Recovery of uranium from sea water. IV. Influence of crosslinking reagent of the uranium adsorption of macroreticular chelating resin containing amidoxime groups

Macroreticular chelating resins (RNH) containing amidoxime groups with various degrees of crosslinking were synthesized by using various amounts of ethyleneglycol dimethacrylate (1G), dimethyleneglycol dimethacrylate (2G), triethyleneglycol dimethacrylate (3G), tetraethyleneglycol dimethacrylate (4G), and nanoethyleneglycol dimethacrylate (9G) as crosslinking reagent. The effect of crosslinking reagents on the pore structure, ion exchange capacity, swelling ratio, and adsorption ability for uranium of RNH was investigated. RNH (RNH–1G) prepared by using 1G were showed to have macroreticular structures by the measure of specific surface area. RNH–1G had the high adsorption ability and physical stability. Though RNH (RNH–4G) obtained by using 4G have little macroreticular structure (macropore), these resins showed the high adsorption ability for uranium by the treatment with 0.1 mol dm^?3 NaOH at 30°C for 15 h (alkali treatment). These results suggest that the formation of not only the favorable macropore but also the micropore is important for the effective recovery of uranium in sea water, whereas RNH–4G was defined to be low physical and chemical stability. For the preparation of RNH which have effective pore structure for the recovery of uranium, chemical, and physical stability, the simultaneous use of divinylbenzene (DVB) and 1G or 4G as crosslinking reagent was examined (abbreviated as RNH–DVB–1G and RNH–DVB–4G). The specific surface area of RNH–DVB–1G increased with an increase of 1G used. These RNH–DVB–1G have been shown the high adsorption ability for uranium. On the other hand, the specific surface area and adsorption ability for uranium of RNH–DVB–4G decreased with an increase of 4G used. Repeated use did not cause the deterioration of both RNH–DVB–1G and RNH–DVB–4G. This result suggests that the simultaneous use of DVB and 1G or 4G contributed the improvement of chemical and physical stability. In particular, RNH–DVB–1G has the effective macropore and micropore for the recovery of uranium.     

Extraction of uranium from sea water using biological origin adsorbents

Waste microbial biomass has been shown to be a good adsorbent for uranium. A small scale pilot plant was operated at Woods Hole Oceanographic Institute in collaboration with the Department of Nuclear Engineering of MIT in order to assess the potential use of the two selected types of microbial biomass to sequester uranium from sea water effectively. The experimental results suggest that factors such as the presence of carbonates in the sea water, suppress substantially the uranium adsorptive uptake capacity of the biomass. The selectivity of the biomass for uranium, is not as good as that of other synthetic inorganic or organic adsorbents as, for example, hydrous titanium oxide.     

Recovery of uranium from seawater V. Preparation and properties of the macroreticular chelating resins containing amidoxime and other functional groups

We have synthesized macroreticular chelating resins containing amidoxime groups from acrylonitrile (AN)-divinylbenzene (DVB)-alkyl acrylate, alkyl methacrylate, or vinylpyridine (VPy) copolymer beads. It was found that the chelating resin (RNMH)-containing amidoxime groups prepared from AN-DVB-methyl acrylate (MA) indicated the highest adsorption ability for uranium in seawater. Hydroxamic acid and carboxylic groups in addition to amidoxime groups were formed during the reaction of the copolymer beads with a methanol solution of hydroxylamine. The adsorption ability for uranium was greatly influenced by the physical pore structure (macropore) and the pore structure formed by the swelling(micropore). RNMH (RNMH10-10) prepared with 10 mol% of DVB and 10 mol% of MA had the highest adsorption ability and physical stability for uranium. On the other hand, improved adsorption ability for uranium was not observed in the case of the macroporous resins (RNPyH) prepared by the copolymerization of VPy as the basic component. After seawater was passed through the column packed with RNMH10-10 at a space velocity (SV) of 180 h^?1 (up-flow) for 10 days, the amount of uranium adsorbed on the resin was about 100 mg/dm³-R and 260 mg/kg-R.     

Recovery of uranium from seawater. XII. Preparation and characterization of lightly crosslinked highly porous chelating resins containing amidoxime groups

A number of lightly cross-linked poly(acrylonitrile-co-divinylbenzene) beads (RN-5) have been synthesized by suspension polymerization. The use of solvating diluents such as chloroform, dichloroethane, and tetrachloroethane resulted in copolymer beads having highly porous structures. The chelating resins containing amidoxime as a functional group (RNH-5) have been prepared by the reaction of copolymer beads with 3% hydroxylamine in methanol. A detailed analysis is made of the pore structure of lightly cross-linked copolymers of acrylonitrile–divinylbenzene and their amidoxime derivatives in the anhydrous state including pore-size distribution, specific surface area, and pore structure in the aqueous media by means of gel permeation chromatography (GPC). A set of experiments have been performed to ascertain the potential of the resins for the adsorption of uranium from seawater. Because of their modified pore structures, the chelating resins exhibited a marked adsorption rate for uranium in seawater as high as 23 μg of U/cm³ of resin/day without alkaline treatment.     

Preparation of fibrous ion-exchangers containing guanidine groups

Conclusions -- The reaction of guanidine with grafted polyglysodylmethacrylate has been investigated. Basic kinetic parameters of the process have been determined.-- Fibrous chemisorbents have been prepared based on graft PCA-PGMA or Cell-PGMA copolymers which have been aminated with guanidine; the content of amino nitrogen was up to 2% by wt.Translated from Khimicheskie Volokna, No. 1, pp. 29–31, January–February, 1991.     

Synthesis of a new type of adsorbent containing carboxyl and amidoxime groups by preirradiation grafting and its absorption of metal ions

A new type of adsorbent containing amidoxime and carboxyl groups was synthesized by the preirradiation graft copolymerization of acrylonitrile (AN) and acrylic acid (AA) onto fibrous‐type poly(vinyl alcohol) followed by amidoximation with hydroxylamine. The radiation dose and ratio of AN and AA monomers influenced the degree of grafting, the content of the amidoxime group, and the adsorption capacity. The synthesis course, structure, and properties of the adsorbent were investigated with Fourier transform infrared, scanning electron microscopy, and thermogravimetry. The adsorption property of the adsorbent for palladium(II) ions was also studied systematically. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 1986–1992, 2002     

Effect of water content of hydrophilic amidoxime polymer on adsorption rate of uranium from seawater

Amidoxime polymers crosslinked with tetraethylene glycol dimethacrylate (40 wt%) and with differing water contents were prepared by poly(acrylonitrile) treatment in various quantities of toluene with hydroxylamine. Adsorption rates of uranium on the amidoxime polymers from seawater were examined in relation to their porosity. The amidoxime polymer prepared from poly(acrylonitrile) in an increasing quantity of toluene exhibits a significantly increasing water content. On the basis of mercury intrusion measurements, the increasing water content was revealed to be predominantly owing to the enhancement of porosity. The adsorption rate of uranium from seawater increased steadily with an increase of porosity, suggesting the dependence of the adsorption rate on a diffusion process of uranium into the pore domain.     

纤维基吸附材料在海水提铀中的应用

介绍了纤维基吸附剂及其制造方法和应用实施情况。主要涉及高比表面纤维、聚合物吸附剂辐射接枝技术、海上作业以及回收铀的洗脱与纯化处理,并对纤维基吸附剂海水提铀的成本作了分析和说明。指出:近年来,国际上采用纤维基吸附剂从海水中提铀技术已取得了长足进展,开展这一方面的研究具有实际的技术经济效益和环境意义;建议我国尽快启动此项研究活动。     

Preparation of carbon-based adsorbents from sewage sludge pyrolysis to remove metals from water

The objective of this study was to evaluate the use of cheap carbon-based adsorbents from sewage sludge pyrolysis to remove Na⁺, K⁺, Ca²⁺ and Mg²⁺ from saline water. Four model solutions of NaCl, KCl, CaCl₂ and MgCl₂ that simulated seawater composition were used. The model solutions were 456.54 mmol_c L⁻¹ NaCl, 9.72 mmol_c L⁻¹ KCl, 19.96 mmol_c L⁻¹ CaCl₂ and 111.09 mmol_c L⁻¹ MgCl₂. Two carbon adsorbents, one with chemical activation, were prepared by a new method and evaluated for ion adsorption. The results indicated that carbon adsorbent without chemical activation was the most effective in removing ions from different solutions and the removal of metals followed the sequence: Na⁺ (76.78−69.66) >K⁺ (66.0−57.80) >Mg²⁺ (44.84−42.85) >Ca²⁺ (35.12−12.38). Results showed that it is to possible prepare carbon-based adsorbents from sewage sludge following inexpensive and environmentally acceptable methods.     

基于PVDF薄膜辐照接枝制备质子交换膜

含氟磺酸型质子交换膜是一类具有高热稳定性、化学稳定性及良好力学性能的离子交换膜,具有极其广阔的应用前景。采用⁶⁰Co辐照接枝技术,在聚偏氟乙烯（PVDF）基膜上产生自由基聚合位点,进而接枝对苯乙烯磺酰氯单体,经过一定条件酸碱处理得到一种新型偏氟磺酸型质子交换膜。并对其进行红外分析,结果显示PVDF膜上成功接枝上了对苯乙烯磺酰氯单体;定量研究了在相同辐照总剂量、不同剂量率条件下,所得质子交换膜的质子传导率、吸水率及离子交换容量与接枝率的关系,结果表明：当剂量率为40 Gy·min^-1时,所得质子交换膜接枝率为52.7%,吸水率为36.85%,80℃时质子传导率达到136 mS·cm^-1,离子交换容量为1.274 mmol·g^-1。     

Recovery of uranium from seawater. VI. Uranium adsorption ability and stability of macroporous chelating resin containing amidoxime groups prepared by the simultaneous use of divinylbenzene and ethyleneglycol dimethacrylate as crosslinking reagent

Macroporous chelating resins (RNH-DVB-1G) containing amidoxime groups with various degrees of crosslinking were synthesized by varying the amount of divinylbenzene (DVB) and ethyleneglycol dimethacrylate (1G). It was confirmed that the content of amidoxime group decreased with an increase in the degree of crosslinking. On the other hand, the amount of amidoxime group hydrolyzed by acid treatment showed a tendency to decrease with an increase in degree of crosslinking. From the measurement of specific surface area and pore size distribution, it was found that the macropore of RNH-DVB-1G with the same degree of crosslinking was remarkably affected by the composition of crosslinking reagent (DVB and 1G). The RNH-DVB-1G prepared in the present work were applied to the recovery of uranium from seawater. It was found that the uranium adsorption ability of RNH-DVB-1G with the same degree of crosslinking was remarkably affected by the proportion of DVB and 1G, although each RNH-DVB-1G had the same content of amidoxime group. In the case of RNH-DVB-1G prepared with 25 mol% of crosslinking reagent, the resin prepared with 10 mol% of DVB and 15 mol% of 1G showed the high adsorption ability for uranium in seawater. These results indicate that the simultaneous use of DVB and 1G contributes to the formation of effective macropore and micropore for recovery of uranium from seawater and the increase of chemical and physical stability.     

丙烯酸丁酯和聚丙二醇二甲基丙烯酸酯水相悬浮接枝PP的制备

以丙烯酸丁酯(BA)为接枝单体,聚丙二醇二甲基丙烯酸酯(PPGDMA)为交联剂,过氧化苯甲酰为引发剂,制备了聚丙烯与BA和PPGDMA的接枝共聚物,并研究了其性能。结果表明:聚丙烯接枝共聚物的接枝率达25.3%(w),接枝效率为94.0%～99.0%;PPGDMA分子中有两个双键,可以形成交联结构,当接枝单体BA和PPGDMA的总用量一定时,随m(PPGDMA)∶m(BA)的增加,接枝效率增大;m(PPGDMA)∶m(BA)=1∶7,BA和PPGDMA总用量为5%(w),10%(w)时,接枝产物的悬臂梁缺口冲击强度分别为4.1,6.7 kJ/m²,拉伸强度分别为40.4,39.2 MPa;聚丙烯接枝BA和PPGDMA可以显著提高其韧性。     

Preparation and application of antimicrobial man-made fibres and of fibrous materials containing quaternary ammonium compounds

Conclusions Biologically active fibres and textile materials based on them, containing salts of quaternary ammonium bases, in particular Katamin AB, have been prepared.It is proposed to used antimicrobial textile materials for biological protection of book and archival materials, purification of air in food industry plants, and in medical practice.Translated from Khimicheskie Volokna, No. 3, pp. 42–44, May–June, 1984.     

Preparation of amidoxime group-containing chelating fibers and their gold absorption properties. II. A preliminary investigation of the absorption behavior of Au3+ onto chelating fibers containing amidoxime groups

The absorption behavior of ionic gold onto chelating fibers containing amidoxime groups has been investigated. Chelating fibers not only present high absorption capacity, high absorption velocity and high selectivity to Au³⁺ ion, but also are able to reduce the absorbed Au³⁺ to metallic gold. When the fiber containing gold is burnt, spongy metallic gold is obtained. In the absorption process, the amidoxime group in the chelating fiber is gradually destroyed and a carboxyl group is formed.     

Preparation and characterization of novel poly(glycidyl methacrylate) beads carrying amidoxime groups

Poly(glycidyl methacrylate) (PGMA) beads with an average size of 350 μm were synthesized by suspension polymerization technique. The PGMA beads were first modified with iminodiacetonitrile (IDAN). Then, the IDAN‐modified beads were subsequently modified by hydroxylamine. The IDAN modification and the conversion of the nitrile groups to amidoxime were followed by FT‐IR spectroscopy. The surface morphology and thermal behavior of the PGMA and its modified forms were also characterized by scanning electron microscopy and thermogravimetric analysis techniques, further confirming modification and amidoximation. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007     

Preparation of macroreticular chelating resins containing dihydroxyphosphino and/or phosphono groups and their adsorption ability for uranium

The macroreticular chelating resins (RSP, RSPO, RCSP, and RCSPO) containing dihydroxy-phosphino and/or phosphono groups were prepared and their adsorption capacity for UO₂²⁺ and the recovery of uranium from sea water were investigated. RSP and RCSP were prepared by phosphorylation of macroreticular styrene–divinylbenzene copolymer beads and the chloromethylated copolymer beads, respectively. RSPO and RCSPO were prepared by oxidation of RSP and RCSP, respectively. The order of recovery of uranium from sea water with these four resins is as follows: RCSPO ? RCSP > RSPO > RSP. The adsorption of uranium in sea water was not only affected by the chemical structure, but also by physical structure of the resins. Uranium absorbed on the resins was eluted with 0.25 ～ 1 mol·dm^?3 Na₂CO₃ or NaHCO₃ solution by batch and column methods. The average recovery ratios of uranium from sea water with Na-form and H-form RCSP on 10 recycles were 84.9% and 90.5%, respectively, when 20 dm³ of sea water was passed through the column (resin 4 cm³, 10 mm ? × 50 mm) at the space velocity of 60 h^?1. RCSP has a high physical stability and resistance against acid and alkali solution.     

胶原纤维负载钛对氟铀废水中铀的吸附特性

将钛负载在胶原纤维上制备吸附材料(TICF),并系统研究了该吸附材料对模拟氟铀废水中UO²⁺₂的吸附规律。结果表明：TICF对UO²⁺₂有较强的吸附能力,当温度为303 K、pH为5.0、UO²⁺₂的初始浓度为1.50 mmol·L^-1时,吸附容量达到0.62 mmol U·g^-1;TICF相似文献   

Studies of the preparation,structure, and properties of an acrylic chelating fiber containing amidoxime groups

Polyacrylonitrile fiber was treated with hydroxylamine to form a chelating fiber containing the amidoxime group with high adsorption capacity to the Au³⁺ ion (up to 626 mg/g, when the nitrile group conversion reaches 53.7%), reasonable mechanical properties, and good thermal stability; the relationship among reaction conditions, fiber structures, and properties were investigated. The amidoxime group content rapidly increases to a steady value with increasing reaction time or HONH₂ ? HCl concentration, the fiber strength drops linearly with increasing reaction time, when the reaction takes place at the temperature where the morphology and order structure begins to be destroyed, and the amidoxime group content increases significantly, while fiber strength decreases remarkably. It is suggested that, to prepare a chelating fiber with high adsorption capacity and reasonable mechanical property, the reaction could be carried out at temperatures from 70 to 75°C, time of about 30 min, and concentration around 75 g/L. © 1993 John Wiley & Sons, Inc.