Department Calendar of Events

Questions? Please contact Delicia Ansalem, Communications Officer & External Relations Liaison delicia.ansalem@utoronto.ca

Mar

16

LLE: AEESP Distinguished Lecture: The Interactions of Airborne Particles with Surfaces (Cliff Davidson, Syracuse University) @ Zoom

Mar 16 @ 12:00 pm – 1:00 pm

AEESP DISTINGUISHED LECTURE

Cliff Davidson, Syracuse University

Host: Prof. Elodie Passeport

“Airborne particles exist in a wide variety of shapes, sizes, and chemical compositions. Some are natural, some are emitted from human activities, and others are formed in the atmosphere from gases. The gases can also be natural or anthropogenic. Once airborne, particles can be carried hundreds or even thousands of kilometers by wind before interacting with surfaces and depositing. In this talk, we examine the many ways in which atmospheric particles interact with surfaces of all kinds – natural vegetation, agriculture crops, landscaping, bare soil, water, snowfields, and urban hardscape surfaces. Such understanding is important when predicting the ultimate fate of particulate matter, whether the particles are inhaled and reach the human respiratory system, or whether they deposit on surfaces and cause damage. In all cases of deposition from the atmosphere, particles carried in the mainstream of the airflow must somehow be delivered to the quasi-laminar boundary layer adjacent to the surface, and must then traverse the boundary layer to rest on the surface. These two steps, as well as a third step in which particles rebound off the surface back into airflow, define the deposition process. For a large field of uniform vegetation less than a few meters in height, the wind field and boundary layer characteristics are well known, and deposition onto the vegetation can be predicted for a range of particle sizes and wind speeds. For more complex vegetation, such as a forest canopy, we usually resort to empirical methods to estimate deposition. For water surfaces, the hygroscopicity of the particles may need to be taken into account. Deposition on large lakes and the oceans must also account for wave action. Deposition to snow is complicated by the porous nature of the surface, and the fact that the surface area of individual snow crystals may influence the motions of very small particles. Finally, estimating deposition to buildings, roads, and other urban surfaces can be a challenge due to the changes in geometry of the surface over short distance scales. We discuss the special case of estimating particle deposition onto urban surfaces, include a large extensive green roof. Both modeling and measurement of particle interaction with surfaces is presented, and use of well-controlled experimental surfaces in wind tunnels as well as in the ambient atmosphere is discussed as a means of improving our understanding of the deposition process. A separate tutorial covering the airflow and rain impinging on a green roof in Syracuse, NY will be presented. The tutorial will explain the capabilities of a new website showing real-time data and archived data from the green roof. The website is intended for use in the classroom to help students understand the physical processes taking place on a green roof and the functions of a green roof.”
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Professor Cliff Davidson is the Thomas and Colleen Wilmot Professor of Engineering in the Department of Civil and Environmental Engineering at Syracuse University in Syracuse, NY. He also serves as Director of Environmental Engineering Programs, and Director of the Center for Sustainable Engineering. He received his B.S. in Electrical Engineering from Carnegie Mellon University, and his M.S. and Ph.D. degrees in Environmental Engineering Science from California Institute of Technology. Following his PhD, he joined the Carnegie Mellon faculty in the Department of Civil Engineering (currently Civil and Environmental Engineering) and the Department of Engineering and Public Policy, where he served for 33 years. He joined Syracuse University in 2010. He has 140 publications in peer reviewed journals, and has given roughly 200 presentations at conferences, seminars, and workshops. He is a Fellow in four organizations: American Association for Aerosol Research (AAAR), the Association of Environmental Engineering and Science Professors (AEESP), the American Society of Civil Engineers (ASCE), and the Syracuse Center of Excellence in Environmental and Energy Systems. He served as President of AAAR in 1999-2000. Davidson’s long-term research interest is transport and fate of environmental pollutants, especially atmospheric acids and heavy metals. More recently, he has studied the role of engineers in sustainable development, focusing on green infrastructure. He has also studied changes in education needed to train an engineering workforce for the 21st century.

Questions? Please contact Delicia Ansalem, Communications Officer & External Relations Liaison delicia.ansalem@utoronto.ca

Mar

23

LLE: Ion Solubility, Diffusivity, and Transport in Charged Polymer Membranes (Benny Freeman, University of Texas at Austin) @ Zoom

Mar 23 @ 12:00 pm – 1:00 pm

Co-hosted with the Institute for Water Innovation (IWI)

Benny Freeman, University of Texas at Austin

Host: Prof. Jay Werber

Charged polymer membranes are widely used for water purification applications involving control of water and ion transport, such as reverse osmosis and electrodialysis. Efforts are also underway worldwide to harness separation properties of such materials for energy generation in related applications such as reverse electrodialysis and pressure retarded osmosis. Additional applications, such as energy recovery ventilation and capacitive deionization, rely on polymer membranes to control transport rates of water, ions, or both. Improving membranes for such processes would benefit from more complete fundamental understanding of the relation between membrane structure and ion sorption, diffusion and transport properties in both cation and anion exchange membrane materials. Ion-exchange membranes often contain strongly acidic or basic functional groups that render the materials hydrophilic, but the presence of such charged groups also has a substantial impact on ion (and water) transport properties through the polymer.

We are exploring the influence of polymer backbone structure, charge density, and water content on ion transport properties. Results from some of these studies will be presented, focusing on transport of salt, primarily NaCl, through various neutral, positively charged and negatively charged membranes via concentration gradient driven transport (i.e., ion permeability) and electric field driven transport (i.e., ionic conductivity). One long-term goal is to develop and validate a common framework to interpret data from both electrically driven and concentration gradient driven mass transport in such polymers and to use it to establish structure/property relations leading to rational design of membranes with improved performance.

Ion sorption and permeability data were used to extract salt diffusion coefficients in charged membranes. Concentrations of both counter-ions and co-ions in the polymers were measured via desorption followed by ion chromatography or flame atomic absorption spectroscopy. Salt permeability, sorption and electrical conductivity data were combined to determine individual ion diffusion coefficients in neutral, cation exchange and anion exchange materials. Manning’s counter-ion condensation models and the Mackie/Meares model were used to correlate and, in some cases, predict the experimental data.
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Professor Benny Freeman is the William J. (Bill) Murray, Jr. Endowed Chair of Engineering in the Chemical Engineering department at The University of Texas at Austin. He is a professor of Chemical Engineering and has been a faculty member for 30 years. He completed graduate training in Chemical Engineering at the University of California, Berkeley, earning a Ph.D. in 1988. In 1988 and 1989, he was a postdoctoral fellow at the Ecole Supérieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI), Laboratoire Physico-Chimie Structurale et Macromoléculaire in Paris, France. Dr. Freeman was a member of the chemical engineering faculty at NC State University from 1989 – 2002, and he has been a professor of chemical engineering at The University of Texas at Austin since 2002. Dr. Freeman’s research is in polymer science and engineering and, more specifically, in mass transport of small molecules in solid polymers. His research group focuses on structure/property correlation development for desalination and gas separation membrane materials, new materials for hydrogen separation, natural gas purification, carbon capture, and new materials for improving fouling resistance in liquid separation membranes. He leads the Center for Materials for Water and Energy Systems (M-WET), a DOE Energy Frontier Research Center and serves as Challenge Area Leader for Membranes in the National Alliance for Water Innovation (NAWI), a five-year, DOE sponsored Energy-Water Desalination Hub to address critical technical barriers needed to radically reduce the cost and energy of water purification.

His research is described in more than 450 publications and 30 patents/patent applications. He has co-edited 5 books on these topics. He has won a number of awards, including a Fulbright Distinguished Chair in Disruptive Separations (2017), Fellow of the North American Membrane Society (NAMS) (2017), the Distinguished Service Award from the Polymeric Materials: Science and Engineering (PMSE) Division of the American Chemical Society (ACS) (2015), Joe J. King Professional Engineering Achievement Award from The University of Texas (2013), American Institute of Chemical Engineers (AIChE) Clarence (Larry) G. Gerhold Award (2013), Society of Plastics Engineers International Award (2013), Roy W. Tess Award in Coatings from the PMSE Division of ACS (2012), the ACS Award in Applied Polymer Science (2009), AIChE Institute Award for Excellence in Industrial Gases Technology (2008), and the Strategic Environmental Research and Development Program Project of the Year (2001). He is a Fellow of the AAAS, AIChE, ACS, and the PMSE and IECR Divisions of ACS. He has served as chair of the PMSE Division of ACS, chair of the Gordon Research Conference on Membranes: Materials and Processes, President of the North American Membrane Society, Chair of the Membranes Area of the Separations Division of the AIChE, and Chair of the Separations Division of AIChE. His research has served as the basis for several startup companies, including Energy-X and NALA Systems.

Questions? Please contact Delicia Ansalem, Communications Officer & External Relations Liaison delicia.ansalem@utoronto.ca

Mar

30

LLE: Mapping and Engineering Microbiomes of the Mammalian Gut and in Soil Environments (Harris Wang, Columbia) @ Zoom

http://wanglab.c2b2.columbia.edu/

Mar 30 @ 12:00 pm – 1:00 pm

Harris Wang, Columbia

Host: Prof. Chris Lawson

Microbes that live in soil are responsible for a variety of key decomposition and remediation activities in the biosphere. Microbes that colonize the gastrointestinal tract play important roles in host metabolism, immunity, and homeostasis. Better tools to study and alter these microbiomes are essential for unlocking their vast potential to improve human health and the environment. This talk will describe our recent efforts to develop next-generation tools to study and modify microbial communities. Specifically, I will discuss new platforms for automated microbial culturomics, techniques to genetically engineer complex microbial consortia and methods for biocontainment. These emerging capabilities provide a foundation to accelerate the development of microbiome-based products and therapies.
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Harris Wang is an Associate Professor at Columbia University jointly appointed in the Department of Systems Biology and the Department of Pathology and Cell Biology. Dr. Wang received his B.S. degrees in Mathematics and Physics from MIT and his Ph.D. in Biophysics from Harvard University. His research group mainly develops enabling genomic technologies to characterize the mammalian gut microbiome and to engineer these microbes with the capacity to monitor and improve human health. Dr. Wang is an Investigator of the Burroughs Wellcome Fund and the recipient of numerous awards, including the Vilcek Prize or Creative Promise in Biomedical Science, NIH Director’s Early Independence Award, NSF CAREER, Sloan Research Fellowship, and the Presidential Early Career Award for Scientists and Engineers (PECASE) from President Obama, which is “the highest honor bestowed by the United States Government on science and engineering professionals in the early stages of their independent research careers.”

Questions? Please contact Delicia Ansalem, Communications Officer & External Relations Liaison delicia.ansalem@utoronto.ca

Apr

6

LLE: Enzyme Technology for Enzymatic Synthesis of Human Milk Oligosaccharides (Anne Meyer, Technical University of Denmark) @ Zoom

Apr 6 @ 12:00 pm – 1:00 pm

Anne Meyer, Technical University of Denmark

Host: Prof. Emma Master

Enzyme technology now targets using enzymes for catalysing very specific molecular conversions for production of particular compounds. Human milk oligosaccharides (HMOs) are a group of lactose-based carbohydrates which are abundant (5-20 g/L) in human milk. More than 200 different HMO structures have been identified in human milk, but these structures are barely present in bovine milk. HMOs play crucial roles in infant health and development. Hence, a large incentive exists for developing infant formulas that more closely resemble human milk. Natural HMOs consist of up to five different monosaccharides, namely β-D-galactose (Gal), β-D-glucose (Glc), β-D-N-acetylglucosamine (GlcNAc), α-L-fucose (Fuc), and the sialic acid α-D-N-acetylneuraminic acid (Neu5Ac). All HMOs have lactose at the reducing end; lactose can be decorated with Fuc or Neu5Ac and/or further elongated by either β-N-acetyllactosamine or lacto-N-biose units to form linear or branched structures. These elongated parts may also be fucosylated or sialylated. At the Technical University of Denmark, we have embarked on enzymatic synthesis of HMOs, focusing on developing enzymatic trans-sialylation and trans-fucosylation reactions by engineering of protozoan and microbial glycoside hydrolases to work ‘in reverse’, and we have aimed at discovering GH20 β-N-acetylhexosaminidases capable of catalysing backbone elongation of lactose via trans-glycosylation. We are also trying to utilize oxazoline, which is a reaction intermediate in the unique GH20 β-N-acetylhexosaminidase catalyzed reactions. The aim of the lecture is to present the different approaches and at the same time discuss various protein engineering strategies to promote trans-glycosylation.
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Anne S. Meyer is Professor of Enzyme Technology at the Technical University of Denmark (DTU) and Head of the Protein Chemistry & Enzyme Technology Division, approx. 75 persons, incl. 7 professor groups, and ~30 PhD students, at Dept. of Biotechnology and Biomedicine (DTU Bioengineering), DTU. She is group leader for the Enzyme Technology group in the Division. Anne holds an MSc from the University of Copenhagen, and an MSc from the University of Reading, UK (1987), and a PhD from DTU (1993). Employed at DTU since 1988 in various positions, and has had two postdoc stays in the USA at University California Davis. She became Full Professor at DTU in 2006 and has headed Center for BioProcess Engineering at DTU until summer 2018, where she assumed her current role as Head of the Protein Chemistry & Enzyme Technology Division at DTU Bioengineering. She has been visiting professor at Dept. Chemical and Biomolecular Engineering, University of Melbourne, Australia from 2017-2020.

Questions? Please contact Delicia Ansalem, Communications Officer & External Relations Liaison delicia.ansalem@utoronto.ca

Apr

13

LLE: Nanoplastics in Our Environment: Small Particles with Big Challenges (Nathalie Tufenkji, McGill) @ Zoom

Apr 13 @ 12:00 pm – 1:00 pm

Co-hosted with the Institute for Water Innovation (IWI)

Nathalie Tufenkji, McGill

Host: Prof. Jay Werber

The degradation of bulk plastics in the environment leads to the release of microplastics that can contaminate water supplies, agricultural fields, and foods we consume. Weathering of a single microplastic particle can yield up to billions of nanoplastics and nanoplastic pollution is expected to be ubiquitous in the environment. Nanoplastics are potentially more hazardous than microplastics because they can cross biological membranes; yet, there is little data on the occurrence, fate and impacts of nanoplastics. A key challenge in understanding the environmental burden of nanoplastics is the detection of such small, carbon-based particles in complex natural matrices such as soils.

Environmental nanoplastics are often thought of as an extension of microplastics with a distinction based on an arbitrary size cut-off, typically 100 nm or 1000 nm. In our view, in terms of environmental implications and analytical challenges, a size cut-off distinction provides little guidance. While a consensus on the precise definition of “nanoplastic” has yet to be reached, we advocate for a characteristic-based distinction between nanoplastics and microplastics. Based on existing literature and analytical methods, we present a set of characteristics, distinct from microplastics and other contaminants, that define environmental nanoplastics.

This lecture will present an overview of our work aimed at overcoming challenges to better understand the fate and impacts of nanoplastics in terrestrial and aquatic environments. I will discuss new approaches for detection of nanoplastics in complex matrices and recent advances in our understanding of the toxicity of nanoplastics.

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Nathalie Tufenkji is a Professor in the Department of Chemical Engineering at McGill University where she holds the Tier I Canada Research Chair in Biocolloids and Surfaces. She works in the area of particle-surface interactions with applications in protection of water resources, plastic pollution as well as the discovery of natural antimicrobials. Professor Tufenkji was awarded the Killam Research Fellowship, the Engineers Canada Award for the Support of Women in the Engineering Profession, the Chemical Institute of Canada Environment Award, an Early Career Research Excellence Award by the Faculty of Engineering at McGill University, the YWCA Woman of Distinction Award in Science and Technology, and the Hatch Innovation Award of the Canadian Society for Chemical Engineers. She was elected to the College of New Scholars, Artists and Scientists of the Royal Society of Canada in 2016 and the Canadian Academy of Engineering in 2020. Beyond her research and teaching roles, Professor Tufenkji also serves as Associate Director of the Brace Center for Water Resources Management at McGill and has co-chaired several major international conferences. She has also served on the editorial advisory boards of the journals Environmental Science and Technology, npj Clean Water, Water Research, Colloids and Surfaces B, Advances in Colloid and Interface Science, and Environmental Science: Nano.