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Uranium and polonium activities in karst water of the Niedźwiedzia Cave system (Sudety Mts.)

Gąsiorowski Michał, Hercman Helena, Sekudewicz Ilona, Mulczyk Anna

Annales Societatis Geologorum Poloniae

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2020

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Vol. 90, No. 4

505--512

EN

Polonium and uranium activities were measured in surface and karst water in the Kleśnica Stream catchment and the Niedźwiedzia Cave system (Sudety Mts., South-West Poland). The highest polonium concentration was recorded in surface water during flood events and in a sinter pool, located close to the touristic trail inside the cave. It points to a detrital source of the polonium and its transport in water absorbed by the clay fraction. Uranium activity increases downstream in the surface water of the Kleśnica Stream, indicating significant input of 234U and 238U from an area of outcropping marble. Water, autochthonous in the marble, that originated from precipitation and infiltration directly into the cave system is characterized by low uranium content. However, the uranium activity increases with the time of water percolation in the soil and epikarst zone and is higher at the lower cave level than at the upper and middle levels. Po and U activities were used as tracers for the area of water recharge and the mode of circulation. The results point to atmospheric precipitation as the almost exclusive source of water at the upper and middle cave levels, while water at the active level of the cave is a mixture of precipitation, infiltrating directly from the area above the cave passages, and horizontal flow, originating out of the marble outcrop.

2

Deconvolution of alpha spectra from air filters applied for measurements of the short-lived radon progeny concentration

Skubacz K.

Nukleonika

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2017

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Vol. 62, No. 3

229--234

EN

The paper contains a description of a method for the analysis of the complex alpha spectra generated during the measurement of the activity of filters outside of a vacuum chamber under environmental conditions. The peaks corresponding to the energies of alpha particles emitted by the specific isotopes are particularly large on the low-energy side of the peak maximum, and the energy resolution strongly depended on the applied filters. The analysis was based on the non-linear regression to a function designed for four, six and eight parameters. Satisfactory results were obtained for each of these functions, and the best-fitting results were achieved for the eight-parameter function. In addition, the uncertainties related to the estimated parameters, as well as the signals corresponding to functions that describe the shape of the energy peak, have been evaluated. There are also examples of the implementation of the method with respect to short-lived radon progeny and thoron decay products.

3

Accurate detrmination of uranium in soils using electroplating and closed-vessels microwave digestion methods

Amoli H. S., Barker J.

Chemia Analityczna

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2007

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Vol. 52, No. 1

35-42

EN

A new technique for accurate and precise determination of uranium by alpha-spectrometry has been developed. The proposed methods are based on microwave digestion and electroplating of uranium in soil. The investigated samples were: surface soil and the soil collected at a depth of 40 cm in the residential area. Extraction column chromatography has been used to extract uranium from the interfering matrix and other elements. H has been found that the proposed microwave method significantly shortens analysis time, reduces the volume of acids used, and eliminates large acid vapour emission. Also the electroplating procedure was simple in operation and produced thin, uniform, and leakage-proof layers on a disc used foralpha-spectroscopic analysis. Recovery of uranium was higher after microwave digestion with HNO3 Hi- than with HNO3. only, however it was lower than the value obtained after HNO3digestion on a hot plate. Reproducibility was acceptable and relative standard deviation ranged between 3 and 6%. Precision of both methods was consistent. Acid volume required for microwave procedures was 5 times smaller, as well as the analysis time was 6 times shorter compared to traditional digestion on a hot plate.

PL

Opracowano nową metodę dokładnego i precyzyjnego oznaczania uranu techniką alfa--spektrometni. Metoda jest oparta na mikro falowo wspomaganym mineralize wan iu gleby i elektroosadzaniu uranu. Próbki pobrano z zaludnionego terenu z powierzchni gleby i z głębokości 40 cm. Do wydzielania uranu użylo chromatografii ekstrakcyjnej. Stwierdzono, że mineralizacja wspomagana mikrofalami znacznie skraca czas analizy, obniża zużycie kwasów i eliminuje emisje kwasowych par. Stwierdzono, te procedura eiektroosadzania jest prosta oraz pozwala na utworzenie cienkich, jednorodnych i nieulegających stratom warstw na dysku użytym w alfa-spektroskopowej analizie. Od/ysk uranu był wyższy w przypadku mineralizacji mieszaniną kwasów HNO3-HF n iż tylko-HNO3,. jadnakże był niższy niż odzysk uzyskany po mineralizacji z HNO3, na gorącej płytce. Odtwarzalność wyników jest zadowalająca, a względne odchylenie standardowe mieści się w granicach 3-6%. Precyzja obu metod była porównywalna. W porównaniu z tradycyjną mineralizacją na gorącej ptytce, opracowana procedura z mikrofalowym wspomaganiem wymaga 5-krotnie mniej kwasu i jest 6-krotnie krótsza.