Spatial trends in uranium distribution in groundwaters of Southwest Punjab,India - A hydrochemical perspective

A hydrochemical study was undertaken in uranium impacted districts of southwest Punjab for evaluating the spatial and vertical trends as well as correlations with other hydrochemical parameters. Results infer that U is present in all samples (12.2–621 µg l⁻¹) and 90% are contaminated. Contour diagram depicts contamination in entire region excepting some pockets in central part of the study area. Shallow zones (<50 m bgl) show higher U compared to deeper ones. Hydrochemistry infers a common source of U for both shallow and deep zones and alkalinity as the governing factor for U mobilization from the sediments.

     

Comparison of radiometric and non-radiometric methods for uranium determination in groundwater of Punjab,India

Uranium in groundwater samples collected from Punjab state, India was determined using radiometric methods (extractive liquid scintillation and Cerenkov counting). Experimental conditions were optimized by studying the effect of sample pH, quenching and amount of extracting agent added to the scintillation cocktail on recovery of uranium. To ensure the accuracy of results, both radiometric methods were compared with non radiometric method such as adsorptive stripping voltammetry and found to be very good agreement. The distinct advantage of proposed radiometric methods is almost 100 % effective especially extractive liquid scintillation for simultaneous measurement of alpha and beta emitting radionuclides with fast and simple sample preparation.     

Analysis of natural radionuclides from uranium and thorium series in briney groundwaters

Analytical procedures for measuring various radionuclides in the²³⁸U and²³²Th chains in briney waters are described. Using methods such as mass spectrometry, and alpha, beta and gamma spectrometry, the desired measurement sensitivity required for each of the radionuclides is achieved.²³³U,²²⁸Th,²⁰⁸Po,²¹²Pb, and¹³³Ba are used as tracers for chemical yield recoveries. Typical precision of the results range from 5–20%.     

Study of uranium contamination of ground water in Punjab state in India using X-ray fluorescence technique

The elemental concentration of uranium in the samples collected from the ground water and the canal water in the Bathinda district of Punjab state, India, have been investigated using X-ray fluorescence technique. The residues obtained after drying the water samples were analysed using the energy dispersive X-ray fluorescence spectrometer consisting of Mo-anode X-ray tube equipped with selective absorbers as an excitation source and an Si(Li) detector. The uranium concentration values in significant fraction of the shallow ground water samples from the hand pumps is found to be above the permissible level of 15?ppb recommended by World Health Organisation for the drinking water, and its values in the canal water samples are below 5?ppb. To investigate the flyash from the coal-fired thermal power plants as a possible source of ground water contamination, the water samples collected from the surroundings of the power plants and the flyash samples were also analyzed. The results rule out flyash as a source of uranium contamination. Agrochemical processes occurring in the calcareous soils in the region are the favoured potential source of uranium contamination of the ground water.     

Distribution of uranium and thorium in fractionated sediment samples obtained from different locations across Thane Creek area (Mumbai,India)

Uranium concentration varies from 9.01 to 12.7, 8.03 to 11.5, 9.1 to 14.0 and 10.1 to 14.2 mg/kg in grab sediment, coarse sand fraction, fine sand fraction, silt and clay fraction respectively. Thorium concentration varies from 20.0 to 29.4, 17.3 to 28.6, 19.6 to 30.4 and 21.1 to 35.9 in grab sediment, coarse sand fraction, fine sand fraction, silt and clay fraction respectively. Uranium and thorium concentrations vary in different size fractionated sediment samples like silt and clay fraction > fine sand fraction > coarse sand fraction.     

Dissolution of metallic uranium and its alloys, Part II: Screening study results: Identification of an effective non-thermal uranium dissolution method

Screening experiments were performed to evaluate reagent systems that deactivate pyrophoric, metallic depleted uranium waste streams at ambient temperature. The results presented led to the selection of two systems, which would be investigated further, for the design of the LLNL onsite treatment process of metallic depleted uranium wastes. The two feasible systems are: (a) 7.5 mol/l H₂ This revised version was published online in July 2006 with corrections to the Cover Date.     

Assessment of chemo-radiological risk of naturally occurred uranium in groundwater from the Beed district,India

The main objective of study is assessment of chemo-radiological risk using measured concentrations of uranium in drinking water. For estimation of U concentration, LED Fluorimeter was used. For data accuracy, statistical tools were applied, geographical distribution GIS based software were used. To assess relation between uranium to other parameters, correlation test was performed. On the basis of presence of U in the water, hazard quotient, effective dose and cumulative dose for lifetime were estimated, it ranges from 0.001 to 1.09, 0.01–18.61 μSv year⁻¹ and 1.22–1303 μSv for lifetime correspondingly. The estimated ingested dose is well below than the suggested limit of 0.1 mSv.

     

Optimisation of laboratory arsenic analysis for groundwaters of West Bengal,India and possible water testing strategy

Regular monitoring of arsenic (As) in groundwater is crucial from public health perspectives as millions of people are suffering due to use of contaminated aquifer water for drinking purposes. The routine analyses, especially in developing nations, are mostly done in localised government/non-government laboratories with limited resources, having the target of analysing large number of samples in each run. Thus apart from analytical sensitivity, cost-effectiveness of the method and eco-friendliness of the experimental operation are key surreptitious factors. This demands optimisation of total As measurement methods and finding a method that gives ‘optimum benefit’ considering all these factors together. The present study therefore evaluates four common As (total) measurement methods [iodometric-colorimetric method, silver diethyl dithiocarbamate method, molybdenum blue method and hydride generation atomic absorption spectrophotometric (HG-AAS) method] practised in the Bengal Delta Plain, in view of their analytical sensitivity, related environmental hazard and experimental costs. It was found that the HG-AAS method is analytically more sensitive, whereas the iodometric-colorimetric method and the molybdenum blue method are better choices in terms of eco-friendliness and cost-effectiveness, respectively. However, when all three factors (analytical reliability, environmental hazard and cost) are considered simultaneously, the molybdenum blue method was found to be placed first in the ‘optimum performance rank’ list. It was also found that both environmental hazard and cost play a more crucial role than analytical reliability, although this is case specific and would differ from place to place around the globe. Finally based on the results, we have hypothesised a water testing strategy for developing countries such as India where the molybdenum blue method can be adapted as a screening method and later the HG-AAS method can be used to precisely identify the groundwater samples with As concentration below the WHO drinking water guideline value of 10 μg/L.     

Profile of selenium in soil and crops in seleniferous area of Punjab,India by neutron activation analysis

In the Nawanshahr–Hoshiarpur region of Punjab, India, more than 1000 hectares of agricultural land is significantly affected by high levels of selenium (Se). Studies were carried out to examine Se levels in soil and crops such as wheat grains, wheat husk, rice, maize and mustard using neutron activation analysis. The Se concentrations in soil and crop products were found to be ranging from 2.7 to 6.5 mg kg⁻¹ and 13 to 670 mg kg⁻¹, respectively, indicating significantly high selenium in these crop products. Two reference materials were analysed for Se contents by INAA as controls.     

Measurement of naturally occurring/fallout radioactive elements and assessment of annual effective dose in soil samples collected from four districts of the Punjab Province,Pakistan

Soil samples were collected from different localities of districts Jhelum, Chakwal, Rawalpindi and Attock, Punjab Province, Pakistan with an aim to measure naturally occurring radionuclides, namely ²²⁶Ra, ²³²Th, ⁴⁰K and fallout ¹³⁷Cs radionuclide using a P-type coaxial high purity germanium (HPGe) γ-ray spectrometer. Measured specific activities of ²²⁶Ra, ²³²Th and ⁴⁰K in these soil samples ranged from 26.02 ± 7.11 to 93.54 ± 8.13 Bq kg⁻¹, 29.34 ± 2.58 to 114.41 ± 2.80 Bq kg⁻¹ and 348.15 ± 3.20 to 752.98 ± 4.20 Bq kg⁻¹, respectively. Activity due to ¹³⁷Cs was observed in some locations which ranged from 0.4 ± 0.2 to 7.8 ± 0.3 Bq kg⁻¹. From the measured activity concentrations, radium equivalent activity concentrations were determined followed by calculations of mean absorbed dose rate and mean annual effective dose for the inhabitants of the studied area. The mean radium equivalent activity, internal and external hazard indices values came out to be 179.26 ± 11.93 Bq kg⁻¹, 0.64 ± 0.05 and 0.48 ± 0.03, respectively. Indoors and outdoor average annual effective dose values were found to be 0.42 ± 0.03 and 0.10 ± 0.01 mSv, respectively. Present data have been compared with the published data for other parts of the world and found to be safe for public and environment.     

Spatial distribution of uranium and chemo-radiological assessment in Hamirpur district,Himachal Pradesh,India

Monitoring of radioactivity in an environment is an important step towards establishing the baseline for environment protection. This work highlights the spatial distribution of uranium (U); assessment of physico-chemical parameters and radiological assessment in groundwater of Hamirpur district, HP, India. The concentration of U ranges from 0.15 to 18.92 μg l^?1. High correlation of U is observed with TDS, Chloride and Nitrate. Major concentration of U is present along the NW–SE trend-line following the Siwalik in the areas where mineralisation is prevalent and is of geogenic source derived from granitic and volcanic rock fragments present in conglomerates. The water-quality-index indicates that the water is suitable for drinking purpose.

     

Comparison of AMS,TIMS, and SIMS techniques for determining uranium isotope ratios in individual particles

The determination of isotope ratios in individual uranium particles is very important for nuclear safeguards. In this work, accelerator mass spectrometry (AMS), thermal ionization mass spectrometry (TIMS), and secondary ion mass spectrometry (SIMS) were applied to isotope ratio analysis of individual uranium particles and compared in terms of background, measurement accuracy, and efficiency. Several individual uranium particles (1–7 μm) from certified reference materials were used as samples. The results show that the average values of blank counting rate of ²³⁵U for AMS, FT-TIMS (FT: fission track), SEM-TIMS (SEM: scanning electron microscope), and SIMS were 7.3, 7.8, 2.7 and 2.2 cps, respectively. The relative error of ²³⁴U/²³⁵U and ²³⁴U/²³⁶U isotope ratios of the particles from U200 for AMS were within 10% and 20%, whereas the results of FT-TIMS and SIMS were within 5% and 10%, respectively. The relative error and external precision of ²³⁴U/²³⁸U and ²³⁵U/²³⁸U of the particles from U850 for the method of AMS, SEM-TIMS, and SIMS were within 10% and 5%, respectively. For ²³⁶U/²³⁸U, the average values of the relative error and external precision measured by AMS were within 5%, which measured by SEM-TIMS and SIMS were all within 10%. AMS has advantages in measuring ²³⁶U/²³⁸U. The measurement time of AMS and SEM-TIMS was shorter than that of FT-TIMS and longer than that of SIMS. It is considered that AMS and SEM-TIMS have a certain development prospect, and it is necessary to research deeply.     

Distribution of uranium in drinking/ground waters in Narsipatnam Revenue Division of Visakhapatnam District of Andhra Pradesh,India and consequent ingestion dose

Journal of Radioanalytical and Nuclear Chemistry - Uranium is a naturally occurring radioactive element. The higher concentrations of U in waters can cause chemical as well as radiological...     

Removal of uranium,cadmium and iron ions from phosphoric acid solution using amberjet 1200 H resin: an experimental,isotherm and kinetic study

Journal of Radioanalytical and Nuclear Chemistry - Amberjet 1200 H resin is an industrial strong acid cation exchanger bearing sulfonic reactive groups that were tested for the removal of uranium,...     

Vertical distribution and radiological risk assessment of natural radionuclides in the alluvial soil profile of south-west Punjab,India

Journal of Radioanalytical and Nuclear Chemistry - Natural radionuclide levels are studied in alluvial sediments upto the depth of 900&nbsp;cm. Eighteen profiles are selected from agricultural...     

Assessment of natural uranium and 226Ra concentration in ground water around the uranium mine at Narwapahar, Jharkhand, India and its radiological significance

A brief study on dissolved radionuclides in aquatic environment, especially in ground water, constitutes the key aspect for assessment and control of natural exposure. In the present study the distribution of natural uranium and ²²⁶Ra concentration were measured in ground water samples collected within a 10 km radius around the Narwapahar uranium mine in the Singhbhum thrust belt of Jharkhand, India in 2007–2008. The natural uranium content in the ground water samples in this region was found to vary from 0.1 to 3.75 μg L^?1 with an average of 0.87 ± 0.73 μg L^?1 and ²²⁶Ra concentration was found to vary from 5.2 to 38.1 mBq L^?1 with an average of 13.73 ± 7.34 mBq L^?1. The mean annual ingestion dose due to intake of natural uranium and ²²⁶Ra through drinking water pathway to male and female adults population was estimated to be 6.55 and 4.78 μSv y^?1, respectively, which constitutes merely a small fraction of the reference dose level of 100 μSv y^?1 as recommended by WHO.