Removal of Radionuclides from Fukushima Daiichi Waste Effluents

This paper describes the processes used at the Fukushima Daiichi plant, Japan, to purify the waste effluents generated in the cooling of damaged reactors. These include primary cesium removal with the Kurion zeolite system and the SARRY system utilizing silicotitanate to remove radiocesium from water recirculated to reactors for cooling. Another process is the ALPS system to purify the retentates of the reverse osmosis plant to further purify the water from radionuclides after primary cesium separation. In ALPS, a major role is played by the transition metal hexacyanoferrate product CsTreat and sodium titanate SrTreat in the removal of radiocesium and radiostrontium, respectively. The performance of these four exchangers (zeolite, silicotitanate, hexacyanoferrate, and sodium titanate) is critically analyzed with respect to processing capacities and the decontamination factors obtained in the processes. Furthermore, general information on preparation, structure and ion exchange of these ion-exchanger categories is given with additional information on their use in nuclear waste effluent treatment processes. Finally, the importance of selectivity and associated factors are discussed.Peer reviewe

PENGEMBANGAN BAHAN AJAR IPA BERBASIS SETS PADA SISWA MTsN 1 KENDARI

This study aims to produce the valid SETS-based science teaching materials for the practical and effective use in improving student learning outcomes on environmental pollution materials. This research is Research and Development with pretest-posstest one group design implemented at VII class’ students of MTsN 1 Kendari in the second semester of academic year 2015/2016. The instruments of the study are valid and reliable observations, questionnaires and cognitive tests to obtain the required data. Meanwhile, the data analysis technique is using descriptive and inferential analysis after meeting the normality and homogeneity requirements test. The results indicate; 1) the results of the validity of the SETS-based science test materials by the material and media experts which are valid and highly feasible materials to use, 2) the product practicality test results in small and large group samples which include all aspects considered to be generally implemented as a whole, and 3) the product effectiveness test results obtained through the average test of student learning outcomes before and after treatment which is significantly different, meaning that students' learning outcomes after treatment is increase. While the response of students and teachers on teaching materials used both in small and large group samples are both very good and suitable to use as a learning material on environmental contamination material in MTsN 1 Kendari

Efficient and Selective Recovery of Trace Scandium by Inorganic Titanium Phosphate Ion-Exchangers from Leachates of Waste Bauxite Residue

The research leading to these results has received funding from the European Union (EU) Horizon 2020 Programme Marie Skłodowska-Curie actions under Grant Agreement no. 636876 (MSCA-ETN REDMUD).Bauxite residue (BR) is an inevitable industrial waste generated through the classic Bayer extraction of alumina from bauxite minerals. It contains relatively significant amount of valuable rare earth elements, including scandium, and therefore, we explored the suitability of trace scandium recovery from BR acid leachate by titanium phosphate (TiP) ion exchangers. Three kinds of TiP materials (amorphous TiP, α-TiP, and γ-TiP) were synthesized through fluorine-free precursors and characterized by chemical analysis, X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), Fourier transform infrared (FTIR), ultraviolet/visible (UV/vis) diffuse reflectance spectrometry, 31P magic angle spinning (MAS) nuclear magnetic resonance (NMR), thermogravimetric analysis (TGA), and potentiometric titration. The Sc3+ exchange capacities were determined as 1.74, 0.55, and 0.22 mequiv g–1 for amorphous, α-, and γ-TiP, respectively. Competition of major elements (Fe, Al, Ca) in BR leachate with Sc uptake were studied in batch experiments using binary equimolar mixtures, and the separation factors of Sc/Fe2+, Sc/Al, and Sc/Ca reached magnitudes of 10–1000 on amorphous TiP. The high Sc3+selectivity by amorphous TiP was suspected to be the matching of Ti4+ lattice radius with Sc3+ ionic radius (both 0.745 Å). Finally, the separation of trace scandium from the simulated BR leachate solution was demonstrated on an amorphous TiP column. The interference of Fe3+ has been partially resolved by on-column reduction using sodium sulphite. The optimized final eluate contained only Sc, Fe, and Al. The concentration ratio of Sc/Fe can be increased by a factor of 8.8 and Sc/Al by 265 through a single cycle of chromatographic separation with an Sc recovery rate of 91.1%.Peer reviewe

Column Separation of Am(III) and Eu(III) by α-Zirconium Phosphate Ion Exchanger in Nitric Acid

The trivalent lanthanide-actinide separations are a major challenge in reprocessing of nuclear fuels. To achieve this, commonly organic extractants and solvents are utilized in elaborate processes. Here we report a simple new method that can perform a supportive or alternative role. A nanocrystalline α-zirconium phosphate ion exchanger was utilized for Eu(III)/Am(III) column separation. Comprehensive preliminary studies were done using batch experiments to optimize the final separation conditions. The distribution coefficients for Eu were determined as a function of pH (from 0 to 3) and salinity (Na, Sr). The distribution coefficients for Am were determined as a function of pH, and Eu concentration, from 1:40 to 10,000:1 Eu:Am molar ratio. The exchanger always preferred Eu over Am in our experimental conditions. Separation factors (Eu:Am) of up to 400 were achieved in binary Eu-Am solution in pH 1. The breakthrough capacity was determined in dynamic column conditions using Eu: 0.3 meq∙g−1, which is approximately 4% of the theoretical maximum capacity. Two types of hot column separation tests were conducted: (i) binary load (selective Am elution), and (ii) continuous equimolar binary feed. In both cases separation was achieved. In (i), the majority (82% of the recovered 93%) of Am could be purified from Eu with extremely high 99.999% molar purity, while alternatively even more (95% of the recovered 93%) at a lower purity of 99.7 mol %. In (ii), up to 330 L∙kg−1 of the equimolar solution per mass of the exchanger could be treated with Am purity above 99.5 mol % in the total eluate. Alternatively, up to 630 L∙kg−1 above 95 mol %, or up to 800 L∙kg−1 above 90 mol % purities

Electrospun sodium titanate fibres for fast and selective water purification

From the environmental and end-​users' viewpoints, electrospun ion exchange fibres provide highly efficient and sustainable material for separation of for example trace pollutants, such as radionuclides and heavy metals. This work aimed to reduce the amount of ion exchange material needed per unit volume of raw material subjected to an ion exchange process. We present a very simple process to electrospinning of sodium titanate fibres, but also test results of ion exchange kinetics measurements. Sodium titanate fibres are very promising material and it is possible that by exploiting electrospun inorganic sub-​micron fibres the ion exchanger mass required for a given capacity can be decreased significantly.Peer reviewe

Separation of cobalt, neodymium and dysprosium using amorphous zirconium phosphate

The purpose of this study was to investigate the separation of Co, Nd and Dy from a ternary Co-Nd-Dy solution using amorphous zirconium phosphate (am-ZrP). Am-ZrP was synthesized by a precipitation method at room temperature and subsequently characterized by Fourier transform-infrared spectrometry, thermogravimetry, scanning electron microscopy, X-ray diffraction, solid-state 31P magic angle spinning nuclear magnetic resonance spectrometry and sodium hydroxide titration (with and without background salt). The ion exchange kinetics of am-ZrP that were determined in ternary 1 mM equimolar solutions at equilibrium pH 2.5. The effect of pH on the adsorption was studied in ternary 1 mM equimolar solutions and the uptakes of the metals increased with increasing pH until approximately pH 3.5. The adsorption isotherms of Co, Nd and Dy were tested in a series of ternary equimolar solution, the total uptake amounted to 4.13 meq/g at pH ~ 3.0. The preference of am-ZrP for these metals occurred in decreasing order Dy > Nd ≫ Co. The separation of Co, Nd and Dy from their 1 mM equimolar ternary mixture was investigated on an am-ZrP column. Effects of loading (7.8%, 62% and 100%) on the separation were compared by measuring the corresponding HNO3 elution fractions. It was found that with a lower metal loading of 7.8%, three clear elution bands were obtained. Am-ZrP exhibited selective separation properties towards the ternary Co-Nd-Dy system, which contribute to the future scale-up studies for the recycling of NdFeB magnets.Peer reviewe

Selvitys työ- ja koulutusperusteisen maahanmuuton viranomaisrakenteesta ja -yhteistyöstä

Työ- ja koulutusperusteisen maahanmuuton edistäminen on noussut avainteemaksi Suomen elinvoiman kannalta. Visio ja toimenpiteet on koottu vuoteen 2035 ulottuvaan tiekarttaan, jota toteuttaa Talent Boost -toimenpideohjelma. Selvityksessä tarkastellaan sitä, millaiset viranomaisrakenteet ja -yhteistyö parhaiten tukevat osaajien maahanmuuton onnistunutta lisäämistä. Tärkein johtopäätös on, että viime vuosien toimet ovat nostaneet työ- ja koulutusperusteisen maahanmuuton politiikan Suomessa uudelle tasolle, ja seuraava askel on työn normalisointi osaksi eri viranomaisten tehtäväkenttää. Selvitys suosittaa Business Finlandin ja KEHA-keskuksen muodostaman Work in Finlandin sekä Maahanmuuttoviraston kytkemistä "kansainvälisen rekrytoinnin viranomaiseksi". Lisäksi on varmistettava valtion ja kuntien toimiva yhteistyö senkin jälkeen, kun työllisyyspalveluiden hoito siirtyy kunnille vuonna 2025. Suuria rakenteellisia muutoksia ei tarvita, vaan selkeä palveluvalikko vastamaan kuntien, työnantajien ja Suomeen muuttavien osaajien tarpeisiin. Talent Boost -yhteistyö on verkostomaista, ja olennaista on tavoitteisiin sitoutuminen yli hallinnonala- ja toimijarajojen. Työ- ja koulutusperusteisen maahanmuuton merkitys erityisesti työllisyys-, elinkeino- ja innovaatiopolitiikan kannalta kasvaa, ja nämä yhteydet on huomioitava myös poliittisessa päätöksenteossa

The effect of phosphonates on lanthanide separation for surface-grafted porous zirconia

The effect of phosphonate groups on selective lanthanide sorption for a series of inorganic-organic hybrid materials was investigated. Four functional ligands with an increasing number of aminomethylenephosphonate groups were attached to the porous zirconia matrix via the post-synthetic grafting method. Successful surface grafting was confirmed by FTIR and P-31 MAS-NMR spectroscopies. All the synthesized hybrids showed a lanthanide uptake of about 100 mu mol g(-1) at pH 3. The sorption studies revealed that the hybrids of ligands with a larger number of phosphonate groups possess higher selectivity, as one with the largest number showed a separation factor of over 80 for La3+ and Lu3+. Fixed-bed column experiments also demonstrated the materials' favored uptake of Lu3+ over La3+ at pH 3, in addition to the reusability and applicability to the actual separation settings. These results propose strategies for the selection of organic ligands for hybrid sorbent synthesis.Peer reviewe