Uranium Isotopes In Groundwater Research Articles

Determination of uranium isotopes in ground water by alpha spectrometry and associated age-dependent ingestion dose.

Determination of uranium isotopes in ground water plays a key role in assessment of geochemical condition of ground water and for estimating ingestion dose received by the general public because of uranium intake through drinking water. An attempt has been made in the present study to estimate isotopic composition and activity ratios (AR) of uranium isotopes by analysing the ground water samples using alpha spectrometry. Associated age-dependent ingestion dose was also calculated for the public of different age groups. 238U, 235U and 234U activity concentration was found to vary in the ranges of 5.85±1.19 to 76.67±4.16, < 0.90 to 3.15±0.84 and 6.52±1.25 to 107.02±4.92 mBq/L, respectively. 235U/238U AR varies from 0.038 to 0.068 with an average of 0.047 which is close to 0.046 implies that uranium in the ground water is from natural origin. Uranium concentration was found to vary in the range of 0.47±0.10μg/L to 6.20±0.34μg/L with a mean value of 3.01±0.23μg/L, which is much lower than national as well as international recommendation value. Annual ingestion dose to the public of all age groups for uranium intake through drinking water ranges from 0.60±0.11 to 19.50±1.03μSv/y.

Uranium isotopes in groundwater in Ho Chi Minh City and related issues: Health risks, environmental effects, and mitigation methods

Groundwater is regularly used for many purposes, such as drinking and agricultural irrigation systems. Still, it contains high levels of radionuclides (e.g., 238U, 232Th, and 226Ra) that are potentially hazardous to humans and the environment. In this study, activity concentrations of uranium isotopes were analyzed in 15 groundwater samples taken from 15 bored wells in Thu Duc district, Ho Chi Minh City, Vietnam. Environmental effects of the irrigation system with groundwater on agricultural soil in the study area were assessed by models. It was found that the activity concentrations of 238U and 234U in groundwater samples were in the ranges of (13.5–268.7) mBq l−1 and (20.2–438.3) mBq l−1, respectively. The ratio 234U/238U values were ranged from 1.12 to 2, with an average value of 1.44. Based on the model prediction, 25 years irrigation with the groundwater can inject 94.8 Bq both uranium isotopes in 1 kg topsoil. For investigated groundwater samples, the proposed removal method using K2FeO4 removed 74.28% and 81.04% for 234U and 238U, respectively.

Distribution of uranium isotopes in groundwater of the UAE: environmental radioactivity assessment

Occurrence of uranium isotopes in groundwater provides a tracer technology for quality, sources, and recharge conditions. Groundwater samples collected from different aquifer types (sand dune, Quaternary clastics, ophiolite, carbonates and sabkha) in the UAE were analyzed for 238U and 235U. In addition to uranium isotopes, monitoring indicators also cover groundwater pH, temperature and TDS. The concentration of uranium isotopes (238U + 235U) range from 4 to 69,745 ng/L. The distribution of the isotopes in the groundwater of the UAE can be linked to aquifer lithological variability, distance from recharge front and seawater intrusion. In general, about 3% of the groundwater analyzed have uranium concentration above the WHO permissible limit for drinking water.

Investigation of uranium geochemistry along groundwater flow path in the Continental Intercalaire aquifer (Southern Tunisia)

Environmental tracers (2H, 18O, isotopes of Uranium) and geochemical processes occurring within groundwaters from the Continental Intercalaire (CI) in Southern Tunisia were used to understand the hydrodynamics and the recharge conditions of this aquifer. This study investigates the chemical and isotopic compositions of the CI groundwater. The water types are dominated by Na+, SO42−, Cl− throughout most of the basin with a general increase in total dissolved solids from the Saharan Platform margins towards the Chotts region. Large scale groundwater flow paths are toward the Chotts region. The stable isotopes composition of the analyzed groundwater ranges from −8.8 to −6‰ vs V-SMOW for δ18O and from −67 to −40‰ vs V-SMOW for δ2H. The relatively enriched stable isotopes contents suggest the contribution of the Dahar sandstones outcrops in the current recharge of the CI aquifer in an arid context. However, the most depleted values in heavy isotopes indicate a paleorecharge of the aquifer under wetter conditions revealing a long residence time of groundwaters. The results from water samples using alpha spectrometry method indicate a range in 238U concentrations and 234U/238U activity ratios (AR) of 0.044–1.285 μg kg−1 and 1.2 to 8.84 respectively. The geochemistry of uranium isotopes in groundwater is controlled by many factors, essentially, the influence of water rock interactions, the preferential dissolution of 234U relative to 238U due to alpha recoil and the mixing processes between different waters with distinct AR as well as 238U concentrations.

Uranium isotopes in groundwater occurring at Amazonas State, Brazil

This paper reports the behavior of the dissolved U-isotopes 238U and 234U in groundwater providing from 15 cities in Amazonas State, Brazil. The isotope dilution technique accompanied by alpha spectrometry were utilized for acquiring the U content and 234U/238U activity ratio (AR) data, 0.01–1.4µgL−1 and 1.0–3.5, respectively. These results suggest that the water is circulating in a reducing environment and leaching strata containing minerals with low uranium concentration. A tendency to increasing ARs values following the groundwater flow direction is identified in Manaus city. The AR also increases according to the SW–NE directions: Uarini→Tefé; Manacapuru→Manaus; Presidente Figueiredo→São Sebastião do Uatumã; and Boa Vista do Ramos→Parintins. Such trends are possibly related to several factors, among them the increasing acid character of the waters. The waters analyzed are used for human consumption and the highest dissolved U content is much lower than the maximum established by the World Health Organization. Therefore, in view of this radiological parameter they can be used for drinking purposes.

Uranium isotopes in groundwater from the “Jeffara coastal aquifer” (southeastern Tunisia)

The distributions of 238U and 234U in groundwater from the “Jeffara aquifer” were studied by using alpha spectrometric methods. The concentration ranges of 238U and 234U/ 238U activity ratios were 1.34 ± 0.17 to 3.43 ± 0.38 ppb, and 1.43 ± 0.23 to 1.82 ± 0.27 respectively. Variations in concentrations can be related not only to lithostratigraphic formations but also to different origins of groundwater. U content of Jeffara are found very similar to those of Continental Intercalaire aquifer in both El Hamma and Chenchou regions, indicating that the Continental Intercalaire is the dominant source of the groundwater.

Uranium isotopes in groundwater from the continental intercalaire aquifer in Algerian Tunisian Sahara (Northern Africa)

The disequilibrium between 234U and 238U is commonly used as a tracer of groundwater flow. This paper aims to identify uranium contents and uranium isotopic disequilibria variation in groundwater sampled from deep Continental Intercalaire aquifer (southern Algeria and Tunisia). Large variations in both U contents (0.006–3.39 ppb) and 234U/ 238U activity ratios (0.4–15.38) are observed. We conduct a first assessment in order to verify whether the results of our investigation support and complete previous hydrogeological and isotopic studies. The dissolved U content and 234U/ 238U activity ratio data were plotted on a two-dimensional diagram that was successfully utilized on sharing the CI aquifer into different compartments submitted to different oxidising/reducing conditions and leads also to distinguished two preferential flow paths in the Nefzaoua/Chott Fejej discharge area. Uranium isotopes disequilibrium indicate that ranium chemistry is mainly controlled by water–rock interaction enhanced by long residence time recognised for this aquifer.

Activity Concentrations of Natural Radium, Thorium and Uranium Isotopes in Ground Water of Two Different Regions

Activity Concentrations of Natural Radium, Thorium and Uranium Isotopes in Ground Water of Two Different Regions

Radon, radium, and other radioactivity in ground water: hydrogeologic impact and application to indoor airborne contamination: proceedings of the NWWA Conference, April 7-9, 1987, Somerset, New Jersey

KEYNOTE. Development of Regulations for Radionuclides in Drinking Water. GEOLOGIC AND HYDROGEOLOGIC CONTROLS INFLUENCING RADON OCCURRENCE. Geologic Controls and Radon Occurrence in New England. The Effect of Uranium Siting in Two-Mica Granites on Uranium Concentrations and Radon Activity in Ground Water. Source and Distribution of Natural Radioactivity in Ground Water of the Newark Basin, New Jersey. MONITORING RADON, RADIUM AND OTHER RADIOACTIVITY FROM GEOLOGIC AND HYDROGEOLOGIC SOURCES. Elevated Levels of Radioactivity in Water Wells in Los Angeles and Orange Counties, California. A Preliminary Assessment of Factors Affecting Radon Levels in Idaho. Natural Radioactivity in Some Ground Waters of the Canadian Shield. Determination of Bulk Radon Emanation Rates by High Resolution Gamma-Ray Spectroscopy. Radon in Ground Water of the Long Valley Caldera, California. MINING IMPACTS ON THE OCCURRENCE OF RADON, RADIUM AND OTHER RADIOACTIVITY IN GROUND WATER. Radioactivity in Hocking River Basin. Factors Controlling Uranium and Radium Isotopic Distributions in Ground Waters of the West Central Florida Phosphate District. SAMPLING AND ANALYSIS OF RADON, RADIUM AND OTHER RADIOACTIVITY IN GROUND WATER. Sampling and Analysis of Dissolved Radon-222 in Surface and Ground Water. Radon-222 Concentrations of Ground Water from a Test Zone in a Shallow Alluvial Aquifer in the Santa Clara Valley, California. An Improved Method for the Simultaneous Determination of Radium-224, Radium-226, and Radium-228 in Water, Soils, and Sediments. Nationwide Distribution of Radium-228, Radium-226, Radon-222, and Uranium in Ground Water. Radon Measurement in Streams to Determine Location and Magnitude of Ground Water Seepage. Polonium in the Surficial Aquifer of West Central Florida. A Technique for the Rapid Extraction of Radon-222 from Water Samples and a Case Study. Relation Between Natural Radionuclide Activities and Chemical Constituents in Ground Water of the Newark Basin, New Jersey. RADON AND RADIUM IN WATER SUPPLY WELLS. Radon Survey of the American Water Works System. A Connecticut Radon Study-Using Limited Water Sampling and a Statewide Ground Gamma Radiation Survey to Help Guide an Indoor Air Testing Program: A Progress Report. Extreme Levels of Radon-222 and Uranium in a Private Water Supply. Radium-226 and Radon-222 in Domestic Water of Houston-Harris County, Texas. Radium, Radon, and Uranium Isotopes in Ground Water from Cambrian-Ordovician Sandstone Aquifers in Illinois. Radon Production in Pumping Wells. Radium-228 and Radon-226 in the Ground Water of the Chickies Formation, Southeastern Pennsylvania. Hydrogeologic Controls on the Occurrence of Radionuclides in Ground Water of Southern Ontario. PREDICTIVE MODELS FOR THE OCCURRENCE OF RADON AND OTHER RADIOACTIVITY. A Predictive Model for Indoor Radon Occurrences-A First Approximation. REMEDIAL ACTIONS FOR RADON, RADIUM AND OTHER RADIOACTIVITY. A Method of Radon Reduction for New Buildings. Treatment Scheme for Controlling the Migration of Radium from a Tailings Impoundment. Assessing the Potential Water Quality Hazards Caused by Disposal of Radium-Containing Waste Solids by Soil Blending. Radon in Water Supply Wells: Treatment Facility Requirements and Costs. Occurrence and Treatment of Uranium in Point of Use Systems in Colorado.

Uranium isotopes in groundwater: Their use in prospecting for sandstone-type uranium deposits

The relative abundances of dissolved 238U and its daughter 234U appear to be greatly affected as the uranium is transported downdip in sandstone aquifers. In an actively forming uranium accumulation at a reducing barrier, an input of 234U occurs in proximity to the isotopically non-selective precipitation of uranium from the water. The result is a downdip water much lower in uranium concentration but relatively enriched in 234U. The measurement of isotopic, as well as concentration, changes may increase the effectiveness of hydrogeochemical exploration for uranium. The investigation includes the uranium isotopic patterns in aquifers associated with known uranium orebodies in the Powder River and Shirley Basins, Wyoming, and Karnes County, Texas, U.S.A. In addition, the Carrizo sandstone aquifer of Texas was studied in detail, and the presence of an uranium accumulation inferred.