The lowly cattail is emerging as the weapon of choice against water contamination, and perhaps even global warming. In addition to its use in large phytoremediation projects to absorb contamination from groundwater and wetlands, the cattail could also work in on a small, inexpensive scale, helping to reduce arsenic contamination in impoverished areas. All this and biofuel, too?
Cattails, Phytoremediation, and Biofuels
There is a long history behind phytoremediation, the use of plants to absorb pollutants from water. A more recent development involves harvesting the plants for biofuel production. If the contamination in question is a petroleum product, that’s a nifty sort of poetic justice. We’re not that far away from it. For example, the U.S. Air Force has been hosting a phytoremediation project for years at its base in Carswell, Texas, using poplars to absorb trichlorethelyne (TCE), a common industrial solvent. The American Society of Plant Biologists also notes that it may be possible to recover and recycle certain metals from plants grown in phytoremediation projects.
Cattails are ideal for large scale phytoremediation projects in wetlands. In an odd twist, cattails are being used to fend off other cattails in the Florida Everglades. The cattails are allowed to thrive in designated pre-treatment areas, where they absorb phosphorus from runoff. This helps keep excess phosphorus out of the Everglades, which in turn helps prevent cattails from overrunning protected areas.
Cattails, Water Pollution, and Global Warming
Phosphorus removal is just the tip of the water pollution iceberg that could be solved by cattails. Cattails have been associated with remediating sites contaminated with arsenic, pharmaceuticals, and even explosives. As for a role in the global warming picture, planting cattails could help prevent excess methane emissions from degraded wetlands.
Cattails and Backyard Water Purifiers
For impoverished areas with enough rainfall to support marsh plants like cattails, micro-scale phytoremediation could be an affordable way to help bring arsenic contamination down to safer levels. Jeremiah Jackson of the engineering firm Kleinfelder has come up with one solution. It’s a backyard cattail water purifier that requires no power or plumbing, which can be assembled from materials at hand using simple instructions. Sometimes it takes a low tech solution to solve a high tech problem.
Image: D’Arcy Norman at flickr.com.