Influence of Uranium Speciation on Plant Uptake

Abstract

Firstly, in order to confirm the proportions of different species of uranium in solutions at different pH levels, carbonate and phosphate concentrations were calculated through Visual MINTEQ 3.1 software. Then, based on the calculation results, solutions with different species of uranium were prepared. Finally, the accumulation behavior of different species of uranium by Azolla-Anabaena was studied through hydroponic experiments. The results show that the growth inhibition rates on Azolla-Anabaena by these species of uranium were significantly different. UO22+, UO2(OH)3−, UO2(CO3)34−, and (UO2)3(OH)5+ species inhibited its growth, but UO2PO4− promoted its growth. The bioaccumulation amounts of these species of uranium by Azolla-Anabaena were significantly different, too. In order to increase the bioaccumulation amounts of uranium by Azolla-Anabaena, the main species of uranium in solution should be regulated to UO22+ or (UO2)3(OH)5+, and the concentrations of carbonate and phosphate in the medium should be reduced.