کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
6464948 | 1422946 | 2018 | 12 صفحه PDF | دانلود رایگان |
- LDO-C nanocomposites was successfully synthesized using simple calcination method.
- LDO-C had higher adsorption capacity for U(VI) than that of LDO.
- The main interaction mechanisms of U(VI) on LDO and LDO-C were electrostatic interaction and surface complexation.
- LDO-C showed high adsorption ability for 241Am.
Herein, a practical and simple calcination method was used to synthesize layered double oxides (denoted as LDO) and layered double oxides/carbon dots nanocomposites (denoted as LDO-C) for U(VI) efficient removal. The U(VI) adsorption on LDO and LDO-C were investigated under various experimental conditions, and the results indicated that U(VI) uptake on LDO and LDO-C were consumingly dependent on pH and ionic strength at pHÂ >Â 6, and independent of ionic strength at pHÂ <Â 6. The adsorption processes of U(VI) on LDO and LDO-C were spontaneous and endothermic, and well simulated by pseudo-second-order model. The maximum adsorption capacity of U(VI) on LDO-C was calculated to be 354.2Â mg/g at pHÂ =Â 5.0 and TÂ =Â 298Â K, which was significantly higher than that of U(VI) on LDO (237.6Â mg/g). Particularly, BET, F T-IR, XPS and EXAFS analysis suggested that the higher adsorption capacity of LDO-C was mainly attributed to higher specific surface area and more abundant surface oxygen-containing functional groups (e.g. C-OH), and the main interaction mechanisms were surface complexation and electrostatic interactions. In addition, LDO-C also showed higher adsorption capacity of 241Am(III) than LDO. All in all, the efficient removal performance and superior versatility of LDO-C indicated that it could be applied as promising candidate for efficient immobilization of radioactive pollutant in environmental pollution management.
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Journal: Chemical Engineering Journal - Volume 332, 15 January 2018, Pages 775-786