Publications (2)7.21 Total impact
-
Article: Amazon kaolinite functionalized with diethylenetriamine moieties for U(VI) removal: thermodynamic of cation-basic interactions.
[show abstract] [hide abstract]
ABSTRACT: The compound N-[3-(trimethoxysilyl)propyl]diethylenetriamine (MPDET) was anchored onto Amazon kaolinite surface (KLT) by heterogeneous route. The modified and natural kaolinite clay samples were characterized by transmission electron microscopy (TEM), scanning electron microscopic (SEM), N(2) adsorption, powder X-ray diffraction, thermal analysis, ion exchange capacities, and nuclear magnetic nuclei of (29)Si and (13)C. The well-defined peaks obtained in the (13)C NMR spectrum in the 5.0-62.1 ppm region confirmed the attachment of organic functional groups as pendant chains bonded into the porous clay. The adsorption of uranyl on natural (KLT) and modified (KLT(MPDET)) kaolinite clays was investigated as a function of the solution pH, metal concentration, temperature, and ionic strength. The ability of these materials to remove U(VI) from aqueous solution was followed by a series of adsorption isotherms adjusted to a Sips equation at room temperature and pH 4.0. The maximum number of moles adsorbed was determined to be 8.37 x 10(-3) and 13.87 x 10(-3) mmol g(-1) for KLT and KLT(MPDET) at 298 K, respectively. The energetic effects (Delta(int)H, Delta(int)G, and Delta(int)S) caused by metal cations adsorption were determined through calorimetric titrations.Journal of hazardous materials 08/2010; 180(1-3):683-92. · 4.14 Impact Factor -
Article: Immobilization of 5-amino-1,3,4-thiadiazole-thiol onto kanemite for thorium(IV) removal: thermodynamics and equilibrium study.
[show abstract] [hide abstract]
ABSTRACT: The compound 5-amino-1,3,4-thiadiazole-thiol (ATT) was anchored onto an Amazon kanemite surface (K) by homogeneous and heterogeneous routes. Both kanemite modification methodologies resulted in similar products, named K(CTT) and K(ATT), respectively. The modified and natural kanemite samples were characterized by textural analysis, FT-Raman, and nuclear magnetic nuclei of (29)Si and (13)C. Elemental analysis proved that the matrix K(ATT) presented a higher ATT immobilization than K(CTT), with values 1.42 and 1.38 mmol g(-1), respectively. NMR and FT-Raman confirmed the immobilization of ATT on both surfaces. The ability of these materials to remove thorium(IV) from aqueous solution was followed by a series of adsorption isotherms adjusted to a Sips equation at room temperature and pH 4.0. The maximum number of moles adsorbed was determined to be 7.48x10(-3), 9.82x10(-3), and 12.94x10(-3) mmol g(-1) for K, K(CTT), and K(ATT), respectively. The energetic effects (Delta(int)H(o), Delta(int)G(o), and Delta(int)S(o)) caused by metal cation adsorption were determined through calorimetric titrations.Journal of Colloid and Interface Science 07/2009; 338(1):30-9. · 3.07 Impact Factor
