Vladimir Aleksandrovich. Kozlov

Ivanovo State University of Chemistry and Technology · кафедра

A composite sorbent based on chitosan and montmorillonite has been developed for the extraction of heavy metal ions from aqueous solutions. The optimal chitosan / montmorillonite ratio for obtaining sorbent granules has been determined. Equilibriumkinetic studies of the process of copper (II) ions extraction in the heterophase system "aqueous solut...

This article proposes a new unconventional form of medium participation in the description of the acidity of strong acids in aqueous solutions, through proton and water concentrations, excluding the use of their activity coefficients. These two concentrations are equal participants in acid–base interactions. The adequacy of the new approach is test...

Sorption of copper ions by composite sorbents based on cross-linked chitosan such as chitosan/colloid silicon dioxide, chitosan/polymethylsiloxane and chitosan/ polymethylsiloxane/gelatin have been studied. Sorption capacity of the sorbents is increased the pristine chitosan 1.5–3.85 times. Eliminating of Cu²⁺ is based on competing mechanism of sal...

Several features of the sorption and proton-desorption mechanisms of heavy metals (M2+) from aqueous solutions of acids and native salts (cellulose, chitosan, keratin) by modified biopolymers with acidic (Cell–COOH), salt (–OOC–W–NH3+), amine (CS–NH2), and other sorption sites were examined. Sorption isotherms of metal cations from their aqueous sa...

The Cu²⁺, Cd²⁺, Ni²⁺ and Zn²⁺ metal ions sorption by wool keratin was evaluated from the thermodynamic and kinetic points of view. The experimental data had a very good fit with Langmuir, Freundlich and Dubinin-Radushkevich isotherm models, and the best coefficient of determination was deduced by Langmuir isotherm having value 0.99. The process kin...

The results of studying the equilibrium and kinetics of Cu²⁺ ions’ sorption from aqueous solutions by the initial and modified wool keratin are presented. The modified sorbent’s strong sorption properties are the result of the formation of hydroxamic acid groups on its surface on retention of the initial keratin’s excess carboxyl groups. The sharp...

The sorption process of heavy metal ions from aqueous solutions using chitosan flakes and chitosan beads was studied. Chitosan gel beads were prepared using covalent crosslinking of chitosan chains by epichlorohydrin with ionic gelation by sodium tripolyphosphate. The capability of chitosan beads to absorb the heavy metal ions from aqueous solution...

The distribution of Cu²⁺ and Ni²⁺ ions in an aqueous solution — flax fiber heterophase system was investigated. The specific surface area of the sorbent and the average pore radius were determined. The sorption isotherms were processed in terms of the Langmuir and Freundlich models and the theory of volume filling of micropores. It was shown that t...

Sorption of d-metal ions (Cu²⁺, Fe²⁺, and Ni²⁺) from aqueous media using modified heterocyclic biopolymers takes place with the participation of sorption sites, with the following acidic groups: α-hydroxycarboxylic (monobasic, bidentate), hydroxamic (monobasic, bidentate), and aldehyde bisulphite (dibasic) in the form of chelate metal complexes, wh...

The possibility of using cellulose-containing biosorbents obtained on the basis of agro-industrial wastes and byproducts to recover heavy metal ions from aqueous solutions was considered. The influence of the nature of sorbents (composition of biopolymers, content of carboxyl groups, specific surface, pore diameter and pore volume, swelling) on the...

The influence of pH on the distribution of metal cations [Cd(II), Cu(II), Fe(II), Ni(II), Zn(II)] in a four-component heterophase system (H2O-H2SO4-MSO4-cellulose sorbent) was studied. Protodesorption of metal cations was studied with indicator and constant quantities of [MSO4] salts and constant solvent-sorbent ratio. Linear dependence lgКDМ2+=f(р...

The effect of pH of the medium on the process of distribution of Co(II), Cu(II), and Ni(II) ions in a heterophase system of H2O-HCl-MCl2-wood cellulose is studied. The specifics of the mechanism of metal cation protodesorption are explained by the experimental linear correlation dependence of the distribution coefficient of metal cations on the aci...

Chemical modification of cotton cellulose with the formation of hydroxamic and aldehyde-bisulphite derivatives has been carried out. Sorption properties of initial and modified sorbents are investigated. It is established that a-hydroxycarboxyl groups, which are present in all three kinds of sorbents, form colourless chelate complexes due to the re...

The sorption properties of nontreated cotton cellulose and cellulose modified with polyvinylpyrrolidone with respect to copper(II) ions are investigated. It is established that modified cellulose adsorbents have high sorption capability associated with the formation of new sorption centers during treatment with nitrogen-containing polymer. A mechan...

The effect of chemical modification on sorption properties of cotton cellulose with respect to Cu(II), Ni(II), and Fe(II) ions is studied. Modification was carried out through oxidation of cellulose with formation of dialdehyde cellulose, its further conversion to dialdoxime cellulose, and further to a sorbent with hydroxame acidic groups. The opti...

The process of distribution of copper ions in the “aqueous CuSO4 solution/cellulose-containing sorbent” system is studied. The sorption isotherms for Cu2+ ions obtained within the temperature range of 296–363 K indicate the exothermic behavior of the process. The experimental data on sorption of Cu2+ ions are treated within the Langmuir model and t...

The effect of chemical modification on the sorption properties of cotton cellulose toward Cu(II) and Ni(II) ions was studied. The modification was carried out in two stages: oxidation of cellulose with the formation of dialdehydocellulose, followed by its sulfonation. The optimal conditions for modifying the cellulose to produce a sorbent capable t...

The specific adsorption of heavy metal ions on hydrophilic monodentate biosorbent sites was studied. The solvation and coordination mechanism of cation distribution in heterophase system was suggested. Bivalent metal cation desorption mechanism affected by monovalent metal salts (NaCl) was represented in the form of cation-cation resolvation on mon...

The treatment of a natural cellulose-containing material with an electrolyte solution activated with a glow-discharge plasma at atmospheric pressure is carried out. The sorption-kinetic characteristics of modified sawdust with respect to zinc ions are obtained. It is found that the kinetics of sorption is adequately described by the pseudofirst-ord...

Sorption of copper ions by cellulose sorbents: pinewood sawdust and cotton and flax fibers, both untreated and chemically modified with a polyfunctional compound, followed by fixation with polyvinylpyrrolidone, was studied.

Sorption of Cd2+, Cu2+, Fe2+, Nu2+, and Zb2+ ions by a polysaccharide biosorbent was studied. The effect of the pH of the medium on the process of distribution of metal cations in a heterophase system constituted by an aqueous solution of a metal sulfate and a cellulose-containing sorbent was determined.

Equilibrium-kinetic properties of a protein sorbent with respect to Cu2+, Fe2+, Ni2+, Cd2+, and Zn2+ ions were studied. The dependences of the degree of recovery of metasl on their structure and pH of the medium were determined.

Copper (II) ion sorption properties were examined for cellulose materials, both untreated and modified with hydrophilic nitrogen-containing polymers.

Effect of plasma modification on the sorption properties of short flax fibers for Zn(II) ions was studied.

The effect of chemical modification on sorption properties of soybean crush with respect to copper(II) ions was examined. The optimal parameters of soybean crush treatment with sodium monochloroacetate to ensure the maximal sorption capacity of the sorbent were determined.

The influence of enzymatic modification on the sorption properties of a short flax fiber with respect to the Cu(II) ions was examined. The optimal parameters were determined for treatment of natural cellulose-containing sorbent with various enzymatic preparations, B1mix, NCE, and protease, which affords the maximal sorption capacity of the sorbent...

The influence of the solvent acidity on the sorption capacity of cellulose ethers and esters for Zn(II) and Cd(II) ions was studied. The suggested scheme of pH dependence of the sorption equilibrium of Zn(II) and Cd(II) ions in anaqueous electrolyte solution-polymer heterogeneous system, takes into account the speciation of metal ions in the aqueou...

The equilibria for the sorption of transition metal ions on cellulose esters from aqueous-alcohol electrolyte solutions under static conditions are studied.

Untersucht wurde die Sulfierung von 1,8-Naphthsultam (I) mit Schwefelsäure und Oleum in Abhängigkeit von der Konzentration und der Temperatur, wobei vorwiegend die Disulfon= Säure (III) erhalten wird.

Untersucht wurde die Sulfierung von Äthylbenzol (I) in den Systemen: 1.) Äthyl: benzol/H2SO4 1:1, Zugabe von 1 bzw. 2 Mol Thionylchlorid 2.) Äthylbenzol/ Thionylchlorid 1:1 und 1:2, Zugabe von 1 Mol H2SO4 3.) Äthylbenzol/Acetanhydrid 1:1, 6, Zugabe von 1 Mol H2SO4.

Äthylbenzol (I) reagiert mit Chlorsulfonsäure bei 0°C zu einer Mischung von Sulfochloriden (II) mit hohem Anteil an o-Isomeren, während bei der Reaktion mit Schwefel= säure bei 180°C überwiegend die m-Sulfonsäure (V) erhalten wird.

Die Sulfonierung von Äthylbenzol (I) mit 100%iger Schwefelsäure oder 10%igem Oleum führt bei Temperaturen von 160°C zu Gemischen der drei isomeren Sulfonsäuren (II) bis (IV), die bis zu 90% der p-Sulfonsäure (II) enthalten.

Kinetics and equilibrium of the sorption of Cu(II), Zn(II) and Cd(II) ions on a natural cellulose-containing material – wood pine chi ps – were investigated. The effect of different methods of modifying the wood chi ps on their sorption properties was studied. Optimal regimes of the chemical modification of wood chi ps were determined. The results...