The cleanup of toxic waste sites poses perplexing environmental process engineering problems. These sites vary greatly in the type of wastes and land size affected. Existing methods of cleanup include the removal of topsoil and taking it to special facilities for chemical processing or incineration of the waste. These approaches are not cost-effective or even feasible in some cases.
One method for cleaning industrial waste being explored is phytoremediation. Biologists and biochemists discovered over time that some species of plants can extract hazardous wastes effectively. While not without risks of its own, this method may prove very useful over time.
Poplars Cleaning Ground Water
One type of contaminant associated with industrial waste is chlorinated solvents. Agronomists and scientists found that poplar trees have the unique ability to suck up these pollutants from the groundwater and process them in a safe way. This method is being employed at Argonne National Laboratory, where the aquifer was contaminated.
Other Promising Plants
A long list of plants are being tested for applications as diverse as removing heavy metal contamination from sites to the cleanup of nuclear accidents like Chernobyl. Indian mustard is one species that show promise for removing heavy metals from water. Water Hyacinth is being examined for the cleanup of nuclear wastes. These plants have even earned the name hyperaccumulators for their ability to take up and bind certain contaminants.
Another potential approach is to genetically alter plants in a way the uniquely suits them to this task. This work is still in its infancy and is not being field-tested yet. As tools and techniques allow scientists better control over specific plant characteristics this may be an answer that will solve otherwise intractable problems.
Mother nature continues to reveal remarkable secrets about the way plants can be applied to some of the most complex problems we face. Scientists and engineers working with phytoremediation are helping bring these solutions to bear waste site cleanups.