کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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5362281 | 1388283 | 2010 | 7 صفحه PDF | دانلود رایگان |

Aluminum hydroxypolycation and cetyltrimethylammonium bromide (CTMAB) were chosen to synthesize inorganic-organic pillared montmorillonite. Three different methods were employed for the intercalation. The characteristics of natural and modified montmorillonite were determined with X-ray diffraction (XRD), Fourier transform infrared spectrum (FTIR), X-ray photoelectron spectrum (XPS), and zeta potential. It was found that aluminum hydroxypolycation and CTMAB had either entered the interlayer or sorbed on the external surface of the clay. Different intercalation orders can result in different structures. Batch adsorption of hexavalent chromium (Cr6+) onto modified montmorillonite was also investigated. The experimental data revealed that if aluminum hydroxypolycation was intercalated before CTMAB, the adsorption capacity was better than that of intercalated simultaneously or CTMAB pre-intercalated. The pH of the solution and environmental temperature had significant influences on the adsorption of Cr6+. The optimal pH for the removal was about 4, and the temperature of 298Â K was best suitable. All adsorption processes were rapid during the first 5Â min and reached equilibrium in 20Â min. The adsorption kinetics can be described quite well by pseudo-second-order model. The adsorption rates of ACM, CAM and ACCOM were 3.814, 0.915, and 3.143Â mg/g/min, respectively. The adsorption capacities of Cr6+ at 298Â K on ACM, CAM, and ACCOM inferred from the Langmuir model were 11.970, 6.541, and 9.090Â mg/g, respectively. The adsorption of Cr6+ on modified montmorillonite was mainly induced by the surface charge and the complexation reaction between CTMA+ and hexavalent chromium species at the edge of the clay particle.
Journal: Applied Surface Science - Volume 257, Issue 3, 15 November 2010, Pages 769-775