Irene Hu, a former graduate student in Professor Harry Hemond’s group at MIT in the Department of Civil and Environmental Engineering, is studying the flux of contaminants between sediments and water. Specifically, her research focuses on the development and testing of novel in situ instrumentation to study the fate and transport of environmental biogeochemicals. As part of Project 1 of the MIT Superfund Research Program, Irene is developing a sensor to measure benthic (sediment-water) fluxes of chemicals in aquatic ecosystems, such as pollutants from contaminated sediments at Superfund and other sites. Knowledge of such pollutant fluxes—including the location of the most problematic areas, and how quickly they are releasing toxins—is critical in to remediation efforts, including assessment of exposures and prioritization of cleanup efforts.
The sensor being developed is based on the eddy correlation technique, which involves correlating fast, simultaneous, and co-located measurements of velocity and concentration. To date, eddy correlation measurements of benthic fluxes have mainly been used to measure dissolved oxygen fluxes, using a dissolved oxygen microelectrode. To expand the range of measurable biogeochemicals, Irene has developed a novel trimodal sensor capable of high-speed, high-resolution measurements of fluorescence, temperature, and conductivity. Coupled to a velocity sensor for eddy correlation measurements, this instrument can be used to measure benthic fluxes of fluorescing materials, heat, and salinity. Thus, it can be used to target sediment-water fluxes of fluorescing pollutants in contaminated groundwater. In addition, it can potentially be used to measure benthic fluxes of a wider range of contaminants by using one flux as a tracer for others. The instrument has so far been used to measure simulated benthic fluxes in a laboratory setting, and will be tested in the field in the spring.
Irene has an undergraduate degree in electrical engineering from Princeton University; as a premed, her interests also extended to chemistry and biology. After graduating, she worked for a few years as a financial management consultant in New York City. She returned to graduate school to study environmental engineering because she wanted to work on projects that would have a positive impact on our environment and public health. She is happy to have found at MIT a research group that allows her to utilize her electrical engineering background for environmental applications, and she appreciates the wide range of skills and knowledge she has developed by working on her project—including electronics, programming, chemistry, fluid dynamics, machine shop work and fieldwork.
Irene Hu successfully defended her dissertation this past October and will continue working with the MIT Superfund program as a postdoctoral associate. In her spare time, she enjoys cycling, ballroom dance, and ice skating.