(Ce-Al)-oxide pillared bentonite: A high affinity sorbent for plutonium

JOURNAL OF HAZARDOUS MATERIALS

卷:352

Article

Leng, Yangchun^1,2  Li, Qintang¹  Chen, Xiaoyuan¹  Almasy, Laszlo^1,3  Liu, Yuliang¹  Sun, Guangai^4,5  Tuo, Xianguo⁶  Yan, Minhao¹  Henderson, Mark J.¹ 

[1] Southwest Univ Sci & Technol, State Key Lab Cultivat Base Nonmet Composites & F, Mianyang 621010, Peoples R China

[2] Southwest Univ Sci & Technol, Lab Natl Def Radioact Waste & Environm Secur, Mianyang 621010, Peoples R China

[3] Wigner Res Ctr Phys, Inst Solid State Phys & Opt, POB 49, H-1525 Budapest, Hungary

[4] CAEP, Key Lab Neutron Phys, Mianyang 621999, Peoples R China

[5] CAEP, Inst Nucl Phys & Chem, Mianyang 621999, Peoples R China

[6] Sichuan Univ Sci & Engn, Zigong 643000, Peoples R China

关键词: Plutonium;    Pillared clay;    Cerium dioxide;    Neutron scattering;   

DOI  :  10.1016/j.jhazmat.2018.03.028

来源: Elsevier

【 摘 要 】

The ability of bentonite and montmorillonite pillared by Al-oxide and mixed (Ln-Al)-oxides (Ln = La, Ce) to remove (239)plutonium solution species from water is comparatively investigated at pH 7 and pH 4. Small-angle scattering and neutron contrast variation with H2O/D2O mixtures is used to verify the ingress of water in the calcined products after hydrophilicity was introduced by an NH3-H2O vapor treatment. The size and shape of the (La/Ce)-Al oxo-hydroxy pillaring cations (2 nm spheres) is determined by small-angle x-ray scattering from the pillaring solutions. Not all of the oxide pillars improved Pu uptake compared with sodium montmorillonite. At neutral and acidic pH only (Ce-Al)-oxide pillared clays showed the ability to remove Pu over the concentration range studied (1.35 x 10(-8)-8 x 10(-8) mol dm(-3)) with distribution coefficient (K-D) values > 10(4). XPS analysis of the (Ce-Al)-oxide pillared days indicates the presence of Ce4+ as cerium dioxide. The progressive improvement in sorption performance in the order of pillar type Al2O3 < La2O3 center dot Al2O3 < < CeO2 center dot Al2O3 reflects the increasing access of Pu solution species to the clay mineral layers by changes to the basal spacing and specific surface area, and also to the higher stability of the (Ce-Al)-oxide pillars.

【 授权许可】

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