scholarly journals Determining Kinetic Constants and Transport Efficiencies at Membrane Interfaces to Optimize the Removal/Recovery of Cu(II) through Lulk Liquid Membranes Containing Benzoylacetone as Carrier

2017 ◽  
Vol 26 (6) ◽  
pp. 2879-2883
Author(s):  
Gerardo León ◽  
Asunción Hidalgo ◽  
María Murcia ◽  
Beatriz Miguel ◽  
Elisa Gómez
Keyword(s):  
Kinetic Constants ◽  
Liquid Membranes ◽  
Membrane Interfaces

scholarly journals EVALUATION OF KINETIC CONSTANTS AND TRANSPORT EFFICIENCIES AT MEMBRANE INTERFACES TO OPTIMIZE Co(II) RECOVERY BY BULK LIQUID MEMBRANES

2018 ◽  
Vol 48 (1) ◽  
pp. 51-55
Author(s):  
G. LEÓN ◽  
M. GÓMEZ ◽  
M. A. GUZMÁN ◽  
B. MIGUEL
Keyword(s):  
Transport Mechanism ◽  
Kinetic Constants ◽  
Bulk Liquid ◽  
Liquid Membranes ◽  
Environment And Public Health ◽  
Phase Volume ◽  
Product Phase ◽  
Operational Parameters ◽  
Counter Ions ◽  
Membrane Interfaces

The harms of heavy metals to the environment and public health joined to their character of valuable resource, have lead to an increasing interest in the search of efficient processes for their removal/recovery. In this paper we study the optimization of cobalt(II) recovery by bulk liquid membranes through a carrier facilitated counter transport mechanism, using DP8R as carrier and H2SO4 as stripping agent (protons as counter-ions), by analyzing the influence of different operational parameters (carrier concentration in the membrane, stripping agent concentration in the product phase, stirring rate and organic phase volume) on both the extraction/stripping kinetic constants and the Co(II) transport efficiencies through the feed/membrane and the membrane/product interfaces.

KINETIC CONSTANTS DETERMINATION OF PETROLEUM REFINERY EFFLUENT TREATMENT IN A UASB REACTOR USING RSM

2017 ◽  
Vol 16 (1) ◽  
pp. 121-130 ◽  
Author(s):  
Seyyed Mohammad Mousavi ◽  
Seyed Omid Rastegar ◽  
Seyed Abbas Shojaosadati ◽  
Soheila Sheibani
Keyword(s):  
Petroleum Refinery ◽  
Kinetic Constants ◽  
Effluent Treatment ◽  
Uasb Reactor ◽  
Refinery Effluent ◽  
Petroleum Refinery Effluent

Synthesis of Calcium Carbonate Micro Particles using Emulsion Membrane Process Applied for Drug Release Studies

2017 ◽  
Vol 68 (10) ◽  
pp. 2320-2324
Author(s):  
Mariana Mateescu ◽  
Sanda Maria Doncea ◽  
Irina Chican ◽  
Cristina Lavinia Nistor ◽  
Ioneta Codrina Bujanca
Keyword(s):  
Light Scattering ◽  
Calcium Carbonate ◽  
Dynamic Light Scattering ◽  
Liquid Membranes ◽  
Membrane Process ◽  
Emulsion Method ◽  
Micro Particles ◽  
Release Studies ◽  
Emulsion Liquid Membranes ◽  
Span 80

The aim of this work is the synthesis of calcium carbonate (CaCO3) nano and microparticles and their application as biomaterials (vehicles) for the sustained release of doxycycline. CaCO3 micro particles were synthesized by water-in oil (W/O) emulsion method using emulsion liquid membranes with bis (2-ethylhexyl) phosphate (D2EHPA) as carrier, Span 80 as surfactant, and toluene and kerosene as organic solvents. The aqueous phases contained 1 M CaCl2, and 1 M Na2CO3, respectively. The Dynamic Light Scattering (DLS) data showed CaCO3 particles with sizes ranging from around 100 nm to 3500 nm. The CaCO3 particles with the average diameters around 600 nm attained an adsorbtion of doxycycline of maximum 97.9%, and a slow and steady release with a cumulative value of approximative 50% after ten days.

Supersaturation of solutions in crystallisers with the well stirred suspension

1980 ◽  
Vol 45 (7) ◽  
pp. 1920-1927 ◽  
Author(s):  
Jaroslav Nývlt
Keyword(s):  
High Accuracy ◽  
Nucleation And Growth ◽  
Kinetic Constants ◽  
Derived Relations ◽  
Metastable Region ◽  
The Given

Relations were derived comparing the steady supersaturation in the continuous MSMPR and/or bath crystallisers with the stirred suspension having the maximum supersaturation corresponding to the boundary of metastable region at the given conditions. The derived relations include only the quantities used for the system constant BN from the corresponding crystallisation experiments. By use of supersaturation in the crystalliser obtained by the described method it is possible to evaluate the kinetic constants of nucleation and growth. However, it is not possible to expect a high accuracy of the data so obtained.

Kinetics and mechanism of the reaction of iron(III) with 6-methyl-2,4-heptanedione and 3,5-heptanedione

1990 ◽  
Vol 55 (8) ◽  
pp. 1984-1990 ◽  
Author(s):  
José M. Hernando ◽  
Olimpio Montero ◽  
Carlos Blanco
Keyword(s):  
Aqueous Solution ◽  
Metal Ion ◽  
Activation Parameters ◽  
Enol Form ◽  
Kinetics And Mechanism ◽  
Kinetic Constants ◽  
Steric Factors ◽  
Kinetics Of ◽  
Mechanism Of The Reaction

The kinetics of the reactions of iron(III) with 6-methyl-2,4-heptanedione and 3,5-heptanedione to form the corresponding monocomplexes have been studied spectrophotometrically in the range 5 °C to 16 °C at I 25 mol l-1 in aqueous solution. In the proposed mechanism for the two complexes, the enol form reacts with the metal ion by parallel acid-independent and inverse-acid paths. The kinetic constants for both pathways have been calculated at five temperatures. Activation parameters have also been calculated. The results are consistent with an associative activation for Fe(H2O)63+ and dissociative activation for Fe(H2O)5(OH)2+. The differences in the results for the complexes of heptanediones studied are interpreted in terms of steric factors.

scholarly journals Investigating the Proton and Ion Transfer Properties of Supported Ionic Liquid Membranes Prepared for Bioelectrochemical Applications Using Hydrophobic Imidazolium-Type Ionic Liquids

Membranes ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 359
Author(s):  
László Koók ◽  
Piroska Lajtai-Szabó ◽  
Péter Bakonyi ◽  
Katalin Bélafi-Bakó ◽  
Nándor Nemestóthy
Keyword(s):  
Mass Transfer ◽  
Ionic Liquid ◽  
Ionic Liquids ◽  
Microbial Fuel Cells ◽  
Transport Numbers ◽  
Liquid Membranes ◽  
Ion Transfer ◽  
Supported Ionic Liquid ◽  
Supported Ionic Liquid Membranes ◽  
Transfer Properties

Hydrophobic ionic liquids (IL) may offer a special electrolyte in the form of supported ionic liquid membranes (SILM) for microbial fuel cells (MFC) due to their advantageous mass transfer characteristics. In this work, the proton and ion transfer properties of SILMs made with IL containing imidazolium cation and [PF6]− and [NTf2]− anions were studied and compared to Nafion. It resulted that both ILs show better proton mass transfer and diffusion coefficient than Nafion. The data implied the presence of water microclusters permeating through [hmim][PF6]-SILM to assist the proton transfer. This mechanism could not be assumed in the case of [NTf2]− containing IL. Ion transport numbers of K+, Na+, and H+ showed that the IL with [PF6]− anion could be beneficial in terms of reducing ion transfer losses in MFCs. Moreover, the conductivity of [bmim][PF6]-SILM at low electrolyte concentration (such as in MFCs) was comparable to Nafion.

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