Fractionation of 137Cs and Pu in natural peatland

Mihalík, Ján; Bartusková, M.; Hölgye, Z.; Ježková, Tereza; Henych, Ondřej

doi:10.1016/j.jenvrad.2014.02.015

Cited by 16 publications

(6 citation statements)

References 21 publications

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“…Coutelot et al, (2022) 4 observed accumulation of plutonium in organic matter rich sediments near the Pond B outlet indicating a strong association between plutonium and iron/carbon cycling. A comparable re-distribution was not observed for Cs-137 which has a relatively lower affinity for organic matter than plutonium 27 . Furthermore, production of Fe-POM stable colloids is known to occur at redox interfaces in organic rich environments 28 .…”

Section: Resultsmentioning

confidence: 70%

Sources, seasonal cycling, and fate of plutonium in a seasonally stratified and radiologically contaminated pond

Wasserman

Merino

Coutelot

et al. 2023

Sci Rep

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Unlike short-term laboratory experiments, studies at sites historically contaminated with radionuclides can provide insight into contaminant migration behavior at environmentally-relevant decadal timescales. One such site is Pond B, a seasonally stratified reservoir within Savannah River Site (SC, USA) has low levels (μBq L−1) of plutonium in the water column. Here, we evaluate the origin of plutonium using high-precision isotope measurements, investigate the impact of water column geochemistry on plutonium cycling during different stratification periods, and re-evaluate long-term mass balance of plutonium in the pond. New isotopic data confirm that reactor-derived plutonium overwhelms input from Northern Hemisphere fallout at this site. Two suggested mechanisms for observed plutonium cycling in the water column include: (1) reductive dissolution of sediment-derived Fe(III)-(oxyhydr)oxides during seasonal stratification and (2) plutonium stabilization complexed strongly to Fe(III)-particulate organic matter (POM) complexes. While plutonium may be mobilized to a limited extent by stratification and reductive dissolution, peak plutonium concentrations are in shallow waters and associated with Fe(III)-POM at the inception of stratification. This suggests that plutonium release from sediments during stratification is not the dominant mechanism driving plutonium cycling in the pond. Importantly, our analysis suggests that the majority is retained in shallow sediments and may become increasingly recalcitrant.

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Section: Resultsmentioning

confidence: 70%

Sources, seasonal cycling, and fate of plutonium in a seasonally stratified and radiologically contaminated pond

Wasserman

Merino

Coutelot

et al. 2023

Sci Rep

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“…In Sweden, Poland and Poland-Slovekia peatlands (Fiałkiewicz-Kozieł et al 2014;Gaca et al 2006;Mihalík et al 2014), a decrease of 40 K activity values with depth was also observed. This behavior was interpreted as being due to the occurrence of living Sphagnum sp.…”

Section: Radioactivitymentioning

confidence: 85%

“…This behavior was interpreted as being due to the occurrence of living Sphagnum sp. that uptakes K as nutrient, inducing a relatively lower concentration of K in deeper layers of this soil (Mihalík et al 2014). In SdEM, there is no living sphagnum, indicating that the living species in SdEM, such as Lagenocarpus rigidus Nees, Rhynchospora speciosa (Kuntze) Boeckeler and others (Silva et al 2019) can also take K and concentrate it at the surface layer.…”

Section: Radioactivitymentioning

confidence: 97%

“…Peatlands are distinctive environments capable of storing carbon, fresh water and radioactive materials as well as atmospheric deposits and pollutants (Mróz et al 2017;Mercader et al 2014;Mihalík et al 2014). The peat formation is favored by acid and anoxic conditions, along with high water content, low redox potential and the inhibitory effect of organic acids (Horák et al 2011).…”

Section: Introductionmentioning

confidence: 99%

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Natural and anthropogenic gamma-ray emitters and iron-bearing compounds distribution in peatlands of the southern Espinhaço mountain chain, Brazil

et al. 2019

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To help understand the dynamics of peatlands forming on the Southern Serra do Espinhaço, Brazil, the occurring natural ( 226 Ra, 232 Th, 40 K) and anthropogenic ( 137 Cs) activity of gamma-ray emitters located at three sites, namely the localities of São João da Chapada (CH), Pinheiro (PIN) and Pau de Fruta (PDF), was studied. The iron compounds were characterized by 57 Fe Mössbauer spectroscopy. Differences on natural radionuclide levels and distributions were found among the peatland sites, indicating differences on mineral composition, hydric regimes and living. Significant correlation was found only for 232 Th-226 Ra activity values (Pearson correlation coefficient of − 0.5), which is different from other South American soils, where significant positive correlations among all radionuclides were determined. In PDF and CH, the dose rate results are lower than the worldwide mean value, but in PIN, they are higher because of the relatively high 226 Ra concentration. The only anthropogenic radionuclide is 137 Cs. The convection-diffusion model fits the CH and PDF activity profiles, although the PIN profile is likely affected by other soil mechanisms as well. Mössbauer spectra reveal Fe 3+ in two different local environments and the occurrence of hematite in the upper samples of the CH site. The iron concentration decreases with depth. Contrary to soils of other regions, no significant correlation was found between iron species and the natural radioactivity. The studied peatlands exhibit clear differences between their natural and anthropogenic radionuclide distributions to those of mineral soils.

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“…To verify the dating data, we used an independent 241 Am chronometer characterised by insignificant migration along the peat section [44][45][46]. Peaks of 241 Am, as well as a number of other man-made isotopes in natural sediments, correspond to the dates of intense radioactive fallout [47].…”

Section: Pb Chronology Of the Peat Corementioning

confidence: 99%

Assessment of the Impact of Anthropogenic Drainage of Raised Peat-Bog on Changing the Physicochemical Parameters and Migration of Atmospheric Fallout Radioisotopes in Russia’s Subarctic Zone (Subarctic Zone of Russia)

et al. 2023

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This paper reports on the research results of the radioactivity levels and upward dispersion of radionuclides of atmospheric fallout 210Pb, 137Cs, 241Am and 234,238U as well as key physicochemical parameters in a peat deposit subjected to drainage in 1969–1971. It was found that drainage of the peat bog led the natural moisture content to shrink in the peat. Active aeration in the peat deposit, accompanied by the growth of Eh, raises the strength of oxidative transformation processes of the organic part of the peat, leading to higher levels of peat degradation and major variations in the elemental content. Changes in these parameters affect the behaviour of radionuclides in the peat section. Thus, in contrast to the sites with a natural hydrological regime, within the dried peat deposit a geochemical barrier of sorption type is not formed, capable of retaining a significant proportion of 137Cs. In this connection, there is an acceleration of 137Cs migration. In addition, changes in the hydrological regime led to the predominance of vascular plants with a more developed root system than that of sphagnum, which also contributed to a more intense transfer of 137Cs by the root system up the section. The findings of 210Pb dating of the dried peat bog showed a significantly lower peat accumulation rate compared to the natural bog massif (0.15 ± 0.02 vs. 0.48 ± 0.08 cm/year). A factor examination of the dataset demonstrated that the leading role in the distribution of radionuclides belongs to redox and acid-base conditions, which have changed significantly after draining the peat deposit.

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Fractionation of 137Cs and Pu in natural peatland

Cited by 16 publications

References 21 publications

Sources, seasonal cycling, and fate of plutonium in a seasonally stratified and radiologically contaminated pond

Sources, seasonal cycling, and fate of plutonium in a seasonally stratified and radiologically contaminated pond

Natural and anthropogenic gamma-ray emitters and iron-bearing compounds distribution in peatlands of the southern Espinhaço mountain chain, Brazil

Assessment of the Impact of Anthropogenic Drainage of Raised Peat-Bog on Changing the Physicochemical Parameters and Migration of Atmospheric Fallout Radioisotopes in Russia’s Subarctic Zone (Subarctic Zone of Russia)

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