components, and water chemistry plays a key role in maintaining the chemical stability of the system. Currently, understanding of distribution system chemistry has been mostly limited to a few empirical chemical indices. Awareness of redox reactivities of accumulated contaminants in corrosion products with residual disinfectants and source waters is largely unknown. Outcome from our work can help to increase access to clean water and improve urban infrastructure – two National Academy of Engineering Grand Challenges.

In your opinion, what is the biggest challenge for drinking water distribution systems?

More cities in the future will deal with aging water infrastructure. Although distribution systems might be functional when operating as they have been for decades, the risks are going to come when source waters are abruptly switched in response to droughts or a decision to use a new water supply. The biggest challenge is how to minimize the adverse impact on water quality when using alternative water sources in the future, while maintaining the chemical integrity of the water distribution system. As environmental engineers, we have sadly seen the catastrophic consequences of ignoring the complex chemical reactivity of water distribution systems when switching the source of surface waters as in Flint, Michigan. Ideas developed through my ongoing work could aid engineers and water system managers in preventing the next Flint. To address these universal challenges and to prevent another Flint crisis with a variety of toxic inorganic contaminants – including but not limited to lead – it is urgent to investigate the redox-driven in situ mobilization of accumulated contaminants from distribution systems.

What do you find most challenging about your research?

The water distribution system is such a complex “reactor”. The focus of redox chemistry in our work is a pivotal step to advance our knowledge towards a comprehensive investigation, but it requires very careful and vigorous investigation of fundamental chemistry, and this take time. In addition, many issues of water distribution systems are still poorly understood, including biofilm, galvanic and bio-corrosion, mass transfer and diffusion processes at the pipe-water interface. This requires a collaborative effort among environmental engineers to solve the problems.

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

I will attend the American Chemical Society Spring Meeting in San Francisco (April 2017), and the biennial conference of Association of Environmental Engineering Science Professors at University of Michigan (June 2017).

How do you spend your spare time?

As an assistant professor, I don’t have too much spare time outside work, but when there is a change, I play tennis or beach volleyball in sunshine California. I also fall in love with learning Italian and other Romantic languages.

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

I would like to be a pianist. I enjoy classical music very much (favorite composer Mozart) and would like to be good at playing it.

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

Work hard, present your work at conferences and interact with you colleagues. All of these will help build a positive system and make your more creative and productive.