Transport of Thorium(IV) Across a Supported Liquid Membrane Containing N,N,N′,N′-Tetraoctyl-3-oxapentanediamide (TODGA) as the Extractant

Abstract

The transport behavior of Th 4þ was investigated from a feed containing 3.0 M HNO 3 into a receiver phase containing 0.1 M oxalic acid across a PTFE flat sheet supported liquid membrane (SLM) which contained TODGA (N,N,N 0 ,N 0 -Tetraoctyl-3-oxapentanediamide) in n-dodecane as the extractant. Effects of the nature of the strippant, extractant concentration, Th concentration in the feed, and feed acidity on the transport rates were investigated. The transport behavior apparently depended on the rate of extraction of the metal ion at the feed-membrane interface and was not diffusion controlled. Influence of Th concentration on flux was also investigated. Transport mechanism was elucidated and the diffusion coefficient was calculated to be 2.13 Â 10 À7 cm 2 / s. Solvent extraction studies at varying feed acidity and TODGA concentration were also carried out.

Studies on uranium(VI) pertraction across a N,N,N′N′-tetraoctyldiglycolamide (TODGA) supported liquid membrane

“…6). This was in sharp contrast to our studies on the transport of other actinide ions such as Th 4+ and Am 3+ where a decrease in the transport rate was reported beyond 0.1 M TODGA [16,24]. With increasing TODGA concentration there was an increase in K d values resulting in high concentration of the complex at the feed-membrane interface ( Table 2).…”

“…It is, therefore, expected on the basis of the extraction equilibrium that the transport rates should increase with increasing nitrate ion concentration. We have reported earlier in analogous extraction/transport systems, strong influence of nitric acid with its increasing concentration [16,24]. Though an increase was observed from 0.5 to 3 M HNO 3 , almost comparable transport rates were observed with 6 M HNO 3 as the feed (Fig.…”

“…5). This is in contrast to our observations with the tetra-and trivalent actinide ions, reported earlier [16,24,25]. The permeability coefficients were calculated using Eq.…”

Facilitated transport of Pd(II) through a supported liquid membrane (SLM) containing N,N,N′,N′-tetra-(2-ethylhexyl) thiodiglycolamide T(2EH)TDGA: A novel carrier

“…It is generally seen that transport of metal ion through supported liquid membrane (SLM) depends on the concentration of carrier molecule in the membrane phase [24][25][26]. Therefore, to understand the effect of T(2EH)TDGA concentration on the transport Fig.…”

Liquid – Liquid Extraction and Pertraction of Eu(III) from Nitric Acid Medium Using Several Substituted Diglycolamide Extractants

“…There have been several reports on the supported liquid membrane (SLM) transport behavior of lanthanides and actinides using TODGA as the carrier extractant which have shown promise for possible large scale applications (15)(16)(17)(18)(19)(20).…”