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Vol. 25 (2022 year), No. 3, DOI: 10.21443/1560-9278-2022-25-3
Vokurova D. A., Nikiforova T. E.
Influence of cellulose-containing sorbent preparation method based on linen fiber on its functional properties
The creation of biosorbents based on modified flax fiber is aimed at solving the problem of water pollution from heavy metal ions. A method for obtaining a sorbent on the basis of linen fiber including sequential treatment of polysaccharide material with sodium metaperiodate and sodium bisulfite has been developed. Modification conditions for obtaining an effective sorbent have been selected. Equilibrium and kinetics of copper ions sorption with the use of native and modified linen fiber in comparison with Lewatit S100 cationic exchange resin have been studied. It is established that the time of achieving sorption equilibrium in the heterophase system 'aqueous solution of copper sulfate – a modified sorbent' is reduced by 1.5–2 times while the degree of extraction of copper ions is increased by about 1.5 times as compared to the initial fiber. The influence of solution pH on the sorption of copper ions by native flax fiber has been studied. It has been found that in the pH range of the medium 1–7, along with the sorption of Cu2+ ions, the sorption of H+ ions is observed, which indicates a competitive mechanism of sorption of heavy metal cations and protons with the participation of the cellulose-containing sorbent. Experimental isotherms of copper ions sorption have been processed in linear coordinates of Langmuir's equation that made it possible to determine the values of maximum sorption capacity of sorbents under study which increase in a series: native flax fiber (0.86 mol/kg) The creation of biosorbents based on modified flax fiber is aimed at solving the problem of water pollution from heavy metal ions. A method for obtaining a sorbent on the basis of linen fiber including sequential treatment of polysaccharide material with sodium metaperiodate and sodium bisulfite has been developed. Modification conditions for obtaining an effective sorbent have been selected. Equilibrium and kinetics of copper ions sorption with the use of native and modified linen fiber in comparison with Lewatit S100 cationic exchange resin have been studied. It is established that the time of achieving sorption equilibrium in the heterophase system 'aqueous solution of copper sulfate – a modified sorbent' is reduced by 1.5–2 times while the degree of extraction of copper ions is increased by about 1.5 times as compared to the initial fiber. The influence of solution pH on the sorption of copper ions by native flax fiber has been studied. It has been found that in the pH range of the medium 1–7, along with the sorption of Cu2+ ions, the sorption of H+ ions is observed, which indicates a competitive mechanism of sorption of heavy metal cations and protons with the participation of the cellulose-containing sorbent. Experimental isotherms of copper ions sorption have been processed in linear coordinates of Langmuir's equation that made it possible to determine the values of maximum sorption capacity of sorbents under study which increase in a series: native flax fiber (0.86 mol/kg) < flax fiber, oxidized and treated with sodium bisulfite (1.69 mol/kg) ? Lewatit S100 cationite (1.89 mol/kg). Data from infrared spectroscopy and elemental analysis indicate the appearance of new sorption-active groups in the sorbent structure. The sorbent has been tested for purification of aqueous solutions and beverages from heavy metal ions under laboratory conditions. Peculiarities of the sorption of copper (II) ions from juice and white wine have been revealed. It has been found that the obtained modified sorbent on the basis of flax fiber in the purification of beverages is not inferior to the industrial cationic exchange resins in its sorption properties. flax fiber, oxidized and treated with sodium bisulfite (1.69 mol/kg) < Lewatit S100 cationite (1.89 mol/kg). Data from infrared spectroscopy and elemental analysis indicate the appearance of new sorption-active groups in the sorbent structure. The sorbent has been tested for purification of aqueous solutions and beverages from heavy metal ions under laboratory conditions. Peculiarities of the sorption of copper (II) ions from juice and white wine have been revealed. It has been found that the obtained modified sorbent on the basis of flax fiber in the purification of beverages is not inferior to the industrial cationic exchange resins in its sorption properties.
(in Russian, стр.14, fig. 8, tables. 2, ref 31, AdobePDF, AdobePDF 0 Kb)
Vol. 28 (2025 year), No. 4, DOI: 10.21443/1560-9278-2025-28-4/2
Pupysheva N. S., Nikiforova T. E., Kozlov V. A.
Sorption of Cu(II) ions from aqueous solutions by chitosan modified with taurine
Modern technologies in almost all industries use one of the most important strategic resources – water. It is used either in pure form or in the form of solutions, suspensions, etc. Recently, there has been a shortage of this resource, since wastewater pollution from industrial waste with various components, including heavy metals, is increasing. It is known that one of the effective methods for cleaning aqueous solutions from heavy metals is their sorption with chitosan, which is obtained by processing a by-product of the fishing industry – chitin. Processing chitin and obtaining chitosan solve the problem of waste disposal. Studies show that the effectiveness of chitosan in terms of increasing its ability to absorb heavy metals can be significantly enhanced by modifying it. The purpose of this work is to search for chitosan modifiers to increase the efficiency of heavy metal sorption from aqueous solutions. Taurine powder has been used as a modifier. As a result of the experiments, it has been established that the optimal ratio of chitosan : taurine is 2 : 1. The paper describes the method for obtaining chitosan gel and spherical sorbent granules, and presents experimental isotherms of Cu(II) ion sorption by granules of the original and taurine-modified chitosan. The presented research results show that the use of taurine as a chitosan modifier leads to an increase in copper ion sorption by 2.5 times.
(in Russian, стр.5, fig. 3, tables. 1, ref 16, AdobePDF, AdobePDF 0 Kb)