Environmental Science: Water Research & Technology blog

Julian Fairey is an Associate Professor in the Department of Civil Engineering at the University of Arkansas with research and teaching interests related to aquatic chemistry and physical-chemical treatment processes for water. His research group focuses on various aspects of drinking water disinfection byproduct formation and control and development of sensors for distribution system monitoring. Prior to joining the University of Arkansas, he earned a BSc at the University of Alberta in Edmonton, Canada, a MS and PhD at The University of Texas at Austin, and had a post-doctoral research appointment at Carnegie Mellon University in Pittsburgh, PA, all in Civil-Environmental Engineering.

Read his Emerging Investigators series article “Trihalomethane, Dihaloacetonitrile, and Total N-nitrosamine Precursor Adsorption by Modified Carbon Nanotubes (CNTs) and CNT Micropillars” and find out more about his research in the interview below:

Your recent Emerging Investigator Series paper focuses on the absorbance of precursors of disinfection byproducts on carbon nanotubes.  How has your research evolved from your first article to this most recent article?

Like many academics, my first article was published when I was a graduate student and was based data I collected in the lab. Now, as a faculty member, I conceive of ideas that are executed (after being improved upon!) by my graduate students – I try to help with experimental design, interpretation, and messaging, but need to rely on others to collect interesting primary data. So, my role has evolved since my first article, from Player to General Manager. But my goal all along has remained the same – to identify and solve important problems related to water treatment.

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

My collaborations – in this particular article, we worked with a material scientist from the University of Cambridge and a data scientist from my institution, the University of Arkansas – the quality and impact of my work are greatly enhanced as a result and am looking forward to continuing these collaborations and developing new ones.

In your opinion, what is the biggest impact to the environment presented by disinfection byproducts?

In the United States, many water utilities have altered their disinfection strategy in an attempt to meet disinfection byproduct regulations. This practice can have unintended consequences that may negatively impact other areas of water treatment and distribution – so, it can be argued that the biggest impact of DBPs has been indirect – in the well- intentioned pursuit of meeting DBP regulations, other aspects of drinking water quality have been compromised, sometimes with devastating results. This has really spurred my interest in improving the understanding DBP formation and developing strategies for DBP precursor removal.

What do you find most challenging about your research?

I worry that I am not identifying the truly important problems related to water treatment and distribution – perhaps in the pursuit of doing something novel, I am preoccupied, and my time could be put to better use if I went a different direction. As an academic, it’s hard to know when and how to course-correct.

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

I reliably attend the AWWA Water Quality & Technology Conference and the Gordon Research Conference for Environmental Sciences: Water.

How do you spend your spare time?

I just bought a house, so I spend a good amount of time learning how to fix various things and driving to and from Lowe’s. To clear my mind, I workout and (try to) play piano and chess; the occasional glass of scotch, bourbon, and beer help too!

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

I love sports and the advising part of my job, so I think I would really enjoy coaching or managing a team. A sabbatical with a MLB or NHL franchise would be pretty cool!

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

Be kind, honest, and humble. I feel certain aspects of academia may (unintentionally) encourage otherwise behaviors.

Dr. Danmeng Shuai is an assistant professor in the Department of Civil and Environmental Engineering at The George Washington University since 2013. He graduated from Tsinghua University, P. R. China with a Bachelor of Engineering in 2005 and a Master of Engineering in 2007, both in Environmental Engineering. He received a Ph.D. in Environmental Engineering from the University of Illinois at Urbana-Champaign in 2012. He worked as a postdoctoral research associate in the University of Iowa from 2012 to 2013. His research interests are in the development of innovative materials for water-energy-health nexus. He has published several peer-review journal articles in Environ. Sci. Technol., ACS Appl. Mater. Interfaces, ACS Sustainable Chem. Eng., ACS Catal., Environ. Sci. Water Res. Technol., etc. His current research is supported by National Science Foundation and US Department of Agriculture-National Institute of Food and Agriculture. Follow Danmeng on Twitter – @DanmengShuai and visit his Research Group’s website – http://materwatersus.weebly.com/

Read his Emerging Investigators series article “Emerging investigators series: Advances and Challenges of Graphitic Carbon Nitride as a Visible-Light-Responsive Photocatalyst for Sustainable Water Purification” and find out more about his research below:

Your recent Emerging Investigator Series paper in Environmental Science: Water Research & Technology focuses on graphitic carbon nitride as a photocatalyst for sustainable water purification. How has your research evolved from your first article to this most recent article?

Our research group has been working on graphitic carbon nitride for photocatalytic water purification since 2014. Graphitic carbon nitride is an emerging photocatalyst since 2009, and it has several unique merits that promote its applications for sustainable, solar-energy-powered water purification. We developed graphitic carbon nitride with improved photocatalytic performance by density functional theory simulations, and evaluated its performance for the degradation of persistent organic micropollutants in complex water matrices that represent water and wastewater treatment practices (http://pubs.acs.org/doi/abs/10.1021/acs.est.6b02579). Beyond the scope of chemical contaminants, we are currently working on antimicrobial applications of graphitic carbon nitride for the inactivation of waterborne, foodborne, airborne, and surface-borne pathogens, by utilizing renewable solar energy and visible indoor light. For example, we collaborated with other researchers for virus inactivation by graphitic carbon nitride (http://www.sciencedirect.com/science/article/pii/S004313541630745X). US Department of Agriculture-National Institute of Food and Agriculture (USDA-NIFA) recently started to support us for developing graphitic carbon nitride-based antimicrobial materials for safe food processing and packaging (https://nifa.usda.gov/announcement/usda-announces-46-million-nanotechnology-research).

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

We are most attracted by the unique feature and diverse applications of graphitic carbon nitride. The interaction between graphitic carbon nitride and chemical contaminants could be tailored for selective contaminant removal. We observed some graphitic carbon nitride samples showed selective photocatalytic degradation of persistent organic micropollutants (e.g., atrazine), and are currently using a combined experimental and simulation approach to understand the mechanism. It will help the rational design of highly reactive and selective photocatalyst for the removal of contaminants of a low concentration and high toxicity, even in the presence of complex water constituents. Graphitic carbon nitride also effectively inactivates microorganisms under simulated indoor light (we used white LED and it worked!), and we are exploring its applications for catalysis, adsorption, and membrane separation. For example, we used graphitic carbon nitride as a catalyst support for Pd-based hydrogenation of contaminant nitrate and nitrite, and observed high reactivity, selectivity toward a desired product, and longevity of the catalysts (http://pubs.acs.org/doi/10.1021/acsami.7b09192).

In your opinion, what is the biggest challenge for sustainable water purification and how does the use of graphitic carbon nitride help to overcome this?

An ideal, sustainable water purification system requires improved performance for the removal of persistent and emerging contaminants, reduced energy and chemical footprint, potential resource recovery from the waste, and minimized adverse impacts of treated water (reduced byproducts). Graphitic carbon nitride can use renewable solar energy for water treatment, and its performance may outperform peer photocatalysts because it can harvest and utilize more visible light. Our previous study demonstrates the viability of graphitic carbon nitride for the removal of persistent organic micropollutants, and the material holds promise for sustainable, small-scale water treatment (e.g., for small communities, rural areas, developing countries). We also believe this material can be tailored for resource recovery in the future.

What do you find most challenging about your research?

Challenges come from two folds, one is the atomic-scale, mechanistic understanding of how the material is interacting with chemicals and biomolecules, and the other one is the large-scale implementation of the material for solving real world problems. For example, scalability, stability, long-term performance of graphitic carbon nitride, as well as photoreactor design are crucial yet challenging for its applications, as we suggested in this perspective.

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

ACS, Gordon (Water, Environmental Nano, Nanoscale Science & Engineering for Agriculture & Food Systems), AEESP conferences.

How do you spend your spare time?

Cooking and staying with my family. I always tell my friends I can cook well because I am working with chemicals. However I don’t need a six digit balance to decide how much salt will be suitable for the dish.

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

A chef maybe?

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

Expand core expertise, diversify research areas, and welcome collaborations. I never thought of working with microorganisms, but thanks to my wife who introduces me into a new, intriguing field (she is an environmental microbiologist).

Professor Robert Delatolla is an Associate Professor at the University of Ottawa. He received his Ph.D. from the Department of Chemical Engineering at McGill University. During his Ph.D. work, Professor Delatolla modified and used molecular and microscopic techniques to investigate the microbiome of wastewater treatment biofilms. His research endeavours include collaborative ventures with industrial and municipal partners. Professor Delatolla’s current research is focused on critical water, stormwater and wastewater issues. His expertise lies in biological treatment with a focus on the characterisation and optimization of biofilm technologies. He has particular interest in developing understanding at the meso, micro and molecular-scale to improve the design and operation of engineered treatment systems. Professor Delatolla is currently working on understanding hydrogen sulfide production in wet stormwater ponds; characterising biofilms in water and wastewater treatment systems; optimization of advanced and hybrid biofilm treatment systems; ammonia removal at cold temperatures by moving bed biofilm reactors; biological treatment of industrial wastewater; biofiltration performance as a means of disinfection by-product removal and optimization of anaerobic digestion.

Read his Emerging Investigators article “Hydrogen sulfide production in municipal stormwater retention ponds under ice covered conditions: a study of water quality and SRB populations” and find out more about his research in the interview below:

Your recent Emerging Investigator Series paper in Environmental Science: Water Research & Technology focuses on hydrogen sulphide production in ice covered stormwater retention ponds. How has your research evolved from your first article to this most recent article?

This article is the research team’s first publication on hydrogen sulphide production in stormwater retention ponds. We have prepared and submitted a second article focussing on the hydraulics and wind effects on hydrogen sulphide production in stormwater retention ponds. Further, we are preparing a third article on the sediment kinetics and the link to sulphate production in stormwater ponds. Hence, this article presents a fundamental study that is built upon to provide a holistic view of hydrogen sulphide production in stormwater ponds.

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

The integration of the water quality and microbial community data to gain a thorough understanding of these systems at both warm and cold operational conditions was perhaps most interesting for the research team. Through this interdisciplinary research approach, the study was able to confirm that sulphide production resulted from increased ubiquitous sulphate reducing bacteria activity at hypoxic conditions as opposed to the proliferation or a population shift towards a specific bacterial population

In your opinion, what is the biggest impact to the environment presented by H₂S production and how much to stormwater retention ponds contribute to this?

Although the emission of hydrogen sulphide gas from stormwater retention ponds is currently rare, the need to understand the design elements that result in these events is necessary as hydrogen sulphide is toxic to the environment, aquatic life and humans. In particular, the recent popularity of retention ponds along with the implication of climate change that lead to increased risk of larger rain events are influencing current guidelines related to the design of stormwater retention ponds. Hence, young and future systems are at an increased risk of hydrogen sulphide production and emission. We hope that our work provides the fundamental knowledge necessary to mitigate the risk to hydrogen sulphide emission from these systems in the future.

What do you find most challenging about your research?

All research is challenging, however in this study the lack of current knowledge regarding hydrogen sulphide production in stormwater ponds required multiple aspects of the studies stormwater ponds to be investigated concurrently. This included the water quality of the pond and the microbial community of the sediment. This challenge was met by forming a multidisciplinary research team to work on the research project.

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

I participate as often as I can at IWA conferences, in particular the Microbial Ecology and Water Engineering (MEWE) and Nutrient Removal and Recovery conferences, WEFTEC and the local Canadian Association of Water Quality (CAWQ) and Canadian Water and Wastewater Association (CWWA) conferences.

How do you spend your spare time?

Spare time is not always easy to square away, but every chance I get I just like to spend time with my family and friends…and of course watch some Game of Thrones.

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

Perhaps a chef, but that may just be my love of eating.

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

My path as a researcher has taught me that there is a lag between your hard work and the fruition of your labour. Patience is definitely required.