Showing papers in "Journal of Radioanalytical and Nuclear Chemistry in 2016"
TL;DR: In this article, metal-organic frameworks (MOFs) with high surface area and unprecedented chemical stability were synthesized and first explored for U(VI) capture from aqueous solutions.
Abstract: Metal–organic frameworks (MOFs) UiO-66 and its amine derivative (UiO-66-NH2) with high surface area and unprecedented chemical stability were synthesized and first explored for U(VI) capture from aqueous solutions. At pH 5.5, U(VI) sorption reach equilibrium in ca. 4 h and the maximum sorption capacity is more than 100 mg g−1. Moreover, they show desirable selectivity towards U(VI) over a range of competing metal ions. Sorption results demonstrate that introduction of amino groups into MOFs does not enhance U(VI) sorption, probably result from the lower activity of aromatic amines, decrease of surface area and formation of intermolecular hydrogen bonds.
167 citations
TL;DR: Hydroxyapatite is a main mineral constituent of bone and tooth and has an outstanding biocompatibility and the HAP column technique is advantageous with respect to the capacity to adsorb 90Sr from water present in the environment.
Abstract: Hydroxyapatite (HAP) is a main mineral constituent of bone and tooth and has an outstanding biocompatibility. HAP is a possible sorbent for heavy metals in wastewater due to its high adsorption capacity and low water solubility. We developed a removal system of 90Sr from aqueous solution by HAP column procedure. More than 90 % of 90Sr was adsorbed and removed from the 90Sr containing solution. Divalent cations, Ca2+, had little effect on the removal of 90Sr up to a concentration of 1 mmol L−1. This clearly indicates that the HAP column technique is advantageous with respect to the capacity to adsorb 90Sr from water present in the environment.
76 citations
TL;DR: The present status of development of software packages and equipment designed for automation of NAA at the reactor IBR-2 of FLNP, JINR, Dubna, RF, is described and details of the design are shown.
Abstract: The present status of development of software packages and equipment designed for automation of NAA at the reactor IBR-2 of FLNP, JINR, Dubna, RF, is described. The NAA database, construction of sample changers and software for automation of spectra measurement and calculation of concentrations are presented. Automation of QC procedures is integrated in the software developed. Details of the design are shown.
73 citations
TL;DR: Magnetic carboxymethylcellulose (CMC) beads were prepared via ionic cross-linking and then CMC beads were coated with polyaniline (PANI).
Abstract: Magnetic carboxymethylcellulose (CMC) beads were prepared via ionic cross-linking. Then CMC beads were coated with polyaniline (PANI). The results of FTIR, SEM, DTA and N2 adsorption–desorption demonstrated that aniline was successfully grafted onto the surface of mCMC beads. The potential use of the prepared adsorbent was used for removal of U(VI) ions. The determined maximum adsorption capacities of the mCMC and mCMC-g-PANI beads for U(VI) ions were 129.4 and 386.5 mg/g dry weight at pH 4.5, respectively. The thermodynamic parameters (ΔH°, ΔS° and ΔG°) were evaluated. The adsorbent systems were regenerated using 0.1 M HCl.
56 citations
TL;DR: A Zn(II)-based metal-organic frameworks (MOFs) containing azo-functionalized pores was synthesized by solvothermal process and batch adsorption experiments for the removal of U(VI) were performed with the MOFs.
Abstract: A Zn(II)-based metal–organic frameworks (MOFs) containing azo-functionalized pores was synthesized by solvothermal process. Batch adsorption experiments for the removal of U(VI) were performed with the MOFs. The adsorption data were successfully modeled by the Langmuir and D–R isotherms, suggesting a chemisorption with monolayer homogeneous adsorption. The thermodynamics research shows the adsorption being a feasible and endothermic process. The larger experimental adsorption capacity of 312.32 mg g−1 suggests that MOFs may be a potential adsorbent material for removal of U(VI) ions from waste water and further development would be warranted in future.
53 citations
TL;DR: The levels of radiocesium in boar appear to be more persistent than would be indicated by the constantly decreasing 137Cs inventory observed in the soil which points to a food source that is highly retentive to 137Cs contamination or to other radioecological anomalies that are not yet fully understood.
Abstract: The impact of Chernobyl on the 137Cs activities found in wild boars in Europe, even in remote locations from the NPP, has been much greater than the impact of Fukushima on boars in Japan. Although there is great variability within the 137Cs concentrations throughout the wild boar populations, some boars in southern Germany in recent years exhibit higher activity concentrations (up to 10,000 Bq/kg and higher) than the highest 137Cs levels found in boars in the governmental food monitoring campaign (7900 Bq/kg) in Fukushima prefecture in Japan. The levels of radiocesium in boar appear to be more persistent than would be indicated by the constantly decreasing 137Cs inventory observed in the soil which points to a food source that is highly retentive to 137Cs contamination or to other radioecological anomalies that are not yet fully understood.
47 citations
TL;DR: In this article, the aboveoxime modified Trametes trogii pellets were prepared by sequential reaction of fungal surfaces with glutaraldehyde, diaminomaleonitrile and hydroxylamine.
Abstract: Amidoxime modified Trametes trogii pellets were prepared by sequential reaction of fungal surfaces with glutaraldehyde, diaminomaleonitrile and hydroxylamine. Maximum biosorption capacities of the modified and native pellets were found to be 447.4 and 238.2 mg U(VI) g−1 fungal pellets, respectively. Biosorption equilibriums were established in about 45 min and the correlation regression coefficients show that the adsorption process can be well-defined by Langmuir equation. The biosorption of U(VI) ions was well described by the pseudo-second order kinetic model. The variations in enthalpy and entropy for the biosorbents were also calculated.
44 citations
TL;DR: In this article, a novel composites based on ethylene-propylene-diene monomer (EPDM) rubber for gamma shielding were prepared by using carbon blacks and ball milled PbWO4 (PWO) powder as fillers.
Abstract: A novel composites based on ethylene-propylene-diene monomer (EPDM) rubber for gamma shielding were prepared by using carbon blacks (CB) and ball milled PbWO4 (PWO) powder as fillers. The microstructure of ball milled PWO powder which has a uniform morphology in these composites was characterized by scanning electron microscope (SEM), X-ray diffraction (XRD). The mechanical and shielding tests were performed to determine mechanical and radiation attenuation properties, respectively. The results show these materials exhibit excellent mechanical and radiation-resistance properties.
43 citations
TL;DR: In this article, the radon activity concentration in drinking water samples and their annual effective dose exposure in Shimoga district was analyzed using the Emanometry technique, which revealed that 44.8% of the tested drinking water sample had radon levels in excess of the EPA recommended maximum contamination level of 11.1 Bq−l−1.
Abstract: This paper presents the distribution of radon activity concentration in drinking water samples and their annual effective dose exposure in Shimoga district. The radon concentrations in 38 drinking water samples were measured by using Emanometry technique. The measured radon concentration in drinking water samples ranged between 3.10 ± 0.25 and 38.50 ± 1.54 Bq l−1 with an average value of 13.60 ± 1.12 Bq l−1. This study reveals that 44.8 % drinking water samples analyzed have radon levels in excess of the EPA recommended maximum contamination level of 11.1 Bq l−1. The total mean annual effective doses of all the samples are significantly lower than the reference level of 0.1 mSv y−1.
40 citations
TL;DR: In this paper, the removal of cesium and strontium from aqueous solutions using chitosan surfacedecorated carbon nanotubes which contains Prussian blue analog (PBA/CS/CNTs) was performed.
Abstract: The removal of cesium and strontium from aqueous solutions using chitosan surface-decorated carbon nanotubes which contains Prussian blue analog (PBA/CS/CNTs) was performed. The experimental data was fitting well with Freundlich equation and Redlich–Peterson model. Sorption kinetic was agreed with pseudo-second-order, and the rate limiting step was mainly controlled by film diffusion. The maximum Cs+/Sr2+ adsorption capacity of adsorbents was 219.8/205.1 mg g−1. The study indicated that PBA/CS/CNTs can be used for the treatment of cesium and strontium contaminated water.
40 citations
TL;DR: In this article, the effect of pH, uranium concentration, mass of the adsorbent, temperature and contact time on the removal efficiency were studied and the results were simulated by Langmuir, Freundlich and Dubinin-Radushkevich isotherm models.
Abstract: The biosorption of uranium from aqueous solutions by Dictyopteris polypodioides brown algae was investigated. The effect of pH, uranium concentration, mass of the adsorbent, temperature and contact time on the removal efficiency were studied and the results were simulated by Langmuir, Freundlich and Dubinin–Radushkevich isotherm models. Kinetics data could be satisfactorily reproduced by the pseudo-second order equation and thermodynamic parameters were determined in order to evaluate the uranium uptake behavior. SEM/EDS and FT-IR were additionally used to characterize the algae and comprehend the sorption process which can be described as a combination of several mechanisms, including physical sorption, ion exchange and complexation.
TL;DR: In this article, the authors measured 210Pb and 7Be fluxes in Kuwait during October 2009-August 2011 and found a strong linear relationship between the two radionuclides and showed that 7Be shows a weaker correlation with dust deposition.
Abstract: Dust fallout fluxes of 210Pb and 7Be were measured in Kuwait during October 2009–August 2011. The annual average depositional fluxes of 210Pb and 7Be were 134 and 422 Bq m−2, respectively. The temporal variations of both radionuclides showed a maximum deposition during April of 2010 and 2011. A strong linear relationship between 7Be and 210Pb was found. The average dust depositional rate was about 50 mg m−2 h−1 with a maximum of 460 mg m−2 h−1, while the extreme value of 664 mg m−2 h−1 was recorded in March 2011 when a massive dust storm hit Kuwait. The 210Pb deposition has a strong correlation with dust deposition because of its terrestrial abundance. Whereas the 7Be a radionuclide shows a weaker correlation with dust deposition.
TL;DR: In this paper, a composite material of SiO2-Al2O3 based on poly(acrylic acid-maleic acid) was synthesized by irradiated with 60Co γ-rays at a dose of 25 KGy.
Abstract: A novel composite material of SiO2–Al2O3 based on poly(acrylic acid–maleic acid) was synthesized by irradiated with 60Co γ-rays at a dose of 25 KGy. The composite material was characterized using FTIR, TGA and BET surface area. Adsorption of 134Cs from HNO3 was studied as a function of contact time, temperature and concentration of Cs. Sorption behavior of 134Cs in different concentration of HCl, HNO3, acetic acid, ascorbic acid, citric acid, NaCl and NaNO3 solutions has been investigated. It can be concluded that the P(AA–MA)/SiO2/Al2O3 is promising adsorbent for Cs removal from acidic liquid radioactive waste.
TL;DR: In this paper, a facile one-pot method to prepare sulfonated graphene oxide (GOS) via vapor-solid transfer reaction of graphene oxide was described and investigated as an adsorbent for the adsorption of U(VI) from aqueous solutions.
Abstract: In this article, we report a facile one-pot method to prepare sulfonated graphene oxide (GOS) via vapor–solid transfer reaction of graphene oxide (GO). The synthesized GOS were characterized and investigated as an adsorbent for the adsorption of U(VI) from aqueous solutions. The results indicated that the adsorption of U(VI) was strongly dependent on pH and independent of ionic strength. The adsorption process followed the pseudo-second-order kinetics and the adsorption isotherm agreed well with the Langmuir model, having a maximum adsorption capacity of 309.09 mg g−1. Thermodynamic parameters indicated that the adsorption reaction was an endothermic and spontaneous process.
TL;DR: The magnetic carboxymethyl chitosan nano-particles functionalized with ethylenediamine (EDA-MCCS) was synthesized for U(VI) adsorption as discussed by the authors.
Abstract: The magnetic carboxymethyl chitosan nano-particles functionalized with ethylenediamine (EDA-MCCS) was synthesized for U(VI) adsorption. The EDA-MCCS showed high affinity and fast kinetic for U(VI) adsorption. The adsorption kinetic could be interpreted by the pseudo-second-order equation. The adsorption isotherm fitted well with the Langmuir equation, with the maximum sorption capacity of 175.4 mg g−1 at 25 °C and pH 4.5. Thermodynamic parameters indicated the exothermic and spontaneous nature of U(VI) adsorption. The EDA-MCCS could be successfully regenerated using 0.20 M EDTA–0.10 M HNO3 as the eluent.
TL;DR: In this article, an extractant-impregnated resin (EIR) was fabricated by impregnation of Ambelite XAD-7 resin beads with titan yellow as extractant.
Abstract: To remove Th(IV) ion from acidic solutions (pH 2.5–2.7), an extractant-impregnated resin (EIR) was fabricated by impregnation of Ambelite XAD-7 resin beads with titan yellow as extractant. Various physicochemical factors such as pH, contact time, temperature, sorbent dose and initial concentration of thorium were investigated. The isotherm data was well interpreted by the Langmuir model. Kinetic experiments data showed that the sorption process could be described by Weber–Morris kinetic model. Thermodynamic studies revealed the feasibility, spontaneity and endothermic nature of sorption process. Desorption experiments showed that the EIR could be reused without significant losses of its initial capacity.
TL;DR: In this paper, a zinc oxide/rectorite composites were synthesized by a sol-gel method and the methanol as sacrificial organics could enhance the adsorption capability and photocatalytic reduction activity of U(VI) onto the zinc oxide and rectorite composite, which still showed the high photoreduction activity after four reaction cycles under visible light irradiation.
Abstract: In this work, zinc oxide/rectorite composites were synthesized by a sol–gel method. The methanol as sacrificial organics could be enhance the adsorption capability and photocatalytic reduction activity of U(VI) onto the zinc oxide/rectorite composites. In addition, the composite still showed the high photoreduction activity after four reaction cycles under visible light irradiation. On the basis of the experimental results and photoluminescence, the enhanced photoreduction activity could be attributed to charge-transfer-complex and the coupling effect of ZnO and rectorite in the composite.
TL;DR: In this paper, a series of isoreticular metal-organic frameworks (MOFs) with the same 3D framework decorated by different organic groups in the pore wall were used to extract U(VI) ions from simulated seawater.
Abstract: We report the studies of uranyl adsorption on a series of isoreticular Metal–organic frameworks (MOFs) with the same 3D framework decorated by different organic groups in the pore wall. Scanning electron microscope and energy dispersive X-ray spectroscopy indicated that the sorbents were capable of encaging uranium from aqueous solution. Typical adsorption isotherms (Langmuir, Freundlich) studies showed different mechanism of sorption process and kinetic studies described different sorption behavior of the MOF materials, which were due to the different functional groups. Finally, two MOFs were successfully employed to extract U(VI) ions from simulated seawater.
TL;DR: The radiocesium derived from the Fukushima Dai-ichi nuclear power plant accident in March 2011 was found in the Bering Sea and western North Pacific between 25°N and 63°N, which agrees with model simulation results of atmospheric deposition as mentioned in this paper.
Abstract: In summer 2012, we measured activity concentration of radiocesium in surface seawater collected in the Arctic Ocean, Bering Sea, western Pacific Ocean, and Antarctic Ocean. The radiocesium derived from the Fukushima Dai-ichi Nuclear Power Plant accident in March 2011 was found in the Bering Sea and western North Pacific between 25°N and 63°N, which agrees with model simulation results of atmospheric deposition. A semi-synoptic view suggests that a main body of radiocesium discharged directly had been transported eastward to 170°W, northward to 50°N, and southward to 30°N by summer 2012, about one and half years after the accident.
TL;DR: Synthesis of a variety of 99mTc carrying biological molecules (antibiotics/antibodies/peptides/amino acids/macro and micro-organic molecules) along with their applications are discussed, to overview key innovations.
Abstract: In the past few years, substantial progress has been made in technetium chemistry, including the synthesis of a variety of 99mTc-radiopharmaceuticals. This synthesis can be made feasible by using suitable reducing agents, highly specific ligands, appropriate buffer, and specific pH etc., which results in high radiochemical purity, minimum labeling time, commercial expediency of 99Mo/99mTc generator and high biological efficacy. 99mTc-radiopharmaceuticals have confirmed their worth in every span of life, especially in clinical and medical applications. Now 99mTc based pharmaceuticals are being used as diagnostic agents for a large number of infections caused by bacteria or any pathogens, tumors, cancers, ulcers etc. In this review, we discuss synthesis of a variety of 99mTc carrying biological molecules (antibiotics/antibodies/peptides/amino acids/macro and micro-organic molecules) along with their applications, to overview key innovations.
TL;DR: The nanoscale zero-valent iron supported on activated charcoal (nZVI/AC) by the reduction of ferrous sulfate heptahydrate with sodium borohydride was synthesized for uranium(VI) adsorption as mentioned in this paper.
Abstract: The nanoscale zero-valent iron supported on activated charcoal (nZVI/AC) by the reduction of ferrous sulfate heptahydrate with sodium borohydride was synthesized for uranium(VI) adsorption. The nZVI/AC was characterized using X-ray radiation diffraction and scanning electron microscope. The adsorption kinetics, adsorption isotherms and adsorption thermodynamics were also examined. The adsorption capacity reached 492.6 mg/g when dosage was 0.5 g/L, initial concentration of uranium(VI) was 250 mg/L, pH was 5, temperature was 35 °C and time was 60 min. The experimental results indicated that nZVI/AC possessed many advantages such as simple and economy for preparation, less adsorbent dosage, short balance time, high adsorption ratio and adsorption capacity. The synthesized adsorbent is promising to efficiently treat the uranium-contained wastewater.
TL;DR: The concentrations of radiocesium in different organs of wild boar inhabiting Iitate, Fukushima were measured, after the Fukushima Daiichi nuclear power plant accident, and indicated its availability in the ecosystem of the forests and villages where the boars matured.
Abstract: The concentrations of radiocesium in different organs of wild boar inhabiting Iitate, Fukushima were measured, after the Fukushima Daiichi nuclear power plant accident. After dissection, about 24 parts were collected and measured using a NaI gamma ray counter. In 2012, the radiocesium concentration (134Cs and 137Cs) was highest in muscle (approximately 15,000 Bq kg−1) and low in ovary, bone and thyroid gland, indicating large variation among tissues. Radiocesium concentrations in 24 different organs revealed the pattern of distribution of radiocesium in wild boar and indicated its availability in the ecosystem of the forests and villages where the boars matured.
TL;DR: The usefulness of 99mTc-mesalamine as a radiotracer for ulcerative colitis was supported and the structure of the complex was confirmed using in silico analysis.
Abstract: Mesalamine was labelled with technetium-99m (99mTc) in high radiolabelling yield (~98.4 %), in vitro stability (~4 h) and in serum persistence (~24 h). Optimum labelling conditions were investigated. The structure of the complex was confirmed using in silico analysis. Molecular docking was performed to evaluate the complex binding to its biochemical target, the PPARγ receptor. Biodistribution and clearance studies were performed in normal and ulcerative colitis models in mice. The tracer’s localization was highest (~65.2 %) in microbial model compared to chemical model (~42.4 %) and normal mice (~22.1 %) at 60 min post injection. All data supported the usefulness of 99mTc-mesalamine as a radiotracer for ulcerative colitis.
TL;DR: In this article, Rice straw-based biochars modified with different chemical regents were used as an adsorbent for uranium(VI) removal, and the effect of pyrolysis temperature and nature of modifying agent's as well as surface chemistry, surface charge, and pore structure was investigated.
Abstract: Rice straw-based biochars modified with different chemical regents were used as an adsorbent for uranium(VI). Effect of pyrolysis temperature and nature of modifying agent’s as well as surface chemistry, surface charge, and pore structure on U(VI) removal was investigated. Amount and nature of the surface groups has, in general, more influence than its porosity on U(VI) adsorption. The adsorption was maximum for the initial pH of 5.5. Rice straw derived biochars had comparable U(VI) adsorption as compared to other adsorbents. The U(VI) removal was 90 % from groundwater. NaHCO3 was found to be the most efficient desorbent eluent for U(VI).
TL;DR: In this article, surface modification of Wool fibers was performed by reactions first with acrylonitrile and followed by hydroxylamine to prepare amidoxime functionalized wool fibers (Wool-g-AO).
Abstract: Surface modification of wool fibers was performed by reactions first with acrylonitrile and followed by hydroxylamine to prepare amidoxime functionalized wool fibers (Wool-g-AO). The Wool-g-AO was used for recovery of U(VI) from aqueous solution by batch experiments. The adsorption kinetics, isotherms, and effects of contact time, pH, and initial U(VI) concentration were investigated. The maximum uptake of U(VI) on Wool-g-AO was achieved at pH 5.0. Kinetic data were fitted well to pseudo second order equations. The adsorption equilibrium of U(VI) on Woo-g-AO could be defined by the Langmuir isotherm model.
TL;DR: This paper developed a lexicon to consistently and objectively describe morphological features observed in scanning electron microscopy (SEM) images, which can be used to characterize texture and surface features, particle structure and size, and grain boundaries.
Abstract: We have developed a lexicon to consistently and objectively describe morphological features observed in scanning electron microscopy (SEM) images. Here we provide the lexicon flowsheet, define the terminology, and detail step-by-step characterization of SEM images collected from a set of actinide oxides. We conclude that this lexicon can be used to characterize texture and surface features, particle structure and size, and grain boundaries in an image of a material. The lexicon should be applicable to characterization of images collected from other techniques for measuring morphology, as well. LA-UR-15-26746
TL;DR: In this article, the sorption and desorption of uranium (VI) on GMZ bentonite was investigated as functions of contact time, pH, ionic strength, foreign ions, HSs and initial U(VI) using batch experiments.
Abstract: The sorption and desorption of uranium(VI) on GMZ bentonite was investigated as functions of contact time, pH, ionic strength, foreign ions, HSs and initial U(VI) using batch experiments. It is revealed that the sorption strongly depended on pH, cations (Li+, Na+ and K+) and anions (CO3
2−, SO4
2− and PO4
3−). HA benefits the sorption at pH <7.0, while inhibited the sorption at higher pH. Moreover, the hysteresis occurred in the sorption–desorption process in the presence/absence of humic substances. The results could provide data base for the safety assessment of the deep geological disposal repository of high radioactive waste.
TL;DR: In this paper, selectivity of uranium using bis(2,4,4-trimethylpentyl)phosphinic acid in xylene and C8mimNTf2 was investigated.
Abstract: Selective separation of uranium using bis(2,4,4-trimethylpentyl)phosphinic acid in xylene and C8mimNTf2 was investigated. For ionic liquid based system, the extraction kinetics was found to be slower with the predominance of ion exchange mechanism through [UO2(NO3)·2L]+, while for xylene based system solvation mechanism. The nature of the extracted species was found to be different in both the media as observed in luminescence study. Ionic liquid based system was more radioresistant than that of molecular diluents. Na2CO3 was successfully used for stripping. The selectivity was investigated by processing simulated high level waste of pressurized heavy water reactor origin.
TL;DR: In this paper, particle induced X-ray emission and energy disperse-X ray fluorescence were used to analyze chemical composition of samples, and five major sources have been identified by using positive matrix factorization.
Abstract: In order to do source apportionment of PM2.5 and source trajectories, particle induced X-ray emission and energy disperse-X ray fluorescence were used to analyze chemical composition of samples. Five major sources have been identified by using positive matrix factorization. Source trajectories have been determined by conditional probability function and the potential source contribution function. Extreme events, such as sandstorms, have been identified and traced.
TL;DR: Radioiodination techniques were critically analyzed and the influence of iodine introduction on physicochemical properties, in vivo or in vitro pharmacological properties of pharmaceutical due to increase of lipophilicity were discussed along with examples.
Abstract: A variety of radioiodination methods is available in the literature depending upon the nature of organic compound to be labeled, however only few can completely fulfill manufacturing requirements.Ideally a selected method should be one which offers maximum benefits like regioselectivity, minimum reaction steps, minimum reaction time, high radiochemical yield and high specific activity. In this review radioiodination techniques were critically analyzed. Advantages, drawbacks, possible mode of action and special reaction conditions required to get high radiochemical yield were taken into account. The influence of iodine introduction on physicochemical properties, in vivo or in vitro pharmacological properties of pharmaceutical due to increase of lipophilicity were discussed along with examples.