Developments to Watch
THESE PLANTS LOVE HEAVY METAL
Utilities may be calling in the "green team" to clean up their act. Halophytes, a group of salt-tolerant plants ranging from cacti to sea grass, can absorb salt and heavy metals such as cadmium and arsenic from the wastewater of power plants.
This January, the Electric Power Research Institute, based in Palo Alto, Calif., and Arizona Public Service Co. began a study of how halophytes can clean wastewater from two coal-fired generating plants. The wastewater, which is laden with heavy-metal byproducts of coal combustion, is soaked up in the tissues of halophyte plants that will later be buried in the nearby desert. In another experiment, deep-rooted halophytes are being tested as a protective barrier to prevent salty water in evaporation ponds from leaching into the water table.EDITED BY RUTH COXETER