Showing papers in "Journal of Radioanalytical and Nuclear Chemistry in 2014"
TL;DR: In this article, a review of the applications of CNTs in treatment of toxic metal-containing wastewater for environmental monitoring and metals recovery is presented, and the latest research progress of using CNT composites for metal treatment is also discussed.
Abstract: Environmental pollution caused by toxic metals (heavy metals, radioactive metals, etc.) is one of the major global issues, thus removal of toxic metals from contaminated water seems to be particularly important. On the other hand, the recovery and enrichment of metals, especially noble metals, from waste water is also crucial. To address these issues, nanotechnology plays an essential role in environmental monitoring and pollution control. To remove metals from contaminated water, or enrich metals from waste water, carbon nanotubes (CNTs) and their composites have attracted great attention due to their excellent adsorption performance. The removal efficiency for metal ions by CNTs was observed aroud 10–80 %, which could be improved to approach 100 % by selectively functionalizing CNTs with organic ligands. Herein, we review the applications of CNTs in treatment of toxic metal-containing wastewater for environmental monitoring and metals recovery. Due to their higher sensitivity and selectivity towards the enrichment of metals or detection of toxic metal pollution of the environment, and the latest research progress of using CNT composites for metal treatment is also discussed.
69 citations
TL;DR: Temperature has weak influence both on pure substance and with citric acid adsorbed, as derivatographic analysis has shown, and characterization of hydroxyapatite structure may be carried out by this thermal analysis.
Abstract: The specific adsorption of citric acid ions at hydroxyapatite interface was investigated by the means of radioisotope method (14C) as a function of citric acid ions concentration, NaCl concentration and pH. Application of the hydroxyapatite has become wide in the biomaterial field as the Ca10(OH)2(PO4)6 possess biocompatibility with human hard tissue. Hydroxyapatite was synthesized using three different methods. The physical properties of the resulting powder were characterized by DTA/TG, XRD, AFM and SEM microscopy. Physicochemical qualities characterizing the electrical double layer of the hydroxyapatite/NaCl solution interface were determined. The zeta potential and the adsorption of citric acid molecule were studied as a function of pH. The point of zero charge and the isoelectric point of samples were determined. Electrical double layer parameters of hydroxyapatite/NaCl interface are influenced by a synthesis method. The points pHpzc and pHIEP for sample 1 are pHpzc 7.5 and pHIEP 3; for sample 2 pHpzc 7.05 and pHIEP 3, for smaple 3 pHpzc 6.7 and pHIEP 3. Temperature has weak influence both on pure substance and with citric acid adsorbed, as derivatographic analysis has shown, and characterization of hydroxyapatite structure may be carried out by this thermal analysis. Two phenomena are responsible for citric acid adsorption: phosphate group’s replacement at hydroxyapatite surface by citric ions parallel to intraspherical complexes formation.
66 citations
TL;DR: In this article, the adsorption of four radionuclides, 134Cs(I), 90Sr(II), 133Ba(II) and 152Eu(III), by an Egyptian bentonite (Bent) and its modified Na+ form (Na-Bent), collected from a deposit within Alexandria governorate was investigated as a function of different parameters.
Abstract: Clays and specially bentonite are widely used as natural adsorbents for wastewater treatment and as a barrier in landfills to prevent the contamination of subsoil and groundwater by leachates containing radioactive materials. The adsorption of four radionuclides, 134Cs(I), 90Sr(II), 133Ba(II) and 152Eu(III) by an Egyptian bentonite (Bent) and its modified Na+ form (Na-Bent) collected from a deposit within Alexandria governorate was investigated as a function of different parameters. The batch equilibrium technique was used and the kinetic results showed that the equilibrium was mostly reached within 10 min and the kinetic data fit well to the pseudo-second order model. The Langmuir model fits well the experimental data of all metals adsorption on Bent and Na-Bent except for adsorption of 133Ba on Bent, while 152Eu adsorption on Na-Bent fits better to the Freundlich model rather than to the Langmuir. Both Bent and Na-Bent fit well to the D-R model with adsorption energy of E > 8 kJ mol−1 that means that the adsorption reaction is expected to be controlled by both cation exchange and surface complexation reactions. At lower concentrations, the values of distribution coefficient (K
d), follow the order of 152Eu > 90Sr > 134Cs > 133Ba for Bent and Na-Bent. The K
d of 152Eu is higher than that of 134Cs in Bent up to 150 mg L−1. This order changes at higher concentration where the K
d of 134Cs becomes higher than 152Eu after 150 mg L−1 for Bent and after 200 mg L−1 for Na-Bent. Na-Bent is preferred than Bent for the uptake of 90Sr and 134Cs especially at high concentration.
63 citations
TL;DR: In this paper, the effects of pH, temperature, ionic strength, biosorbent dosage, and initial uranium concentrations on uranium biosorption were investigated in a batch system using bare CMC beads as a control system.
Abstract: Biosorption of uranium from aqueous solution onto the free and entrapped algae, “Chlamydomonas reinhardtii” in carboxymethyl cellulose (CMC) beads was investigated in a batch system using bare CMC beads as a control system. CMC can be a potential natural biosorbent for radionuclide removal as it contains carboxyl groups. However, limited information is available with the biosorption of uranium by CMC, when adsorption isotherm, kinetics and thermodynamics parameters are concerned. The biosorbent preparations were characterized by swelling tests, FTIR, and surface area studies. The effects of pH, temperature, ionic strength, biosorbent dosage, and initial uranium concentrations on uranium biosorption were investigated. Freely suspended algae exhibited the highest uranium uptake capacity with an initial uranium ion concentration of 1,000 mg/L at pH of 4.5 and at 25 °C. The removal of U(VI) ion from the aqueous solution with all the tested biosorbents increased as the initial concentration of U(VI) ion increased in the medium. Maximum biosorption capacities for free algal cells, entrapped algal cells, and bare CMC beads were found to be 337.2, 196.8, and 153.4 mg U(VI)/g, respectively. The kinetic studies indicated that the biosorption of U(VI) ion was well described by the pseudo-second order kinetic model. The variations in enthalpy and entropy for the tested biosorbent were calculated from the experimental data. The algal cells entrapped beads were regenerated using 10 mM HNO3, with up to 94 % recovery. Algal cells entrapped CMC beads is a low cost and a potential composite biosorbent with high biosorption capacity for the removal of U(VI) from waters.
61 citations
TL;DR: Activity concentration of the 222Rn radionuclide was determined in drinking water samples from the Sothern Greater Poland region by liquid scintillation technique and the calculated average annual effective doses from ingestion with water and inhalation of this radon escaping from water were 1.15 and 11.8 μSv, respectively.
Abstract: Activity concentration of the 222Rn radionuclide was determined in drinking water samples from the Sothern Greater Poland region by liquid scintillation technique. The measured values ranged from 0.42 to 10.52 Bq/dm3 with the geometric mean value of 1.92 Bq/dm3. The calculated average annual effective doses from ingestion with water and inhalation of this radionuclide escaping from water were 1.15 and 11.8 μSv, respectively. Therefore, it should be underlined that, generally, it’s not the ingestion of natural radionuclides with water but inhalation of the radon escaping from water which is a substantial part of the radiological hazard due to the presence of the natural radionuclides from the uranium and thorium series in the drinking water.
58 citations
TL;DR: In this paper, a batch adsorption method as a green technology has been investigated for removal and recovery of Nd and Sm using magnetic nano-hydroxyapatite adsorbent (MNHA).
Abstract: The removal and recovery of lanthanides has become important because of their wide applications in industry and also in environmental protection. The necessity for these elements requires the selective and effective separation technique. In this study, batch adsorption method as a green technology has been investigated for removal and recovery of Nd and Sm using magnetic nano-hydroxyapatite adsorbent (MNHA). According to results, the maximum adsorption capacities of Nd and Sm were calculated as 323 and 370 mg/g at optimum pH 5.5, respectively. Different types of adsorption isotherms and kinetic models were used to describe the Nd and Sm adsorption behavior, and the experimental results fitted Langmuir model and the pseudo-second-order kinetic models well. The adsorption of Nd and Sm was found as endothermic and spontaneous process with respect to obtained thermodynamic parameters. Recovery of adsorbed lanthanides and reusability of adsorbent was tested. Possible adsorption mechanisms were also discussed. The proposed adsorbent, MNHA has good adsorption ability and high sorption capacity for Nd and Sm with a chemisorption mechanism.
57 citations
TL;DR: In this paper, the authors present an overview of studies carried out in their laboratory on different aspects of reprocessing of U and Th based spent fuels employing N,N-dialkyl amides as extractants.
Abstract: Reprocessing of spent nuclear fuel is vital for the long-term global nuclear power growth and is the major motivation for developing novel separation schemes. Conventionally, PUREX and THOREX processes have been proposed for the reprocessing of U and Th based spent fuels employing tri-n-butyl phosphate (TBP) as extractant. However, based on the experiences gained over last five–six decades on the reprocessing of spent fuels, some major drawbacks of TBP have been identified. Evaluation of alternative extractants is, therefore, desirable which can overcome at least some of these problems. Extensive studies have been carried out on the evaluation of N,N-dialkyl amides as extractants in the back-end of the nuclear fuel cycle for addressing the issues related to the reprocessing of U and Th based spent fuels. Under advanced fuel cycle scenario, efforts are also being made by countries with a developed nuclear technological base to provide safe nuclear power to other countries and to minimize proliferation concerns worldwide. This paper presents an overview of studies carried out in our laboratory on different aspects of reprocessing of U and Th based spent fuels employing N,N-dialkyl amides as extractants.
50 citations
TL;DR: This review attempts to collate and critically analyze the available researches on how the ionizing radiation might interact with crops at the whole plant or tissue or cell level to affect economic yield under various edaphic variables where not only the productivity but also the quality of the agri-produce may become vulnerable.
Abstract: Applications involving radioisotopes and radiations reveal a great promise particularly for the welfare of the society. However, in the event of a nuclear accident, the direct and indirect effect of radionuclide and radiation transfers in soil–plant–air environment are envisaged on almost all the components of the food chain. It also assumes significance as we often overlook the fact that radiations, emitted by any radioisotope although cannot be seen or felt, interacts with matter and could alter its biochemical, biophysical and biological characteristics. The interaction of ionizing radiation with human body and consequent biological effects are well characterized and quantified using data derived from the radiation workers and/or the nuclear accidents around the world. However, radiation impact on agriculture viz a viz economic productivity are not well understood and available data is scanty, scattered and inconclusive. At the plant level the effects could be visualized at morphological, biochemical, physiological and/or biophysical levels, where the magnitude of the effected change depends heavily on the exposure dose, soil, farm management and other environmental variables. This review attempts to collate and critically analyze the available researches on how the ionizing radiation might interact with crops at the whole plant or tissue or cell level to affect economic yield under various edaphic variables where not only the productivity but also the quality of the agri-produce may become vulnerable.
48 citations
TL;DR: In this article, the phosphorylated hydrothermal carbon spheres (HCS-PO4) were developed by functionalizing HCS with o-phosphoethanolamine, and the structure and textural property were characterized by SEM and FT-IR.
Abstract: The phosphorylated hydrothermal carbon spheres (HCS-PO4) were developed by functionalizing hydrothermal carbon spheres (HCS) with o-phosphoethanolamine, and the structure and textural property were characterized by SEM and FT-IR. The parameters that affect the uranium(VI) sorption, such as solution pH, initial U(VI) concentration, contact time, and temperature, had been investigated. The HCS-PO4 showed the highest uranium sorption capacity at initial pH 6.0 and contact time of 120 min. The adsorption kinetics was better described by the pseudo-second-order model, and the adsorption process could be well defined by the Langmuir isotherm and the maximum monolayer adsorption capacity increased from 80.00 to 434.78 mg/g after phosphorylation. The thermodynamic parameters, ∆G° (298 K), ∆H° and ∆S°, demonstrated shown that the sorption process of U(VI) onto HCS-PO4 was feasible, spontaneous and endothermic in nature. The spent HCS-PO4 could be effectively regenerated by 0.1 mol/L EDTA solution for the removal and recovery of U(VI) and reused for ten cycles at least. Selective adsorption studies showed that the HCS-PO4 could selectively remove U(VI), and the selectivity coefficients of HCS in the presence of co-existing ions, Mg(II), Na(I), Zn(II), Mn(II),Co(II), Ni(II), Sr(II), Cs(I) and Hg(II) improved after functionalization.
44 citations
TL;DR: This work revealed that there is a significant tendency for an increase in Bi, Cd, Co, Fe, Hg, Sc, Sn, Th, U, and Zn mass fraction in normal prostate from age 21 years to the sixth decade.
Abstract: The variation with age of the mass fraction of 54 trace elements (Ag, Al, As, Au, B, Be, Bi, Br, Cd, Ce, Co, Cr, Cs, Dy, Er, Eu, Fe, Ga, Gd, Hf, Hg, Ho, Ir, La, Li, Lu, Mn, Mo, Nb, Nd, Ni, Pb, Pd, Pr, Pt, Rb, Re, Sb, Sc, Se, Sm, Sn, Ta, Tb, Te, Th, Ti, Tl, Tm, U, Y, Yb, Zn, and Zr) in intact nonhyperplastic prostate of 65 healthy 21–87 year old males was investigated by instrumental neutron activation analysis with high resolution spectrometry of long-lived radionuclides and inductively coupled plasma mass spectrometry. This work revealed that there is a significant tendency for an increase in Bi, Cd, Co, Fe, Hg, Sc, Sn, Th, U, and Zn (p < 0.0014) mass fraction in normal prostate from age 21 years to the sixth decade. In the sixth to ninth decades the mass fractions of almost all chemical elements investigated in nonhyperplastic prostates were maintained at approximately stable levels. Our finding of correlation between pairs of prostatic chemical element mass fractions indicates that there is a great disturbance of prostatic chemical element relationships with increasing age.
44 citations
TL;DR: In this article, a study was undertaken to assess uranium in groundwater and radiological and chemical risks associated with its ingestion in rural habitats in the vicinity of proposed nuclear power project in Western Haryana, India.
Abstract: This study was undertaken to assess uranium in groundwater and radiological and chemical risks associated with its ingestion in rural habitats in the vicinity of proposed nuclear power project in Western Haryana, India. Uranium concentration in the groundwater of the study area varied from 0.3 to 256.4 μg L−1. Radiological risk calculated in the form of average life time dose was found 5.1 × 10−2 mSv to the residents of the area from the ingestion of groundwater. The average cancer mortality and average cancer morbidity risk were calculated to be 4.9 × 10−6 and 7.7 × 10−6 respectively indicating the absence of carcinogenic risks. Chemical risk was in the range of 0.02–18.8 µg kg−1 day−1. Hazard quotient for 72 % samples was greater than unity which indicates health risk due to chemical toxicity of uranium in groundwater. The results indicate that uranium concentrations in the groundwater of the study area are important due to chemical risk than radiological risk.
TL;DR: In this paper, the uptake behavior of Am3+ was investigated by using alginic acid and alginate polymer gels, and the column packed with calcium alginates beads was effective for the removal of trace amounts of Am 3+ from acidic nitrate solutions.
Abstract: The uptake behavior of Am3+ was investigated by using alginic acid and alginate polymer gels. The affinity of radioactive nuclides for carboxyl groups in gel matrices increased in the order of Na+ < Cs+ < Co2+ < Pd2+, Sr2+, Fe3+ < Eu3+, Am3+. Among alginate gels, calcium alginate exhibited relatively higher uptake rate and distribution coefficient of Am3+. The column packed with calcium alginate beads was effective for the removal of trace amounts of Am3+ from acidic nitrate solutions.
TL;DR: In this article, a review of the principles behind, advantages and disadvantages of different types of active neutron interrogation is presented, including thermal neutron analysis, pulsed fast/thermal neutron analysis and fast neutron radiography.
Abstract: Conventional explosives are relatively easy to obtain and may cause massive harm to people and property. There are several tools employed by law enforcement to detect explosives, but these can be subverted. Active neutron interrogation is a viable alternative to those techniques, and includes: fast neutron analysis, thermal neutron analysis, pulsed fast/thermal neutron analysis, neutron elastic scatter, and fast neutron radiography. These methods vary based on neutron energy and radiation detected. A thorough review of the principles behind, advantages, and disadvantages of the different types of active neutron interrogation is presented.
TL;DR: The production of 244Pu, 243Am, 248Cm, 249Bk, and 249Cf targets on thin Ti backings by molecular plating using ion chromatographic techniques is reported on.
Abstract: The heaviest elements are synthesized in heavy-ion induced hot fusion reactions with various actinide targets. Because the actinide material is often available only in very limited amounts, a deposition method with high yields (~90 %) is needed. We report on the production of 244Pu, 243Am, 248Cm, 249Bk, and 249Cf targets on thin Ti backings by molecular plating. Different chemical purification steps using ion chromatographic techniques were applied for the purification of 249Cf and 244Pu. The deposition procedure applied for the production of ~0.4–0.8 mg/cm2 thick targets is described. The deposition yield was determined either by α-particle or γ-ray spectroscopy. Furthermore, neutron activation analysis has been applied in the case of 244Pu, 243Am, and 248Cm. Information about the spatial distribution and homogeneity of the target layer was obtained by radiographic imaging.
TL;DR: In this article, the authors simulated the effects of proton irradiation on bilayer graphene on SiC using SRIM code, a very detailed code capable of modeling ranging from very thick materials to single layer structures.
Abstract: Graphene is experienced its golden age in the world of nanotechnology. Despite the fact that it takes key roles in the very complex areas, it is a simple two-dimensional material which is formed by only carbon atoms with a honeycomb form on especially another material. Graphene monolayer is usually supported by a known SiC substrate. SiC is a valuable material for both electronics and nuclear researches because of the excellent shielding and conduction properties. We simulated 500 keV proton irradiation effects on bilayer graphene on SiC by SRIM code in this paper. SRIM is a very detailed code capable of modeling ranging from very thick materials to single layer structures. This code is based on sending ions with specific energy to a target material. We presented damages and displacements caused by 500 keV protons to bilayer graphene/SiC target in the view of promising face of space and solar cell technology.
TL;DR: In this paper, commercial charcoal was applied to the removal of surfactant from liquid radioactive waste, where the data obtained can be used for designing a plant for treatment of ocean water and wastewater economically.
Abstract: In nuclear power plants and nuclear laboratories, laundry wastewater is generated from decontaminating polluted instruments, worker’s clothes and taking shower after work. Laundry wastewater contains radionuclides and surfactants. The surfactants included in laundry wastewater affect the extraction of radionuclides. Therefore, surfactants should be removed before extraction of radionuclides. The objective of the present work is to assess the ability of commercial charcoal for the removal of nonionic surfactants, where, commercial charcoal is a commonly available adsorbent for treatment. Charcoal was characterized using different analytical techniques. The isotherm models and thermodynamic parameters were evaluated. Charcoal was applied to the removal of surfactant from liquid radioactive waste. The data obtained can be used for designing a plant for treatment of surfactant rich water and wastewater economically.
TL;DR: In this paper, a novel graphene oxide-carbon nanotubes (GO-CNTs) hybrid aerogels were fabricated via a freeze-drying method using aqueous solutions of GO and CNTs.
Abstract: Novel graphene oxide–carbon nanotubes (GO–CNTs) hybrid aerogels were fabricated via a freeze-drying method using aqueous solutions of GO and CNTs. The resulting aerogels were characterized by scanning electron microscopy, X-ray diffraction, Fourier transformed infrared spectroscopy and thermal gravity analysis. The three-dimensional GO–CNTs aerogels were used to remove uranium(VI) from aqueous solutions. The results showed that GO–CNTs aerogels had high removal ability to uranium(VI) and could be a promising sorbent for many environment applications.
TL;DR: The simple and effective technique of fission track etch has been applied to determine trace concentration of uranium in human blood samples taken from two groups of male and female participants: leukemia patients and healthy subjects group, and it has been found that the uranium concentrations in humanBlood samples of leukemia patients are higher than those of the healthy group.
Abstract: The simple and effective technique of fission track etch has been applied to determine trace concentration of uranium in human blood samples taken from two groups of male and female participants: leukemia patients and healthy subjects group. The blood samples of leukemia patients and healthy subjects were collected from three key southern governorates namely, Basrah, Muthanna and Dhi-Qar. These governorates were the centers of intensive military activities during the 1991 and 2003 Gulf wars, and the discarded weapons are still lying around in these regions. CR-39 track detector was used for registration of induced fission tracks. The results show that the highest recorded uranium concentration in the blood samples of leukemia patients was 4.71 ppb (female, 45 years old, from Basrah) and the minimum concentration was 1.91 ppb (male, 3 years old, from Muthanna). For healthy group, the maximum uranium concentration was 2.15 ppb (female, 55 years old, from Basrah) and the minimum concentration was 0.86 ppb (male, 5 years old, from Dhi-Qar). It has been found that the uranium concentrations in human blood samples of leukemia patients are higher than those of the healthy group. These uranium concentrations in the leukemia patients group were significantly different (P < 0.001) from those in the healthy group.
TL;DR: In this article, fly ash samples from and around six coal-fired power stations across India were measured for 238U, 226Ra, 232Th and 40K activity by an HPGe γ-ray spectrometer.
Abstract: In India about 70 % of the total power generation originates from thermal power plants. Increasing demands of power in a developing country like India has resulted in rapid increase in thermal generation capacity. Coal fired power generation results in huge amounts of fly ash and bottom ash of varying properties. Coal which contains the naturally occurring radionuclides, on burning results in enrichment of these radionuclides in the ashes. Despite the implementation of best possible mechanisms to restrict release of fly ash from the stack, huge amounts of the same gets released in the environment. Fly ash samples from and around six coal-fired power station across India were measured for 238U, 226Ra, 232Th and 40K activity by an HPGe γ-ray spectrometer. Radium equivalent activity and external hazard index were calculated to assess the radiation hazards arising due to fly ash.
TL;DR: In this article, the effect of contact time, initial concentration of radioactive solutions, sorbent mass, pH value and temperature on the adsorption capacity of the sorbent was investigated.
Abstract: Adsorption behavior of uranyl and thorium ions from synthetic radioactive solutions onto functionalized silica as sorbent has been investigated. The effect of contact time, initial concentration of radioactive solutions, sorbent mass, pH value and temperature on the adsorption capacity of the sorbent was investigated. Negative values of Gibbs free energy of adsorption suggested the spontaneity of the adsorption process on both functionalized silica with –NH2 groups and with –SH groups. Positive values obtained for ΔH° indicates that the adsorption is an endothermic process. The adsorption isotherms were better fitted by Freundlich model and the adsorption kinetic was well described by the pseudo-second order equation. Desorption studies indicated that the most favorable desorptive reagents for UO2
2+ is HNO3 1 M and for Th4+ is EDTA 1 M solutions.
TL;DR: In this article, the authors discuss the consequences for age plutonium determination when the basic assumptions of the methodology are not fully met: Incomplete removal of the daughter nuclides at the production date and uranium contamination of plutonium samples.
Abstract: This article discusses the age dating results of plutonium/uranium chronometers with a focus on the consequences for age plutonium determination when the basic assumptions of the methodology are not fully met: Incomplete removal of the daughter nuclides at the production date and uranium contamination of plutonium samples. In addition to the 238Pu/234U, 239Pu/235U and 240Pu/236U, the 242Pu/238U chronometer is discussed. The 242Pu/238U radiochronometer has only scarcely been used, due to its high sensitivity to residual uranium. However, it can be a very useful indicator for uranium contamination of aged plutonium samples.
TL;DR: In this paper, Ag/13X adsorbents were synthesized, characterized and tested for decontamination of gaseous effluents from 131I2 at high temperatures.
Abstract: Ag/13X adsorbents were synthesized, characterized and tested for decontamination of gaseous effluents from 131I2 at high temperatures. X-ray diffraction patterns showed that the Ag/13X samples maintained a stable structure after calcined at 650 °C for 2 h. The decontamination factors achieved with 15 % Ag/13X and 20 % Ag/13X adsorbents for 131I2 were nearly close to 103 at 650 °C. In addition, 15 % Ag/13X had a stable performance for removal of 131I2 at 550 and 650 °C, even after calcined at 550 and 650 °C for over 10 h, which might be suitable for future potential use during nuclear reactor operation or in the case of nuclear accidents.
TL;DR: Montmorillonite-supported nanoscale zero-valent iron (M-nZVI) was synthesized by sodium borohydride reduction and characterized by X-ray diffraction, Xray photoelectron spectroscopy, and field emission scanning electron microscopy (FE-SEM) as discussed by the authors.
Abstract: Montmorillonite-supported nanoscale zero-valent iron (M-nZVI) was synthesized by sodium borohydride reduction and characterized by X-ray diffraction, X-ray photoelectron spectroscopy, and field emission scanning electron microscopy (FE-SEM). The interaction of uranium with M-nZVI was studied using batch technique under different experimental conditions such as pH, ionic strength, initial U(VI) concentration, solid-to-liquid ration (m/V), and temperature. The presence of montmorillonite decreased the aggregation while increased the specific surface area (SSA) of the iron nanoparticles. The SSA for as-synthesized M-nZVI was 91.42 m2/g, higher than 26.60 and 10.23 m2/g for nZVI and montmorillonite, respectively. The removal efficiency of U(VI) using M-nZVI was significantly affected by the pH of the aqueous solution, whereas it was slightly affected by ionic strength and temperature. The isoelectric point of M-nZVI was at pH 5.6; however the results indicated that the optimum removal efficiency of U(VI) using M-nZVI was achieved at a pH range 3.0–5.0. The experiments with aqueous solution containing 100 μg/L of U(VI) showed that the removal efficiency of the as-synthesized M-nZVI was about 978 μg/g at pH 3.0. These results show that M-nZVI has a potential as a novel material for removing U(VI) from aqueous solution.
TL;DR: In this article, the practical aspects and intricate technicalities involved in the large-scale production of 177Lu with specific activity >740 GBq−mg−1 following (n,γ)177Lu route in a medium flux (~1.2 × 1014 n−cm−2−s−1 thermal neutron) research reactor were discussed in detail.
Abstract: This paper accentuates on the practical aspects and intricate technicalities involved in the large-scale production of 177Lu with specific activity >740 GBq mg−1 following (n,γ)177Lu route in a medium flux (~1.2 × 1014 n cm−2 s−1 thermal neutron) research reactor. The implication of target burn-up on the specific activity of 177Lu during irradiation was discussed in detail. 177Lu obtained from this route has been extensively utilized for targeted therapy in patients with neuroendocrine tumor in India. The important details available from our experience, as well as technical know-how, would be of considerable value for institutions planning to pursue 177Lu production through (n,γ)177Lu route.
TL;DR: In this paper, the radon activity measurements in water samples were performed using RAD 7 radon detector equipped with RAD H2O (radon in water) accessory and following a protocol proposed by the manufacturer.
Abstract: The radon concentration has been measured in thermal waters used for medical therapy and drinking purposes in Yalova basin, Turkey. Radon activity measurements in water samples were performed using RAD 7 radon detector equipped with RAD H2O (radon in water) accessory and following a protocol proposed by the manufacturer. The results show that the concentration of 222Rn in thermal waters ranges from 0.21 to 5.82 Bql−1 with an average value of 2.4 Bql−1. In addition to radon concentration, physicochemical parameters of water such as temperature (T), electrical conductivity, pH and redox potential (Eh) were also measured. The annual effective doses from radon in water due to its ingestion and inhalation were also estimated. The annual effective doses range from 0.2 to 0.75 μSvy−1 for ingestion of radon in water and from 2.44 to 9 μSvy−1 for inhalation of radon released from the water.
TL;DR: In this paper, the adsorption of uranyl on nanoporous ZnO powders were examined as a function of the contact times, pH of the solution, concentration of uranium(VI) and temperature.
Abstract: The adsorption of the uranyl ions from aqueous solutions on the nanoporous ZnO powders has been investigated under different experimental conditions. The adsorption of uranyl on nanoporous ZnO powders were examined as a function of the contact times, pH of the solution, concentration of uranium(VI) and temperature. The ability of this material to remove U(VI) from aqueous solution was followed by a series of Langmuir and Freunlinch adsorption isotherms. The adsorption percent and distribution coefficient for nanoporous ZnO powders were 98.65 % ± 1.05 and 7,304 mL g−1, respectively. The optimum conditions were found as at pH 5.0, contact time 1 h, at 1/5 Zn2+/urea ratio, 50 ppm U(VI) concentration and 303 K. The monomolecular adsorption capacity of nanoporous ZnO powders for U(VI) was found to be 1,111 mg g−1 at 303 K. Using the thermodynamic equilibrium constants obtained at different temperatures, various thermodynamic parameters, such as ΔG°, ΔH° and ΔS°, have been calculated. Thermodynamic parameters (ΔH° = 28.1 kJ mol −1, ΔS° = 160.30 J mol−1 K−1, ΔG° = −48.54 kJ mol−1) showed the endothermic and spontaneous of the process. The results suggested that nanoporous ZnO powders was suitable as sorbent material for recovery and adsorption of U(VI) ions from aqueous solutions.
TL;DR: Eggshell material was used as low-cost and eco-friendly biosorbent for removal of 134Cs, 60Co and 152+154Eu radionuclides from aqueous solution as discussed by the authors.
Abstract: Eggshell material was used as low-cost and eco-friendly biosorbent for removal of 134Cs, 60Co and 152+154Eu radionuclides from aqueous solution. The eggshell material was calcined at 500 and 800 °C, and then characterized. Comparative studies on the natural and calcined eggshell for sorption of the three radionuclides were carried out. It was found that, the uptake is in the order: Eu(III) > Co(II) > Cs(I). Further, column chromatography was used in separation of 134Cs, 60Co and 152+154Eu using 0.15, 0.2 and 0.5 mol/l nitric acid, respectively. Eggshell material can be considered as a promising material for separation of radionuclides from radioactive waste solution.
TL;DR: In this paper, Limestone samples from Assuit Governrate in Upper Egypt were subjected to elemental analysis by instrumental neutron activation analysis and X-ray fluorescence techniques using TRIGA research reactor at Mainz.
Abstract: Limestone samples from Assuit Governrate in Upper Egypt were subjected to elemental analysis by instrumental neutron activation analysis and X-ray fluorescence techniques. The samples were properly prepared together with their standards and simultaneously irradiated in a neutron flux of the order 7 × 1011 n/cm2 s using TRIGA research reactor at Mainz. After activation the samples were subjected to γ-ray spectrometry using a high purity germanium detection system and computerized multichannel analyzer. Nineteen elements: Na, Ca, Mn, Fe, Sc, Cr, Co, Zn, Sn, La, Ce, Nd, Eu, Sm, Yb, Lu, Hf, Th and U were analyzed. X-ray fluorescence spectrometry have been also used. The presence of any elements in higher or lower levels in certain limestone samples is contingent on the occurrence of its bearing minerals, nature of parent sediments and depositional environments of these sediments. The major elements in the samples were also observed to be among the elements that had high enrichment factors in the study of suspended dust particulate within and around cement industries. This confirms cement as the major contributor to the airborne particulate matter in the environs.
TL;DR: In this paper, a study was carried out to find out the distribution of radon (222Rn) activity concentration measured in the groundwater samples from the East coast of West Bengal, India.
Abstract: This study was carried out to find out the distribution of radon (222Rn) activity concentration measured in the groundwater samples from the East coast of West Bengal, India. The 222Rn activity in 20 groundwater samples were measured using Durridge RAD-7and the values of 222Rn were found between 1.9 ± 0.78 and 9.0 ± 1.13 Bq L−1 with average of 5.0 ± 0.83 Bq L−1. These are well within the EPA’s maximum contaminant level of 11.1 Bq L−1.
TL;DR: In this article, the phosphorus-rich hydrothermal carbon spheres (HCSs-PO4) have been synthesized via one-step carbonization of glucose in the presence of phosphoric acid.
Abstract: The novel phosphorus-rich hydrothermal carbon spheres (HCSs–PO4) have been synthesized via one-step hydrothermal carbonization of glucose in the presence of phosphoric acid. The textural and surface chemistry properties were characterized using Boehm titrations, scanning electron microscopy and Fourier transform infrared spectrometer. The content of oxygen-containing functional groups on the surface of HCSs increased from 0.053 to 1.009 mmol g−1 by phosphate group modification. The adsorption ability of HCSs–PO4 has been explored for the removal of uranium from aqueous solutions. The adsorption kinetic data were best described by the pseudo-second-order equation. Adsorption process could be well defined by the Langmuir isotherm, the adsorption capacity of HCSs increased from 80.00 to 285.70 mg g−1 after phosphate group modification. And thermodynamic parameters indicated the adsorption process was feasible,endothermic and spontaneous. Selective adsorption studies showed that the HCSs–PO4 could selectively remove U(VI), and the selectivity coefficients had been improved in the presence of co-existing ions, Na(I), Ni(II), Sr(II), Mn(II), Mg(II) and Zn(II). Complete removal (99.9 %) of U(VI) from 1.0 L industry wastewater containing 15.0 mg U(VI) ions was possible with 12.0 g HCSs–PO4.