The sorption of 241Am3+, 85Sr2+ and 137Cs+ by calcium, strontium and barium alginates has been studied under different operation conditions. The most prominent adsorption was found in the pH range of 5–6 for all systems, even if the observed dependence on the acidity of the solution was small. The most favourable time for the adsorption process was found to be about 2 h for calcium alginate and 4 h for the other two sorbents.
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Praca stanowi przegląd literatury na temat sorpcji jonów metali ciężkich i pierwiastków radioaktywnych z roztworów wodnych na żywicach poliamino-epichlorohydrynowych (PE). Przedstawiono syntezę żywicy poliamino-epichlorohydrynowej (PE) oraz jej formy magnetycznej. Scharakteryzowano ich właściwości sorpcyjne i możliwość zastosowania do usuwania plutonu i ameryku.
EN
The synthesis of both polyamine-epichlorohydrin resin (PE) and its magnetic form (MPE) has been presented. The sorption property of obtained materials as well as their application to removal of radionuclides of plutonium and americium has been explained. Subjecting the resin to a magnetic field significantly improves the efficiency of plutonium and americium sorption. However, using the resin in water treatment processes requires the suitable attestation from institutions, which are empowered to assess the quality of the goods.
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The assessment of contribution of the global and the Chernobyl NPP (Nuclear Power Plant) accident plutonium and americium to plutonium pollution in sediments of Lithuanian lakes is presented. Theoretical evaluation of activity ratios of 238Pu/239+240Pu and 241Pu/239+240Pu in the reactor of unit 4 of the Chernobyl NPP before the accident was performed by means of the ORIGEN-ARP code from the SCALE 4.4A program package. Non-uniform distribution of radionuclides in depositions on the Lithuanian territory after nuclear weapon tests and the Chernobyl NPP accident is experimentally observed by measuring the lake sediment pollution with actinides. The activity concentration of sediments polluted with plutonium ranges from 2.0 š 0.5 Bq/kg d.w. (dry weight) in Lake Asave . lis to 14 š 2 Bq/kg d.w. in Lake Juodis. The ratio of activity concentrations of plutonium isotopes 238Pu/239+240Pu measured by á-spectrometry in the 10-cm-thick upper layer of bottom sediment varies from 0.03 in Lake Juodis to 0.3 in Lake Žuvintas. The analysis of the ratio values shows that the deposition of the Chernobyl origin plutonium is prevailing in southern and south-western regions of Lithuania. Plutonium of nuclear weapon tests origin in sediments of lakes is observed on the whole territory of Lithuania, and it is especially distinct in central Lithuania. The americium activity due to 241Pu decay after the Chernobyl NPP accident and global depositions in bottom sediments of Lithuanian lakes has been evaluated to be from 0.9 to 5.7 Bq/kg.
A novel material, Apatite II, obtained from a natural source, has been determined to be a good adsorbent for radionuclides of strontium, europium and trivalent actinides, but not caesium, from neutral aqueous solutions containing common chelating agents and inorganic salts at moderate concentrations. This inexpensive, easily available material seems to be a promising backfill for engineered barriers in nuclear waste repositories. However, encapsulation of the sorbent grains loaded with radiostrontium in the Portland cement matrix results in undesirably high leaching rate for this particular radionuclide.
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