Kinetic aspects of copper (II) transport across liquid membrane containing LIX-860 as a carrier

The possibility of using a mathematical model based on consecutive first-order reactions to describe the Cr(III) ions pertraction in DCSLM system

“…For diffusioncontrolled processes the E a values are lower than 20 kJ/mol, while those for processes controlled by chemical reaction are higher than 42 kJ/mol. In the case when the activation energy values are in the range from 20 to 42 kJ/mol, the transport processes are controlled by both diffusion and chemical reaction [17,18,21]. In our investigations, the value of the activation energy indicates that chromium(III) transport through DCSLM with D2EHPA/Cyanex272 mixture as an ion carrier is controlled by chemical reaction occurring at interface of boundary layers.…”

“…We noted a decrease in the activation energy even to a value 24 kJ/mol. As reported Konczyk The possibility of using a mathematical model based on… 5583 et al [17] and Lazarov et al [21] in the liquid membrane system, under certain conditions and such values of activation energy the transport processes may be controlled by both chemical reaction and diffusion. Probably, in the DCSLM system with D2EHPA/Cyanex272 mixture the diffusion is significant at carriers concentrations ratio other than the most efficient.…”

“…Figure 5 shows the initial flux variation for Cr(III) transport as a function of the process temperature. The relation log J Z versus 1/T (a straight line) indicates that the process is controlled by chemical reaction and the constant rate is strongly dependent on temperature regardless of the initial concentration of Cr(III) ions [17,21].…”

Carrier-Facilitated Coupled Transport Through Liquid Membranes

“…There are two general approaches to modeling LM transport mechanisms: the differential and the integral approach. According to the differential approach [8][9][10][11][12][13][14], all phenomena taking place in the feed or in the strip phase, such as diffusion, chemical reactions, etc., are totally ignored. The measured transfer fluxes are dependent on phenomena occurring in the LM or at the surfaces of the membrane only.…”

Carrier mediated transport of toxic elements, part II Transport modeling for extraction of Pb (II) by Cyanex302/xylene as carrier from nitrate medium using SLM

“…A relatively simple alternative for preparation of the solid phase is based upon the impregnation of reagents on solid supports. Interesting studies using acidic organophosphorous extractant such as DEHPA (di-(2-ethylhexyl) phosphoric acid), Cyanex 272 (bis(2,4,4-trimethyl pentyl) 1 phosphinic acid), Cyanex302 (bis(2,4,4-trimethylpentyl) monothiophosphinic acid), Cyanex301(bis(2,4,4-trimethylpentyl) dithio phosphinic acid) and PC-88A or IONOQUEST 801 (2-ethylhexyl hydrogen 2-ethylhexyl phosphonate) impregnated on a solid support have been reported [29][30][31][32][33][34]. Mechanism and kinetics of the sorption of cadmium (II) with Cyanex302 [31] and Cyanex301 [32] was undertaken.…”