The Academy for Global Citizenship (AGC) and Argonne National Laboratory (Argonne) have begun a conversation about the quality of soil found in urban environments. As AGC is interested in urban agriculture and potential reuse of an industrial site for it expansion, this conversation is particularly relevant. AGC is also interested in Argonne’s commitment to education and community outreach. Our students currently learn about science, technology, and math within the context of renewable energy, urban farming, and energy efficiency. Similarly, they can learn valuable academic lessons from Argonne’s study of urban soil composition. Even better, they can learn about an exciting plant-based soil remediation technique known as ‘phytoremediation’.
Argonne, one of the U.S. Department of Energy’s oldest and largest national laboratories for science and engineering research, is located on 1,500 acres in southwest DuPage County. The site is completely encircled by the Waterfall Glen Forest Preserve. Argonne employs roughly 3,200 employees, including about 1,000 scientists and engineers, three-quarters of whom hold doctoral degrees. Argonne’s annual operating budget of around $630 million supports upwards of 200 research projects. Since 1990, Argonne has worked with more than 600 companies and numerous federal agencies and other organizations. Argonne’s mission is to apply a unique mix of world-class science, engineering and user facilities to deliver innovative research and technologies. Argonne actively seeks opportunities to work with industry to transfer their technologies to the marketplace through licensing, joint research and other collaborative relationships.
Argonne’s Division of Educational Programs (DEP) serves as the interface between the Department of Energy, Argonne National Laboratory (ANL) and the academic community. Argonne offers numerous opportunities for domestic and international participants interested in energy research and training in science and technology. DEP remains a full partner with scientific divisions at Argonne in identifying and providing educational opportunities for persons at all educational levels.
AGC is very interested in Argonne’s community and student outreach efforts. Alyssa Caruso, then a Senior at Downers Grove South High School, wrote the following for Argonne’s 2008 Summary Site Environmental Report:
“Argonne National Laboratory interacts with the public on a daily basis. About 50,000 people visit Argonne each year. In addition, more than 3,500 students participate in Argonne education programs. Argonne works to inspire the next generation of scientists and engineers through a variety of eduacation programs from kindergarten through the PhD level. Argonne provides both graduate and undergraduate internships as well as postdoctoral appointments and fellowships. For K-12 levels of education, programs at Argonne include “Introduce a Girl to Engineering Day”, “Rube Goldberg Machine Contest”, educational field trips, and much more.”
As mentioned above, AGC is intrigued by Argonne’s phytoremediation studies. Since AGC is preparing to acquire land in a heavily industrial area, AGC has initiated a conversation with Argonne about their program related to phytoremediation of soil and groundwater. Phytoremediation is the use of plants to remediate groundwater or soil. The contaminants may range from metals and radionuclides to agrochemicals and hydrocarbons to waste solvents and nitroaromatics. These contaminants may be present in topsoils or in deeper soils and groundwater.
Phytotechnologies target the contaminants using various mechanisms, including:
- plant uptake (followed by harvesting the plants to collect the concentrated contaminants),
- stabilization (the use of argonomic principles and plants to sequester contaminants in soils in a non-bioavailable form, thus reducing risk)
- removal (such as slow release of volatile organic compounds through leaves), and
- degradation (transformation of contaminants into less-toxic forms, either within the plant tissues or within the microbially active soil containing the roots).
For groundwater applications, intensive water use trees (such as poplar and willow) may work in tandem with these approaches by providing hydraulic containment at a site.
Key issues in phytoremediation are:
- Assessing the suitability of phytoremediation for a site and determining the appropriate plant(s) for the given contaminants, concentrations, target depth, soil type, climate, and remediation schedule,
- Devising a proper scheme and tools for monitoring the progress of the remediation,
- Designing the optimal system, and
- Predicting completion times.
At an Argonne test pytoremediation site, a full-scale plantation of 800 trees was installed and instrumented in 1999. Here, the remedial design was comprised of robust hybrid willows in a contaminated area and hybrid poplars in the downstream groundwater contamination. Because this groundwater contamination flows beneath surface clay over 25 feet thick, the poplars were installed using a specific method to direct the trees’ roots toward the contaminated underground stream as their sole source of water. Monitoring and sampling of the site is on-going and includes groundwater, surface water, soil, tree tissues, groundwater levels, and climatic data.
The key benefit of a successful use of phytotechnology is remediation of target contaminants within an anticipated time frame. Because the technology has its roots in the 1990s, results of most initial pilot plantings and full-scale are only now coming into focus. As the trees mature, monitoring data show improved water use and contaminant removal and a growing degree of hydraulic containment of the contamination.
Intangible benefits of this green technology include high aesthetic value, public approval, and growing regulatory acceptance. In addition, Argonne believes that this technology fits well with ecological restoration and carbon sequestration principles and strategies.
Not only does this research offer our students a unique opportunity to learn about an exciting and potentially valuable practice, it may very well be a key to the eventual cleanup of our industrial neighborhood. AGC will continue to monitor Argonne’s studies and may soon host a collection of Argonne soil-scientists at AGC for an informative presentation. Stay tuned!