Abstract
As people spend most of our time indoors, exposure to indoor pollutants can have major health impacts. Indoor air quality (IAQ) also plays a significant role in cognitive performance and learning, making it particularly important in classroom environments. The rise in availability of low-cost air pollutant sensors provides a growing opportunity to leverage low-cost sensor measurements and big data analysis to assess IAQ and the impacts of building design on IAQ. In this study, we first evaluated the performance of different low-cost sensors (PurpleAir, QuantAQ MODULAIR-PM and MODULAIR) in both outdoor and indoor environments on the Georgia Tech Campus, by comparison with co-located research-grade instrumentation. Results highlight the direct impact of aerosol particle water on the low-cost sensor performance, in addition to the expected dependence on particle size distribution. A network of sensors was also deployed on campus beginning in Fall 2020, over an extended period (> 1 year) and across many buildings (> 20). This unique, continuous, and comprehensive data set allowed for investigation of the most important parameters that impact IAQ of various rooms and building designs. The data were used to train and test a Tree based machine learning model, which had high prediction accuracy for indoor pollutant levels. Various building design factors such as ventilation type were identified important predictors of indoor pollutant levels. Overall, results from this study provide data-driven insights into what types of environments different sensor types are best suited for, under what aerosol conditions they face the most limitations, and indicate that outdoor low-cost sensor networks may provide sufficient data to evaluate indoor pollutant concentrations across a wide range of buildings.
Speaker Bio
Dr. Nga Lee “Sally” Ng is the Love Family Professor in the School of Chemical & Biomolecular Engineering, School of Earth & Atmospheric Sciences, and School of Civil & Environmental Engineering at the Georgia Institute of Technology. She earned her doctorate in Chemical Engineering from the California Institute of Technology and was a postdoctoral scientist at Aerodyne Research Inc. Dr. Ng’s research focuses on the understanding of the chemical mechanisms of aerosol formation and composition, as well as their health effects. Her group combines laboratory chamber studies and ambient field measurements to study aerosols using advanced mass spectrometry techniques. Dr. Ng serves as the Editor-in-Chief of ACS ES&T Air. Dr. Ng’s research contribution has been recognized by a number of awards, including the Sheldon K. Friedlander Award and the Kenneth T. Whitby Award from the American Association for Aerosol Research (AAAR) and the Ascent Award from the American Geophysical Union (AGU). Dr. Ng is currently leading collaborative efforts to establish the Atmospheric Science and mEasurement NeTwork (ASCENT) in the US.
Abstract
Electrocatalysis has the potential to revolutionize the production of chemicals and consumer goods in an environmentally sustainable manner, by replacing traditional fossil fuel based processes with energy-efficient technologies powered by renewable electricity. This approach also holds great promise in addressing global challenges related to the remediation of per- and poly-fluoroalkyl substances (PFAS) water pollutants. To be successful, electrocatalytic processes must employ nonprecious nontoxic materials, utilize aqueous environments, consume minimal energy, and effectively eliminate harmful chemicals. Achieving functional electrocatalytic processes necessitates a comprehensive understanding of mechanisms and the strategic design of nanomaterials with controlled properties. In our approach, we employ pulsed laser in liquids synthesis for the development of nanocatalysts with controlled surface chemistries, to facilitate a quantitative mechanistic understanding of electrocatalytic processes, particularly within the anode microenvironment. For example, laser-made earth-abundant mixed-metal nanocatalysts on high-surface-area carbon supports selectively electrooxidized toluene to benzyl alcohol with unprecedentedly high activity. For PFAS remediation, we achieved complete defluorination of perfluorooctane sulfonate and GenX in aqueous electrolytes with laser-made bimetallic nanocatalysts. My group’s overarching goal is advanced design and fabrication of nanocatalysts for the electrocatalytic generation of oxidants and reductants from water, predicated on a detailed atomistic understanding of mechanisms and nanomaterials, with the ultimate goal of driving forward scalable sustainable solutions for chemical manufacturing and water remediation.
Speaker Bio
Astrid M. Müller is an Assistant Professor of Chemical Engineering at the University of Rochester since 2018. Prof. Müller earned a PhD in Physical Chemistry for work on ultrafast reaction dynamics at the Max Planck Institute of Quantum Optics. Her postdoctoral work centered on developing a fundamental understanding of laser–matter interactions. Her independent research focuses on pulsed laser in liquids synthesis of mixed-metal nanomaterials with controlled structural and electronic properties. This uniquely positions Prof. Müller’s group to quantitatively understand how nanocatalysts and electrocatalytic mechanisms impact the performance of nanomaterials in sustainable energy, green chemistry, and aqueous PFAS destruction applications.
Abstract
Our current linear way of producing chemicals and fuels is unsustainable. The petrochemical industry needs to transform from its current fossil basis to renewable resources for its energy and raw materials. Since chemicals and most fuels cannot be decarbonized in the literal sense, renewable carbon sources are needed to close the carbon cycle.
In this presentation, we will present our recent contributions towards a process systems engineering toolbox for developing a circular carbon economy. Circular carbon flows can be established by employing biomass, CO2, and waste recycling as carbon feedstock for chemical transformations. To optimize the required novel conversion processes, we integrate the molecular design of solvents and catalysts directly into process design. Design objectives are not only economics but also environmental impacts. For this purpose, methods are developed to predict environmental impacts for molecules designed in silico. The resulting optimized processes are then integrated into a bottom-up model of the carbon-based industry for chemicals and fuels. Thereby, trade-offs and potential synergies can be resolved between the renewable carbon sources biomass, CO2, and waste recycling. The industry-wide model allows us to identify promising pathways towards a circular carbon industry within the planetary boundaries.
Speaker Bio
André Bardow is the professor for energy & process systems engineering at ETH Zurich since 2020. Previously, he was a professor and head of the Institute of Technical Thermodynamics at RWTH Aachen University (2010-2020); director of the Institute for Energy and Climate Research (IEK-10) at Forschungszentrum Jülich, Germany (part-time, 2017-2022) and associate professor at TU Delft (2007-2010). He was a visiting professor at the University of California, Santa Barbara (2015/16). He earned his Ph.D. degree at RWTH Aachen University.
André is a fellow of the Royal Chemical Society and chairs the Technical Committee for Thermodynamics of VDI – The Association of German Engineers. He received the Recent Innovative Contribution Award of the CAPE-Working Party of the European Federation of Chemical Engineering (EFCE) in 2019, and the PSE Model-Based Innovation (MBI) Prize by Process Systems Enterprise in 2018. He was the first recipient of the Covestro Science Award. In 2009, he received the Arnold-Eucken-Award of the VDI-Society for Chemical Engineering (GVC). He is the recipient of RWTH’s “FAMOS für Familie” award for family-friendly leadership, and of teaching awards at RWTH and TU Delft.