Chromium and zinc uptake in Elodea densa and Ceratophyllum demersum : applications for bioremediation

South American waterweed, Elodea densa (Planch.) Casp., and Coontail Ceratophyllum demersum L., were studied for their potential to take up chromium and zinc and as a possible indicator of arsenic, cadmium, copper, and lead pollution. Plants were collected from the Willamette River in Oregon and exposed for 48 hours to either zinc or chromium at 0.05 μg/ml, 0.1 μg/ml or 1.0 μg/ml. Dried plant material was digested by using microwave acid digestion and analyzed for heavy metals by using an Induced Coupled Plasma Spectrometer (ICP). Both species showed uptake of zinc and chromium. At the 1.0 μg/mI exposure Elodea densa showed the highest concentration of zinc at 2244.58 μg/g, and the highest concentration of chromium at 41.4975 μg/g. Elodea densa and Ceratophyllum demersum contained copper, lead and cadmium. The highest concentrations were in Elodea densa with copper at 115.101 μg/g, lead at 4.755 μg/g and cadmium at 0.805 pg/g