Showing papers in "Journal of Radioanalytical and Nuclear Chemistry in 2021"
TL;DR: In this paper, the effect of pH value, original content of uranyl ions, time and temperature on the adsorption of uranium by phosphorylated activated carbon were studied by static experiments.
Abstract: Phosphorylated activated carbon was prepared from silk gourd loofah rattan by phosphoric acid modification. The effect of pH value, original content of uranyl ions, time and temperature on the adsorption of uranium by phosphorylated activated carbon were studied by static experiments. In this paper, the adsorption process was analyzed by thermodynamics, kinetics and isotherm model. The adsorbent was characterized using infrared spectroscopy and scanning electron microscopy. The results showed that the pH of the solution can significantly affect the adsorption performance and the pH value of the best adsorption was 5.0. The adsorption equilibrium time was about 240 min and when the adsorption quantity was 197 mg/g, it reaches the summit, and the pseudo-second-order equation and Langmuir equation were more suitable to describe the adsorption process.
23 citations
TL;DR: In this article, the average activity concentration of 226Ra, 232Th and 40K was measured using a NaI(Tl) gamma-spectroscopy system, and the studied samples had a higher activity concentration than the world average.
Abstract: Wadi El Reddah, Egypt, is mostly enclosed by scattered exposure to the chronological sequence of a metavolcanic and metagabbro-diorite complex. There are radiological impacts due to internal and external exposure to the high natural background radiation caused by 226Ra, 232Th, and 40K in the Wadi El-Reddah stream sediments. 72 samples were collected and the activity concentration was measured using a NaI(Tl) gamma-spectroscopy system. The average activity concentration of 226Ra, 232Th and 40K was 215 ± 118 Bq kg−1, 131 ± 90 Bq kg−1 and 822 ± 125 Bq kg−1, respectively. Most of the studied samples had a higher activity concentration than the world average.
22 citations
TL;DR: In this article, a polyacrylonitrile ball clay nanocomposites (PAN/BC) were examined using various analysis methods; the structural morphology, functional groups, and also chemical structures of prepared composites were examined.
Abstract: Gamma radiation at varying radiation doses was utilized to produce polyacrylonitrile ball clay nanocomposites (PAN/BC). Various analysis methods; The structural morphology, functional groups, and also chemical structures of prepared composites were examined utilizing XRD, XRF, IR, SEMT Co2+ > Cu2+ > Zn2+ > Cs+. Optical characteristics for PAN/BC nanocomposite prepared at 60 kGy were investigated before and after saturation by investigated ions and the data represented an enrichment of the bandgap by saturation technique.
20 citations
TL;DR: In this paper, a new material containing Chitosan (Ch)-Vermiculite composite beads was synthesized with epichlorohydrin cross-linking agent and used to remove uranyl ions from the aqueous solution.
Abstract: In this study, a new material containing Chitosan (Ch)–Vermiculite (V) composite beads was synthesized with epichlorohydrin cross-linking agent and used to remove uranyl ions from the aqueous solution. The prepared new material was characterized by SEM, XRD, FTIR analyses and PZC measurement. The effects of significant parameters on adsorption including temperature, pH, concentration and time were investigated. The obtained results indicated that the new composites of Ch–V was revealed in different structure. The zeta potential analyses showed that electrostatic attraction existed during the adsorption process between the uranyl ions and Ch–V. The maximum adsorption capacity of material was calculated as 0.665 mol kg−1 by considering Langmuir equation. Adsorption kinetic was also explained with pseudo second order and intra particular diffusion models. Experimental studies clearly showed that the adsorption was endothermic and occurred spontaneously. The newly developed smart material has many advantages such as reusability, high adsorption capacity, selectivity and economics.
20 citations
TL;DR: In this article, a ZnO/Chitosan nanocomposite (nZnOCS) was successfully prepared by sol-gel method and used as a sorbent for Cs(I) and Sr(II).
Abstract: 1:1 ZnO/Chitosan nanocomposite (nZnOCS nanocomposite) successfully prepared by sol–gel method and used as a sorbent for Cs(I) and Sr(II). The prepared samples characterized by different analytical techniques as FTIR, SEM, TEM, XRD, particle size analyzer, TGA/DTA, and pore size distribution. Optimization of pH of the medium, contact time, initial metal ion concentration and temperature for the sorption reaction performed. The sorption reaction kinetics follows pseudo-2nd order. The monolayer capacities at 298 K are 253.81 and 116.1 mgg−1 for Cs(I) and Sr(II), respectively. The sorption process is spontaneous and endothermic.
18 citations
TL;DR: In this paper, a novel porous cCS/PVA/UiO-66-NH2 membrane absorbent comprising of crosslinked chitosan (cCS), polyvinyl alcohol (PVA) and UiO 66 NH2 was designed and prepared for U(VI)-containing radioactive wastewater treatment.
Abstract: The development of highly efficient adsorbent presents an enticing prospect for U(VI)-containing radioactive wastewater treatment. In this work, a novel porous cCS/PVA/UiO-66-NH2 membrane absorbent comprising of crosslinked chitosan (cCS), polyvinyl alcohol (PVA) and UiO-66-NH2 is designed and prepared. The adsorption capacity of porous cCS/PVA/UiO-66-NH2 membrane achieves 316.50 mg g−1 under an optimal condition. Furthermore, the porous cCS/PVA/UiO-66-NH2 membrane exhibits a high selectivity for U(VI) adsorption in simulated radioactive wastewater treatment. The possible mechanism of U(VI) adsorption onto porous cCS/PVA/UiO-66-NH2 membrane mainly includes surface complexation and cation exchange processes. In addition, the porous cCS/PVA/UiO-66-NH2 membrane also exhibits excellent cycling adsorption-desorption performance. All these results demonstrate that the porous cCS/PVA/UiO-66-NH2 membrane is a promising candidate for application in U(VI) removal from radioactive wastewater.
17 citations
TL;DR: In this article, the saturation sorption capacity of TiO2(0.5)/SiO2 (0. 5) composite towards 134Cs at pH 9.5 and 60Co at pH 5.5 are investigated.
Abstract: TiO2 is supported on silica gel surface (TiO2(0.5)/SiO2(0.5) composite) by physical mixing technique of TiO2 and silica gel with mole ratio 1:1.329 TiO2(0.5)/SiO2(0.5) composite characterized by physico-chemical techniques; (SEM), (FT-IR), (DTA-TG), porosity measurements, and X-ray diffraction and used as a sorbent for 134Cs and 60Co radionuclides from aqueous solutions. Optimization of the parameters affecting sorption process is studied. The saturation sorption capacity of TiO2(0.5)/SiO2(0.5) composite towards 134Cs at pH 9.5 and 60Co at pH 5.5 are 33.1 and 17.7 m g g-1, respectively. The adsorption reaction mechanism is applicable with Freundlich isotherm and the process is spontaneous and favorable.
15 citations
TL;DR: In this article, the activity concentration of 238U, the ambient gamma absorbed dose rates (DR), and the 222Rn concentration levels in ground and surface water samples from gold and lead mining area of Moro, Kwara State, Nigeria.
Abstract: This work investigates the activity concentration of 238U, the ambient gamma absorbed dose rates (DR), and the 222Rn concentration levels in ground and surface water samples from gold and lead mining area of Moro, Kwara State, Nigeria. In situ measurements of activity concentration of 238U and DR were carried out using Super SPEC RS-125 gamma spectrometer and 222Rn activity concentration in ground and surface waters were analysed using a calibrated RAD7 big bottle system. The results show that the risk of radiation exposure at the mining area is high and the public are not safe from exposure to ionizing radiation.
15 citations
TL;DR: In this paper, a new low-cost biochar adsorbent derived from Salvadora persica branches (BSP) was prepared, characterized and investigated for removal of U(VI) and Th(IV) radioactive elements from water.
Abstract: In recent years, biochar based adsorbents have been given more attention for organic and inorganic pollutants removal. Therefore, in this study, a new low-cost biochar adsorbent derived from Salvadora persica branches (BSP) was prepared, characterized and investigated for removal of U(VI) and Th(IV) radioactive elements from water. The effects of batch adsorption conditions were studied. The maximum removal efficiencies are around 99% for each of U(VI) and Th(IV), with adsorption capacities 85.71 mg g−1 and 84.97 mg g−1 respectively. It has been found the adsorption process of U(VI) and Th(IV) is spontaneous, exothermic and follows pseudo-second-order kinetics.
14 citations
TL;DR: In this paper, a three-dimensional (3D) porous structure graphene oxide nanoribbons (GONRs) aerogel has been prepared via hydrothermal method to overcome the challenges of solid-liquid separation for powdered carbon-based nanomaterials.
Abstract: An three-dimensional (3D) porous structure graphene oxide nanoribbons (GONRs) aerogel has been prepared via hydrothermal method to overcome the challenges of solid–liquid separation for powdered carbon-based nanomaterials. GONRs aerogel showed low density, good mechanical strength and easy separation from water. Uranium(VI) and thorium(IV) adsorption by GONRs aerogel was investigated by batch experiments, demonstrating their strongly pH-dependent, spontaneous and endothermic adsorption processes. GONRs aerogel exhibited the maximum U(VI)- and Th(IV)-uptake capacity (430.6 and 380.4 mg g−1, respectively) due to its large specific area (597.4 m2 g−1) and abundant oxygen-containing groups. This work suggests that GONRs aerogel has great potential for treatment of uranium and thorium-containing effluents.
13 citations
TL;DR: The thorium uptake from aqueous solution using SA/PVA/PEO/ZSM5 nanohybrid adsorbent has been investigated in this article, where the effect of zeolite content, pH, adsorbents dose, contact time, initial concentration, and temperature parameters was scrutinized.
Abstract: In this paper, the thorium uptake from aqueous solution using SA/PVA/PEO/ZSM5 nanohybrid adsorbent has been investigated. The effect of zeolite content, pH, adsorbent dose, contact time, initial concentration, and temperature parameters was scrutinized. Using adsorbent containing 10 wt% zeolite and at pH 5 and 45 °C, the highest uptake of thorium (139.2 mg g−1) occurred. Kinetic studies have shown that the process of thorium uptake follows the double-exponential kinetic model. Using different isothermal models, uptake isotherm was studied. The results showed that the thorium uptake onto the adsorbent is physical, spontaneous and endothermic reaction.
TL;DR: In this article, Co0.5Mn 0.5Fe2O4 nanoparticles were successfully synthesized for uranium removal from aquatic media, and the results showed that the Co0Mn0.4 is an effective adsorbent with a higher affinity toward the removal of uranium ions, adsorption capacities of 104mg/g.
Abstract: Co0.5Mn0.5Fe2O4 nanoparticles were successfully synthesized for uranium removal from aquatic media. The Co0.5Mn0.5Fe2O4 was analyzed by XRD, EDX, FTIR, and DLS. The DLS analysis of Co0.5Mn0.5Fe2O4 showed the size of nanoparticles in the range of 3–20 nm. The removal of U(VI) ions by Co0.5Mn0.5Fe2O4 was studied at different experimental conditions. The initial uranium concentrations, pH, and time parameters have a significant effect on the removal process. Isotherms data showed a favorable adsorption process of second-order kinetics. The results show that Co0.5Mn0.5Fe2O4 is an effective adsorbent with a higher affinity toward the removal of uranium ions, adsorption capacities of 104 mg/g.
TL;DR: In this paper, the authors used gamma-ray spectrometers to determine the activity concentrations of natural radionuclides and associated radiation hazards in soils of Elephant hills, Tamil Nadu, India.
Abstract: The aim of the present work is to determine the activity concentrations of natural radionuclides and the associated radiation hazards in soils of Elephant hills, Tamil Nadu, India using gamma-ray spectrometry. The average activity concentrations of 238U, 232Th and 40K are 52, 48, and 840 Bq kg−1respectively. The average dose rate of 89 nGy h−1 is nearly 1.5 times higher than the outdoor world average, but the average annual effective dose equivalent (AEDE) is less than the recommended limit of unity. Pearson correlation analysis indicates that 40K does not contribute to radioactivity in these soils.
TL;DR: In this article, a kind of amino-functionalized clay was prepared by grafting APTES from clay in the Alxa area (Inner Mongolia, China), and its application for the U(VI) removal from Alxa groundwater was studied.
Abstract: A kind of amino-functionalized clay was prepared by grafting APTES from clay in the Alxa area (Inner Mongolia, China), and its application for the U(VI) removal from Alxa groundwater was studied in this work. The results indicate that the sorption strongly depended on the pH and ions. The presence of amino functional groups significantly enhances the adsorption of uranium on clay in groundwater. The sorption isotherms fitted well with the Langmuir model, whereas the sorption kinetics could be fitted by a pseudo-second-order model. These findings indicate that amino-functionalized clay can effectively adsorb U(VI) in complex groundwater samples.
TL;DR: In this paper, the authors assess dose received by individual tissues or organs of human beings from the exposure of indoor radon (Rn-222), thoron and their progeny concentrations using single entry pinhole dosimeters and deposition based progeny sensors (DRPS/DTPS).
Abstract: The purpose of the present study is to assess dose received by individual tissues or organs of human beings from the exposure of indoor radon (Rn-222), thoron (Rn-220) and their progeny concentrations using single entry pinhole dosimeters and deposition based progeny sensors (DRPS/DTPS) The deployment of dosimeters were carried out in 75 dwellings across Hanumangarh district of Rajasthan, India Annual and seasonal activity concentrations were monitored based on which dose distribution to various tissues and organs were assessed The estimated average annual effective dose of the study area is 08 mSvy−1, which is lower than the ICRP recommended limit of 4 mSvy−1 (at work place) and 14 mSvy−1 (for residential buildings) (International Commission on Radiological Protection (ICRP) in Radiological protection against radon exposure, ICRP, Stockholm, 2018) Consequently, indoor radon may pose no health risk to the local population of the studied area
TL;DR: In this article, the effect of several parameters such as contact time, pH, adsorbent dose, initial concentration, and temperature on adsorption of strontium was investigated.
Abstract: In this work, graphene oxide (GO) and (aminomethyl)phosphonic acid–Graphene oxide (AMPA–GO) adsorbents were prepared by the modified Hummers method. The effect of several parameters such as contact time, pH, adsorbent dose, initial concentration, and temperature on adsorption of strontium was investigated. The results showed that experimental data was fitted well by Pseudo-second-order kinetic and Langmuir isotherm models. The maximum adsorption capacity of Sr ions with GO and AMPA–GO adsorbent was 122.36 and 142.39 mg g−1 at a pH of 2.0 and a temperature of 45 °C, respectively.
TL;DR: In this article, a biocomposite sorbent composed of sugar beet pulp and pomelo peel was utilized for the biosorption of uranium (VI) from the aqueous solution.
Abstract: A biocomposite sorbent composed of sugar beet pulp and pomelo peel was utilized for the biosorption of uranium (VI) from the aqueous solution. Parameters such as solution pH, biocomposite amount, contact time, temperature and initial concentration of U(VI) ions on the adsorption performance of biocomposite sorbent was studied. The equilibrium data fitted best to the Langmuir’s isotherm model (qe,max = 79.36 mg g–1). Obtained thermodynamic and kinetic parameters demonstrated that the biosorption process is spontaneous, exothermic, and fitted best to the pseudo-second order. The desorption study revealed that uranium recovery by 0.1 M NaHCO3 was 99.24% in the first cycle for used biocomposite.
TL;DR: In this article, a microwave-assisted microwave assisted hydrothermal carbon (MHC-PA) was successfully synthesized by using phytic acid (PA) and Sodium tripolyphosphate as functional monomers.
Abstract: In this study, hydrothermal carbon doped with phosphorus using phytic acid (PA) and Sodium tripolyphosphate as functional monomers was successfully synthesized by the hydrothermal route combined with microwave-assisted hydrothermal carbon as matrix material. The uranium(VI) adsorption capacity by phytic acid functionalized microwave-assisted hydrothermal carbon (MHC-PA) was up to 382.2 mg/g at pH of 6.0 and the temperature of 298.15 K. The adsorption mechanism of uranium(VI) onto the MHC-PA was mainly the chelation of P=O, P–OH functional group and uranium(VI), which improves the selective adsorption performance of MHC-PA for uranium(VI).
TL;DR: In this article, the ZnS@g-C3N4 (ZSGCN) heterojunctions complexes were compounded as catalysts to reduce radioactive pollution in radioactive wastewater.
Abstract: The photocatalytic reduction of soluble $${\text{UO}}_{2}^{2 + }$$
from radioactive wastewater is becoming an effective method to reduce radioactive pollution, while available catalysts are considerable limitation. Herein, the ZnS@g-C3N4 (ZSGCN) heterojunctions complexes were compounded as catalysts to reduce $${\text{UO}}_{2}^{2 + }$$
. The results from TEM, XRD, XPS, EIS, DRS and PL showed that the ZnS nanoparticles combined with graphite carbon nitride (GCN), which is the construction of heterojunctions broadened the absorption range of sunlight. The ZSGCN-5 presented the optimal photocatalytic reduction activity to $${\text{UO}}_{2}^{2 + }$$
, which was 4.34 times than that of pristine GCN. The ZSGCN-5 heterojunction becomes a promising photocatalyst for radioactive environment remediation.
TL;DR: In this paper, the authors presented a characterization of Shahbazpur structure in terms of elemental abundances obtained from INAA core samples from Shabazpur gas-field, Bangladesh.
Abstract: Geochemical characterization of Shahbazpur structure (Bengal Foredeep) in terms of elemental abundances obtained from INAA are presented by investigating core samples from Shabazpur gas-field, Bangladesh. Major oxides’ abundances were 12.4–20.8, 0.63–1.03, 4.45–8.02, 0.05–0.09, 2.60–4.10 and 1.31–1.87% for Al2O3, TiO2, Fe2O3(T), MnO, K2O and Na2O, respectively. Elemental ratios and enrichment pattern (× 1.10–2.11 UCC) indicate that sedimentary processes originated from Himalayan felsic source-rock. Weathering index and Th/U(= 5.90–6.59), V/Cr(= 1.07–1.38) ratios revel that sediments/rocks were experienced moderate to high degree of chemical weathering with oxidizing environment. La-Th-Sc immobile trace elements diagram invoke depositional tectonic settings which was transitional between active and passive continental margin.
TL;DR: The content of radionuclide uranium in the water, soil and rice around the decommissioned uranium mine was analyzed, and the radioactive pollution, distribution characteristics, migration pattern and health risks were evaluated.
Abstract: The content of radionuclide uranium in the water, soil and rice around the decommissioned uranium mine was analyzed, and the radioactive pollution, distribution characteristics, migration pattern and health risks were evaluated. Its radioactive contamination may have potentially harmful biological effects on the ecosystem and food chain. This paper pays more attention to the pollution of radionuclide 238U, 235U around the tailings dam, and makes a comprehensive comparative analysis of the pollution of water, soil and rice at 500 m, 1000 m and even 60 km around the dam. The single factor index method was mainly used to evaluate the pollution degree, and it was found that the water, soil and rice in the area around the uranium field were all polluted to different degrees. Radionuclide uranium pollution is mainly caused by uranium mining, quarry discharge and ecological cycle in the early stage. According to the characteristics of the uranium content in the study area, it is recommended to use the farmland around the tailing dam as a test site to study the radioactivity of different crops, improve wastewater treatment technology, and prevent crops with excessive levels of radioactive elements from entering the market.
TL;DR: In this paper, modified pomegranate peel was used as a sorbent for the biosorption of uranium(VI) from the aqueous solution, which was characterized by infrared spectroscopy with Fourier transformation, energy dispersive X-ray fluorescence spectrometry, particle size analyser and determination of pHpzc.
Abstract: Modified pomegranate peel was utilized as a sorbent for the biosorption of uranium(VI) from the aqueous solution. The biosorbent was characterized by infrared spectroscopy with Fourier transformation, energy dispersive X-ray fluorescence spectrometry, particle size analyser and determination of pHpzc. “Under optimized experimental conditions” the maximum adsorption capacity was 93.40 mg L−1. The equilibrium data fitted well to the Freundlich’s and Temkin’s isotherm model. Calculated data from applied kinetics model showed best agreement to the pseudo-second order model. Thermodynamic study showed the adsorption process is endothermic and nonspontaneous.
TL;DR: In this article, the extraction and separation of thorium(IV) and a few representative rare earths in HNO3 media was evaluated using trioctylmethylammonium nitrate ([A336][NO3]) ionic liquid.
Abstract: In this study, extraction and separation of thorium(IV) and a few representative rare earths in HNO3 media was evaluated using trioctylmethylammonium nitrate ([A336][NO3]) ionic liquid. An unexpected novel extraction mechanism was identified based on the studies in the slope analysis and ESI–MS spectrum. The trimer of [A336][NO3] was confirmed to dominate the extraction reaction by ESI–MS spectrum before and after the extraction. The extraction efficiency of La(III), Eu(III) and Lu(III) by [A336][NO3] are much lower than Th(IV) in acid medium, which means that it is possible to separate thorium from rare earths or the rare earth ores by using [A336][NO3].
TL;DR: In this article, the native and 2,5-diaminobenzene sulfonic acid (DABSA) attached Lentinus concinnus biomasses were utilized for removal of U(VI) ions from solutions.
Abstract: In this study, the native and 2,5-diaminobenzene sulfonic acid (DABSA) attached Lentinus concinnus biomasses were utilized for removal of U(VI) ions from solutions. At 25 °C, the maximum uranium ion adsorption capacity of the native and DABSA attached fungal biomasses were found to be 118.6 and 539.2 mg/g, respectively, at pH 6.0. The negative ΔG° values of U(VI) removal showed that the adsorption procedure were spontaneous. ATR-FTIR data showed that U(VI) ions adsorption the adsorbents was mainly attributed by amine, carboxyl and sulfate groups.
TL;DR: In this article, samples of building material additives were analyzed for naturally occurring radioisotope activity such as uranium, radium, and radon, and the radon exhalation and the annual effective doses, were also calculated.
Abstract: In this study, samples of building material additives were analyzed for naturally occurring radioisotope activity such as uranium, radium, and radon. The radon exhalation and the annual effective doses, were also calculated. The activities of the samples, were determined using HPGe gamma spectrometry and ionization detector. The results were used to calculate dose values by using RESRAD BUILD code. The activity concentration of the samples ranges between 9–494 Bq/kg Ra-226, 1–119 Bq/kg Th-232 and 24–730 Bq/kg K-40. In conclusion the investigated samples can be used safely as building material additives as they do not pose a major risk to humans.
TL;DR: In this article, the measurements of primordial radionuclides (226Ra, 232Th and 40K) and radon exhalation rates in soil samples were performed in Bageshwar region of Kumaun Himalaya, India using gamma-ray spectrometry and scintillation detector based radon monitor, respectively.
Abstract: The measurements of primordial radionuclides (226Ra, 232Th and 40K) and radon exhalation rates in soil samples were performed in Bageshwar region of Kumaun Himalaya, India using gamma-ray spectrometry and scintillation detector based radon monitor, respectively. The average concentrations of 226Ra, 232Th and 40K in the investigated region were found to be 36 Bq kg−1, 50 Bq kg−1 and 1595 Bq kg−1, respectively. The average values of radon and thoron mass exhalation rates were observed to be 29 mBq−1 kg−1 s−1 and 256 mBq−1 kg−1 s−1, respectively. The average value of thoron surface exhalation rates was observed to be 2281 mBq−1 m−2 s−1. The external exposure to 226Ra, 232Th and 40K is estimated in terms of different hazard assessment indices and dose quantities. The high values of 232Th content in soil samples indicate the presence of thorium mineralization in the vicinity of study area. The methodology adopted and results obtained are discussed in details.
TL;DR: In this article, the influence of geological depth and formation on activity concentrations of 232Th, 226Ra and 40K in soil and groundwater, and radio-chemical health risks was assessed.
Abstract: This study assessed the influence of geological depth and formation on activity concentrations of 232Th, 226Ra and 40K in soil and groundwater, and radio-chemical health risks. Preference ranking organisation method for enrichment evaluation and geometrical analysis for interactive aid indicated significant correlation between 232Th and 40K, thus indicating potential similar primordial origin. Deepest depth rocks at 145 m and 148 m constituted of dark coloured silicified schist exhibited minimal activity with potential hydro-geological interactions with groundwater. Age-dependent annual effective ingestion dose for 226Ra and 232Th are higher than the UNSCEAR reference dose, thus the groundwater is unsuitable for long-term consumption.
TL;DR: In this article, a novel schematic reaction mechanism for the thermal decomposition of studtite is proposed and changes in bond distances in the uranyl group are discussed with respect to studtites calcination temperature.
Abstract: Studtite is known to exist at the back-end of the nuclear fuel cycle as an intermediate phase formed in the reprocessing of spent nuclear fuel. In the thermal decomposition of studtite, an amorphous phase is obtained at calcination temperatures between 200 and 500 °C. This amorphous compound, referred to elsewhere in the literature as U2O7, has been characterised by analytical spectroscopic methods. The local structure of the amorphous compound has been found to contain uranyl bonding by X-ray absorption near edge (XANES), Fourier transform infrared and Raman spectroscopy. Changes in bond distances in the uranyl group are discussed with respect to studtite calcination temperature. The reaction of the amorphous compound with water to form metaschoepite is also discussed and compared with the structure of schoepite and metaschoepite by X-ray diffraction. A novel schematic reaction mechanism for the thermal decomposition of studtite is proposed.
TL;DR: In this article, a comprehensive radiological survey was carried out in an open-cut slate stone quarry and radiological activity of 226Ra, 228Ra and 40 K in the ore samples were measured as 38.5, 41.6 and 869 Bq kg1, respectively.
Abstract: A comprehensive radiological survey was carried out in an open-cut slate stone quarry. The activity of 226Ra, 228Ra and 40 K in the ore samples were measured as 38 ± 5, 41 ± 6 and 869 ± 52 Bq kg1, respectively. Outdoor radon and indoor radon concentrations were measured from 37 ± 7 to 193 ± 11 Bq m−3 (77 ± 8 Bq m−3), and 49 ± 6 to 253 ± 23 Bq m−3 (131 ± 13 Bq m−3), respectively. The average indoor and outdoor gamma dose were measured as 116 and 84 nSv h− 1, respectively. The annual effective doses were estimated between 1.0 ± 0.1 and 3.3 ± 0.3 mSv year−1. The annual lung cancer risks were calculated in the range of 3.3 × 10−2 to 13.12 × 10−2 % (7.72 × 10−2%).