Kinetics of solvent extraction of metal ions with HDEHP—I Kinetics and mechanism of solvent extraction of Ti(IV) from acidic aqueous solutions with bis-(2-ethyl hexyl) phosphoric acid in benzene

1978 ◽  
Vol 40 (3) ◽  
pp. 559-566 ◽  
Author(s):  
F. Islam ◽  
R.K. Biswas
Keyword(s):  
Solvent Extraction ◽  
Phosphoric Acid ◽  
Aqueous Solutions ◽  
Metal Ions ◽  
Kinetics And Mechanism ◽  
Ethyl Hexyl ◽  
Kinetics Of

The kinetics and mechanism of solvent extraction of Pr(iii) from chloride medium in the presence of two complexing agents with di-(2-ethylhexyl) phosphoric acid

RSC Advances ◽  
2015 ◽  
Vol 5 (60) ◽  
pp. 48659-48664 ◽  
Author(s):  
Shao-Hua Yin ◽  
Shi-Wei Li ◽  
Jin-Hui Peng ◽  
Li-Bo Zhang
Keyword(s):  
Lactic Acid ◽  
Citric Acid ◽  
Solvent Extraction ◽  
Phosphoric Acid ◽  
Interfacial Area ◽  
Kinetics And Mechanism ◽  
Complexing Agents ◽  
Extraction Kinetics ◽  
Chloride Medium ◽  
Kinetics Of

The extraction kinetics of Pr(iii) from chloride medium containing two complexing agents lactic acid (HLac) and citric acid (H3cit) with di-(2-ethylhexyl)phosphoric acid (D2EHPA, H2A2) have been investigated by constant interfacial area cell with lamina flow.

Kinetics of solvent extraction of metal ions with HEDHP. III. The kinetics and mechanism of solvent extraction of Cr(III) from acidic aqueous solutions with bis-(2-ethyl hexyl) phosphoric acid in benzene

1979 ◽  
Vol 57 (23) ◽  
pp. 3011-3016 ◽  
Author(s):  
Muhammad Fakhrul Islam ◽  
Ranjit Kumar Biswas
Keyword(s):  
Solvent Extraction ◽  
Phosphoric Acid ◽  
Aqueous Phase ◽  
Organic Phase ◽  
Forward Rate ◽  
Nitrate Ions ◽  
Rate Determining Step ◽  
Ethyl Hexyl ◽  
Ph Range ◽  
Kinetics Of

The rate of solvent extraction of chromium(III) from aqueous sulphuric acid solutions (containing 0.05 mol dm−3 sulphate ion and 0.25 mol dm−3 acetate buffer, ionic strength, I = 0.40 mol dm−3) with bis-(2-ethyl hexyl) phosphoric acid (HDEHP or H2A2) in benzene has been measured under various conditions. The rate of backward extraction measurement of Cr(III) from organic phase to aqueous phase is not possible due to the inert property of Cr(III)–DEHP chelate. The forward rate is found to be first-order w.r.t. Cr(III) concentration in the aqueous phase and HDEHP concentration in the organic phase. The order w.r.t. H+ concentration varies from −1 to 1 over the pH range 1.5 to 5.25. The rate is found to decrease with increasing sulphate and nitrate ions concentrations in the aqueous phase. At (30 ± 1) °C, the rate expression, in the presence of sulphate, acetate, and nitrate ions, is found to be represented by:[Formula: see text]In the absence of the anions, the formation of CrHA22+ intermediate complex (Cr(OH)2+ + H2A2(0) → CrHA22+ + H2O) is the rate determining step at all acidities. The effects of the anions on the rate are discussed.

Kinetics of removal of zinc ions from aqueous solutions by a modified acrylnitrile copolymer

1999 ◽  
Vol 39 (8) ◽  
pp. 139-146
Author(s):  
R. Y. Stefanova
Keyword(s):  
Aqueous Solutions ◽  
Metal Ions ◽  
Sorption Process ◽  
Intraparticle Diffusion ◽  
Zinc Ions ◽  
Sorption System ◽  
Modified Polymer ◽  
Rate Limiting Step ◽  
High Sorption ◽  
Kinetics Of

The kinetics of removal of zinc ions from aqueous solutions by a modified acrylnitrile copolymer containing carboxyl and amino groups has been investigated. The dependence of the rate of removal on the intensity of stirring, the size of the sorbent's particles, the initial concentration of metal ions and the temperature of the solution have been established. Attempts have been made to identify the rate limiting step and to determine the batch kinetic parameters. The limiting conditions of the transition from external to intraparticle diffusion step of mass transfer in a sorption system have been determined. The coefficients of intraparticle diffusion and the energy of activation of the sorption process have been established. The data obtained in this work show that the modified polymer with a high sorption capacity and very good kinetic characteristics can be successfully used for removal of heavy metal ions from water solutions and industrial wastewaters.

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