عنوان مجله
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Journal of Environmental Management
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چکیده
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Functionalized SBA-15 mesoporous silica particles, bearing N-propylsalicylaldimine and ethyl-
enediaminepropylesalicylaldimine Schiff base ligands, abbreviated as SBA/SA and SBA/EnSA respectively,
were prepared and characterized by FT-IR, elemental analysis, TGA, XRD, TEM and SEM techniques. The
potentials of these adsorbents were examined by using them in solid phase extraction of U(VI) ions from
water samples. It is shown that 20 mg of SBA/SA or SBA/EnSA can remove rapidly (~15 min) and
quantitatively uranium(VI) ions from 10 to 200 mL of water solutions (pH 4) containing 0.2 mg of the
ions, at 25 C. The adsorbed ions were stripped by 1 mL of dilute nitric acid solution (0.1 mol L 1). It
means that the studied adsorbents are able to be used for removal and concentration of uranyl ions. This
allowed achieving to a concentration factor of 200 for uranyl ions. The variation in the ionic strength in
the range 0e1 mol L 1 did not affect the extraction ef fi ciencies of the adsorbents. The adsorbents showed
selective separation of uranyl ions from Cd2 þ, Co2 þ, Ni2 þ, Mn2 þ, Cr3 þ, Ba2 þ, Fe3 þ and Eu3 þ ions. Ther-
modynamic investigations revealed that the adsorption of uranyl ions by the adsorbents was sponta-
neous and endothermic. The Langmuir model described suitably the adsorption isotherms. This model
determined the maximum adsorption capacity of the adsorbents SBA/SA and SBA/EnSA as 54 and
105.3 mg uranyl/g adsorbent, respectively. The kinetics of the processes was interpreted by using
Pseudo-second-order model.
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