Hybrid poplar cuttings growing in hydroponics at the University of Georgia
Savannah River Ecology Lab in Aiken SC where Dr. Tracy Punshon's does
T.Punshon & D.C.Adriano
is an alternative clean-up technology that exploits the action of plants and their associated microbes to alleviate hazardous soil contamination. Research has shown that certain plant species are adapted to growth in soils contaminated with heavy metals (such as nickel, lead, zinc and copper) and organic contaminants such as trinitrotoluene (TNT), trichloroethylene (TCE). Careful selection of the species of plant used can lead to removal of heavy metals and the degradation of organic compounds, leaving the soil significantly cleaner.
Research at the University of Georgia's Savannah River Ecology Laboratory in Aiken, SC aims to develop a core Phytoremediation technology for mixed-waste contaminated profiles. The majority of Phytoremediation studies carried out in the past have concentrated on a single contaminant; for example the use of Indian mustard Brassica juncea to extract lead from contaminated soils. Phytotech The research at SREL aims to take Phytoremediation further toward a successful site deployment by studying the interactions between heavy metals and organics in the same profile. This is carried out by using solution culture techniques followed by pot studies, before moving into larger trials in the field.
Poplars are the plant species of choice for the Phytoremediation studies due to recent findings suggesting they can take up and degrade organic contaminants and certain heavy metals. A group working primarily at the University of Washington have shown that the de-greasing agent TCE is degraded and transpired by hybrid poplar trichocarpa deltoides Furthermore, poplars and willows have been used for some time in Sweden as 'biological filters' to remove contaminants such as cadmium from sewage sludge while producing valuable bio mass, which is then turned into energy. The fast growth of poplar and willow trees makes them ideal Phytoremediation trees, due to their fast establishment, deep roots, rich associated fauna and most importantly their adaptability. It is expected that these types of trees will feature largely in Phytoremediation research in the future.
Researchers Dr. Tracy Punshon and Dr. Domy C. Adriano are currently working to develop these fast-growing, adaptable trees into phytoremediators that are able to cope with a realistic mixture of contaminants. For more information, e-mail Tracy Punshon
Note from Frank: Dr Punshon has graciously sent us the picture of some of the cuttings growing in her lab. If "Phytoremediation" gives you the creeps, don't worry it is a word meaning the art of picking up all the toxic waste we have spilled before it kills us. Some race... Not only we started late... but we are dumping faster than we are picking up!