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Plant uptake of radiocesium from contaminated soil

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Pipíška M. , Lesný J. , Hornik M. , Augustín J.

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tom Vol. 49,suppl.1

9-11

EN

Phytoextraction field experiments were conducted on soil contaminated with radiocesium to determine the capacity of autochthonous grasses and weeds to accumulate 137Cs. The aim of the study was to evaluate the potential of spontaneously growing vegetation as a tool for decontamination of non-agricultural contaminated land. As a test field, the closed monitored area of the radioactive wastewater treatment plant of the Nuclear Power Plant in Jaslovské Bohunice, Slovakia was used. Contamination was irregularly distributed from the level of background to spots with maximal activity up to 900 Bq/g soil. Sequential extraction analysis of soil samples showed the following extractability of radiocesium (as percent of the total): water < 0.01%; 1 M MgCl2 = 0.3-1.1%; 1 M CH3COONa = 0.3-0.9%; 0.04 M NH4Cl (in 25% CH3COOH) = 0.9-1.4%; and 30% H2O2 - 0.02 M HNO3 = 4.5-9.0%. Specific radioactivity of the most efficiently bioaccumulating plant species did not exceed 4.0 kBq kg 1 (dry weight biomass). These correspond to the soil-to-plant transfer factor (TF) values up to 44.4 × 10 4 (Bq kg 1 crop, d.w.)/(Bq kg 1 soil, d.w.). Aggregated transfer factor (Tag) of the average sample of the whole crop harvested from defined area was 0.5 × 10 5 (Bq kg 1 d.w. crop)/(Bq m 2 soil). It can be concluded that low mobility of radiocesium in analysed soil type, confirmed by sequential extraction analyses, is the main hindrance for practical application of autochthonous plants as a phytoremediation tool for aged contaminated area of non-cultivated sites. Plant cover can efficiently serve only as a soil surface-stabilising layer, mitigating the migration of radiocesium into the surrounding environment.

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Isotopic investigations of uppermost sediments from Lake Wigry (NE Poland) and its environment

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Pawlyta J. , Pazdur A. , Piotrowska N. , Poręba G. , Sikorski J. , Szczepanek M. , Król K. , Rutkowski J. , Hałas S.

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2004

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tom Vol. 23

71-78

EN

This paper presents the results of the first isotopic investigations of sediments recovered from Lake Wigry (NE-Poland). In the spring/summer 2002 few sediment cores, plant samples and water profiles were collected specially for isotopic investigations. We obtained 210Pb activity profiles, 137Cs activity profiles and 14C activity/age profiles. Apparent ages of carbonate fraction for all sediment cores were determined. Sedimentation rates for collected cores were estimated using 14C dating method. In addition oxygen isotopic ratios of the water profiles, carbon stable isotopes ratio of collected sediment cores were determined.

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Badanie mobilności radiocezu w glebowym kompleksie sorpcyjnym

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Majcherczyk T. , Dołhańczuk-Śródka A. , Wacławek M. , Wacławek W.

Proceedings of ECOpole

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2008

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tom Vol. 2, No. 1

221--225

PL

W warunkach laboratoryjnych badano proces desorpcji radiocezu z gleby (w układzie gleba-roztwór) w obecności selektywnego jonitu Purolite NRW-160-Li7. Jednocześnie prowadzono badania w układzie odniesienia, który był analogiczny, lecz bez jonitu. Próbki gleby wykorzystane do badań pochodziły z obszaru Anomalii Opolskiej z okolic Łambinowic. Pomiaru aktywności właściwej radiocezu w glebie i w jonicie dokonano za pomocą spektrometru półprzewodnikowego gamma (Canberra). Wykazano, że obecność selektywnego jonitu miała znaczący wpływ na proces ustalania się równowagi jonowymiennej radiocezu w układzie gleba-roztwór. Eksperyment wykazał, że w układzie pomiarowym w obecności jonitu z gleby desorbowało znacznie więcej jonów radiocezu niż w analogicznym układzie odniesienia (bez jonitu). Stwierdzono korelujące ze sobą zmiany aktywności radionuklidu w poszczególnych etapach procesu desorpcji radiocezu z gleby i procesu jego akumulacji w jonicie.

EN

In laboratory conditions, using a system permitting free flow of ions, the radiocesium desorption from soil process in the soil-solution system in the presence of selective ionite Purolite NRW-160-Li7 was tested. Simultaneously tests were led in comparative system without ionite. Soil samples used for the tests originated from the area of the so-called Opole Anomaly nearby the town of Łambinowice. The specific activities of radiocesium in the soil and in the ion exchanger were measured using a gamma semiconductor spectrometr (Canberra). The selective ionite resulting in a decrease of cesium ion concentration in the solution affected the shift of the soil-solution state of equilibrium towards cesium desorption of the soil. In the test demonstrated that in the main system in presence of ionite, in soil decrcased the considerably more ions of cesium than in the analogous system of reference (without ionite). The tests demonstrated correlating changes of radionuclide activities in individual stages of the radiocesium desorption process of the soil and its accumulation in the ionite.

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Measurement of anthropogenic radionuclides in post-Fukushima Pacific seawater samples

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Lutter G. , Tzika F. , Hult M. , Aoyama M. , Hamajima Y. , Marissens G. , Stroh H.

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tom Vol. 60, No. 3, part 2

545--550

EN

Following the accident at the Daiichi Fukushima nuclear power plant in 2011, a vast number of Pacific seawater samples from many locations far from Fukushima have been collected by Japanese investigators. Due to dilution, the activities of radionuclides from North Pacifi c seawater samples are very low, which calls for extraordinary measures when being measured. This study focuses on the metrological aspects of the gamma-ray spectrometry measurements performed on such samples in two underground laboratories; at HADES (by JRC- -IRMM in Belgium), and at Ogoya (by Kanazawa University in Japan). Due to many samples and long measurement times, all available HPGe detectors needed to be employed. In addition to single coaxial detectors, this involved multidetector systems and well detectors. Optimization of detection limits for different radionuclides and detectors was performed using Monte Carlo simulations.

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On the radiocesium behavior in a small humic lake (Lithuania)

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Tarasiuk N. , Moisejenkova A. , Koviazina E. , Karpicz R. , Astrauskiene N.

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2009

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tom Vol. 54, No. 3

211-220

EN

Peculiarities of radiocesium contamination of a small humic lake, which became meromictic some thirty-five years ago due to the inflow of a large amount of humic water, are presented. The lake consists of two separate water layers, which do not intermix. A lower water layer of the lake below some 3-m depth is stagnant and anaerobic, and radiocesium load of the sediments is mainly caused by nuclear weapons fallout. The radiocesium load of the sediments of the upper monomictic water layer is significantly larger due to additional contamination after the Chernobyl accident. Radiocesium activity concentrations in lake water increase with depth, and even in the surface layer, they are commonly the largest among the neighboring lakes with transparent water. It is shown that bottom areas of the monomictic part of the lake with the elevated radiocesium deepening into sediments are related to the favorite sites of the tench (Tinca tinca) winter torpor. Sediment bioturbation and redistribution due to tench activities distort naturally formed radiocesium vertical profiles and they cannot be used for estimations of sedimentation rates and sediment chronology. The studied lake can be useful as an analogous model in analyzing structural and radiological consequences of humic water inflows to closed lakes. Concerning extreme radiological situations in closed humic lakes related to their specific vertical structure, they may be treated as critical objects in assessing the risk to humans after radionuclide deposition events.

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Pomiar radioaktywności cezu-137 w grzybach z lasów opolszczyzny

86%

Wacławek W. , Majcherczyk T. , Dołhańczuk A.

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2000

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tom Vol. 7, nr 4

405-415

PL

Pomiary aktywności właściwej 137Cs wykonano w próbkach grzybów pobranych z lasów Opolszczyzny w 12 lat po awarii EJ w Czarnobylu. Uzyskane wyniki potwierdzają różnice w zdolności do akumulacji 137Cs przez odmienne gatunki grzybów. Najwyższe aktywności właściwe cezu stwierdzono w próbkach podgrzybka brunatnego (Xerocomus badius). Zaobserwowano znaczne zróżnicowanie stężenia cezu w podgrzybku, które w większości przypadków koresponduje z rozkładem aktywności cezu w glebie na tych samych terenach. Wykazano, że średnia aktywność 137Cs w badanych próbkach podgrzybka z Opolszczyzny ponad sześciokrotnie przewyższa średnią aktywność dla tego gatunku w Polsce.

EN

Measurements of specific activity of I37Cs made for the samples of edible mushrooms taken from woods of the Opole region 12 years after the Chemobyl nuclear power station catastrophe. The obtained results confirm the differences in ability to accumulate I37Cs by different species of mushrooms. The highest activity of caesium has been observed in the samples of mushrooms Xerocomus badius. A major difference in the caesium concentration in the edible mushroom has been observed, which usually corresponds to the caesium concentration in the soil of the same region. The average activity of 137 Cs in considered sampIes of edible mushroom from the Opole region are 6 times bigger than the average activity for this type of mushrooms in Poland.

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Modeling Radiocesium Contamination of Sunflower Products in the Zaporizhzhia Region

86%

Polevoy A. , Lyashenko G. , Zhygailo O. , Volvach O. , Zhygailo T. , Popovych I. , Tolmachova A. , Kolosovska V. , Kostyukevych T. , Barsukova O.

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tom Vol. 24, nr 4

279--287

EN

The accident at the Chornobyl nuclear power plant was one of the most serious nuclear incidents in human history. A radioactive plume covered a whole strip of northeastern Europe. The consequences of this catastrophe are still being felt, both in Ukraine and around the world. The article is devoted to the assessment of the consequences of radiocesium contamination of agricultural lands and irrigated waters during a possible accident at the Zaporizhzhia NPP and the associated Cs137 contamination of sunflower products in the Zaporizhzhia region. The studies were carried out using a dynamic mathematical model for the formation of radionuclide activity in the "water-soil-plant-product" system, ECOSIS-87 (Ecoplant). The article presents the results of studies of possible contamination of the environment by radiocesium according the Chornobyl NPP-86 scenario and sunflower production by the method of mathematical dynamic modeling. The calculations were carried out on the basis of the results of an agrochemical and agroecological survey of the state of soils in Ukraine and the Dnipro cascade of reservoirs. If an explosion occurs at the Zaporizhzhia NPP, the power of which will be equal to the Chornobyl NPP, then 100,000 hectares of agricultural land in the region will be taken out of the agricultural production of the Zaporizhzhia region. On agricultural lands where soil contamination with radiocaesium will be more than 5 Ci/km2, and the concentration in irrigated waters will reach 2 Bq/dm3, sunflower, which was grown for seeds to produce oil will need to be replaced with an industrial crop, which will also lead to loss of seed yield sunflower. Crop losses will lead to a decrease in the volume of sunflower oil. It should also be taken into account that the purification of soil and water does not occur in one year. At least in 5 years the situation will begin to improve.