Advances in a Bioprocess for the Treatment of Nuclear Waste: Spent Ionic Exchange Resins

2012 ◽  
Vol 1475 ◽  
Author(s):  
León Mosquera Rodríguez ◽  
Ramón A. Pizarro

ABSTRACTDevelopment of a bioprocess intended to achieve a volume reduction of spent resins (either from research and power reactors) is the main purpose of this research project. Search is constrained to microorganisms that exhibit radioresistance, and which can be cultured in a heavy metal environment with additives of nuclear reactor waters such as boron, lithium and gadolinium compounds.Bacteria adapted to a radioactive environment were obtained by treating a RA-3 Reactor spent ionic exchange resin sample (kept at Área de Gestión Ezeiza: AGE) with sterile water; microorganisms suspended were isolated, subject to purity controls and characterized.Experiments performed with these strains include:-Culture in a mineral-broth having polystyrene as source of both carbon and energy. The strain RMB 1200 gave the highest number of viable cells, then being tested with some aromatic compounds, and with some additives of nuclear reactor waters and other elements found in spent resins.-An anionic exchange resin sample was heated, yielding a chemical environment resembling to that of radiolysed resins, and then RMB 1200 strain was cultured with this solid.-A technique to stain polymers was developed in order to find morphological changes caused by microbiological activity. Microscopic examination of cultured polymer samples has been performed.Results obtained with RMB 1200 include metabolic capabilities to use aromatic carbon sources (benzoate, polyphenols), its growth with polystyrene and resin, and short-term tolerance to several xenobiotics assayed at higher concentration levels than the ones of spent resins.


Molecules ◽  
2018 ◽  
Vol 23 (11) ◽  
pp. 2973 ◽  
Author(s):  
Gabriella Tamasi ◽  
Alessio Pardini ◽  
Claudia Bonechi ◽  
Alessandro Donati ◽  
Mario Casolaro ◽  
...  

Samples of sweet and dessert wines, Vin Santo (VSR) from Malvasia grapes, and Granello (GR) from Sauvignon grapes were collected and analyzed for the content of selected macro- and micro-nutrients (Na, K, Mg, Ca, Mn, Fe, Cu and Zn) and of Pb. GR wines had low levels for Fe, Cu and Zn, when compared to VSR and in particular Zn was two orders of magnitude lower. Methods to decrease the content of Zn and Cu in VSR, as well as those for reducing, at the same time, the concentrations of Ca, Mg and K in both VSR and GR, to avoid the formation of opalescence and depots of metal tartrates, were studied. Synthetic hydrogels containing l-histidine residue were tested. The overall relative lowering effects were by ca 4, 23, and 12% for K, Mg and Ca contents, and ca 6, 27 and 10%, for Mn, Cu and Zn contents, in GR wine samples. Commercial ion exchange resin Lanxess Lewatit L-207 and L-208 were then assayed, being legally allowed in the agro-food industry. The L-207 resin revealed great lowering effects on the concentrations of Mn, Cu and Zn, being 75, 91 and 97%, respectively, in VSR wines and 77, 76 and 92%, respectively, in GR wines. The content of Zn was reduced from 49.3 ± 1.2 mg/L in the original wine, down to 1.1 ± 0.1 mg/L, within 48 h soaking. The effects on the character of the dessert wines by the resin L-207 was also taken under control, measuring pH and color index. The color index changed by ca 15% and pH by ca 6% upon treatment of VSR wine with L-207 resins (48 h).



Author(s):  
Jochen Seitz ◽  
Katharina Bühren ◽  
Georg G. von Polier ◽  
Nicole Heussen ◽  
Beate Herpertz-Dahlmann ◽  
...  

Objective: Acute anorexia nervosa (AN) leads to reduced gray (GM) and white matter (WM) volume in the brain, which however improves again upon restoration of weight. Yet little is known about the extent and clinical correlates of these brain changes, nor do we know much about the time-course and completeness of their recovery. Methods: We conducted a meta-analysis and a qualitative review of all magnetic resonance imaging studies involving volume analyses of the brain in both acute and recovered AN. Results: We identified structural neuroimaging studies with a total of 214 acute AN patients and 177 weight-recovered AN patients. In acute AN, GM was reduced by 5.6% and WM by 3.8% compared to healthy controls (HC). Short-term weight recovery 2–5 months after admission resulted in restitution of about half of the GM aberrations and almost full WM recovery. After 2–8 years of remission GM and WM were nearly normalized, and differences to HC (GM: –1.0%, WM: –0.7%) were no longer significant, although small residual changes could not be ruled out. In the qualitative review some studies found GM volume loss to be associated with cognitive deficits and clinical prognosis. Conclusions: GM and WM were strongly reduced in acute AN. The completeness of brain volume rehabilitation remained equivocal.



Author(s):  
Itsuki KURITANI ◽  
Shigeru KATO ◽  
Takahiro TABATA ◽  
Ryota NAKAMURA ◽  
Takumi OKABE


2020 ◽  
Vol 92 (8) ◽  
pp. 1329-1340
Author(s):  
A. G. Kolmakov ◽  
A. S. Baikin ◽  
S. V. Gudkov ◽  
K. N. Belosludtsev ◽  
E. O. Nasakina ◽  
...  

AbstractThe paper describes synthesis and testing of novel biodegradable polylactide-based polymer membranes with desired mechanical properties, which are capable of sustained and directed release of biomacromolecules with high molecular weight (in particular, streptokinase; m.w. 47 kDa). Streptokinase is a pharmaceutical agent, possessing a pronounced thrombolytic activity. The membranes synthesized had a percentage elongation of 2–11% and tensile strength of 25–85 MPa. They were biodegradable – yet being stored in aqueous media in the absence of biological objects, would be dissolved by no more than 10% in 6 months. The synthesized membranes were capable of controlled release of streptokinase into the intercellular space, with the enzyme retaining more than 90% of its initial activity. The rate of streptokinase release from the membranes varied from 0.01 to 0.04 mg/day per cm2 of membrane surface. The membrane samples tested in the work did not have any short-term toxic effects on the cells growing de novo on the membrane surface. The mitotic index of those cells was approximately 1.5%, and the number of non-viable cells on the surface of the polymer films did not exceed 3–4% of their total amount. The implantation of the synthesized polymers – as both individual films and coatings of nitinol stents – was not accompanied by any postoperative complications. The subsequent histological examination revealed no abnormalities. Two months after the implantation of polymer films, only traces of polylactide were found in the implant-surrounding tissues. The implantation of stents coated with streptokinase-containing polymers resulted in the formation of a mature and thick connective-tissue capsules. Thus, the polylactide membranes synthesized and tested in this work are biodegradable, possess the necessary mechanical properties and are capable of sustained and directed release of streptokinase macromolecules.



1982 ◽  
Vol 60 (6) ◽  
pp. 856-858 ◽  
Author(s):  
Clément Gauthier ◽  
Ross Layberry

A method for the determination of the specific activity of plasma glycerol is described. Anionic contaminants are first removed from deproteinized plasma by anionic exchange resins (treated plasma). Glycerol in treated plasma is then quantitatively converted to glycerol-3-phosphate (G3P), which is isolated by column chromatography and counted for 14C radioactivity. The specific activity thus calculated was 100.1 ± 2.9% of a standard of known specific activity. When the specific-activity of glycerol is determined from plasma without prior removal of anionic contaminants (untreated plasma), the calculated specific activity is 1.99 ± 0.15 times higher than the one calculated after their removal. Omission of the removal of contaminants leads to a near 100% error in the calculation of the turnover rate of glycerol.not available



2016 ◽  
Vol 75 (6) ◽  
pp. 1309-1318 ◽  
Author(s):  
Ying Wang ◽  
Zhun Li ◽  
Yansheng Li ◽  
Zhigang Liu

Fouled anion exchange resins were regenerated by electric field intensification of Mg/Al double-metal hydroxides. Regenerative experiments were performed with varying voltages (10–30 V) and dosages of Mg/Al hydroxides (0.045–0.135 mol and 0.015–0.045 mol, respectively) for 1–5 h. Optimal results were obtained under the following regenerative conditions: 20 V, 4 h, and 0.09/0.03 mol of Mg/Al hydroxides. The maximum regenerative capacity of resins was increased to 41.07%. The regenerative mechanism was presented by Fourier-transform infrared spectrum of resins and Mg/Al hydroxides, and the regenerative degree was analyzed with respect to conductivity, pH value, and electric current. Mg/Al hydroxides were also recycled after the regeneration. This method was proven to be cost-effective and environmentally friendly.



Author(s):  
Людмила Сергеевна Авфукова

Статья посвящена одному из современных методов и технологий извлечения никеля, кобальта и меди из многокомпонентных растворов - сорбционный метод. В качестве сорбентов выступают ионообменная смола КУ-2-8 и хелатообразующие смолы. Рассмотрен один изметодов удаления веществ, сопутствующих, мешающих извлечению ценных компонентов, одним из которых является железо. The paper considers one of the modern methods and technologies of nickel, cobalt and copper recovery from multicomponent solutions; that is a sorption method. KU-2-8 ion exchange resin and chelating resins are present as sorbents. One of the method of substances which prevent removing valuable components is discussed. One of such substance is considered to be iron.



2008 ◽  
Vol 26 (9) ◽  
pp. 693-703 ◽  
Author(s):  
P. Senthil Kumar ◽  
K. Kirthika ◽  
K. Sathish Kumar

The removal of hexavalent chromium, Cr(VI), from aqueous solutions under different conditions using an anion-exchange resin (AXR) as an adsorbent was investigated under batch conditions. Such studies indicated that the percentage adsorption decreased with increasing initial Cr(VI) concentration, with the maximum removal of such ions occurred at a pH value of ca. 2.0. Both the Langmuir and Freundlich isotherm models were capable of reproducing the isotherms obtained experimentally. The sorption process was rapid during the first 20 min with equilibrium being attained within 30 min. The process followed first-order kinetics. The results demonstrate that such anion-exchange resins can be used for the efficient removal of Cr(VI) ions from water and wastewater.



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