Sarah Preheim
Johns Hopkins University, MD·Earth & Environmental Science
Excess nitrogen pollution harms waters such as the Chesapeake Bay and must be removed in wastewater treatment plants. Much of that removal is done by microbes through denitrification, a process that turns nitrate into nitrogen gas.
- Fields
Earth & Environmental Science
Microbiology & Immunology
Engineering
- Topics
denitrification
nitrogen pollution
nutrient management
- Grants
- 1 known grant, through Dec 2026
What they work on
- Test how the abundance of denitrification genes, measured by quantitative PCR, relates to denitrification rates in controlled bioreactor experiments, and whether disturbance frequency changes that relationship.
- Compare Chesapeake Bay models that treat denitrification as cell-density dependent versus independent, to see which gives more accurate predictions.
- Test whether gene abundance can serve as a tracer to calibrate other cell-density dependent microbial reactions in Chesapeake Bay and wastewater treatment models.
- Work with water management partners to identify budget and technical limits on adding gene measurements to monitoring and modeling, and design practical solutions.
More about the research
Water managers rely on computer models to predict how these ecosystems respond to cleanup efforts or climate change. Yet those models rarely use any direct measurement of the microbes doing the work. This collaborative project asks whether counting microbial genes can make those models more accurate.
Why it matters
Better predictions of nitrogen removal could help agencies that manage the Chesapeake Bay and operators of wastewater treatment plants make sounder decisions about water quality. Adding affordable gene measurements to monitoring and models may improve forecasts of how these systems respond to remediation or climate change. The work focuses on benefiting communities most affected by wastewater and Bay water quality.
Known grants
From NIH and NSF research grants. Labs often have other funding we can't see.
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The school
Johns Hopkins University: 100 labs on PI Pages, $4.1B a year on research, 622 research doctorates a year.
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