Sorption of U(VI) from sulfate solutions with spherically granulated chitosans

Veleshko, A. N.; Rumyantseva, E. V.; Kulyukhin, S. A.; Veleshko, I. E.; Вихорева, Г. А.; Lobanov, N. S.

doi:10.1134/s1066362208050147

Cited by 4 publications

(6 citation statements)

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“…On the other hand, cross-linking of the polymer by SO 4 groups could occur in Na 2 SO 4 solutions and was accompanied by a decrease of available active groups for 233 UO 2 2+ binding. Similar phenomena were observed [21,22] during a study of the reaction of U with chitosan.…”

Section: +supporting

confidence: 74%

Co-precipitation of radionuclides by water-soluble melanin from the chitin—melanin glucan complex “Mikoton” in solutions

Veleshko

Rumyantseva

et al. 2012

Fibre Chem

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a chitin-melanin glucan complex, was studied in solutions. It was shown that the degree of coprecipitation (α) of the radionuclides depended on the solution content of polymer. The maximum value of α was at least 80% for metal-ion concentration 250 mg/L and 0.8% melanin. It was hypothesized that UO 2 2+ , Eu 3+ , and Sr 2+ were bound mainly by carboxylic and phenolic groups of melanin. The developed co-precipitation process could be recommended for isolation and concentration of radionuclides from low-salt process solutions and natural media.The practical use of atomic energy created a complicated problem for the ecological safety of the environment and the population residing near nuclear fuel-cycle facilities. This was due to the fact that long-lived radionuclides such as 235 U, 239 Pu, transuranium elements, 137 Cs, 90 Sr, 60 Co, 152,154 Eu, etc. present a potential hazard for hundreds of years. Measures to limit the spread of hazardous substances include not only improvement of waste treatment technology and volume reduction of industrial wastes and releases but also post-radiative and toxicological rehabilitation of people and environmental sites.A trend toward the expanded use of compounds of natural origin focused special attention on melanin polymers, which can act as active binding agents for heavy metals [1,2]. Melanins are high-molecular-weight compounds of irregular phenolic and (or) indolic structure [3]. They are subdivided according to chemical structure into three classes: eu-, pheo-, and allomelanins [4]. Eumelanins include black N-containing compounds that occur in animals and more rarely in plants. Pheomelanins are also characterized by their distinctive color (red, yellow, brown) and the presence in them of not only N but also S. This class of melanins is encountered only in animals. Allomelanins are blackish-brown compounds of higher plants and fungi that typically have a low N content. Highly stable paramagnetic centers, various reactive functional groups, and systems of conjugated double bonds are characteristic of melanin polymers. A lack of systematic information on the structure and physicochemical properties of melanin polymers is currently hindering their broad use. Nevertheless, low toxicity, a broad spectrum of biological activity, and the ability to bind heavy metals portends with great promise their use in medicine, the food industry, agriculture, and biotechnology, including environmental protection.A comparison of the sorption capabilities of the chitin-melanin glucan complex Mikoton from higher basidiomycetes, chitin-and chitosan-melanin complexes from dead bee bodies, and chitosan isolated from crab shells showed [5, 6] that polymeric sorbents containing melanin were most effective for radionuclides. The distribution coefficients (K d ) obtained for 233 UO 2 2+ by using melanin-containing complexes of various origin ranged from 1.2·10 3 to 8.1·10 3 mL/g whereas K d values for chitosan were less than 5.8·10 2 mL/g. An analogous dependence was observed for 90 Sr 2+ .

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Section: +supporting

confidence: 74%

Co-precipitation of radionuclides by water-soluble melanin from the chitin—melanin glucan complex “Mikoton” in solutions

Veleshko

Rumyantseva

et al. 2012

Fibre Chem

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supporting

confidence: 93%

“…In their opinion, UO 2 2+ is surrounded by two hydroxy groups and one amino group, and also by the water molecule or hydroxy group at the С3 atom of the glucopyranose ring. Similar results were obtained in [3].In this work we studied by X-ray photoelectron spectroscopy (XPES) the interaction of UO 2 2+ with SSLMWC in comparison with the starting polymer containing unsubstituted amino groups. …”

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confidence: 83%

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An X-ray photoelectron study of the interaction of uranyl group with sulfosuccinyl chitosan

Veleshko

Teterin

et al. 2012

Radiochemistry

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Interaction of uranium with low-molecular-weight sulfosuccinyl chitosan (SSLMWC) from sulfate solutions was studied by X-ray photoelectron spectroscopy. The interaction involves formation of complexes with the uranyl group on the SSLMWC surface. The equatorial plane of these complexes can contain nitrogen atom of the amino group and oxygen atoms of the sulfato and sulfo groups SO 4 2-and -SO 3 H, carboxy groups, and free hydroxy groups. On keeping the complex in a vacuum, two chemically nonequivalent states of U ions, U 4+ and UO 2 2+ , are observed. The U 4+ formation in solid U-containing samples of chitosan and SSLMWC is attributed to the radical reaction of the UO 2 2+ reduction with the primary hydroxy group of chitosan in a vacuum of the spectrometer under the action of X-ray radiation.Recently there has been a great deal of interest in sulfo derivatives of chitosan, which is due to the discovery of new kinds of their biological activity in combination with low toxicity. Furthermore, the presence of sulfo groups in chitosan can alter its physicochemical properties and enhance the ability to form complexes with metal ions.In [1] we examined the effect of low-molecularweight sulfosuccinyl chitosan (SSLMWC) on the stability of a 5 × 10 -3 M aqueous solution of UO 2 SO 4 in the pH range 1-10. We showed that, at the SSLMWC content lower than 2.5 g l -1 , hydrolyzed UO 2 2+ species precipitated fully or partially. At SSLMWC concentrations of 2.5 g l -1 and above, uranium was quantitatively retained in the solution for 200 days. This stability suggested formation of a stable complex. It was confirmed by differences in the absorption spectra of UO 2 SO 4 solutions in the presence of SSLMWC and without it. With SSLMWC, the absorption band splitting characteristic of UO 2 SO 4 solutions was not observed. The maximum observed at λ = 414 nm underwent red shift in the course of solution storage.Unfortunately, there is still no common opinion on the character of the interaction of UO 2 2+ with chitosan. Piron and Domard [2] made assumptions on the composition of the UO 2 2+ chitosan complex. In their opinion, UO 2 2+ is surrounded by two hydroxy groups and one amino group, and also by the water molecule or hydroxy group at the С3 atom of the glucopyranose ring. Similar results were obtained in [3].In this work we studied by X-ray photoelectron spectroscopy (XPES) the interaction of UO 2 2+ with SSLMWC in comparison with the starting polymer containing unsubstituted amino groups.

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“…Trends in the sorptive processes of Cu 2+ and radionuclides ( 238 U and 137 Cs) were studied in order to identify the conditions providing the highest capacity of chitosan sorbents and to establish the relationship of their properties and structural specifics [3,5,14,15]. * The sorption was carried out under static and dynamic conditions from model solutions of CuSO 4 , UO 2 SO 4 , UO 2 (NO 3 ) 2 , and CsCl of various concentrations and from Barents Sea water.…”

Section: Sorptive Properties Of Granulated and Fibrous Chitosan Sorbementioning

confidence: 99%

Processing of chitosan biopolymer into granules, films, and fibers

Вихорева

2012

Fibre Chem

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Research of the last 10 years that was aimed at developing the theoretical bases for processing chitosan into granules, films, and fibers were reviewed. These items are interesting as sorbents, wound dressings, and separation membranes. Technically acceptable methods for preparing spherical granulated and fibrous, including nanofibrous, sorbents from chitosan and its composites with polyvinyl alcohol and potassium and copper hexacyanoferrate that exhibited high sorption capacity for heavy metals and radionuclides and were interesting for use in systems for reprocessing low-level liquid radioactive wastes and for performing ecological monitoring were developed.Research on chitin technology at the Department of Chemical Fiber and Nanomaterial Technology headed by L. S. Gal2braikh was carried out over 30 years. The results were published in over 200 articles, 10 patents, 15 candidate and 1 doctoral dissertation, and a monograph. The first 20 years of the research were mainly synthetic in nature and resulted in the development of improved methods for preparing chitosan; its sulfated derivatives, blood anticoagulants; carboxymethylated derivatives, polyampholytic complexants; polyelectrolyte complexes of chitosan, including effective hydrogel separation membranes; and surfactant-polyelectrolyte complexes with high surface and emulsifying activity. Herein we review briefly research results of the last 10 years, which were aimed at the development of the theoretical bases for processing chitosan into granules, films, and fibers, including nanofibers, which are interesting as sorbents, wound dressings, and separation membranes. These results were discussed in detail in the dissertations of M. A. Zotkin, E. V. Rumyantseva, S. A. Uspenskii, and A. N. Sonina.Chitosan is manufactured as amorphous crystalline powders. This makes it difficult to carry out sorption processes, especially under dynamic conditions. Processing of polymer solutions can produce sorbents of spherical or fibrous shape with high porosity and specific surface area, an amorphous structure, and increased sorption capacity. Such physical modification of the polymer can be combined with the preparation of chitosan composites with other sorbents (ferrite, kaolin, carbon), the specific properties of which expand the range of applications. Therefore, the development of sorbents based on chitosan with given functions and compositions, supramolecular and porous structure, physical shape, strength, and stability is a timely problem. Preparation and properties of acetic-acid solutions of chitosanChitosan is a high-melting amorphous crystalline polymer that is processed into items using solutions. The solvent for this is usually dilute acetic acid (AA), in which the polybase chitosan is converted into the water-soluble salt form. The swelling stage during dissolution of the polymer, which affects mainly its amorphous regions, is exothermic. Subsequent destruction of crystallites and dissolution are accelerated with heating. Formation of a gelatinous surface layer on...

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Sorption of U(VI) from sulfate solutions with spherically granulated chitosans

Cited by 4 publications

References 4 publications

Co-precipitation of radionuclides by water-soluble melanin from the chitin—melanin glucan complex “Mikoton” in solutions

Co-precipitation of radionuclides by water-soluble melanin from the chitin—melanin glucan complex “Mikoton” in solutions

An X-ray photoelectron study of the interaction of uranyl group with sulfosuccinyl chitosan

Processing of chitosan biopolymer into granules, films, and fibers

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