Membrane Exit Rate Research Articles

Kinetic study of mercury (II) transport through a liquid membrane containing calix[4]arene nitrile derivatives as a carrier in chloroform

In this study, the kinetics studies of mercury (II) ion transport through a bulk liquid membrane system which contains calix[4]arene nitrile derivatives (5,11,17,23-Tetra-tert-butyl-25,27-bis-(2-cyanobenzyloxy)-26,28-dihydroxycalix-[4]arene (membrane I) and 25,27-bis-(2-cyanomethoxy)-26,28-dihydroxycalix-[4]arene (membrane II) as a membrane were investigated at different temperatures and stirring rates. The kinetics was analyzed by means of a kinetic model involving two consecutive irreversible first order reactions. The parameters such as transport rate constants, membrane entrance rate, k 1, and the membrane exit rate, k 2, and the maximum values for membrane entrance and exit values J d max and J a max were determined for the experimental data. It was found that both membrane entrance and exit rate constants increase with temperature. The activation energies were found as 6.96 ± 0.15 and 6.91 ± 0.15 kcal/mol, for ligand membranes I and II, respectively. These activation values indicate that the transport process for both membranes is controlled by species diffusion.

Liquid Membrane Transport Kinetics of Hg (II) by Dithio Derivatized Macrotricyclic Compound

The present study has been undertaken to investigate a process that removes inorganic mercury from waste water streams by use of a liquid membrane system in which a novel macrocyclic ligand based on dithio derivatized biscrown ether has been used as a cation carrier. The effect of temperature, stirring rate and different solvents on the kinetic parameters like k1, k2 and flux values J a max, J d max and tmax were also investigated. It was found that the membrane entrance rate constant (k1) and the membrane exit rate constant (k2) increased with increasing temperature and stirring rate. The membrane entrance rate constants (k1), exit rate constants (k2), as well as the flux values vary in the order of CH2Cl2 > CHCl3 > CCl4 in different solvents study

Carrier‐Mediated Transport of Hg(II) through Bulk and Supported Liquid Membranes

The transport of Hg (II) ions from an aqueous solution into an aqueous receiving solution through bulk and supported liquid membranes containing a calix[4]arene derivative 1 as a carrier was examined. The kinetic parameters of bulk liquid membrane studies were analyzed assuming two consecutive, irreversible first‐order reactions. The influence of temperature, stirring rate, carrier concentration and solvent on the kinetic parameters (k1, k2, Rm max, tmax, Jd max, Ja max) has also been investigated. The membrane entrance rate, k1, and the membrane exit rate, k2, increased with increasing temperature and stirring rate. The activation energy values are calculated as 4.87 and 48.63 kj mol−1 for extraction and reextraction, respectively. The values of calculated activation energy indicate that the process is diffusionally controlled by species. Also, the transport behavior of Hg2+ from aqueous solution through a flat‐sheet supported liquid membrane has been investigated by the use of calix[4]arene derivative 1 as carrier and Celgard 2500 as the solid support. A Danesi mass transfer model was used to calculate the permeability coefficients for each parameter studied. The highest values of permeability were obtained with 2‐nitrophenyloctyl‐ether (NPOE) solvent and the influence was found to be in the order of NPOE>chloroform>xylene.

Kinetic Study of Hg2+ Transport Through a Liquid Membrane Containing Calix[4]arene Dinitrile Oligomer as Carrier

In this article, calix[4]arene dinitrile‐oligomer (1) carrier was used as a carrier to transport Hg2+ ions from an aqueous solution into an aqueous receiving solution. The kinetic parameters (k1, k2, Rm max, tmax, Jd max, Ja max) were investigated with a temperature influence, solvent, and stirring rate, and analyzed in the formation of two consecutive, irreversible first order reactions. The membrane entrance rate, k1, and the membrane exit rate, k2, constants were increased with the temperature and stirring rate, and found to be dependent on the solvent type in order to CH2Cl2>CHCl3>CCl4. For the maximum membrane exit flux, Ja max, the activation energy was found from the slope of the linear Arrhenius relationship to be 4.78 kcal/mol, which indicates that the process is controlled by species diffusion.

Study on the Transport Kinetics of Hg2+ Through Calix‐Oligomer Bulk Liquid Membrane

In this article, a calix‐oligomer derivative is used (1) as a carrier to transport Hg2+ ions from an aqueous solution into an aqueuos receiving solution. The kinetic parameters were analyzed in the formation of two consecutive, irreversible first order reactions. The influence of temperature and solvent and stirring rate on the kinetic parameters (k1, k2, Rm max, tmax, Jd max, Ja max) have also been investigated. The membrane entrance rate, k1, and the membrane exit rate, k2, constants were increased with temperature and stirring rate. The membrane entrance and exit rate constants depend on the solvent type and are found to be in the order CH2Cl2>CHCl3>CCl4. For the maximum membrane exit flux, Ja max, the activation energy was found from the slope of the linear Arrhenius relationship to be 7.06 kcal/mol, which indicates that the process is controlled by species diffusion.

Transport Kinetics of Hg2+ Through Bulk Liquid Membrane Using Calix[4]arene Ketone Derivative as Carrier

In this article, calix[4]arene ketone derivative was used as a carrier to transport Hg2+ ions from an aqueous solution into an aqueous receiving solution. The kinetic parameters (k 1, k 2, R m max, t max, J d max, J a max) were investigated with influence of temperature, the solvent, and stirring rate and analyzed in the formation of two consecutive, irreversible first order reactions. The membrane entrance rate, k 1, and the membrane exit rate, k 2, constants were increased with temperature and stirring rate and found to be dependent on the solvent type in the order CH2Cl2 > CHCl3 > CCl4. The activation energy was obtained as 5.28 kcal/mol from the slope of the Arrhenius plot for the case of maximum membrane exit flux, J a max. This value indicates that the process is controlled by species diffusion.

Kinetics of Mercury(II) Transport Through a Bulk Liquid Membrane Containing Calix[4]arene Derivatives as Carrier

The kinetics of transport of mercury (II) ions through a bulk liquid membrane (chloroform) containing calix[4]arene nitrile derivatives as a carrier was examined at different temperatures and different stirring rates. The kinetics of mercury (II) transport could be analyzed in the formalism of two, consecutive, irreversible first-order reactions. The influence of temperature and stirring rate on kinetic parameters also have been investigated. The membrane entrance rate, k1, and the membrane exit rate, k2, increased with increasing temperature and increasing stirring rate. For maximum membrane exit fluxes, the activation energies were found as 1.923 ± 0.15 and 2.112 ± 0.2 kj/mol, for ligand carrier 1 and 2, respectively. The values for the found activation energy indicate that the process is controlled by species diffusion.

Transport of Hg2+ through bulk liquid membrane using a bis-calix[4]arene nitrile derivative as carrier: kinetic analysis

The transport of Hg(II) ions from an aqueous solution into an aqueous receiving solution through a bulk liquid membrane containing a bis-calix[4]arene nitrile derivative (1) as a carrier was examined. The kinetic parameters were analyzed assuming two consecutive, irreversible first-order reactions. The influence of temperature, the solvent and stirring rate on the kinetic parameters (k1, k2, Rmmax, tmax, Jdmax, Jamax) has also been investigated. The membrane entrance rate, k1, and the membrane exit rate, k2, increased with increasing temperature and stirring rate. The membrane entrance and exit rate constants are found to vary in the order CH2Cl2 > CHCl3 > CCl4. For the maximum membrane exit flux, Jamax, the activation energy was found from the slope of the linear Arrhenius relationship to be 9.95 kcal mol−1, which indicates that the process is controlled by species diffusion.