Immobilization of trivalent actinides by sorption onto quartz and incorporation into siliceous bulk: investigations by TRLFS.
Immobilization of trivalent actinides by sorption onto quartz and incorporation into siliceous bulk: investigations by TRLFS.
复制标题
通过吸附在石英上并掺入硅质块体来固定三价锕系元素：TRLFS 的研究。
DOI：
10.1016/j.jcis.2007.09.080
复制
发表时间：
2008
影响因子：
9.9
通讯作者：
Th. Fanghänel
中科院分区：
文献类型：
--
作者：
S. Stumpf;T. Stumpf;Johannes Lützenkirchen;Clemens Walther;Th. Fanghänel;Th. Fanghänel
采用时间分辨激光荧光光谱法（TRLFS）研究了在pH值为3.75 ~ 9.45范围内石英对Cm（III）的吸附。将原始光谱解卷积为三个单一组分。第一个发射峰位于593.8nm，属于Cm（III）水离子，发射寿命为68±3 μs。第二个对应于吸附物种，在601.4nm处具有最大峰，发射寿命为123±10 μs。第三组分的峰最大值向更高的波长（603.6nm）移动，而寿命保持恒定。此外，在间歇实验中，Am（III）在石英上的吸附进行了研究。基于光谱数据的吸附机理的建议。此外，所获得的Am摄取数据和Cm-TRLFS数据建模同时使用一个单一的网站基本斯特恩模型结合电荷分布的概念Pauling。最后建议的模型由两个双齿表面络合物，其中第二个是第一吸附物种的水解产物。在一组单独的实验中，不同浓度的柠檬酸对石英体系中Cm（III）形态的影响通过TRLFS进行了研究。在悬浮液中，低浓度（3.5×10− 4 mol/L）的酒石酸对Cm（III）的形态没有影响。在高浓度（3.5×10− 2 mol/L）时，Cm（III）的形态变化受到明显影响。在较高浓度下的结果表明，形成的Cm（III）/草酸络合物和Cm（III）的掺入到硅质本体。这通过在石英单晶表面处的测量来证实。此外，这些测量表明，石英/Cm（III）/草酸三元复合物在矿物表面的形成。
The adsorption of Cm(III) on quartz is studied by time resolved laser fluorescence spectroscopy (TRLFS) in the pH range from 3.75 to 9.45. The raw spectra are deconvoluted into three single components. The first one has a peak maximum at 593.8 nm and can be attributed to the Cm(III) aquo ion with an emission lifetime of 68±3 μs. The second one corresponds to an adsorbed species and has a peak maximum at 601.4 nm and an emission lifetime of 123±10 μs. The peak maximum of the third component is shifted to higher wavelength (603.6 nm) while the lifetime remains constant. Additionally, the adsorption of Am(III) on quartz is investigated in batch experiments. Based on the spectroscopic data a sorption mechanism is suggested. In addition, the obtained Am uptake data and the Cm-TRLFS data are modeled simultaneously using a single site Basic Stern model in combination with the charge distribution concept of Pauling. The finally suggested model consists of two bidentate surface complexes where the second one is the product of hydrolysis of the first sorption species. In a separate set of experiments the influence of silicic acid at different concentrations on the Cm(III) speciation in a quartz system is investigated by TRLFS. In suspension silicic acid at low concentration (3.5×10−4mol/L) has no influence on the Cm(III) speciation. At high concentration (3.5×10−2mol/L) the Cm(III) speciation is definitely influenced. The results at higher concentration indicate the formation of Cm(III)/silicic acid complexes and the incorporation of Cm(III) into siliceous bulk. This is confirmed by measurements at a quartz single crystal surface. Moreover, these measurements indicate the formation of quartz/Cm(III)/silicic acid ternary complexes at the mineral surface.