Uranium accumulation in the lichen Cladonia rangiferina. Part I. Uptake of cationic, neutral, and anionic forms of the uranyl ion

Publisher Website
Google Scholar
Abstract
Evidence from published work is first reviewed to show that cationic, neutral, and anionic complexes of the uranyl ion are available to plants growing in uranium-enriched environments. The results of a study on the uptake of uranyl ions by the lichen C. rangiferina L. Wigg are then presented. Uptake was examined from 3 different uranyl solutions each predominantly containing a single species: namely, the cation UO22+ (in distilled water), the neutral 1:1 complex with phthalate (UO2l), and the anionic complex of oxalate (UO2l22+). Uptake decreased along the chemical speciation series: cation .mchgt. neutral species .mchgt. anion. Maximum observable capacities for this series were, respectively, 49, 17 and 1.6 .mu.mol/g for 1 g samples in 100 ml containing 840 .mu.mol of total uranium. The UO22+ uptake curve was observed to be monophasic, while biphasic patterns appeared to apply for the phthalate and oxalate buffers. Heat-killed tissues showed marginally higher uptake capacities than live material.