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Publication
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| Title of Article |
The Improvement of Natural Thai Bentonite Modified with
Cationic Surfactants on Hexavalent Chromium Adsorption from
an Aqueous Solution
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| Date of Acceptance |
21 May 2022 |
| Journal |
| Title of Journal |
Adsorption Science and Technology |
| Standard |
SCOPUS |
| Institute of Journal |
Hindawi Limited |
| ISBN/ISSN |
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| Volume |
2022 |
| Issue |
2022 |
| Month |
May |
| Year of Publication |
2022 |
| Page |
1-15 |
| Abstract |
This work was performed to evaluate the adsorption properties of modified Thai bentonites (MTBs) on hexavalent chromium (Cr
(VI)) by using a popularly capable surfactant (hexadecyltrimethylammonium bromide (HDTMA)) compared to an alternative
surfactant (cetylpyridinium chloride (CPC)). The adsorption properties of the surfactant load, adsorbent weight, contact time,
initial Cr(VI) concentration, and temperature of the MTBs were evaluated. The results revealed that a higher surfactant load
significantly affected the Cr(VI) adsorption, and the equilibrium adsorption was achieved at 60 min. The adsorption capacity
improved when the adsorbent weight, contact time, initial concentration, and temperature increased as the highest adsorption
capacities of 1CPC and 1HDTMA were 45.55 and 46.03 mg g-1, respectively. The isotherm and kinetic adsorptions were
described by the Freundlich model and pseudo-second-order model, respectively, while thermodynamics indicated
endothermic adsorption. After adsorption, X-ray absorption near-edge structure and extended X-ray absorption fine structure
data showed that Cr ions did not change the valency state between Cr(VI) and Cr(III). Additionally, the adsorption
mechanism can be depicted as the ion exchange between the Cr(VI) ion and the surfactant molecule. Structural evaluations by
XRD, FTIR, FESEM, EDS, and TEM found that both MTBs (1CPC and 1HDTMA) with the best adsorption performance for
Cr(VI) had obvious changes at both the interlayer structure and the external surface. The interlayer spacing was expanded
from 14.85 Å to 20.48 Å (1CPC) and 18.79 Å (1HDTMA), and the new functional groups (CH2 scissoring, C–H symmetric
stretching, C–H asymmetric stretching, and N–CH3 scissoring) and elemental compositions (Br and Cl) were observed in both
MTBs. They demonstrated that the complete intercalation of surfactant molecules on bentonite structures supported Cr(VI)
adsorption. Overall, the data indicate that MTBs were perfectly adsorbed on Cr(VI), and CPC was demonstrated to be a cheap
alternative agent due to its adsorption capacity compared to the popularly capable HDTMA. |
| Keyword |
Adsorption, Bentonite, Cr(VI) |
| Author |
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| Reviewing Status |
มีผู้ประเมินอิสระ |
| Status |
ตีพิมพ์แล้ว |
| Level of Publication |
นานาชาติ |
| citation |
false |
| Part of thesis |
true |
| Attach file |
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| Citation |
0
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Journal Publication
ไทย