عنوان مقاله [English]
نویسندگان [English]چکیده [English]
In this study, polyvinyl pyrrolidone/silica composite nanofiber adsorbents were synthesized by the electrospinning method, and their applications for adsorption of thorium ions from aqueous solution in a batch sorption process were studied. The functional groups of the composite nanofiber and its morphology were characterized by FTIR and SEM analyses. The influences of several variables such as SiO2 content, 3-aminpropyltriethoxysilane content, pH, adsorbent dosage, contact time, solution initial concentration and temperature were evaluated. The maximum adsorption capacity of thorium ions was found to be 161.3 mg/g at 45°C and pH 5. The kinetic data were analyzed by the pseudo-first-order, pseudo-second-order and double-exponential kinetic models. The Freundlich, Lanmuir and Dubinin-Radushkevich isotherm models, were applied to describe the equilibrium data. Thermodynamic parameters indicated that the thorium adsorption onto the composite nanofiber adsorbent is an endothermic and spontaneous process. The modified polyvinyl pyrrolidone/silica composite nanofiber with amine functional group is regenerated by 0.5 M HNO3/0.1 M HCl in the equal ratio solution and the adsorption capacity did not change remarkably after the five sorption-desorption cycles.
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