Selective and efficient tripodal receptors for competitive solvent extraction and bulk liquid membrane transport of Hg2+.
ABSTRACT A series of tripodal receptors that are different from each other in their end groups were synthesized. The extraction ability and the transport rate of these receptors were evaluated for transition metal ions (Fe(3+), Ni(2+), Cu(2+), Zn(2+) and Hg(2+)). The receptor bearing pyridyl nitrogens extracted Hg(2+) from a buffered aqueous medium containing a mixture of metal ions and transported it into an organic phase with a complete selectivity over the other metal ions. This receptor was effectively used for transporting Hg(2+) from aqueous buffered source phase to aqueous receiving phase through a chloroform membrane.
- European Journal of Pain Supplements 09/2011; 5(1):135-136.
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ABSTRACT: Kinetic study of Cu(II) transport through a soybean oil-based bulk liquid membrane (BLM) containing di-2-ethylhexylphosphoric acid (carrier) and tributylphosphate (phase modifier) diluted in soybean oil (diluent) was conducted. Effects of initial Cu(II) concentration in the feed phase and temperature were investigated and their kinetic parameters were determined from the kinetic models of two consecutive irreversible first-order reactions. Various initial Cu(II) concentrations in the feed phase (50–500mg/L (0.788–7.88mM)) and temperatures (27–43°C) were found not to affect the rate of extraction process significantly, but enhanced the rate of stripping process with decreasing initial Cu(II) concentration in the feed phase and increasing temperature. The rate-controlling steps of both extraction (diffusion-controlled) and stripping (chemical reaction-controlled) processes were determined and a plausible transport mechanism was proposed. The kinetics of Cu(II) transport through soybean oil-based BLM was then compared with that of a similar kerosene-based BLM and their extraction (k1) and stripping (k2) rate constants (soybean oil-based BLM: k1=1.94h−1, k2=0.11h−1; kerosene-based BLM: k1=1.73h−1, k2=0.13h−1) were determined. Application of soybean oil-based BLM in real industrial wastewater was also studied.Chemical Engineering Journal 09/2011; 173(2):352-360. · 4.06 Impact Factor
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ABSTRACT: The transport of Cr(VI) from aqueous solutions through bulk liquid membrane was studied using p-tert-butylcalixarene 3-diethylaminopropyl diamide derivative as a carrier. The aqueous solution of potassium dichromate was used as the model contaminant. The kinetic parameters (k1, k2, tmax, Rmmax, Jdmax and Jamax) for the forward and the back extraction were calculated by means of Cr(VI) concentrations of the donor and the acceptor phase. The results showed that it was possible to transport 96.65% of Cr(VI) from the acidic donor solutions to the acceptor solutions at the optimum operating conditions after 10h contact time. The highest transport efficiency was observed at pH 2 in the donor phase and at pH 5 in the acceptor phase. It was shown that the transport of Cr(VI) stem from pH difference between the donor and the acceptor phases. The activation energy values were calculated as 5.77 and 7.99 kJmol−1 for the forward and the back extraction, respectively. It was indicated that the process was diffusionally controlled by dichromate anions. The experimental results demonstrated that p-tert-butylcalixarene derivative was an effective carrier for the transport of Cr(VI).Desalination 07/2011; 275(1):166-171. · 3.96 Impact Factor