کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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5366506 | 1388350 | 2012 | 6 صفحه PDF | دانلود رایگان |
To distinguish the ion exchanged and physically adsorbed methylene blue cations (MB+) on ionic surfaces, acid activated bentonite samples were used as porous adsorbents. A natural calcium bentonite (CaB) sample from Enez/Edirne, Turkey, was acid activated at 90 °C for 16 h with various HCl/CaB ratios. The irreversible exchange and physical adsorption of MB+ cations on the ionic solids have simultaneously occurred. The ion exchanged (mex) and physically adsorbed (mad) MB+ contents were obtained as the values of sorption capacity at c = 0 and the increase to a plateaus of adsorption isotherms, respectively. The mad value was taken to be monolayer adsorption capacity. Cation exchange capacity (CEC) and specific surface area (SMB) for each sample were calculated from the mex and mad values, respectively. Also, the BET specific surface areas (SBET) and pore size distribution were determined from low temperature nitrogen adsorption/desorption data. A linear correlation between the SMB and SBET values was found.
The ion exchanged (mex) and physically adsorbed (mad) methylene blue contents were obtained as the values of sorption capacity at c = 0 and the increase to a plateaus of adsorption isotherms, respectively. The mad value was taken to be monolayer adsorption capacity. Cation exchange capacity and specific surface area for each powder were calculated from the mex and mad values, respectively.Highlights⺠Modification of the ionic surfaces of a bentonitic clay by acid treatment. ⺠Cation exchange capacity of the ionic solids. ⺠Determination of surface area from physical adsorptions. Correlation between methylene blue and nitrogen surfaces areas.
Journal: Applied Surface Science - Volume 258, Issue 7, 15 January 2012, Pages 2534-2539