球形亚铁氰化镍钾聚丙烯腈吸附剂的制备及应用

制备了以聚丙烯腈(PAN)为骨架、亚铁氰化镍钾(KNiFC)为核心的球形复合吸附剂(KNiFC/PAN),并通过X射线衍射仪、金相显微镜和电感耦合等离子体质谱仪等手段对该吸附剂进行了分析表征。采用批式实验,研究了硝酸浓度、Na⁺、NH⁺₄、接触时间等对KNiFC/PAN吸附Cs⁺的影响,研究了吸附过程的反应动力学和吸附等温线。结果表明,该吸附剂对Cs⁺的典型吸附分配系数(K_d)为10⁴～10⁵ mL/g,平衡时间小于5 min;硝酸浓度小于1.0 mol/L时,K_d值基本不变,之后随酸度增加,K_d值逐步减小;随着Na⁺浓度增加K_d值逐步减小;NH⁺₄对Cs⁺的吸附有明显的竞争。KNiFC/PAN对Cs⁺的等温吸附较符合Langmuir模型,...     

Simultaneous Adsorption of Cs-137 and I-131 from Water and Milk on “Metal Ferrocyanide-Anion Exchange Resin”

“Metal ferrocyanide-anion exchange resin”, which is made by precipitating the metal ferrocyanide in an anion exchange resin matrix, has been used for selective adsorption of Cs ion in a variety of aqueous solutions.

The “resin” has both properties of metal ferrocyanide and anion exchange resin. Therefore, we tried simultaneous adsorption of radiocesium and radioiodine from water and milk on the “resin”.

Results showed that “metal ferrocyanide-anion exchange resin” such as Cu, Fe and Ni ferrocyanide can be used for a rapid and simple concentration of radiocesium and radioiodine quantitatively from a large volume of sample solutions.

This paper also touches upon the removal of ¹³⁷Cs and ¹³¹I in rain water and milk collected in Japan after the Chernobyl accident.     

从高放废液中分离79 Se的流程研究

建立了离子交换法与沉淀法相结合的、从高放废液中分离79Se的放化流程.该流程具有去污效果好的特点,对137Cs,90Sr,90Y,99Tc,154Eu的去污因子大于104,对125Sb,113Sn的去污因子大于103,对237Np为2×102.整个流程的收率约为53%.由该流程分离出的79Se样品能够很好地满足液闪测量和质谱测量的要求.     

含铯废水膜处理工艺中吸附剂的选择

在含铯废水无机离子交换吸附-微滤膜处理工艺的吸附剂研究中,以134Cs为示踪剂研究了蒙脱石、蛭石及亚铁氰化锌钾对Cs的吸附效果以及体系各种因素对吸附的影响。依据研究结果,结合絮凝沉淀和中空纤维膜微滤一体化处理工艺（CMF）运行参数,从中筛选出亚铁氰化锌钾作为含铯废水膜处理工艺中的吸附剂,初步确定吸附剂投加量为0.33g/L。     

The Application of an Advanced Ion Exchange Process to Reprocessing Spent Nuclear Fuels, (I)

In order to develop an advanced ion exchange process for the reprocessing of spent nuclear fuels, a novel anion exchanger, AR-01 with the resin embedded in porous silica beads and benzimidazoles as functional groups has been manufactured. Adsorption behavior of various fission product elements (FPs) and uranium in nitric acid medium were investigated experimentally using this anion exchanger. Separation performance of FPs from U(VI) in simulated spent fuel solutions was demonstrated by column chromatography utilizing dilute HNO₃ and thiourea as eluents.

Most FPs such as Cs(I), Sr(II), Mo(VI), Rh(III) and trivalent rare earths showed negligibly slight adsorption and could be separated from U(VI) satisfactorily. Cerium(IV) was strongly adsorbed, but was gradually reduced to non-adsorptive Ce(III) by the anion exchanger. Zirconium(IV) presented weak adsorption and its a part mixed with U(VI) in the column experiments. Ruthenium(III) exhibited quite strong adsorption in a broad HNO₃ concentration range as the form of anionic nitrosylnitrato-complexes, its most amount mixed with U(VI). Palladium(II) showed significantly strong adsorption probably due to complexes formation with the anion exchanger. The adsorbed Pd(II) was effectively eluted out by thiourea and separated from U(VI) and other FPs completely.     

除Sr、Cs无机交换剂的制备及性能

为去除废液中的Sr、Cs等裂变产物,用制备的亚铁氰化铜钾和亚铁氰化钴钾无机交换剂进行了初步研究。结果显示,亚铁氰化铜钾交换剂对Sr、Cs离子的静态饱和交换容量最大值分别为80、160mg／g,对Sr、Cs离子的动态交换容量最大值分别为17、130mg／g;亚铁氰化钴钾交换剂对Sr、Cs离子的静态饱和交换容量最大值分别为80、70     

硅基磷钼酸铵吸附剂的合成及其对Cs的吸附

采用孔内结晶法合成了磷钼酸铵二氧化硅吸附剂(AMP/SiO2),通过XRD、BET、EPMA等手段对其进行了表征。研究了接触时间、钠钾钙镁四种共存离子对AMP/SiO2吸附Cs的影响。结果表明,AMP/SiO2对Cs的吸附在10min即可达平衡,且受钾离子的影响较大而受其他三种共存离子的影响较小,吸附过程符合Langmuir吸附模型和假二级动力学方程,在0.6mol/L的钠溶液中对Cs的静态及动态交换容量分别可达0.390mmol/g和0.323mmol/g。     

Formation of radioactive cesium microparticles originating from the Fukushima Daiichi Nuclear Power Plant accident: characteristics and perspectives

ABSTRACT

Following identification of radioactive Cs microparticles (CsMPs) in aerosol samples from the Fukushima Daiichi Nuclear Power Plant (FDNPP), numerous reports on CsMPs have been published. This paper reviews recent progress in the measurement and characterization of CsMPs by advanced analytical techniques, including advanced transmission electron microscopy (TEM) and synchrotron X-ray analysis. These analyses revealed that the CsMPs contained Si, Fe, Zn, Cs, and minor quantities of U together with some fission products. Uranium in the CsMPs was identified as being in the form of uraninite and (U,Zr)O₂. Detailed advanced TEM analysis has clarified some of the processes resulting in the alteration of constituents of the nuclear fuels and containment vessel materials during this severe accident. In addition, a detailed report on the elemental compositions and structures of the fuel debris fragments collected inside and outside of the primary containment vessel²⁵ highlighted the fact that the fuel debris fragments contained nanoparticles with the U and Zr components having similar structures to that of the CsMPs. This similarity in structures has stimulated further research on the structure and elemental constituents, especially for U and Zr in the CsMPs, and has opened up new avenues for studying the chemical characteristics of the fuel debris.     

Radiochemical Application of “Iron Ferrocyanide-Anion Exchange Resin”

Preparation of iron ferrocyanide-anion exchange resin and adsorption of ¹³⁷Cs on the resin are described.

The resin was found to effectively adsorb ¹³⁷Cs from concentrated nitric acid solution, contrast to the negative results previously obtained with copper ferrocyanide-anion exchange resin.

A discussion is given of the possibility of applying the iron resin to the removal of ¹³⁷Cs from fuel reprocessing waste solution.

Fission products were effectively separated from each other with a column of this resin, utilizing the properties possessed by it of both iron ferrocyanide and the parent ion exchange resin.     

铀的离子交换反应——Ⅳ.盐酸介质中铀(Ⅵ)在强碱性阴离子交换树脂上的化学状态

用当量计算、分配比的测定以及红外光谱等三种实验方法,证明从盐酸介质中吸附到强碱性阴离子交换树脂上的铀酰,主要是以(UO_2Cl_4)~(2-)存在。     

Studies on Ion-Exchange Equilibria for Cesium-Hydrogen System

Ion-exchange equilibrium between Cs and H on a sulfonated polystyrene resin of Dowex 50W with 8% crosslinking has been studied over a temperature range of 25°to 60°C, using 137Cs as radioactive tracer; the various experimental data related to the equilibrium experiments were examined in detail by several different methods; a new treatment to take into account the water uptake in the exchange system Cs-H was also applied with the aid of a radioactive tracer technique. The thermodynamic equilibrium constant K^cs _H determined by the present study compares well with the values calculated indirectly from experimental data found by other investigators. Data are also given for the heats, free energies and entropies of the exchange reaction involving Dowex 50W. Fairly good results have been obtained on the exchange of Cs and H.     

离子交换法提取大量钍中微量铀

采用浓盐酸溶解ThO_2和U_3O_8、以Dowex1×8阴离子交换树脂和Dowex50×8阳离子交换树脂作离子交换剂,研究了从大量钍及微量裂变产物(FPs)中提取微量铀的方法。考察了裂变产物元素Cs、Sr、Y、Zr、Nb、Ru、Rh、La、Ce、Eu的去污效果。结果表明,用离子交换法可以实现从百克每升Th及FPs中分离出微量U。最优工艺条件是料液调至8mol/L HCl介质,大量Th和微量的FPs在8mol/L HCl-0.2mol/L NH4F洗涤条件下直接通过阴离子交换柱,而U吸附于树脂上,再用0.05mol/L HNO_3淋洗U。低HNO_3淋洗U后,直接过阳离子柱吸附微量Th,再用2mol/L HNO_3淋洗得到纯U。结果表明,U收率大于98%,产品中Th及FPs的含量均小于0.05μg/L。     

Alkali Hydrothermal Synthesis of Zeolites from Coal Fly Ash and Their Uptake Properties of Cesium Ion

Zeolites were synthesized from coal fly ash by hydrothermal treatment with KOH solutions. K-H zeolite (K₂Al₂Si₄O₁₂-nH₂O) was produced under optimum conditions of 160°C, 3 d, 1 M (=mol/dm³) KOH and liquid-solid ratio of 15cm³/g. The uptake behavior of radioactive cesium for the products was investigated by batch and column methods. The uptake equilibrium of Cs+ for the above product was attained within 2h yielding the distribution coefficient of above 10⁴ cm³/g. The uptake of Cs⁺ was followed by a Langmuir adsorption isotherm and the maximum uptake capacity was estimated to be 3.34 mmol/g. The successive removal of Cs⁺ was accomplished through the column packed with granular composites of product-alginate gel polymer.     

Analysis of Cs-adsorption behavior using a column filled with microcapsule beads of potassium copper hexacyanoferrate

Ash-washing technology is a crucially important technology for removing radioactive Cs from contaminated ash. For that technology, Cs⁺ removal from the ash-washing solution by the adsorbent is necessary. This study was conducted to establish rapid preparation of appropriate adsorption columns for Cs⁺ uptake. A one-site model was not used for analysis because the model cannot accommodate sites with different adsorption speed. Results demonstrated that the adsorption behavior of the column filled with the granules of potassium copper hexacyanoferrate was well reproduced by a two-site adsorption model with parameters chosen through analysis of batch adsorption test results.     

Impregnation structure of cobalt ferrocyanide microparticles by the polymer chain grafted onto nylon fiber

At Tokyo Electric Power Company (TEPCO) Fukushima Daiichi nuclear power plant (NPP), water contaminated with radionuclides such as Cs-137 and Sr-90 has been stored in tanks and seawater-intake area. We have prepared cobalt-ferrocyanide-impregnated fibers via four steps: the grafting of an epoxy-group-containing monomer, the conversion of the epoxy group into positively charged groups, the binding of ferrocyanide ions ([Fe(CN)₆]^4?), and the precipitation of cobalt ferrocyanide (Co₂[Fe(CN)₆]) by contact with cobalt ions. However, the impregnation structure of cobalt ferrocyanide microparticles onto the fiber remains unclear. Here, we describe the impregnation structure from the results of rebinding [Fe(CN)₆]^4? to the cobalt-ferrocyanide-impregnated fiber. The amount of [Fe(CN)₆]^4? re-bound onto the fiber was found to decrease with increasing amount of Co₂[Fe(CN)₆] initially impregnated. This suggests that the microparticles of cobalt ferrocyanide become entangled with the grafted polymer chains via multipoint electrostatic interactions.     

用钛酸盐陶瓷固化含铯亚铁氰化钛钾无机离子交换剂的初步研究

本文对在我国高放废液全分离流程中产生的含铯亚铁氰化钛钾无机离子交换剂的固化进行了初步研究。结果表明,对于含铯亚铁氰化钛钾无机离子交换剂,可先用热分解－催化氧化法除去其中的氰并将其转变为各种固体氧化物,然后用由碱硬锰矿（ＢａＡｌ２Ｔｉ６Ｏ１６）、假板钛矿（ＦｅＴｉ２Ｏ５）及金红石（ＴｉＯ２）三种矿相组成的钛酸盐陶瓷固化体对其进行固化包容。制备出的陶瓷固化体性能稳定,物理稳定性和化学稳定性与硼硅酸盐玻     

Separation of strontium from low level radioactive waste solutions using hydrous manganese dioxide composite materials

⁹⁰Sr is one of the major isotopes present in the low level radioactive liquid waste (LLW) generated during operation of nuclear reactors and spent fuel reprocessing plants. A composite ion exchange material consisting of hydrous manganese oxide and poly methyl methacrylate (PMMA) was developed for removal of strontium from aqueous radioactive waste. The prepared composite material showed very good strontium adsorption properties in aqueous solutions. Sorption of strontium on the composite material as a function of pH, equilibration time and strontium ion concentrations were studied. The process of sorption of strontium from solution was analysed using different isotherm models like Langmuir, D-R and Freundlich. Four different error functions were employed to find out the most suitable isotherm model to represent the experimental data and it was found that Freundlich model best fits the sorption of strontium on the composite material. Analysis of the data obtained from the sorption kinetics studies showed that the data fitted better to the pseudo-second order kinetic model. Lab scale column performance study of the composite material revealed that the material could be effectively used in column operations to remove strontium from LLW solutions.     

球形亚铁氰化钴钾-硅胶无机离子交换剂的制备及其用于~(137)Cs-~(137m)Ba发生器的研究

利用137 Cs-137mBa的放射性级联衰变关系和137 Cs、137mBa之间不同的化学性质,可以制备137 Cs-137mBa核素发生器。本研究制备了球形亚铁氰化钴钾-硅胶无机离子吸附材料,其对Cs+的静态吸附容量为0.311mmol/g,吸附平衡常数为2.2×104。用上述材料制备了活度为1.85×109 Bq(50mCi)的用于工业示踪的137mBa同位素发生器,淋洗效率大于50%,Cs+的漏穿率为10-7/mL量级,使用寿命大于1年。该发生器性能稳定,使用寿命长。     

复合无机离子交换材料及其在水体放射性Cs检测中的应用

离子交换法速度快、能与检测仪器联用,已逐渐成为水体中放射性Cs的主要富集方法。由于单一的离子交换材料无法兼顾抗辐照性、强选择性和高吸附速率等性能,因此研发兼顾各种性能的新型离子交换材料将成为提高水体中放射性Cs富集效率的关键。本文通过总结复合无机离子交换材料在水体放射性Cs富集分离方面的研究进展及相关应用,分析了各类复合无机离子交换材料的优缺点,并针对不同复合无机离子交换材料的制备提出了溶胶 凝胶、多孔支撑体和有机物黏接等改进方法。这为制备更高效的复合无机离子交换材料和提高放射性Cs检测的效率提供了参考,也为离子交换法在其他领域中的应用提供了新的思路。     

Assessment of <Superscript>137</Superscript>Cs decontamination of concrete by the reagent method

The particulars of radioactive contamination of concrete wastes by ¹³⁷Cs were studied. x-Ray phase analysis and chemical analysis show that clayey materials, including Al₂O₃, Fe₂O₃, K₂O, and MgO, on which ¹³⁷Cs sorption is possible, were present in the concrete wastes. The content and form in which ¹³⁷Cs was found in radioactive concrete wastes from nuclear power facilities as well as in model samples were determined. When the wastes were treated with nitric acid the binder dissolved and a polydisperse suspension formed. The suspension consisted of three phases: solution, fine suspension, and rapidly settling precipitate of heavy filler particles. x-Ray phase analysis was performed and the ¹³⁷Cs mass ratio and distribution in the phases were determined. The possibility of decontaminating the concrete by a reagent method was evaluated.