The Princeton Environmental Institute (PEI) gave awards to 13 projects, including five within the School of Engineering and Applied Science, as part of its Water and the Environment Grand Challenge program. Totaling $1.01 million, the newly awarded undertakings explore an array of topics in multiple disciplines, from wastewater emissions and the role of climate change in spreading plant diseases, to nitrogen-hungry bacteria and a plan to capture carbon dioxide while mitigating mining runoff. The projects run from 2019 to 2021.

Part of PEI's Grand Challenges program, the Water and the Environment Challenge focuses on critical environmental issues associated with physical, chemical and biological aspects of oceans and freshwater systems. Results from these projects are not only published, but also form the basis of community outreach efforts. Each project includes an educational component - particularly in the form of Princeton courses and PEI internships - that perpetuate the knowledge needed for a sustainable future.

Descriptions of the most recently funded projects involving engineering faculty are below.

A New Trait-Based Approach for Resolving Plant-Root-Water Interactions Across Plant Communities and Land Biomes

Lars Hedin, the George M. Moffett Professor of Biology and professor of ecology and evolutionary biology and the Princeton Environmental Institute, and Amilcare Porporato, the Thomas J. Wu '94 Professor of Civil and Environmental Engineering and the Princeton Environmental Institute, will conduct the first in-depth study of how root traits and below-ground competition for water shape the structure and resilience of land ecosystems in a changing world. Their results could have a significant impact in understanding how climate change will influence the movement and stability of land ecosystems, as well as inform strategies for agriculture and conservation in a warmer world.

Assessing Wastewater Emissions of Greenhouse Gases and Air Pollutants and Their Impacts

Mark Zondlo, associate professor of civil and environmental engineering, and Z. Jason Ren, professor of civil and environmental engineering and the Andlinger Center for Energy and the Environment, will conduct a pilot field study to measure emissions of methane and nitrous oxide - both potent greenhouse gases - from wastewater treatment plants. Wastewater treatment accounts for 5% of global non-carbon dioxide greenhouse gas emissions, but these emissions are difficult to gauge due to chemical cycling, weather exposure and the locations of treatment plants. If successful, the project will be expanded to monitor plants nationwide to shed light on the wastewater industry's impact on the environment and explore potential mitigation strategies.

The Water-Mining-Climate Nexus in South Africa: A Global Solution for a Local Problem

Professors Catherine Peters in civil and environmental engineering and Satish Myneni in geosciences will lead a team working in South Africa to develop a dual-purpose tool for mitigating atmospheric carbon dioxide while treating water polluted with mine runoff. South Africa is facing imminent climate extremes and water shortages, yet, many of the country's freshwater resources are polluted with the toxic byproducts of mining for gold, platinum and other resources. Peters and Myneni will build off of a technique that uses mining waste to chemically capture carbon dioxide, and expand it to include the removal and containment of sulfates and trace elements from water.

Targeted Groundwater Remediation Using Engineered Nanoparticles

Sujit Datta and Rodney Priestley, assistant professor and professor, respectively, of chemical and biological engineering, will develop synthetic nanoparticles with controllable sizes, morphologies and chemistries that could be used to safely and affordably remove contaminants from groundwater aquifers. The novel structures - which they call engineered nanoscale zero valent iron (enZVI) particles - will be embedded with naturally occurring particles that have been shown to degrade common contaminants, but are unable to target specific pollutants. The researchers will refine the design and delivery of their enZVIs so they can be stably transported through an aquifer to target and remediate trapped contaminants.

Microphysics of Water in Secondary Organic Aerosol

Ian Bourg, assistant professor of civil and environmental engineering and the Princeton Environmental Institute, will use molecular-dynamics simulation to characterize the microphysics of water in secondary organic aerosol (SOA) particles, which are nanosized mixtures of water, organic compounds and inorganic ions. Although these tiny droplets have a strong influence on the Earth's heat budget and on human health, how they form and behave in the atmosphere is poorly understood. Bourg's research could shed light on the role of atmospheric water on climate and air quality, as well as enable more accurate predictions of Earth's future climate and its effect on human health.

For the full list of projects receiving this award, see the original story published by the Princeton Environmental Institute.