Investigation of sorption of Tb(III) by 2-thenoyltrifluoroacetone supported onto polyurethane foam

Abstract

The sorption studies Tb(III) was investigated on HTTA loaded PUR foam. The adsorption conditions were optimized with respect to pH, shaking time, loading capacity and adsorbent weight. The adsorption data followed the classical Freundlich and Langmuir type isotherms successfully. The Freundlich constant (1/n) is estimated to be 0.47 ± 0.01, reflects a surface heterogeneity of the PUR foam. Langmuir isotherm gives a saturated capacity of 0.042 ± 0.001 mmole g −1 which suggests a monolayer coverage of the surface. The Dubinin-Radushkevich (D-R) isotherm is applied and the sorption mean free energy (E) is calculated and found to be 11.32 ± 0.14 kJ mol −1 suggesting that chemisorption involving chemical bonding is responsible for the adsorption process. The isosteric heat of adsorption of Tb(III) is high which decipher the surface heterogeneity, new bond formation and endothermic type chemisorption. The thermodynamics parameters such as enthalpy (∆H), entropy (∆S) and Gibbs free energy (∆G) were calculated and interpreted. The positive values of ∆H indicate that the adsorption of metal ions on HTTA-loaded PUR foam is an endothermic process. A possible explanation of this endothermicity and sorption mechanism have been discussed. The selectivity and sensitivity of the adsorbent was also studied. The sorption of Tb(III) is greatly affected in the presence of oxalate and fluoride. The sorptive affinity of different cations towards HTTA loaded PUR foam was also discussed.

Development of an Analytical Method for Trace Gold in Aqueous Solution Using Polyurethane Foam Sorbents: Kinetic and Thermodynamic Characteristic of Gold(III) Sorption

“…In the initial stage, the diffusion rate was found to be high, and decreased upon the passage of time, indicating that the rate of the retention step is film diffusion at the early stage of extraction. 25,26 The values of Rd computed from the two distinct slopes of the Weber-Morris plots for the unloaded PUFs were found to be equal to 0.584 ± 0.01 and 0.34 ± 0.03 mmol g -1 , with R 2 = 0.997 towards gold(III). In the case of the THA + Br -immobilized PUFs (Fig.…”

“…The change in the slope for the unloaded PUFs or reagent THA + Br -is most likely due to the existence of different pore sizes. 25,26 The values of Rd indicated that the intraparticle diffusion step can be considered as the rate-controlling step. The lines do not pass through the origin, thus confirming particle film diffusion along with intraparticle diffusion.…”

“…The lines do not pass through the origin, thus confirming particle film diffusion along with intraparticle diffusion. 25,26 Moreover, the rate constant for the retention step of gold(III) onto the tested solid sorbents was also evaluated in light of the Lagergren rate equation: 27 log(qe -qt) = log qekLager 2.303 t where qe is the amount of gold(III) sorbed at equilibrium, per unite mass of the sorbent (mmol g -1 ) and kLager is the first-order overall rate constant for the retention process, s -1 and t = time, s. The plots of log(qe -qt) versus time were found to be linear ( …”

Development of radiochemistry in Pakistan – 1960 to 2010

“…Bis-2-(butoxyethyl ether) was used in solvent extraction of Th(IV) [173], diphenyl-2-pyridylmethane in solvent extraction of Ga (III) [174] and hexafluoroacetylacetone (HHFA), and triphenylphosphine oxide (TPPO) for Ce(III), Tb(III) and Lu(III) [175]. HTTA loaded PUR foam was used for adsorption of Tb(III) [176], nalidixic acid (HNA) was used in solvent extraction of Nd(III) and Eu(III) [177], polymeric material containing phthalic acid as a chelating agent was employed in adsorption of Pb(II) [178]. Toluene-3,4-dithiol (TDT) and trioctylamine (TOA) were applied in solvent extraction of Mn(II), Co(II), Zn(II), Hg(II), Cd(II) and Se(IV) [179], and tribenzylamine (TBA) in solvent extraction for the separation of Sb and As [180].…”

Adsorption modeling and thermodynamic characteristics of uranium(VI) ions onto 1-(2-pyridylazo)-2-naphthol (PAN) supported polyurethane foam

“…However, the decrease in sorption with pH is due to the hydrolysis of uranium(VI) ions and/or formation of different anionic species of PAN in basic medium. The pH 7 borate buffer solution was selected as an appropriate medium for the sorption of uranium(VI) metal ions and 7.25 mg cm −3 of PAN loaded PUF for further studies [18].…”