| 000 | 04498nlm1a2200541 4500 | ||
|---|---|---|---|
| 001 | 664816 | ||
| 005 | 20231030041942.0 | ||
| 035 | _a(RuTPU)RU\TPU\network\36001 | ||
| 035 | _aRU\TPU\network\12643 | ||
| 090 | _a664816 | ||
| 100 | _a20210519a2017 k y0engy50 ba | ||
| 101 | 0 | _aeng | |
| 102 | _aNL | ||
| 135 | _adrcn ---uucaa | ||
| 181 | 0 | _ai | |
| 182 | 0 | _ab | |
| 200 | 1 |
_aModelling of the dissolution and reprecipitation of uranium under oxidising conditions in the zone of shallow groundwater circulation _fE. M. Dutova, A. N. Nikitenkov, V. D. Pokrovsky [et al.] |
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| 203 |
_aText _celectronic |
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| 300 | _aTitle screen | ||
| 320 | _a[References: 64 tit.] | ||
| 330 | _aGeneric hydrochemical modelling of a grantoid-groundwater system, using the Russian software "HydroGeo", has been carried out with an emphasis on simulating the accumulation of uranium in the aqueous phase. The baseline model run simulates shallow granitoid aquifers (U content 5 ppm) under conditions broadly representative of southern Norway and southwestern Siberia: i.e. temperature 10 °C, equilibrated with a soil gas partial CO2 pressure (PCO2, open system) of 10-2.5 atm. and a mildly oxidising redox environment (Eh = +50 mV). Modelling indicates that aqueous uranium accumulates in parallel with total dissolved solids (or groundwater mineralisation M - regarded as an indicator of degree of hydrochemical evolution), accumulating most rapidly when M = 550-1000 mg L-1. Accumulation slows at the onset of saturation and precipitation of secondary uranium minerals at M = c. 1000 mg L-1 (which, under baseline modelling conditions, also corresponds approximately to calcite saturation and transition to Na-HCO3 hydrofacies). The secondary minerals are typically "black" uranium oxides of mixed oxidation state (e.g. U3O7 and U4O9). For rock U content of 5-50 ppm, it is possible to generate a wide variety of aqueous uranium concentrations, up to a maximum of just over 1 mg L-1, but with typical concentrations of up to 10 μg L-1 for modest degrees of hydrochemical maturity (as indicated by M). These observations correspond extremely well with real groundwater analyses from the Altai-Sayan region of Russia and Norwegian crystalline bedrock aquifers. The timing (with respect to M) and degree of aqueous uranium accumulation are also sensitive to Eh (greater mobilisation at higher Eh), uranium content of rocks (aqueous concentration increases as rock content increases) and PCO2 (low PCO2 favours higher pH, rapid accumulation of aqueous U and earlier saturation with respect to uranium minerals). | ||
| 333 | _aРежим доступа: по договору с организацией-держателем ресурса | ||
| 461 | _tJournal of Environmental Radioactivity | ||
| 463 |
_tVol. 178-179 _v[P. 63-76] _d2017 |
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| 610 | 1 | _aэлектронный ресурс | |
| 610 | 1 | _aтруды учёных ТПУ | |
| 610 | 1 | _agroundwater | |
| 610 | 1 | _ahydrochemical modelling | |
| 610 | 1 | _amineralisation | |
| 610 | 1 | _anatural uranium | |
| 610 | 1 | _aore | |
| 610 | 1 | _asolubility | |
| 610 | 1 | _aгрунтовые воды | |
| 610 | 1 | _aмоделирование | |
| 610 | 1 | _aминерализация | |
| 610 | 1 | _aприродный уран | |
| 610 | 1 | _aруды | |
| 610 | 1 | _aрастворимость | |
| 701 | 1 |
_aDutova _bE. M. _chydrogeologist _cProfessor of Tomsk Polytechnic University, Doctor of geological and mineralogical sciences _f1956- _gEkaterina Matveevna _2stltpush _3(RuTPU)RU\TPU\pers\31021 |
|
| 701 | 1 |
_aNikitenkov _bA. N. _cphysicist, hydrogeologist _cassociate Professor of Tomsk Polytechnic University, candidate of geological and mineralogical Sciences _f1983- _gAleksey Nikolaevich _2stltpush _3(RuTPU)RU\TPU\pers\33263 |
|
| 701 | 1 |
_aPokrovsky _bV. D. _cSpecialist in the field of higher professional education _cAnalyst of the Tomsk Polytechnic University _f1989- _gVitaly Dmitrievich _2stltpush _3(RuTPU)RU\TPU\pers\32204 |
|
| 701 | 1 |
_aBanks _bD. _gDavid |
|
| 701 | 1 |
_aFrengstad _bB. S. _gBjorn |
|
| 701 | 1 |
_aParnachyov _bV. P. _gValery Petrovich |
|
| 712 | 0 | 2 |
_aНациональный исследовательский Томский политехнический университет _bИнженерная школа природных ресурсов _bОтделение геологии _h8083 _2stltpush _3(RuTPU)RU\TPU\col\23542 |
| 801 | 2 |
_aRU _b63413507 _c20210519 _gRCR |
|
| 856 | 4 | _uhttps://doi.org/10.1016/j.jenvrad.2017.07.016 | |
| 942 | _cCF | ||