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Średni czas pobytu wód podziemnych w zlewniach Wisły i Narwi na podstawie oznaczeń trytu

Nowicki Z., Leśniak P. M., Wilamowski A.

Przegląd Geologiczny

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2016

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Vol. 64, nr 8

545--551

EN

An issue of mean residence time (MRT) evaluation, i.e. the period of time from rainfall until drainage of groundwater by rivers (Danube River Basin, Vistula River Basin and Narew River Basin), is discussed Asimple method of evaluating the groundwater MRT for the Danube River Basin based on tritium data is introduced. It has been confirmed that the historical tritium level in the rivers, being higher than in precipitation, has its end and is reversed, opening a new pathway in understanding the surface-groundwater interaction and specifically in evaluating MRT of groundwater. The authors have defined a separate notification for mean residence time of the whole water in the basin (τ) and mean residence time for groundwater in the basin (τwp). Based on the tritium study the obtained τ values are 6.5 and 5.7 years for the Vistula River Basin (VRB) and the Narew River Basin (NRB), respectively. In turn, the obtained τwp values are 8.0 and 6.0 years, respectively. NRB is a lowland plain and a morphologically, geologically and hydrogeologically uniform basin. The obtained τ wp of groundwater is thus representative for the whole basin. Instead inmorphologically non uniform VRB basin groundwater τwp is a generalized value,i.e.averaged over contributed parts of the basin.

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Podatność wód podziemnych na zanieczyszczenie w obszarze Górnej Odry (JCWPd nr 128) wraz z oceną zawartości azotanów w wodach pierwszego poziomu wodonośnego

Guzik M.

Biuletyn Państwowego Instytutu Geologicznego

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2013

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nr 456 Hydrogeologia z. 14/1

199--204

PL

Obszar badań leży w regionie Górnej Odry, w strefie granicznej z Republiką Czeską. Celem prowadzonych badań była ocena podatności wód podziemnych na zanieczyszczenia w obrębie JCWPd nr 128. Powierzchnia badanego obszaru wynosi 833,39 km2. Na bazie materiałów archiwalnych oraz danych pozyskanych podczas kartowania sozologicznego i hydrogeologicznego opracowano warstwy tematyczne zintegrowane w środowisku GIS. Kompilacja poszczególnych parametrów umożliwiła obliczenie dla wyznaczonych obszarów sumarycznego czasu wymiany polowej pojemności wodnej gleb i utworów strefy aeracji (MRT). Na tej podstawie określono stopień podatności wód pierwszego poziomu wodonośnego na zanieczyszczenie. Na badanym obszarze wyznaczono 5 klas podatności, różniących się czasem dopływu zanieczyszczeń z powierzchni terenu do wód pierwszego poziomu wodonośnego. W celu oceny zanieczyszczenia wód podziemnych azotanami wykonano badania polowe oraz pobrano próbki wód do badań laboratoryjnych. Relacje zachodzące pomiędzy podatnością naturalną a zanieczyszczeniem wód azotanami przedstawiono na mapie zawartości azotanów w wodach pierwszego poziomu wodonośnego.

EN

The research area is located in the Upper Odra region, on the border-line of Poland and Czech Republic. The aim of the study was the evaluation of natural groundwater vulnerability to contamination within GWB 128. The study area is 833,39 km2. The evaluation of groundwater contamination vulnerability within the research area was performed with the use of MRT parametric method, based on filtration and infiltration time. On the basis of archival materials and data obtained during sozological and hydrogeological mapping the integrated thematic layers in GIS environment were developed. The compilation of individual parameters allowed the calculation of the total time of field water capacity of soils and vadose zone formations (MRT) for designated areas. On the basis of MRT values the degree of contamination vulnerability of the first aquifer was defined. In the area of research five vulnerability classes were defined, conditioned by travel time of contaminants from the surface to first aquifer. In order to evaluate nitrate contamination of groundwater the field work was performed and water samples were collected for laboratory analyses. The relations between natural vulnerability and nitrate groundwater contamination was presented on the map of nitrate content of the first aquifer.

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Radioisotope tracer study in an indirectly heated rotary dryer

Pant H.

Nukleonika

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2002

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Vol. 47, nr 4

173-176

EN

A radioisotope tracer study was carried-out in a pilot scale indirectly heated rotary dryer to measure residence time distribution (RTD) of sand particles. Lanthanum-140 labeled sand was used as a tracer. Mean residence time (MRT) and variance of the tracer distribution curves were calculated from the measured RTD curves. From the calculated MRTs, solid holdup in the dryer was estimated. The qualitative comparison of the dimensionless variance with the data published in the literature led to the conclusion that the rotary dryer behaves as a plug flow system. The results of the study were used to design a full-scale industrial rotary dryer.

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Measurement of liquid holdup and axial dispersion in trickle bed reactors using radiotracer technique

Pant H., Saroha A., Nigam K.

Nukleonika

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2000

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Vol. 45, nr 4

235-241

EN

The holdup and axial dispersion of aqueous phase has been measured in trickle bed reactors as a function of liquid and gas flow rates using radioisotope tracer technique. Experiments were carried out in a glass column of inner diameter 15.2´10-2 m column for air-water system using three different types of packings i.e. non-porous glass beads, porous catalysts of tablet and extrudate shape. The range of liquid and gas flow rates used were 8.3´10-5-3.3´10-4 m3/s and 0-6.67´10-4 m3/s, respectively. Residence time distributions of liquid phase were measured and mean residence times were determined. The values of liquid holdup were calculated from the measured mean residence times. It was observed that liquid holdup increased with increase in liquid flow rates and was independent of increase in gas flow rates used in the study. Two-parameter axial dispersion model was used to simulate measured residence time distribution data and values of mean residence time and Peclet number were obtained. It was observed that values of Peclet number increases with increase in liquid flow rate for glass beads and tablets and remains almost constant for extrudates. The values of mean residence time obtained from model simulation were found to be in good agreement with the values measured experimentally.