Complexes of Cu(II) with D-aldonic and D-alduronic acids in aqueous solution

1992 ◽  
Vol 70 (7) ◽  
pp. 2053-2057 ◽  
Author(s):  
Graciela M. Escandar ◽  
Luis F. Sala
Keyword(s):  
Aqueous Solution ◽  
Ionic Strength ◽  
Computer Program ◽  
Quantitative Study ◽  
Hydrogen Ion ◽  
Complex Species ◽  
Ion Concentrations ◽  
Aldonic Acid ◽  
Potentiometric Measurements ◽  
Equilibrium Data

A quantitative study of the equilibria involved in the interaction of Cu(II) ion with D-glucoheptonic, D-gluconic, D-galactonic, D-ribonic, D-glucuronic, and D-galacturonic acids in aqueous medium has been carried out by means of potentiometric measurements of hydrogen ion concentrations at a constant temperature of 20 °C and an ionic strength of 0.10 (NaNO3). The equilibrium data were processed with the FORTRAN computer program BEST. It was found that Cu(II) interacts with D-aldonic acids to form 1:1, 2:2, and 1:2 (M/L) complexes. The copper(II) complexes with D-galacturonic and D-glucuronic acids are considerably weaker than those of D-aldonic acid. Possible structures of the complex species formed are discussed.

Determination of the complexation properties of a crosslinked poly(acrylic acid) gel with copper(II), nickel(II), and lead(II) in dilute aqueous solution

2001 ◽  
Vol 79 (4) ◽  
pp. 370-376 ◽  
Author(s):  
Catherine Morlay ◽  
Yolande Mouginot ◽  
Monique Cromer ◽  
Olivier Vittori
Keyword(s):  
Aqueous Solution ◽  
Ionic Strength ◽  
Acrylic Acid ◽  
Metal Ion ◽  
Conditional Stability ◽  
Binding Properties ◽  
Complex Species ◽  
Complexing Capacity ◽  
Dilute Aqueous Solution ◽  
Poly Acrylic Acid

The possible removal of copper(II), nickel(II), or lead(II) by an insoluble crosslinked poly(acrylic acid) was investigated in dilute aqueous solution. The binding properties of the polymer were examined at pH = 6.0 or 4.0 with an ionic strength of the medium µ = 0.1 or 1.0 M (NaNO3) using differential pulse polarography as an investigation means. The highest complexing capacity of the polyacid was obtained with lead(II) at pH = 6.0 with µ = 0.1 M, 4.8 mmol Pb(II)/g polymer. The conditional stability constants of the complex species formed were determined using the method proposed by Ruzic assuming that only the 1:1 complex species was formed; for lead(II) at pH = 6.0 and µ = 0.1 M, log K' = 5.3 ± 0.2. It appeared that the binding properties of the polymer increased, depending on the metal ion, in the following order: Ni(II) < Cu(II) < Pb(II). The complexing capacity and log K' values decreased with the pH or with an increase of the ionic strength. These results were in agreement with the conclusions of our previous studies of the hydrosoluble linear analogues. Finally, with the insoluble polymer, the log K' values were comparable to those previously obtained with the linear analogue whereas the complexing capacity values expressed in mmol g-1 were slightly lower.Key words: insoluble crosslinked poly(acrylic acid), copper(II), nickel(II), and lead(II) complexation.

scholarly journals The efficiency of nano-TiO2 and γ-Al2O3 in copper removal from aqueous solution by characterization and adsorption study

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Fatemeh Ezati ◽  
Ebrahim Sepehr ◽  
Fatemeh Ahmadi
Keyword(s):  
Aqueous Solution ◽  
Ionic Strength ◽  
Ph Value ◽  
Physical Adsorption ◽  
Geochemical Modeling ◽  
Low Cost ◽  
Background Electrolyte ◽  
Isotherm Models ◽  
Batch Adsorption ◽  
Equilibrium Data

AbstractWater pollution is a major global challenge given the increasing growth in the industry and the human population. The present study aims to investigate the efficiency of TiO2 and γ-Al2O3 nanoadsorbents for removal of copper (Cu(II)) from aqueous solution as influenced by different chemical factors including pH, initial concentration, background electrolyte and, ionic strength. The batch adsorption experiment was performed according to standard experimental methods. Various isotherm models (Freundlich, Langmuir, Temkin, and Dubinin–Radushkevich) were fitted to the equilibrium data. According to geochemical modeling data, adsorption was a predominant mechanism for Cu(II) removal from aqueous solution. Calculated isotherm equations parameters were evidence of the physical adsorption mechanism of Cu(II) onto the surface of the nanoparticles. The Freundlich adsorption isotherm model could well fit the experimental equilibrium data at different pH values. The maximum monolayer adsorption capacity of TiO2 and γ-Al2O3 nanosorbents were found to 9288 and 3607 mg kg−1 at the highest pH value (pH 8) and the highest initial Cu(II) concentration (80 mg L−1) respectively. Copper )Cu(II) (removal efficiency with TiO2 and γ-Al2O3 nanoparticles increased by increasing pH. Copper )Cu(II) (adsorption deceased by increasing ionic strength. The maximum Cu(II) adsorption (4510 mg kg−1) with TiO2 nanoparticles was found at 0.01 M ionic strength in the presence of NaCl. Thermodynamic calculations show the adsorption of Cu(II) ions onto the nanoparticles was spontaneous in nature. Titanium oxide (TiO2) nanosorbents could, therefore, serve as an efficient and low-cost nanomaterial for the remediation of Cu(II) ions polluted aqueous solutions.

A simple and accurate evaluation of hydrogen-ion concentrations in aqueous solutions of fixed ionic strength

1979 ◽  
Vol 105 (2) ◽  
pp. 237-246 ◽  
Author(s):  
M. Molina ◽  
C. Melios ◽  
J.O. Tognolli ◽  
L.C. Luchiari ◽  
M. Jafelicci
Keyword(s):  
Ionic Strength ◽  
Aqueous Solutions ◽  
Hydrogen Ion ◽  
Accurate Evaluation ◽  
Ion Concentrations

THE KINETICS OF THE CHELATION OF NICKEL (II) AND 1,10-PHENANTHROLINE

1964 ◽  
Vol 42 (4) ◽  
pp. 934-940 ◽  
Author(s):  
P. F. Barrett ◽  
W. MacF. Smith
Keyword(s):  
Ionic Strength ◽  
Rate Constant ◽  
Order Rate Constant ◽  
Second Order ◽  
Hydrogen Ion ◽  
Kinetic Behavior ◽  
Ion Concentrations ◽  
Order Rate ◽  
Kinetics Of ◽  
Limiting Values

The kinetics of the formation of the bidentate monocomplex of 1,10-phenanthroline and nickel (II) have been examined spectrophotometrically at ionic strength 0.5 over the range of temperatures 8 to 37 °C and over the range of hydrogen ion concentrations 0.01 to 0.30 molar. The kinetic behavior over the range of conditions is consistent with that found at 25 °C by Margerum, Bystroff, and Banks. The limiting values for the second-order rate constant for the reaction at high acidities have been assessed and imply associated values of ΔH≠and ΔS≠ of 9.5 kcal mol−1 and −5.3 e.u. respectively.

THE MONO-OXALATO COMPLEXES OF IRON(III): PART I. EQUILIBRIA

1965 ◽  
Vol 43 (10) ◽  
pp. 2755-2762 ◽  
Author(s):  
R. F. Bauer ◽  
W. MacF. Smith
Keyword(s):  
Ionic Strength ◽  
Hydrogen Ion ◽  
Extinction Coefficients ◽  
Ion Concentrations ◽  
Oxalato Complexes ◽  
Significant Concentration

The formation of the mono-oxalato complexes of iron(III) has been examined spectrophotometrically at ionic strength 0.50, between 5 and 25 °C and hydrogen ion concentrations 0.2 to 0.5 M. Evidence is presented that the protonated complex FeHC2O4++ is present in significant concentration in these solutions. The formation quotients of the species FeC2O4++ and FeHC2O4++ for temperatures 5, 15, and 25 °C have been determined and the extinction coefficients at 310 mμ have been estimated.

scholarly journals Effect of micelles on the chemical speciation of binary complexes of Co(II), Nii(II), Cu(II) and Zn(II) with succinic acid

2009 ◽  
Vol 74 (7) ◽  
pp. 745-754
Author(s):  
Bathula Srikanth ◽  
Srinivasa Rao ◽  
Siva Rao ◽  
Kamala Sastry ◽  
Nageswara Rao
Keyword(s):  
Ionic Strength ◽  
Computer Program ◽  
Succinic Acid ◽  
Mole Fraction ◽  
Chemical Speciation ◽  
Ionic Surfactants ◽  
Binary Complex ◽  
Complex Species ◽  
Binary Complexes ◽  
Modelling Studies

Speciation of Co(II), Ni(II), Cu(II) and Zn(II) complexes with succinic acid in the presence of anionic, cationic and non-ionic surfactants at an ionic strength of 0.16 mol dm-3 and temperature 303 K were investigated pH metrically. The existence of different binary complex species was established from modelling studies using the computer program MINIQUAD75. The decreased stability of the complexes with increasing micellar content was explained by electrostatic forces. The influence of the micelles on the chemical speciation is discussed based on the mole fraction of the medium. Distribution diagrams of various species of the complexes in relation to pH are presented.

scholarly journals A Novel Biosorbent, Water-Hyacinth, Uptaking Methylene Blue from Aqueous Solution: Kinetics and Equilibrium Studies

2014 ◽  
Vol 2014 ◽  
pp. 1-13 ◽  
Author(s):  
Md. Nasir Uddin ◽  
Md. Tariqul Islam ◽  
Sreejon Das
Keyword(s):  
Aqueous Solution ◽  
Ionic Strength ◽  
Water Hyacinth ◽  
Goodness Of Fit ◽  
Negative Impact ◽  
Coefficient Of Determination ◽  
Maximum Adsorption Capacity ◽  
Equilibrium Studies ◽  
Initial Stage ◽  
Equilibrium Data

The adsorption of MB dye from aqueous solution onto HCl acid treated water-hyacinth (H-WH) was investigated by carried out batch sorption experiments. The effect of process parameters such as pH, adsorbent dosage, concentrations and contact time, and ionic strength were studied. Adsorption of MB onto H-WH was found highly pH dependent and ionic strength shows negative impact on MB removal. To predict the biosorption isotherms and to determine the characteristic parameters for process design, Langmuir, Freundlich, Temkin, and Halsey isotherms models were utilized to equilibrium data. The adsorption kinetics was tested for pseudo-first-order (PFO), pseudo-second-order (PSO), intraparticle diffusion (IPD), and Bangham’s kinetic models. The Langmuir isotherm model showed the goodness-of-fit among the tested models for equilibrium adsorption of MB over H-WH and indicated the maximum adsorption capacity as 63.30 mg/g. Higher coefficient of determination (R2>0.99) and better agreement between the qe (experimental) andqe(calculated) values predicted that PSO kinetic model showed the goodness-of-fit for kinetic data along with rate constant1.66×10-3,4.42×10-3, and3.57×10-3 mg·g-1min⁡-1/2⁡, respectively, for the studied concentration range. At the initial stage of adsorption, the overall rate of dye uptake was found to be dominated by external mass transfer, and afterwards, it is controlled by IPD mechanism.

scholarly journals STUDIES ON PITUITARY LACTOGENIC HORMONE

1940 ◽  
Vol 23 (4) ◽  
pp. 433-438 ◽  
Author(s):  
Choh Hao Li ◽  
William R. Lyons ◽  
Herbert M. Evans
Keyword(s):  
Ionic Strength ◽  
Phosphate Buffer ◽  
Hydrogen Ion ◽  
High Potency ◽  
Ion Concentrations ◽  
Lactogenic Hormone ◽  
Sharp Band ◽  
The Difference ◽  
High Degree

The Tiselius technique of electrophoresis has been used to study the homogeneity and mobility of pituitary lactogenic hormone. The lactogenic preparation employed by us shows only one sharp band in schlieren photographs, indicating a high degree of homogeneity. From the determination of the mobility of the hormone at different hydrogen ion concentrations in acetate and phosphate buffer of ionic strength 0.055, the isoelectric point was found to be 5.70 and the See PDF for Equation value 4.5 x 10–5. The difference in the mobility reported for White's crystalline preparation and that found with our high potency lactogenic preparation is discussed.

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