Uranium Values Research Articles

Hydrogeochemical characteristics and enrichment regularities of groundwater uranium in the Erlian basin, China

Groundwater is a key medium for the migration and enrichment of elements into ore bodies in sandstone-type uranium deposits, with anomalies of uranium elements and their associated components in water serving as indicators for exploring such deposits. The Erlian Basin, located in central-northern Inner Mongolia, is a crucial production area for sandstone-type uranium deposits in China. The groundwater flow system in the basin plays a significant role in the formation of uranium deposits. To study the hydrogeochemical characteristics and enrichment regularities of groundwater uranium in the Erlian Basin, 269 groundwater samples were collected. Hydrogeochemical analysis methods, such as Piper diagrams, Gibbs diagrams, and contour maps, were employed to determine the distribution characteristics and occurrence forms of groundwater uranium in the study area. The primary water chemistry types in the study area were HCO3–Ca•Na, HCO3–Na, HCO3•SO4–Na, and SO4•HCO3–Na•Ca. The distribution range of uranium content in groundwater in the study area was 0.1–453 μg/L (average of 53.08 μg/L). A comprehensive analysis, based on the direction of groundwater flow and changes in the redox environment, suggested that the higher uranium values in groundwater were distributed in the runoff and discharge areas, with uranium anomaly points existing in areas with alternating oxidation and reduction zones. These uranium anomaly points were in good agreement with the known large uranium deposits of Nuheting, Qiharigetu, Daoersu, and others, thereby predicting six other uranium hydrochemical anomaly points as prospective areas for uranium mineralization. The pH value distribution range in the study area's groundwater was 6.8–9.1, and the redox potential (Eh) value range was -126–52 mV, indicating that uranium exists in groundwater in the form of UO2(CO3)34− and UO2(CO3)22−. An increase in bicarbonate (HCO3−) is conducive to uranium dissolution. The enrichment and occurrence forms of uranium in groundwater are influenced by the concentrations of Fe and (Ca2++Mg2+), with uranium precipitation and enrichment occurring as the groundwater evolves and changes in the redox environment. The uranium content in deep wells is higher than in nearby shallow wells, indicating that deep water circulation is beneficial for mineralization. The pH, Eh, HCO3−, Fe, and other hydrogeochemical indicators are indicative of uranium enrichment; thus, they can be considered as reference bases when exploring for potential uranium resources.

A study of the concentration of uranium in soil samples was evaluated using the CR_39 detector in the south of Amara Governorate

The quantity of uranium in soil samples taken from various residential, industrial, and agricultural areas in southern Iraq's Southern Omara governorate was evaluated using the neutron activation technique for solid-state nuclear track detectors CR-39. Uranium values in soil samples varied from 0.77 ppm to 1.94 ppm, according to the findings. Soil samples were collected at a depth of 10 cm. The outcomes were compared to publicly available data and found to be within acceptable ranges.

SELECTING OF MATRIX COMPOSITION FOR IMMOBILIZATION OF IRRADIATED FUEL OF THE IGR REACTOR

Impulse Graphite Reactor (IGR) is a unique nuclear installation namely research reactor with the core consisting of uranium-graphite fuel elements with 90% enrichment by U235. Possible immobilization of the first core taken from the reactor in 1967 is studied here as part of the IGR reactor conversion to low-enriched uranium fuel. Irradiated fuel is related to the category of mediumactive waste according to the content of beta-emitters. Expected value of highly-enriched uranium fuel (HEU) burnup rate was less than 1 % mass. The experts from the Institute of Atomic Energy (IAE) proposed the way how to immobilize irradiated IGR reactor fuel into the cement matrix. First, the fuel is suggested to dilute with depleted uranium in order to lower the enrichment up to the <20 mass. % by U235. The properties of the matrix should meet the engineering criteria ruled by international and national standards. So, according to aforesaid, The IAE team is facing an actual problem of selection the matrix and understanding its characteristics.The work was aimed at selection of composition of cement mortar for making robust matrix to immobilize irradiated IGR reactor fuel.The paper describes techniques and results of the time identification (start) of solidification, gradual volume change, water separation, velocity and uniform cement mortar.

Thorium and uranium rapid quantification in soil with portable X‐ray fluorescence

AbstractThis study aims to evaluate the thorium (Th) and uranium (U) quantification in soil employing a commercial routine in a portable X‐ray fluorescence (pXRF) spectrometer. Certified reference materials (CRMs), as well as a soil sample set, were measured by pXRF and gamma‐ray spectrometry. The pXRF results showed that the thorium average detection and quantification limits (in mg kg−1) were 3.3 ± 0.5 and 11.0 ± 1.7, respectively. The uranium values were 3.0 ± 0.4 and 9.9 ± 1.3. Quantitative pXRF results for Th were in accordance with the reference reported for most CRMs analyzed, and the same accordance was obtained in the comparison with gamma‐ray spectrometry results for the soil sample set. However, U results were overestimated by pXRF when compared both with the CRM‐reported values and the gamma‐ray spectrometry results. In conclusion, the tested pXRF commercial routine may be a viable technique to identify variations in natural Th levels in soil but needs to be used with caution to identify and quantify U.

Reconstructing the thermal history of the Morondava Basin, Madagascar, after Gondwanan breakup as resolved through detrital zircon (U–Th)/He and U–Pb geochronology

Formation of the Phanerozoic basins of Madagascar coincided with the initial stages of Permian break-up of Gondwana. The largest of these, the Morondava Basin, records the tectonic history of rifting, drifting, and uplift of the Malagasy terrane over the last 300 Myr. Herein, we have applied detrital zircon U–Pb geochronology and (U–Th)/He low-temperature thermochronology to resolve the thermal history of the basin as Madagascar separated from Africa and subsequently India. Coarse-grained siliciclastic samples were taken along two transects parallel to the Morondava River in the central basin, including from the Permo-Triassic failed rift basin and from post-Jurassic passive margin sequences. Detrital zircon U–Pb age distributions are defined by common Neoarchean and Neoproterozoic populations which suggests input from the basement terranes of the Malagasy Central Highlands (Antananarivo domain). Samples also contain Paleo-to Mesoarchean and Cambrian populations likely associated with metamorphic terranes amalgamated during the Pan-African orogeny. Single crystal zircon (U–Th)/He dates are 503 ± 17 Ma to 40 ± 1 Ma with effective uranium (eU) values ranging from 35 to 1760 ppm, which exhibit a strong negative date-eU relationship that indicates partial resetting of the He systematics in zircon throughout the basin. Inverse and forward thermal history models from the data reveal separate thermal histories for strata on either side of basin-dividing Illovo Fault. Under an elevated geothermal gradient, temperatures did not exceed 180 °C either during post-Gondwanan burial of Jurassic rift strata or during Late Cretaceous burial of Early Cretaceous passive margin strata. Intrusion of Turonian-age dikes and sills related to the Marion hot spot likely promoted subtle yet widespread heating. The time of latest cooling during the Paleogene recorded in the basin is poorly constrained by the detrital zircon thermochronology.

Uncovering the Distribution Zones of Uranium and Thorium in Bangka Island

Radioactive minerals, especially containing uranium and thorium, can be used as a core element of nuclear fuel. Bangka Island is located in The Southeast Asian Tin Belt where it has a large uranium and thorium potential. The purpose of this study is to delineate distribution zone of uranium and thorium in Bangka Island. The study methods consist of radiometric measurement and mapping, petrographic analysis, and mineralogical analysis of pan concentrate samples. Based on radiometric measurement, positive anomaly value of equivalent uranium (eU) is ranging from 5-15 ppm while of equivalent thorium (eTh) is ranging from 45-75 ppm. The result of petrographic analysis from several outcrops of Klabat Granite indicated that there are monazites found in several samples of Mangkol Granite and of Bebuluh Granite. Radioactive mineral indication also can be identified as pleochroic halo within biotite in samples of Pelangas Granite and Menumbing Granite. Based on the result of mineralogical analysis of pan concentrate samples, it was identified that monazites can be found in all samples. Monazites constitute the percentages ranging from 2.82-10.66 %. Zircon also can be identified with percentages ranging from 9.13-76.75 % while ilmenite and magnetite minerals have average percentages of 24.09 % and 5.97 %, respectively. Favorable zones can be delineated in outcrops of Klabat Granite, Ranggam Formation and alluvial deposits in northern, northwestern, northeastern, central, and southeastern parts of Bangka Island. The occurrences of monazites in those lithological units are the main factors of high radioactivity in Bangka Island. Based on petrographic and mineralogical composition, those granite bodies which are correlated with Klabat Granite are mostly associated with ilmenite series with S-Type granitic rocks.

Determination of radon activity among beach soil samples in Jeddah and Al-Qunfudhah, Saudi Arabia

Natural radioactive materials have a negative impact on public health, especially on people exposed to the sun on beaches. Due to the high temperature in Makkah Al-Mukarramah region, many people resort to going to the sea, and regarding the risks that the public is exposed to, we focus our research on studying and drawing a radiation map of the Red Sea beaches. Also, identify the risks that the public is exposed to while on the various beaches. The study was carried out using a CR-39 solid-state nuclear track detector. The results showed that the average concentration of radon gas on the beaches of Jeddah was 481.34 ± 40.63 Bq / cm3, while the average concentration of radon gas in the city of Al-Qunfudhah was 282.36 ± 38.40 Bq / cm3. 10% of the radon gas concentration values were higher than the safe limit. The mean values for radium for all measured samples were 4.41 ± 0.61 Bq/kg, while the mean values for uranium were 0.22 ± 0.03 ppm. All radium and uranium values were within the internationally permitted limits. The results of the measured beaches indicate that the Red Sea beaches in the Makkah Al-Mukarramah region are safe for use and do not have high life-threatening rates, except for Al-Hamra Corniche Beach in Jeddah, which was higher than permissible. It is recommended to monitor the beach and remove any waste so that its percentage on the beach does not increase. It is also recommended to complete the study on the rest of the Red Sea beaches.

PATTERNS OF THE REGIONAL URANIUM STATUS FORMATION ON THE EXAMPLE OF THE REPUBLIC OF BASHKORTOSTAN

Link for citation: Zlobina A.N., Farkhutdinova L.M., Farkhutdinov I.M., Belyanovskaya N.V., Baranovskaya N.V., Chesalova E.I., Farkhutdinov A.M., Khayrulina L.A., Krestyannikova E.V. Patterns of the regional uranium status formation on the example of the Republic of Bashkortostan. Bulletin of the Tomsk Polytechnic University. Geo Аssets Engineering, 2023, vol. 334, no. 10, рр. 153-168. In Rus. The relevance of the research. Uranium is a radioactive, carcinogenic, toxic element that can be accumulated in human body and cause various pathologies (the risk of kidney dysfunction, the development of leukemia, colorectal cancer etc.). This determines the relevance of studying the patterns of distribution of this chemical element in the living environment. Drinking water is the main source of uranium for the human body. This fact can be confirmed by calculating the accumulation coefficient and correlation analysis, which showed a high dependence of the concentration of uranium in hair on its content in the scale of drinking water. The method for assessing the uranium status of a territory, including geochemical, lithological, hydrogeological, tectonic analyses, and the study of technogenic factors, makes it possible to fairly accurately determine the main sources of uranium feeding of drinking water. The main aim: to assess the significance of geoecological factors on the territory of the Republic of Bashkortostan in the formation of the regional uranium status based on the study of the uranium content in drinking water and hair of residents. Methods. Uranium concentration in the scale of drinking water and the hair of children was studied using instrumental neutron activation analysis applying the research nuclear reactor IRT-T TPU. For data processing, the Statistica 10 and Microsoft Excel 2013 software packages were used. A map of uranium spatial distribution was built using the ArcGIS 10.2 software in the Geostatistical Analyst module applying the inverse distance weighting method. Results. On the territory of the Republic of Bashkortostan, there is a wide range of uranium values both in the scale of drinking water (range from 0,01 to 61,0 mg/kg) and in hair of residents (range from 0,001 to 0,411 mg/kg). The average content of uranium in the scale of drinking water (515 samples) was 5,4 mg/kg and in hair (182 samples) was 0,04 mg/kg. Uranium spatial distribution is in clear agreement with the geoecological conditions of the area. Zones of increased uranium concentration in scale and hair are distinguished, where the uranium content is higher than the background value in the republic: the western platform and southern mountain zones. Along with positive anomalies, there are negative ones, where the level of the element is below the average: the northern platform and northern mountain zones. Uneven uranium distribution is explained by both natural (a wide variety of rocks, hydrogeological and tectonic factors) and technogenic factors (development of oil and ore deposits). The conducted correlation analysis showed a direct dependence of U content in children's hair on its concentration in the scale of drinking water (R2=0,8), which indicates the leading role of drinking water in uranium intake into human body. Considering the revealed higher level of uranium in hair of the inhabitants of Bashkortostan compared to a number of other regions of the Russian Federation and the world, as well as the ability of this chemical element to be accumulated in the body, the study of the uranium status influence on health of the population is of particular relevance. The results obtained can serve as a theoretical basis for elucidating the biological role of uranium and solving the fundamental problem of the relationship between geoecology and human health.

Mobility, activity ratio significance and risk assessment of radionuclides in sandstone of Magharet El Miah, Southwestern Sinai, Egypt

Sedimentary rocks of Magharet El Miah were radiometrically analyzed for determination of radionuclides 238U, 232Th, 226Ra and 40K activity concentrations. The U-content and Th/U ratio in these rocks illustrated poor weathering and rapid deposition of rock detritus. Preferential dissolution of 234U due to α-decay related processes and its re-adsorption and precipitation are responsible for the observed radioactive disequilibrium in 234U/238U of Magharet El Miah sandstone. 234U mobilization could be related to the effect of surficial or underground water. 226Ra/238U disequilibrium could be revised to the difference in the geochemical characteristics of the two isotopes. 230Th/238U activity ratios were lower than unity in all samples (10 samples) except sample number 1, suggesting selective uranium accumulation in most samples or 230Th leaching by acidified water where the rocks contain high sulpher contents. Many of the 238U/235U activity ratios were shifted from the natural ratio due to the changes in redox conditions that leads to fractionation of higher isotope from lighter one. The plotted value of 234U/238U and 230Th/238U illustrated that the U-accumulation occurred in the period from <6 × 104–105 years. The studied sandstone had higher values for uranium (95.4 ± 7.1 to 130.3 ± 12.3 Bq.kg−1), thorium (65.8 ± 4.2 and 78.4 ± 6.7 Bq.kg−1) and radium (68.2 ± 4.4 and 80.3 ± 9.1 Bq.kg−1) but lower for potassium (38.4 ± 1.2 and 54.2 ± 2.3 Bq.kg−1) in comparison with international permissible levels. All the estimated environmental hazard indices illustrated that most samples lied in the permissible level ranges. Cluster analyses indicated that the main environmental health hazard parameters exist due to the activity concentrations of 238U and 226Ra.

Distribution of Radionuclides in the Surface Covering of the Barun Uranium Mining Area in Erlian Basin, Inner Mongolia

In order to identify the distribution pattern of radionuclides in the surface soil in the area of a sandstone-type uranium deposit, and to explore its spatial relationship with the location of the orebody, soil radon measurements and ground gamma-ray spectroscopy were carried out in the Barun study area, and soil properties were analyzed. The results show that the soil radon concentrations exhibited a bimodal feature, while the uranium content showed a decreasing trend along the tendency direction of the orebody. In the ground projection area of the orebody, radon concentration showed a positive correlation with uranium content, with both showing relatively low values. Combined with the results of field geological observation and soil property analysis, it is believed that the relatively low radon concentration and uranium content above the orebody is related to the soil being mainly sandy soil. Relatively high uranium values are distributed within approximately 1.5 km north of the northern boundary of the orebody and near the southern boundary of the orebody. High-value radon anomalies occur within about 2 km north of the northern boundary of the orebody and within about 1.3 km south of the southern boundary of the orebody.

Research on the formulation and revision of radiological parameters in the "Standards for Drinking Water Quality（GB5749-2022）" in China

The radioactive safety of drinking water has attracted increasing public concern. The newly issued Standards for Drinking Water Quality (GB5749-2022) in China has revised the radiological parameters. This article provides an overview of the main sources, levels of radionuclides in drinking water, and summarized the individual doses criterion and adverse health effects associated with exposure of the public to radionuclides from drinking-water. It analyzes and discusses the relevant revision content of radiological parameters, including the guidance values for screening gross α and gross β, subtracting the contribution of potassium-40 from gross β activity when the gross β activity concentration exceeds the screening level, and the basis for establishing the limit values of reference indices uranium and radium-226. Specific implementation and evaluation suggestions are also proposed.

Detection of potential hydrocarbon accumulations at Qaret El-Soda area, Western Desert, Egypt, based on airborne geophysical survey data

Airborne spectral gamma-ray survey data were processed using Th-normalization technique for oil and gas exploration in the Qaret El-Soda area, Western Desert of Egypt. This technique was applied to suppress the effects of surface lithology, which are the main factors influencing the variation of radioelement content in rocks. Normalization of K and U by thorium yielded residual potassium and residual uranium estimates. Possible occurrences of new hydrocarbon microseepages were determined by mapping low values of residual potassium and high values of residual uranium relative to potassium, which are indicated as DRAD values, which were obtained by subtracting residual potassium from residual uranium values (eUresid – Kresid). Lower residual values of K, which were associated with higher DRAD anomaly values, highlight areas of prospective hydrocarbon accumulations. The obtained results from quantitative analysis and interpretation of aeromagnetic data show sufficiently thick sediments, probably suitable for the accumulation of hydrocarbons. This means that the study area may possess a potential for hydrocarbon exploration if supported by other detailed geophysical and geochemical exploration techniques.

A comparison of the chemo- and radiotoxicity of thorium and uranium at different enrichment grades

Uranium and thorium are heavy metals, and all of their isotopes are radioactive, so it is impossible to study chemical effects entirely independent of the radiation effects. In the present study, we tried to compare the chemo- and radiotoxicity of both metals, taking into account deterministic radiation damages reflected by acute radiation sickness and stochastic radiation damages leading to long-term health impairments (e.g., tumor induction). We made at first a literature search on acute median lethal doses that may be expected to be caused by chemical effects, as even acute radiation sickness as a manifestation of acute radiotoxicity occurs with latency. By simulations based on the biokinetic models of the International Commission on Radiological Protection and using the Integrated Modules for Bioassay Analysis software, we determined the amounts of uranium at different enrichment grades and thorium-232 leading to a short-term red bone marrow equivalent dose of 3.5 Sv considered to cause 50% lethality in humans. Different intake pathways for incorporation were considered, and values were compared to the mean lethal doses by chemotoxicity. To assess stochastic radiotoxicity, we calculated the uranium and thorium amounts leading to a committed effective dose of 200 mSv that is often considered critical. Mean lethal values for uranium and thorium are in the same order of magnitude so that the data do not give evidence for substantial differences in acute chemical toxicity. When comparing radiotoxicity, the reference units (activity in Bq or weight in g) must always be taken into account. The mean lethal equivalent dose to the red bone marrow of 3.5 Sv is reached by lower activities of thorium compared to uranium in soluble compounds. However, for uranium as well as thorium-232, acute radiation sickness is expected only after incorporation of amounts exceeding the mean lethal doses by chemotoxicity. Thus, acute radiation sickness is not a relevant clinical issue for either metal. Concerning stochastic radiation damages, thorium-232 is more radiotoxic than uranium if incorporating the same activities. Using weight units for comparison show that for soluble compounds, thorium-232 is more radiotoxic than low-enriched uranium in the case of ingestion but even more toxic than high-enriched uranium after inhalation or intravenous administration. For insoluble compounds, the situation differs as the stochastic radiotoxicity of thorium-232 ranges between depleted and natural uranium. For acute effects, the chemotoxicity of uranium, even at high enrichment grades, as well as thorium-232 exceeds deterministic radiotoxicity. Simulations show that thorium-232 is more radiotoxic than uranium expressed in activity units. If the comparison is based on weight units, the rankings depend on the uranium enrichment grades and the route of intake.

Synergistic strategy design of (malonamide-amidoxime) bifunctional branching network crosslinked membrane and application in uranium (VI) resource recovery

The efficient recovery of uranium resources from complex systems was of great significance to the sustainable development of nuclear energy and to prevent the potential effects of environmental radioactivity and chemical toxicity of uranium. Herein, we reported a novel highly crosslinked two-dimensional branched network poly (malonamide-amidoxime) difunctional membrane (MAFPM) using malonamide-based polymer as the skeleton and chitosan membrane with abundant surface groups as the substrate. By introducing bromoacetonitrile and hydroxylamine oxime, (malonamide-amidoxime) difunctional synergistic strategy was realized. As a result of the high polymer synergy strategy, MAFPM-2 showed remarkable adsorption capacity of 876.45 mg/g for uranium (VI), excellent uranium-selectivity of 93.46% and the Kd value for uranium (VI) was 2.79 × 106 mL/g. Through the cross-linking with chitosan membrane, the recycling ability of the material was improved, and the recovery rate was maintained at 82% after four adsorption cycles. In addition, combined with characterization and DFT calculation, the synergistic effect between functional groups was elucidated, the carbonyl of amines used additional sites to form a more stable five- coordinated of uranium (VI) with the oxime group. The finding of this study indicated that MAFPM-2 provided a promising approach for uranium (VI) resource recovery.

Well-logging evaluation of the shale gas potential in the lower Silurian Longmaxi Formation, Weiyuan, southern Sichuan Basin, China

Recent observations of shale gas breakthroughs in the Weiyuan marine shale gas play in the Sichuan Basin have attracted great interest. To better understand these breakthroughs, we have used core description, cyro-focused ion beam scanning electron microscopy data, X-ray diffraction data, organic geochemistry, and well-logging data to better understand the reservoir characteristics carbonaceous shale, calcareous shale, and siliceous shale lithology, with a focus on organic-rich shale units. We find that conventional well-log methods are effective in mapping the spatial distribution of organic-rich shale in the Weiyuan area where the total organic carbon (TOC) content in the Longmaxi Formation ranges from 1.35% to 6.95%, averaging 4.42%. The kerogen is type I-II, and the vitrinite reflectance (Ro) is greater than 2.57%, which indicates that the formation is susceptible to shale gas accumulation. The clay mineral content ranges from 48 to 63 wt% (avg. 51 wt%) with illite and chlorite averaging 73.8% and 25.7%, respectively. The brittle mineral quartz and plagioclase content ranges from 32 to 61 wt% (avg. 47 wt%). Compared to the surrounding lithologic units, the marine shale exhibits relatively high gamma ray, neutron, sonic, resistivity, potassium, and uranium (U) values and relatively low density, photoelectric effect, and thorium/U values, allowing us to construct crossplots to define the units of interest. Using the same process, we quantify the TOC content providing a spatial distribution of organic-rich shale using conventional well logging.

Gamma spectrometric measurement of uranium isotopic composition and mass in sintered UO2 pellets using the efficiency transfer method

Gamma spectrometric measurements to determine the isotopic composition and total uranium mass in UO2 pellets (D = 7.5 mm; H = 3.5 mm, ρ = 10 g/cm3) were carried out. The required efficiency curve was obtained by applying the efficiency transfer method from a calibration standard (D = 65 mm; H = 20 mm) of a slightly acidified water solution. The average isotopic composition of ten UO2 pellets was consistent with values of natural uranium given by IUPAC. The average relative bias for the 235U/238U amount ratio was −0.73% using the 1001 keV gamma line for 238U and 0.50% using the 63 keV gamma line (186 keV was always used for 235U). For the total uranium mass, the mean deviation as compared to mass determinations using a balance was 5.5% using the 1001 keV gamma line for 238U and 4.3% using the 63 keV gamma line.

Functionalized GO-doped double network antibacterial hydrogels for efficient uranium extraction from seawater

Uranium extraction from seawater provides the new idea for the development of uranium resources. However, the concentration of uranium in seawater is extremely low (∼3.3 μg/L). Meanwhile, there are a large number of competing ions and microorganisms in the seawater. It is a huge challenge to extract uranium from seawater. In this paper, a double network hydrogels material with effective antifouling ability was prepared for highly efficient uranium sorption. First, poly(hexamethylene biguanide) hydrochloride (PHMB) modified graphene oxide(GO) was prepared (PHMB-GO), and then PHMB-GO was doped into the double network hydrogels structure formed by acrylamide and gelatin in order to obtain (GO-PHMB)0.4@Gelatin-PAM, which showed the maximum uranium adsorption capacity reached 625.00 mg∙g−1. More importantly, it exhibited excellent selectivity towards uranium(VI) in the presence of multiple coexisting metal ions in simulated seawater. The Kd value for uranium is 1.73 × 104 mL∙g−1, which is far more than other metal ions. The antibacterial and antialgae experiments prove that the adsorption material has a good inhibitory effect on Escherichia coli (E. coli), vibrio vulnificus (V vulnificus) and Staphylococcus aureus (S. aureus). Therefore, (GO-PHMB)0.4@Gelatin-PAM is an outstanding candidate for efficient uranium extraction from seawater.

Aggregated germanium saponite: Removal and retention of polymeric thorium and uranium complexes

The present study concerns the removal of thorium and uranium from aqueous solution, and particularly the effect of clay particle size and morphology on the adsorption of polynuclear actinide complexes by synthetic saponite nanoscale powders. Saponites were synthesized from a reactant mixture containing aluminum nitrate, magnesium nitrate, and either sodium silicate or sodium germanate. The saponite powders were analyzed by TEM, XRD, SAXS, N2-adsorption-desorption isotherms and FT-IR. Ge-saponite contained randomly stacked platelets ≈ 100 nm long and 80 nm wide, while Si-saponite showed roughly spherical agglomerates ≈ 60–80 nm in size. Small-angle X-ray scattering measurements indicated a hierarchical pore network among the plates and their agglomerates. Thorium polymers composed of fractal aggregates of branched filaments were characterized by synchrotron radiation-SAXS. The distribution coefficient (Kd mL/g) values for thorium (20 μg/mL) at pH 4 were: Ge-saponite (105) ≈ Si-saponite (105) > raw saponite (104) ≈ raw saponite (washed) (104). The Kd values for uranium (20 μg/mL) at pH 5.5 were: Ge-saponite (103) ≈ raw saponite (washed) (103) ≈ Si-saponite (103) ≈ raw saponite (103). The difference in uranyl adsorption performance observed between the two nanoparticle forms of saponite was attributed to a larger pore width for Ge-saponite (3.5 nm) compared with Si-saponite (0.8 nm). The results have implications for mineral ore tailings containing thorium(IV) and, by analogy, Pu(IV) in a clay buffer environment within a geological repository for high-level nuclear waste.

Elemental geochemistry and organic facies of selected cretaceous coals from the Benue Trough basin in Nigeria: Implication for paleodepositional environments

Benue Trough basin is geologically subdivided into three segments. It consists of marine and continental sediments that are affected by folding movements. In the upper section, the continental coal-bearing Campano-Maastrichtian-age is found within Gombe Sandstone and the Cenozoic Kerri-Kerri Formation of the Tertiary. In the middle segment, the late Turonian/early Santonian coal-bearing Awgu Formation lies conformably on the Ezeaku Formation. In the lower part, shales at Nkporo mark marine incursion and deposition of the Maastrichtian Mamu Formation coal measures. Cretaceous coal samples taken from the three segments of Benue Trough basin were examined using ultimate and proximate, organic petrographic, x-ray fluorescence (XRF) and laser ablation-induced coupled plasma spectroscopy (LA-ICPMS) analytical techniques. Results of trace element ratios, Ce/Ce* values (“where Ce* is the theoretical Ce value derived from a chondrite-normalized rare earth element (REE) pattern”), authigenic uranium values, and low hydrogen content indicate deposition under oxic to suboxic conditions. However, the V/Ni and V/Sc ratios indicate under oxic, suboxic to reducing conditions. The Y/Ho values for selected coals are lower than the range for seawater, indicating terrigenous influence. The Sr/Ba values indicate low influence of saline water during deposition and a strong continental rather than marine influence. High value of vitrinite and low proportion of liptinite/intertinite suggest that peat in the study areas were situated on the irregular basin floor where sediment thicknesses vary from place to place thus the depositional environments shifted causing mineral matter filling in coal. Based on the tissue preservation index (TPI) and gelification index (GI), LFB, CHK, OKB, LMZ, IMG; and ENG (high GI and high TPI) were deposited in telmatic facies; wet-forest swamps with rapid organic matter accumulation. This trend indicates mild humification and strong gelification of plant tissues which ascribed to high rate of subsidence with wood- and bark-derived telovitrinite. The MGA peats were deposited in terrestrial facies in a dry-forest swamp with wood-derived telo-inertinite. The coal samples code-named IMG and ENG were deposited in planar margin mires. However, coal samples code-named LFB, CHK and LMZ were deposited in planar central mires. Lastly, OKB and MGA were deposited in transitional-wet and transitional-dry mire. The low V and Ni concentrations, low H/C, high O/C, high C/N, and very low N/C ratios <0.05 implies Type III land-plant organic matter that is not oil-prone. The depositional environments interpretations of investigated coal seams indicate that the coals were deposited within a telmatic, limnic, limno-telmatic and open march zone. Generally, a combination of results from inorganic geochemistry and organic petrology is required for precise and all-inclusive determination of coal depositional environments.

Measuring the concentration of uranium in the Qayyarah oilfield and refinery

In this research, the Concentrations of uranium and radon gas were measured in the samples collected from the Qayyarah refinery and field, which is located south of Mosul. The samples included soil and water associated with the production of oil, sludge and crude oil. After prepared samples, the radioactivity was measured using the CR-39 solid-state nuclear trace detector. Radon levels ranged between 10.79-19.67 in soil samples, and in water samples 7.25 , in sludge samples 13.42-16.96 and in crude oil 8.57 . While uranium concentration levels, ranged in soil samples from 0.870 - 1.457 , in water samples 0.585 , in sludge samples 1.299 - 1.369 , and in crude oil samples 0.692 . These results indicate that it is within the internationally permissible limits, as the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) determined the value of uranium in soil at 32 and in water at 50 , and the International Atomic Energy Agency (IAEA) determined the value of uranium in The slag has a value of and the International Association of Oil and Gas Producers (IOGP) has determined the value of uranium in crude oil and therefore does not pose any danger to the lives of workers in the refinery. field and environment.