The Experts below are selected from a list of 144 Experts worldwide ranked by ideXlab platform
E. H. Borai - One of the best experts on this subject based on the ideXlab platform.
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Performance Characteristics of Sequential Separation and Quantification of Lead‐210 and Polonium‐210 by Ion Exchange Chromatography and Nuclear Spectrometric Measurements
Journal of environmental quality, 2006Co-Authors: E. M. El Afifi, E. H. BoraiAbstract:A selective separation and quantitative determination procedure for 210 Pb and 210 Po in various environmental matrices from different sources such as IAEA-326 soil, phosphate rocks (PR), and phosphogypsum (PG) was developed. The tested samples were digested sequentially using concentrated mineral acids (HF, HNO 3 ) by a programmable high-pressure microwave digestion system. The sample solution was loaded onto a preconditioned ion exchange column (Sr-resin) for chromatographic separation. Polonium-210 was eluted by 6 M HNO 3 then spontaneously deposited onto polished silver discs to be measured using low-background alpha spectrometry. Lead-210 was sequentially eluted using 6 M HCI solution, precipitated as Lead oxalate, dissolved in HNO 3 solution, and mixed with scintillation cocktail to be measured by liquid scintillation counting (LSC). Performance of the developed procedure was tested using a reference soil (IAEA-326), with recommended isotope values, that was used as a quality control to assess separation and quantification efficiency (recovery %). The minimum detectable activities of 210 Pb and 210 Po were found to be 24 and 0.28 Bq kg -1 for the measurements using LSC and alpha spectrometry, respectively. The recoveries (%) of 210 Pb and 210 Po were found to be 80 and 60%, respectively. To test the validity of the proposed LSC method, a comparative study was performed by measuring 210 Pb activity concentration in test samples by nondestructive gamma-ray spectrometry.
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performance characteristics of sequential separation and quantification of Lead 210 and polonium 210 by ion exchange chromatography and nuclear spectrometric measurements
Journal of Environmental Quality, 2006Co-Authors: E El M Afifi, E. H. BoraiAbstract:A selective separation and quantitative determination procedure for 210 Pb and 210 Po in various environmental matrices from different sources such as IAEA-326 soil, phosphate rocks (PR), and phosphogypsum (PG) was developed. The tested samples were digested sequentially using concentrated mineral acids (HF, HNO 3 ) by a programmable high-pressure microwave digestion system. The sample solution was loaded onto a preconditioned ion exchange column (Sr-resin) for chromatographic separation. Polonium-210 was eluted by 6 M HNO 3 then spontaneously deposited onto polished silver discs to be measured using low-background alpha spectrometry. Lead-210 was sequentially eluted using 6 M HCI solution, precipitated as Lead oxalate, dissolved in HNO 3 solution, and mixed with scintillation cocktail to be measured by liquid scintillation counting (LSC). Performance of the developed procedure was tested using a reference soil (IAEA-326), with recommended isotope values, that was used as a quality control to assess separation and quantification efficiency (recovery %). The minimum detectable activities of 210 Pb and 210 Po were found to be 24 and 0.28 Bq kg -1 for the measurements using LSC and alpha spectrometry, respectively. The recoveries (%) of 210 Pb and 210 Po were found to be 80 and 60%, respectively. To test the validity of the proposed LSC method, a comparative study was performed by measuring 210 Pb activity concentration in test samples by nondestructive gamma-ray spectrometry.
Christine Alewell - One of the best experts on this subject based on the ideXlab platform.
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excess Lead 210 and plutonium 239 240 two suitable radiogenic soil erosion tracers for mountain grassland sites
Environmental Research, 2018Co-Authors: Katrin Meusburger, Paolo Porto, Lionel Mabit, C La Spada, Laura Arata, Christine AlewellAbstract:Abstract The expected growing population and challenges associated with globalisation will increase local food and feed demands and enhance the pressure on local and regional upland soil resources. In light of these potential future developments it is necessary to define sustainable land use and tolerable soil loss rates with methods applicable and adapted to mountainous areas. Fallout-radionuclides (FRNs) are proven techniques to increase our knowledge about the status and resilience of agro-ecosystems. However, the use of the Caesium-137 ( 137 Cs) method is complicated in the European Alps due to its heterogeneous input and the timing of the Chernobyl fallout, which occurred during a few single rain events on partly snow covered ground. Other radioisotopic techniques have been proposed to overcome these limitations. The objective of this study is to evaluate the suitability of excess Lead-210 ( 210 Pb ex ) and Plutonium-239+240 ( 239+240 Pu) as soil erosion tracers for three different grassland management types at the steep slopes (slope angles between 35 and 38°) located in the Central Swiss Alps. All three FRNs identified pastures as having the highest mean (± standard deviation) net soil loss of −6.7 ± 1.1, −9.8 ± 6.8 and −7.0 ± 5.2 Mg ha -1 yr -1 for 137 Cs, 210 Pb ex and 239+240 Pu, respectively. A mean soil loss of −5.7 ± 1.5, −5.2 ± 1.5 and-5.6 ± 2.1 was assessed for hayfields and the lowest rates were established for pastures with dwarf-shrubs (−5.2 ± 2.5, −4.5 ± 2.5 and −3.3 ± 2.4 Mg ha -1 yr -1 for 137 Cs, 210 Pb ex and 239+240 Pu, respectively). These rates, evaluated at sites with an elevated soil erosion risk exceed the respective soil production rates. Among the three FRN methods used, 239+240 Pu appears as the most promising tracer in terms of measurement uncertainty and reduced small scale variability (CV of 13%). Despite a higher level of uncertainty, 210 Pb ex produced comparable results, with a wide range of erosion rates sensitive to changes in grassland management. 210 Pb ex can then be as well considered as a suitable soil tracer to investigate alpine agroecosystems.
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Excess Lead-210 and Plutonium-239+240: Two suitable radiogenic soil erosion tracers for mountain grassland sites
Environmental research, 2017Co-Authors: Katrin Meusburger, Paolo Porto, Lionel Mabit, C La Spada, Laura Arata, Christine AlewellAbstract:Abstract The expected growing population and challenges associated with globalisation will increase local food and feed demands and enhance the pressure on local and regional upland soil resources. In light of these potential future developments it is necessary to define sustainable land use and tolerable soil loss rates with methods applicable and adapted to mountainous areas. Fallout-radionuclides (FRNs) are proven techniques to increase our knowledge about the status and resilience of agro-ecosystems. However, the use of the Caesium-137 ( 137 Cs) method is complicated in the European Alps due to its heterogeneous input and the timing of the Chernobyl fallout, which occurred during a few single rain events on partly snow covered ground. Other radioisotopic techniques have been proposed to overcome these limitations. The objective of this study is to evaluate the suitability of excess Lead-210 ( 210 Pb ex ) and Plutonium-239+240 ( 239+240 Pu) as soil erosion tracers for three different grassland management types at the steep slopes (slope angles between 35 and 38°) located in the Central Swiss Alps. All three FRNs identified pastures as having the highest mean (± standard deviation) net soil loss of −6.7 ± 1.1, −9.8 ± 6.8 and −7.0 ± 5.2 Mg ha -1 yr -1 for 137 Cs, 210 Pb ex and 239+240 Pu, respectively. A mean soil loss of −5.7 ± 1.5, −5.2 ± 1.5 and-5.6 ± 2.1 was assessed for hayfields and the lowest rates were established for pastures with dwarf-shrubs (−5.2 ± 2.5, −4.5 ± 2.5 and −3.3 ± 2.4 Mg ha -1 yr -1 for 137 Cs, 210 Pb ex and 239+240 Pu, respectively). These rates, evaluated at sites with an elevated soil erosion risk exceed the respective soil production rates. Among the three FRN methods used, 239+240 Pu appears as the most promising tracer in terms of measurement uncertainty and reduced small scale variability (CV of 13%). Despite a higher level of uncertainty, 210 Pb ex produced comparable results, with a wide range of erosion rates sensitive to changes in grassland management. 210 Pb ex can then be as well considered as a suitable soil tracer to investigate alpine agroecosystems.
K. Schwartzman - One of the best experts on this subject based on the ideXlab platform.
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an ion exchange model of Lead 210 and Lead uptake in a foliose lichen application to quantitative monitoring of airborne Lead fallout
Science of The Total Environment, 1991Co-Authors: David Schwartzman, Lorin Stieff, Margaret Kasim, E. Kombe, S. Aung, Estella A. Atekwana, James H. Johnson, K. SchwartzmanAbstract:Lead, 210Pb and 210Po levels were determined in dated sequential growth of thalli of the foliose lichen Flavoparmelia baltimorensis from Great Falls and Plummers Island, Maryland. An ion-exchange model for uptake of Pb and 210Pb applied to these data is consistent with the experimentally measured Pb partition coefficient between water and lichen as well as the expected Lead concentrations in rain. Lead-210/Polonium-210 activity ratios are significantly elevated in very young growth (<3 years old), as expected from model calculations. Retrospective Pb fallouts are computed which reflect the drop in gasoline Lead emissions in the period sampled (1973–1986). With experimental determination of partition coefficients this methodology is a basis for retrospective quantitative monitoring of other airborne heavy metals using foliose lichens.
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An ion-exchange model of Lead-210 and Lead uptake in a foliose lichen ; application to quantitative monitoring of airborne Lead fallout
Science of The Total Environment, 1991Co-Authors: David Schwartzman, Lorin Stieff, Margaret Kasim, E. Kombe, S. Aung, Estella A. Atekwana, James H. Johnson, K. SchwartzmanAbstract:Lead, 210Pb and 210Po levels were determined in dated sequential growth of thalli of the foliose lichen Flavoparmelia baltimorensis from Great Falls and Plummers Island, Maryland. An ion-exchange model for uptake of Pb and 210Pb applied to these data is consistent with the experimentally measured Pb partition coefficient between water and lichen as well as the expected Lead concentrations in rain. Lead-210/Polonium-210 activity ratios are significantly elevated in very young growth (
Abdulraheem Abdulrahman Kinsara - One of the best experts on this subject based on the ideXlab platform.
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Accumulation of Lead-210 and Polonium-210 in the Groundwater of Wadi Nu’man, Mecca Province
Arabian Journal for Science and Engineering, 2016Co-Authors: El-said Ibrahim Shabana, Maher Mohammad Taher Qutub, Abdulraheem Abdulrahman KinsaraAbstract:Groundwater of Wadi Nu’man (30 km southeast of Mecca city) of high radon-222 (\({^{222}}\)Rn) content, emanated directly from the bed rock into the water reservoir, has been analyzed for Lead-210 (\({^{210}}\)Pb) and polonium-210 (\({^{210}}\)Po), the comparatively long- lived \({^{222}}\)Rn progenies, to study the effect of the continuous \({^{222}}\)Rn emanation on the accumulation of both radionuclides in this water. Emanation of \({^{222}}\)Rn directly from rock to water may be affected seasonally by atmospheric temperature and pressure; therefore, \({^{222}}\)Rn and \({^{222}}\)Rn progenies were reanalyzed in seasonal samples of the same wells. The obtained results showed \({^{210}}\)Pb and \({^{210}}\)Po activity levels ranging from
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accumulation of Lead 210 and polonium 210 in the groundwater of wadi nu man mecca province
Arabian Journal for Science and Engineering, 2016Co-Authors: El-said Ibrahim Shabana, Maher Mohammad Taher Qutub, Abdulraheem Abdulrahman KinsaraAbstract:Groundwater of Wadi Nu’man (30 km southeast of Mecca city) of high radon-222 (\({^{222}}\)Rn) content, emanated directly from the bed rock into the water reservoir, has been analyzed for Lead-210 (\({^{210}}\)Pb) and polonium-210 (\({^{210}}\)Po), the comparatively long- lived \({^{222}}\)Rn progenies, to study the effect of the continuous \({^{222}}\)Rn emanation on the accumulation of both radionuclides in this water. Emanation of \({^{222}}\)Rn directly from rock to water may be affected seasonally by atmospheric temperature and pressure; therefore, \({^{222}}\)Rn and \({^{222}}\)Rn progenies were reanalyzed in seasonal samples of the same wells. The obtained results showed \({^{210}}\)Pb and \({^{210}}\)Po activity levels ranging from <6 to 29.9 and from 0.6 to 18.2 mBq/L, respectively, which was far below the recorded level of their parent radionuclide \({^{222}}\)Rn (10.9–99.7 Bq/L). The data have been discussed in detail.
Katrin Meusburger - One of the best experts on this subject based on the ideXlab platform.
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excess Lead 210 and plutonium 239 240 two suitable radiogenic soil erosion tracers for mountain grassland sites
Environmental Research, 2018Co-Authors: Katrin Meusburger, Paolo Porto, Lionel Mabit, C La Spada, Laura Arata, Christine AlewellAbstract:Abstract The expected growing population and challenges associated with globalisation will increase local food and feed demands and enhance the pressure on local and regional upland soil resources. In light of these potential future developments it is necessary to define sustainable land use and tolerable soil loss rates with methods applicable and adapted to mountainous areas. Fallout-radionuclides (FRNs) are proven techniques to increase our knowledge about the status and resilience of agro-ecosystems. However, the use of the Caesium-137 ( 137 Cs) method is complicated in the European Alps due to its heterogeneous input and the timing of the Chernobyl fallout, which occurred during a few single rain events on partly snow covered ground. Other radioisotopic techniques have been proposed to overcome these limitations. The objective of this study is to evaluate the suitability of excess Lead-210 ( 210 Pb ex ) and Plutonium-239+240 ( 239+240 Pu) as soil erosion tracers for three different grassland management types at the steep slopes (slope angles between 35 and 38°) located in the Central Swiss Alps. All three FRNs identified pastures as having the highest mean (± standard deviation) net soil loss of −6.7 ± 1.1, −9.8 ± 6.8 and −7.0 ± 5.2 Mg ha -1 yr -1 for 137 Cs, 210 Pb ex and 239+240 Pu, respectively. A mean soil loss of −5.7 ± 1.5, −5.2 ± 1.5 and-5.6 ± 2.1 was assessed for hayfields and the lowest rates were established for pastures with dwarf-shrubs (−5.2 ± 2.5, −4.5 ± 2.5 and −3.3 ± 2.4 Mg ha -1 yr -1 for 137 Cs, 210 Pb ex and 239+240 Pu, respectively). These rates, evaluated at sites with an elevated soil erosion risk exceed the respective soil production rates. Among the three FRN methods used, 239+240 Pu appears as the most promising tracer in terms of measurement uncertainty and reduced small scale variability (CV of 13%). Despite a higher level of uncertainty, 210 Pb ex produced comparable results, with a wide range of erosion rates sensitive to changes in grassland management. 210 Pb ex can then be as well considered as a suitable soil tracer to investigate alpine agroecosystems.
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Excess Lead-210 and Plutonium-239+240: Two suitable radiogenic soil erosion tracers for mountain grassland sites
Environmental research, 2017Co-Authors: Katrin Meusburger, Paolo Porto, Lionel Mabit, C La Spada, Laura Arata, Christine AlewellAbstract:Abstract The expected growing population and challenges associated with globalisation will increase local food and feed demands and enhance the pressure on local and regional upland soil resources. In light of these potential future developments it is necessary to define sustainable land use and tolerable soil loss rates with methods applicable and adapted to mountainous areas. Fallout-radionuclides (FRNs) are proven techniques to increase our knowledge about the status and resilience of agro-ecosystems. However, the use of the Caesium-137 ( 137 Cs) method is complicated in the European Alps due to its heterogeneous input and the timing of the Chernobyl fallout, which occurred during a few single rain events on partly snow covered ground. Other radioisotopic techniques have been proposed to overcome these limitations. The objective of this study is to evaluate the suitability of excess Lead-210 ( 210 Pb ex ) and Plutonium-239+240 ( 239+240 Pu) as soil erosion tracers for three different grassland management types at the steep slopes (slope angles between 35 and 38°) located in the Central Swiss Alps. All three FRNs identified pastures as having the highest mean (± standard deviation) net soil loss of −6.7 ± 1.1, −9.8 ± 6.8 and −7.0 ± 5.2 Mg ha -1 yr -1 for 137 Cs, 210 Pb ex and 239+240 Pu, respectively. A mean soil loss of −5.7 ± 1.5, −5.2 ± 1.5 and-5.6 ± 2.1 was assessed for hayfields and the lowest rates were established for pastures with dwarf-shrubs (−5.2 ± 2.5, −4.5 ± 2.5 and −3.3 ± 2.4 Mg ha -1 yr -1 for 137 Cs, 210 Pb ex and 239+240 Pu, respectively). These rates, evaluated at sites with an elevated soil erosion risk exceed the respective soil production rates. Among the three FRN methods used, 239+240 Pu appears as the most promising tracer in terms of measurement uncertainty and reduced small scale variability (CV of 13%). Despite a higher level of uncertainty, 210 Pb ex produced comparable results, with a wide range of erosion rates sensitive to changes in grassland management. 210 Pb ex can then be as well considered as a suitable soil tracer to investigate alpine agroecosystems.