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© Springer Nature Switzerland AG 2020
D. K. Gupta, C. Walther (eds.), Uranium in Plants and the Environment,
Radionuclides and Heavy Metals in the Environment,
https://doi.org/10.1007/978-3-030-14961-1_9
Influence of Uranium Speciation on Plant
Uptake
Nan Hu, Hui Zhang, Dexin Ding, Yujian Tan, and Guangyue Li
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. UO 2
2+
, UO 2 (OH) 3
−
, UO 2 (CO 3 ) 3
4−
, and (UO 2 ) 3 (OH) 5
+
species inhibited its
growth, but UO 2 PO 4
−
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 UO 2
2+
or (UO 2 ) 3 (OH) 5
+
, and
the concentrations of carbonate and phosphate in the medium should be reduced.
Keywords Phytoremediation · Uranium · Speciation · Bioaccumulation
1 Introduction
Phytoextraction is a process that includes the uptake of elemental/compound by
plant roots from the contaminated soil and water and translocation and accumulation of the elemental/compound into plant shoots and leaves. The uranium species
in solution have great influence on the bioaccumulation of uranium by plant
(Markich 2002). The predominant uranium species in aqueous solutions are UO 2
2+
under low pH conditions, which is stable and can migrate freely (Ragnarsdottir and
Charlet 2000; Song et al. 2012). With the increase of pH, the UO 2
2+
in the aqueous
solution tends to be hydrolyzed to the hydroxide complex UO 2 (OH) x (Ebbs et al.
1998). Lee and Yang (2010) reported the phytoremediation of different uranium
N. Hu · H. Zhang · D. Ding (*) · Y. Tan · G. Li
Key Discipline Laboratory for National Defense for Biotechnology in Uranium Mining and
Hydrometallurgy, University of South China, Hengyang, Hunan, P. R. China
© Springer Nature Switzerland AG 2020
D. K. Gupta, C. Walther (eds.), Uranium in Plants and the Environment,
Radionuclides and Heavy Metals in the Environment,
https://doi.org/10.1007/978-3-030-14961-1_9
Influence of Uranium Speciation on Plant
Uptake
Nan Hu, Hui Zhang, Dexin Ding, Yujian Tan, and Guangyue Li
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. UO 2
2+
, UO 2 (OH) 3
−
, UO 2 (CO 3 ) 3
4−
, and (UO 2 ) 3 (OH) 5
+
species inhibited its
growth, but UO 2 PO 4
−
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 UO 2
2+
or (UO 2 ) 3 (OH) 5
+
, and
the concentrations of carbonate and phosphate in the medium should be reduced.
Keywords Phytoremediation · Uranium · Speciation · Bioaccumulation
1 Introduction
Phytoextraction is a process that includes the uptake of elemental/compound by
plant roots from the contaminated soil and water and translocation and accumulation of the elemental/compound into plant shoots and leaves. The uranium species
in solution have great influence on the bioaccumulation of uranium by plant
(Markich 2002). The predominant uranium species in aqueous solutions are UO 2
2+
under low pH conditions, which is stable and can migrate freely (Ragnarsdottir and
Charlet 2000; Song et al. 2012). With the increase of pH, the UO 2
2+
in the aqueous
solution tends to be hydrolyzed to the hydroxide complex UO 2 (OH) x (Ebbs et al.
1998). Lee and Yang (2010) reported the phytoremediation of different uranium
N. Hu · H. Zhang · D. Ding (*) · Y. Tan · G. Li
Key Discipline Laboratory for National Defense for Biotechnology in Uranium Mining and
Hydrometallurgy, University of South China, Hengyang, Hunan, P. R. China