Uranium, radium

Although not part of soil, lichens, by virtue of their solubilising action on rocks, contribute to the elemental enrichment of soil. Several studies have identified lichen acids as complexing agents for the iron and aluminium of rocks (95, 96). An examination of the various structures indicates that the basic structure responsible for the chelation is the carboxylic acid group with an orthophenolic group. Grodzinskii (97) has found lichens to be intense accumulators of elements in the uranium-radium, actinouranium and thorium orders. 

Keywords phytoremediation, radionuclides, 137-caesium, 90-strontium, 125-iodine, uranium, radium, uranium mill tailings, biomonitoring... 

Keywords constructed wetlands, passive biological water treatment, adsorbents, uranium, radium, arsenic, iron, manganese... 

U 99.27 4.51 x 109 Uranium-radium decay line 206Pb 8 4He 24.1 U-bearing minerals and rocks... 

The Uranium-Radium Series. This series commences with 318U and ends with the stable isotope n6Pb. The decay scheme is represented by ... 

Radium occurs in pitchblende, and in camolile along with uranium. Radium was first obtained from the uranium residues of pitchblende of. loachimsthal. the Czech Republic and Slovakia, later from carnotite of southwestern Colorado and eastern Utah. Richer ores have been found in Republic of Congo and in the Great Bear region of northwestern Canada. 

Todd, J.F., Elsinger, R.J., and Moore, W.S. (1988) The distributions of uranium, radium, and thorium isotopes in two anoxic fjords Framvaren Fjord (Norway) and Saanich Inlet (British Columbia). Mar. Chem. 23, 393—415. 

Phair, G., and H. Levin Notes on the differential leading of uranium, radium and lead from pitchblende in H2S04 solutions. Econ. Geol. 48, 358 (1953). 

Emitted by heavy atoms, such as uranium, radium, radon, and plutonium (to name a few), alpha particles are helium nuclei, making them the most massive kind of radiation. Alpha radiation can cause a great deal of damage to the living cells it encounters, but has such a short range in tissue (only a few microns) that external alpha radiation cannot penetrate the dead cells of the epidermis to irradiate the living cells beneath. If inhaled, swallowed, or introduced into open wounds, however, alpha radiation can be very damaging. In nature, alpha radiation is found in rocks and soils as part of the minerals, in air as radon gas, and dissolved in water as radium, uranium, or radon. Alpha emitters are also found in nuclear power plants, nuclear weapons, some luminous paints (radium may be used for this), smoke detectors, and some consumer products. Objects and patients exposed to alpha radiation may become contaminated, but they do not become radioactive. 

Uranium, Radium and Vanadium Ores Effluent Guidelines and Standards 40 CFR 440, Subpart C EPA 1982b... 

The great variety of radionuclides present in thorium and uranium ores are listed in Tables 4.1, 4.2 and 4.3. Whereas thorium has only one isotope with a very long half-life (- Th), uranium has two and giving ri.se to one decay scries for Th and two for U. In order to distinguish the two decay series of U, they were named after long-lived members of practical importance the uranium-radium series and the actinium series. The uranium-radium series includes the most important radium isotope ( Ra) and the actinium scries the most important actinium isotope ( Ac),... 

Table 4.2. Uranium-radium decay series (uranium family) A = An+ 2.

The final members of the decay series are stable nuclides ° Pb at the end of the thorium family, Pb at the end of the uranium-radium family, Pb at the end of the actinium family, and Bi at the end of the neptunium family. In all four decay series one or more branchings are observed. For instance, Bi decays with a certain probabihty by emission of an a particle into Tl, and with another probability by emission of an electron into Po. os-pj decays by emission of an electron into Pb, and Po by emission of an a particle into the same nuclide (Table 4.1), thus closing the branching. In both branches the sequence of decay alternates either a decay is followed by P decay or p decay is followed by a decay. 

The nuclear reactions in the uranium-radium series are shown in Figure 3S-2. The principal isotope of uranium, constitutes... 

The 4n series - the thorium series The 4n + 1 series — the neptunium series The 4n + 2 series = the uranium-radium series The 4n + 3 series - the uranium-actinium series... 

The series of Radioactive disintegrations the uranium-radium series, the uranium-actinium series, the thorium series, and the neptunium series. The age of the earth. The fundamental particles electron, proton, positron, neutron, positive, negative, and neutral mesons, neutrino. The photon (light quantum) the energy of a photon, hv. Planck s constant. The wave-particle duality of light and of matter. The wavelengths of electrons. 

Be, with its 1.5 Ma half-life, adds a longer-lived subduction tracer to the arsenal, one that will decay away in the mantle on a time frame of several million years. The data for the SVZ of S Chile (Figure 6(a)) illustrate the power of the combined approach. The very well correlated U-Th, Ra-Th, and Be/ Be data indicate that uranium, radium, and Be, but not thorium, were transported from slab to mantle to produce the nearly horizontal arrays on the disequilibria diagrams (right panel) and the strong correlations between Be addition and uranium and radium excesses (left panel). Taken at face value, these results suggest that a slab/sediment-derived fluid was added to the... 

The Straz deposit in the Hamr District of the Czech Republic provides a good example of this problem (Slezak, 1997). Starting in 1968, more than 4 Mt of sulfuric acid, 3 X 10 t of nitric acid, and 1.2 X 10 t of ammonia were injected into the subsurface to mine uranium ore. Now, —266 Mm in the North Bohemian Cretaceous Cenomanian and Turonian aquifers are contaminated with uranium, radium, and manganese and other solutes. The contaminated area is more than 24 km and threatens the watershed of the Plucnice River. 

Menzel, R.G., Uranium, Radium and Thorium content in phosphate rocks and their possible radiation hazard. J. Agric. Food Chem., 16 (1968) 231-234. 

Asikainen, M. and Kahlos, H., 1979. Anomalously high concentrations of uranium, radium and radon in water from drilled wells in the Helsinki region. Geochim. Cosmochim. Acta, 43 1681-1686. 

Fig. 3. Three sections showing uranium, radium, specific conductivity and HjS data across the region of study. The locations of samples is shown in Fig. 2. Profile A does not extend into the transitional zone. The values shown for samples 7, 8 and 9 are somewhat anomalous for the area and seem to be from Isolated zones of possibly relict water. Profiles B and C show a large decrease in uranium concentration associated with the edge of the transition zone and the sympathetic variation of radium with specific electrical conductance (in /zS/cm).

Since monazite contains an appreciable amount of uranium, radium is always present and the methods of extracting mesothorium concentrate the radium also. Consequently, commercial mesothorium contains considerable radium, which is responsible for 20-25 per cent of the radioactivity produced. Since, however, the mesothorium is much more active than radium, it is estimated that commercial mesothorium is composed, weight for weight, of 99 per cent radium chloride and 1 per cent mesothorium chloride. 

In 1911 Ernest Rutherford asked a student, George de Hevesy, to separate a lead impurity from a decay product of uranium, radium-D. De Hevesy did not succeed in this task (we now know that radium-D is the radioactive isotope °Pb), but this failure gave rise to the idea of using radioactive isotopes as tracers of chemical processes. With Friedrich Paneth in Vieima in 1913, de Hevesy used °Pb to measure the solubifity of lead salts—the first appfication of an isotopic tracer technique. De Hevesy went... 

The main source of terrestrial radiation is long-living isotopes of the uranium-radium series the thorium series ( Th) and the actinium series... 

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