Uranium uptake by algae: experimental and natural environments

Monocultures of the freshwater green algae Ankistrodesmus sp. grown at pH 8.1–8.2 and 13–16 °C, in solutions containing 2 ppm U chelated with EDTA, acquired 1000 – 10 000 ppm uranium by dry weight. In some algae, a uranium mineral of cubic habit was detected. At Elliot Lake, Ontario, Euglena sp. thriving in tailings discharge contain on average 184 ppm U. Tailings waters contain high concentrations of dissolved uranium, on average 273 ppb. In natural drainage waters, above and below tailings, dissolved U averages 0.23 ppb. Thames River algae average 28 ppm U, whereas waters have an average dissolved U of 1.46 ppb, representing about twice the global mean riverine value of 0.6 ppb U.