^68Ge—^68Ga发生器的研制—硅胶柱上^68Ge与Ga,Cu,Zn的分离

测量了硫酸介质中Ｇｅ在硅胶上的分配比及Ｇａ、Ｃｕ、Ｚｎ在硅胶上的吸附。研究了硫酸浓度、Ｇａ浓度及原始溶液中Ｇｅ载体量对Ｇｅ分配比的影响。实验结果表明：用１０ｍｍ×３０ｍｍ硅胶柱，上柱料液为５０ｍＬ０．４μｇ／ｍＬＧｅ－０．２８ｍｏｌ／ＬＧａ－９ｍｏｌ／ＬＨ２ＳＯ４溶液，淋洗液为３０ｍＬ９ｍｏｌ／ＬＨ２ＳＯ４，流速为０．８５ｍＬ／ｃｍ２·ｍｉｎ时，Ｇｅ的穿透率为０．３９％，Ｇａ、Ｃｕ、Ｚｎ的去污系数分别为１．８×１０６、５．０×１０６、２．６×１０６。     

离子交换色层地分离和富集水中微量有机胂

研究了用阳离子交换色层法分离和富集水中甲基胂酸（ＭＭＡ）和二甲基胂酸（ＤＭＡ）的实验条件。对样品的吸附酸度、淋洗液的组成及淋洗速度进行了选择。在吸附酸度ＰＨ＝２条件下,用６０ｍＬ０．５ｍｏｌ／Ｌ,ＣＨ３ＣＯＯＨ－ＣＨ３ＣＯＯＮＨ４（ｐＨ＝４．７）洗脱ＭＭＡ,继续用６０ｍＬ３ｍｏｌ／ＬＮＨ３．Ｈ２Ｏ洗脱ＤＭＳ,淋洗速度控制在０．１～０．１５ｍＬ／ｍｉｎ,洗脱液用吕了活化法进行测定。实际水样的加标回收     

高吸附活性硅胶的合成及其对锆的选择分离

以水玻璃和盐酸为原料,通过添加表面活性剂制备出高比表面、高吸附活性的硅胶.用BET,DTA-TGA,IR,XRD,TEM等手段对硅胶的结构和性能进行了表征.结果表明,合成硅胶的适宜工艺条件为:水玻璃浓度4%,盐酸浓度5 mol/L,表面活性剂浓度5%,老化时间1 h,煅烧温度600 ℃.该硅胶的比表面积可达998 m2/g,对锆的静态吸附量可达32.6 mg/g,吸附分配系数为56.1 ml/g.     

离子交换色层法分离和富集水中微量有机胂

研究了用阳离子交换色层法分离和富集水中甲基胂酸（ＭＭＡ）和二甲基胂酸（ＤＭＡ）的实验条件。对样品的吸附酸度、淋洗液的组成及淋洗速度进行了选择。在吸附酸度ｐＨ＝ ２ 条件下,用６０ ｍ Ｌ０．５ ｍ ｏｌ／ＬＣＨ３ＣＯＯＨ－ＣＨ３ＣＯＯＮＨ４（ｐＨ＝ ４．７）洗脱ＭＭＡ,继续用６０ ｍ Ｌ ３ｍ ｏｌ／ＬＮＨ３·Ｈ２Ｏ洗脱ＤＭＡ,淋洗速度控制在０．１～０．１５ ｍ Ｌ／ｍ ｉｎ,洗脱液用中子活化法进行测定。实际水样的加标回收率：ＭＭＡ为（９６±２）％ ,ＤＭＡ为（１０３±３）％ ,它们的相对标准偏差分别为６％ 和３％ 。     

自制SnO2·xH2O对68Ge-68Ga发生器吸附性能的影响

用自制的ＳｎＯ２·ｘＨ２Ｏ经热处理后作为＾６８Ｇｅ－＾６８Ｇａ发生器的吸附剂,用模拟试验的方法研究了Ｇｅ的吸附与Ｇａ的淋洗。结果表明,自制ＳｎＯ２·ｘＨ２Ｏ对Ｇｅ有较好的选择吸附性能,２．０ｍＬ０．１ｍｏｌ／Ｌ ＨＣｌ溶液对＾６８Ｇａ的淋洗效率可达８８％。     

^153Sm—EDTMp在羟基磷灰石上的吸附

用ＨＡ作骨体外模型，研究了配合物＾１５３Ｓｍ－ＥＤＴＭＰ在ＨＡ上的吸附规律和几种共存离子对吸附和解吸的影响。在ｐＨ＝７．０±０．２的条件下，体系中配合物量≤４０μｍｏｌ／（ｇ ＨＡ），吸附定量进行；当配合物量〉４０μｍｏｌ／（ｇ ＨＡ），则不能定量吸附。     

硅胶吸附去除高放废液中的锆

实验研究硅胶对硝酸体系中Zr、Pu(Ⅳ)的静态吸附和动态吸附行为。在1.0～4.0mol/LHNO₃中，硅胶对Zr的静态吸附容量(以干硅胶计)约为20mg/g，对Pu(Ⅳ)的吸附分配系数为0.7～1.4mL/g。随着料液酸度的降低，硅胶对Zr、Pu的吸附增加。动态吸附实验结果表明，进料酸度为2.0mol/LHNO₃时，硅胶吸附柱的工作容量约为3.5倍柱体积。使用2mol/LHNO₃淋洗液可将吸附Zr、Pu后的硅胶柱中的部分Zr、Pu洗脱，但洗脱不完全。用2倍柱体积的0.2mol/LH₂C₂O₄可将硅胶吸附的Zr、Pu解吸下来。硅胶柱用0.2mol/LH₂C₂O₄解吸后复用6次，Zr的穿透曲线位置相同。     

用电解精炼法回收和纯化铀和钚的研究Ⅰ．铀－锆合金芯块的直接溶解

采用直接溶解法，研究了时间、温度、搅拌与否及芯块表面积等参数对铀－锆合金在液态镉中的溶解影响。实验结果表明，在４００℃和５００℃、搅拌速度约为１５０ｒ／ｍｉｎ时，铀在液态镉中的溶解度分别为０．４ｇ和２．２ｇ；初始０．５ｈ时，铀溶解速度分别为０．３２ｇ／ｃｍ￣２·ｈ和０．０５ｇ／ｃｍ￣２·ｈ。Ｕ－１０Ｚｒ合金芯块在液态镉中（液态镉与Ｕ－１０Ｚｒ芯块质量比约为７）直接溶解的合适条件为：溶解温度约４８０℃，搅拌速度约１５０ｒ／ｍｉｎ，溶解时间约４ｈ。     

满江红鱼腥藻吸附低浓度铀的研究

用蓝细菌满江红鱼腥藻为吸附材料，研究了时间、ｐＨ、阳离子、阴离子等对水相中低浓度Ｕ（Ⅵ）的吸附影响。实验结果表明，满江红鱼腥藻对浓度低于５．５ｍｇ／Ｌ铀吸附迅速，平衡时间不超过２ｍｉｎ；富集铀酰离子的最佳ｐＨ范围在５．０—８．５，铀酰离子可能以［ＵＯ２ＯＨ］＋形式与藻细胞结合；Ｌｉ＋、Ｎａ＋、Ｋ＋、ＮＨ４＋不与ＵＯ２＋２竞争；Ｃｕ２＋、Ｃｄ２＋、Ｍｎ２＋、Ｚｎ２＋使满江红鱼腥藻的吸附容量下降；Ｃｌ－、ＳＯ２－４、ＮＯ－３不影响藻细胞对铀的吸附；经过简单串级，３．５‰—４．５‰鲜藻可将模拟废水中的铀从５．５ｍｇ／Ｌ降低至０．０５ｍｇ／Ｌ。     

用电解精炼法回收和纯化铀和环的研究：I.铀—锆合金芯块的直接…

采用直接溶解法，研究了时间、温度、搅拌与否及芯块表面积等参数对铀－锆合金在液态镉中的溶解影响。实验结果表明，在４００℃和５００℃、搅拌速度约为１５０ｒ／ｍｉｎ时，铀在液态镉中的溶解度分别为０．４ｇ和２．２ｇ；初始０．５ｈ，铀溶解速度分别为０．３２ｇ／ｃｍ＾２．ｈ和０．０５ｇ／ｃｍ＾２．ｈ．Ｕ－１０Ｚｒ合金芯块在液态镉中（液态镉与Ｕ－１０Ｚｒ芯块质量比约为７）直接溶解的合适条件为：溶解温度约４８０℃     

硅胶吸附处理含高浓度硝酸根的含铀工艺废液

利用硅胶对铀的吸附作用,实现了对同时含高浓度硝酸根及微量铀的放射性废液中铀的回收。利用模拟废液进行静态实验,研究了溶液pH值、铀初始浓度、硝酸盐浓度及硅胶比表面积对吸附效果的影响。结果表明：溶液pH值增大有利于硅胶对铀的吸附;而溶液中铀初始浓度的升高会使铀在硅胶上的吸附效率降低;pH值为8.1时的吸附过程符合Freundlich等温吸附模型;硝酸根在硅胶上不吸附,且对铀的吸附几乎无影响;具有较大比表面积的硅胶有利于铀的吸附。利用实际工艺废液进行的动态柱实验结果表明,当pH值为8.1时,硅胶对铀的吸附容量可达22.3 mg/g。吸附在硅胶上的铀可被1 mol/L的硝酸溶液淋洗下来,解吸效率达近100%。     

硅胶对锆钚(Ⅳ)吸附的研究

为了去除乏燃料溶解液和高放废液中的Zr,研究了酸性条件下硅胶对Zr的静态吸附和对Zr,Pu的动态吸附。研究结果表明,在25℃和1mol/L HNO3时,硅胶对Zr的静态吸附容量约为0225mmol/g,随着料液酸度的降低、硅胶粒度的减小、Zr浓度及固液比的升高,硅胶吸附Zr的能力增大;在4mol/L HNO3溶液中,硅胶吸附Zr而几乎不吸附Pu(Ⅳ),因此可用硅胶吸附法使Zr与Pu(Ⅳ)分离。用2个柱体积的02mol/L H2C2O4可将吸附在硅胶上的Zr解吸下来,洗脱率可达992%。硅胶再次吸附Zr时,吸附性能曲线和吸附容量均无明显变化,硅胶可重复使用。     

硅胶对Ge的吸附性能研究

研究了硅胶对Ge的吸附性能.结果表明,硅胶对Ge的吸附在15 min基本达到静态吸附平衡;高浓度HNO3环境有利于硅胶对Ge的吸附;温度对吸附率的影响不大;Ge质量浓度大于0.65 g/L时,吸附处于饱和状态,有利于吸附均匀性.硅胶吸附Ge的过程符合Langmuir模型和Freundlich模型,是一个吸热过程,动力学...     

Preliminary Observations of Single Crystals of UO2 by Transmission Electron Microscope

Adsorption behavior of inorganic ions were systematically surveyed through radiochemical methods. Adsorbents used were zirconium phosphate, silica gel and charcoal, and the aqueous phases were 0.01N-10N nitric acid and 0.01M-10M ammonium nitrate solutions. The distribution ratios of about 50 chemical elements from Na to Cm were determined by batch method using radioactive tracers.

In the zirconium phosphate system, Cs shows the highest Kd value and most bivalent species are not adsorbed.

A few elements are adsorbed on silica gel from acid solution. High Kd values are shown by Zr, Nb and Pa.

In the charcoal system, most chemical elements are adsorbed to some extent except for alkali and alkaline earth ions.     

Application of photoluminescence microspectroscopy: a study on transfer of uranyl and europium ions on dry silica gel plate

ABSTRACT

When water contacts with porous materials, water and chemical species dissolved in the water transfer into the inside of the porous materials. Here, to study the transfer of uranyl and europium ions on a dry silica gel plate, we dropped a small amount of aqueous solution (~0.5 μL) dissolving the two ions on a dry silica gel plate, and the distributions of the two ions spread on the silica gel plate were observed by photoluminescence microspectroscopy. Photoluminescence images of uranyl and europium ions clearly show that when uranyl ion coexists in the solution, europium ion transfers in a larger area compared to uranyl ion. It can be interpreted that the larger-area distribution of europium ion is caused because uranyl ion is preferentially adsorbed to silica gel and the uranyl adsorption disturbs the adsorption of europium ion. The coexistence of uranyl ion may influence the mobility of other ion species.     

β-环糊精键合硅胶材料对钍的吸附

利用氨基功能化硅胶为固相载体,以可双向反应的环氧氯丙烷为链接剂,将β-环糊精吸附材料接枝到硅胶表面,制备了性能稳定、耐酸碱性的β-环糊精键合硅胶固相吸附富集材料。通过金属离子螯合剂二苯甲酰甲烷辅助作用对钍离子进行快速吸附,材料可重复利用。X-射线光电子能谱仪(XPS)对各实验材料进行了元素分析,确认了材料合成成功的可靠性,扫描电镜分析了材料的外部形貌,傅里叶红外对材料吸附钍离子前后进行了表征,紫外分光光度计对吸附后样品进行了浓度分析。酸性条件(pH=2～3)、室温下所制备材料对钍的吸附3h可达平衡,最大吸附容量可达7.8mg/g,吸附率达78%。以25mg/L的Fe3+、Al 3+,20mg/L的Ca2+、Zn2+、Fe2+、Mg2+、Cu2+为干扰离子,对Th4+的吸附几乎不产生影响。     

Adsorption of Th(Ⅳ) and Ce(Ⅳ) on Zirconium Based Metal-organic Framework Zr-CAU-24

In this paper, zirconium based metal-organic frameworks (MOFs) Zr-CAU-24 was successfully prepared by using solvothermal method, which was one kind of zirconium based MOFs. Zr-CAU-24 has nanoporous structure with BET specific surface area of 1 610 m²/g. Thermogravimetric analysis (TGA) and irradiation stability test were conducted. Taking Zr-CAU-24 as adsorbent, the adsorption characteristics of Th(Ⅳ) and Ce(Ⅳ) on Zr-CAU-24 were investigated through static adsorption experiments. The effects of contact time, initial pH on Th(Ⅳ) and Ce(Ⅳ) adsorption by Zr-CAU-24 were investigated respectively, and the kinetics and thermodynamics were investigated. The results indicate that Zr-CAU-24 has good thermal stability and irradiation stability. The quasi-second-order model provides a good explanation for the adsorption process of Th(Ⅳ) and Ce(Ⅳ) on Zr-CAU-24, which is a chemical adsorption process. The active site of Zr-CAU-24 is evenly distributed, and the adsorption is a single layer adsorption. Through the study of selective adsorption of mixed metal ions on Zr-CAU-24, it is found that Zr-CAU-24 has the adsorption selectivity for Th(Ⅳ) and Ce(Ⅳ).     

锆基MOFs材料Zr-CAU-24对Th(Ⅳ)和Ce(Ⅳ)的吸附性能研究

本文采用溶剂热法合成了微孔结构的锆基金属-有机框架(MOFs)材料Zr-CAU-24,该材料比表面积为1 610 m²/g。对所合成的Zr-CAU-24进行了热重分析(TGA)和辐照稳定性测试,考察了接触时间、初始pH值等对Zr-CAU-24对Th(Ⅳ)和Ce(Ⅳ)吸附性能的影响,并探讨了Zr-CAU-24对Th(Ⅳ)和Ce(Ⅳ)吸附过程的动力学和热力学。结果表明：Zr-CAU-24具有良好的热稳定性和辐照稳定性;准二级动力学模型为Th(Ⅳ)和Ce(Ⅳ)在Zr-CAU-24上的吸附过程提供了很好的解释,即该过程为化学吸附过程;Zr-CAU-24活性位点分布均匀,为单层吸附;混合金属离子溶液吸附研究发现,Zr-CAU-24对Th(Ⅳ)和Ce(Ⅳ)具有吸附选择性。     

Modification of Ni/SiO2 Catalysts by Means of a Novel Plasma Technology

Atmospheric high frequency cold plasma jet was applied to modify Ni/SiO2 catalysts. The catalysts prepared by two different methods with plasma jet were compared with conventional catalysts. BET, XRD, H2-TPD and high-resolution transmission electron microscopy （HRTEM） were used to characterize these catalysts. The results showed that the catalyst prepared with plasma jet had higher nickel dispersion, larger specific surface area and smaller nickel particle size, about 5 nanometres. Detailed analyses revealed that improved structure and characteristic of the plasma catalyst were benefited from the large amount of hydrogen atoms in the plasma jet, by which the catalyst reduction can be easily achieved in shorter period of time at lower temperature, thus avoiding sintering and conglomeration of the active particles and the support. The activity of catalysts was investigated in the methane reforming with CO2. It is shown that the conversions of CH4 and CO2, the yields of H2 and CO were all significantly increased for the plasma catalysts.