TY - JOUR
T1 - Mechanism of tyramine adsorption on Ca-montmorillonite
AU - Chang, Po Hsiang
AU - Jiang, Wei Teh
AU - Li, Zhaohui
N1 - Funding Information:
Supports under grants from the Ministry of Science and Technology, Taiwan ( 105-2116-M-006-009 , 106-2116-M-006-004 , 106-2119-M-006-016 , and 106-2811-M-006-017 ) are greatly appreciated.
Publisher Copyright:
© 2018 Elsevier B.V.
PY - 2018/11/15
Y1 - 2018/11/15
N2 - Tyramine (TY) adsorption on a Ca-montmorillonite (SAz-2) was investigated with batch experiments and complementary analyses utilizing ultra-high performance liquid chromatography, ion chromatography, X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, and thermogravimetry (TG). The adsorption reached equilibrium in 8 h, complying with the pseudo-second-order rate equation, and came to an adsorption capacity of 682 mmol kg−1 at pH 6–8.1, utilizing the Langmuir isotherm model. The adsorption of TY and desorption of exchangeable cations exhibited a linear relationship with a slope of 0.9, implying that the adsorption was largely influenced by a cation exchange mechanism. The effective adsorption was further verified by the characteristic TY bands in the FTIR spectra and the signals of mass loss due to TY decomposition in the TG measurements of the clay after adsorption experiments. Intercalation of hydrated TY into the clay interlayer was confirmed by XRD and TG analyses of the heated samples loaded with TY. The adsorption reached only 0.57 cation exchange capacity of the clay which was probably limited by the low charge density of TY as compared to the negative charge density of the clay surface and by the steric effects arising from the hydration of TY that increased its molecular size. Adsorption of TY on montmorillonite can make TY more resistant to thermal decomposition and possibly better preserved in aquatic and soil environments.
AB - Tyramine (TY) adsorption on a Ca-montmorillonite (SAz-2) was investigated with batch experiments and complementary analyses utilizing ultra-high performance liquid chromatography, ion chromatography, X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, and thermogravimetry (TG). The adsorption reached equilibrium in 8 h, complying with the pseudo-second-order rate equation, and came to an adsorption capacity of 682 mmol kg−1 at pH 6–8.1, utilizing the Langmuir isotherm model. The adsorption of TY and desorption of exchangeable cations exhibited a linear relationship with a slope of 0.9, implying that the adsorption was largely influenced by a cation exchange mechanism. The effective adsorption was further verified by the characteristic TY bands in the FTIR spectra and the signals of mass loss due to TY decomposition in the TG measurements of the clay after adsorption experiments. Intercalation of hydrated TY into the clay interlayer was confirmed by XRD and TG analyses of the heated samples loaded with TY. The adsorption reached only 0.57 cation exchange capacity of the clay which was probably limited by the low charge density of TY as compared to the negative charge density of the clay surface and by the steric effects arising from the hydration of TY that increased its molecular size. Adsorption of TY on montmorillonite can make TY more resistant to thermal decomposition and possibly better preserved in aquatic and soil environments.
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U2 - 10.1016/j.scitotenv.2018.05.190
DO - 10.1016/j.scitotenv.2018.05.190
M3 - Article
C2 - 29898425
AN - SCOPUS:85048530988
SN - 0048-9697
VL - 642
SP - 198
EP - 207
JO - Science of the Total Environment
JF - Science of the Total Environment
ER -