TY - JOUR
T1 - Mechanisms of Cu2+, triethylenetetramine (TETA), and Cu-TETA sorption on rectorite and its use for metal removal via metal-TETA complexation
AU - Li, Zhaohui
AU - Chang, Po Hsiang
AU - Jiang, Wei Teh
N1 - Funding Information:
This work was supported by grants 106-2116-M-006-004 (Jiang), 106-2119-M-006-016 (Jiang), 106-2811-M-006-017 (Chang and Jiang), and 107-2811-M-006-002 (Li and Jiang) from the Ministry of Science and Technology, Taiwan , and by a Prototype Development Fund from Wisys Technology Foundation, Inc. (Li).
Publisher Copyright:
© 2019 Elsevier B.V.
PY - 2019/7/5
Y1 - 2019/7/5
N2 - Uptake of metals, organics, and formation of metal-organic complexes on the surface or in the interlayer of clay minerals had been studied extensively over the last half century. In this study, we investigated the uptake mechanisms of Cu2+, triethylenetetramine (TETA), and Cu-TETA on rectorite and its use for metal removal via metal-TETA complexation. The uptake of Cu2+, TETA, and Cu-TETA by rectorite occurred on the external as well as in the interlayer space, resulting in a change of d001-spacing due to differences in sizes of interlayer cations or complexes. Although the uptake of Cu2+ and Cu-TETA by rectorite was via a cation exchange process as evidenced by the stoichiometric desorption of dominant interlayer cation Ca2+, the uptake of TETA alone on rectorite was via complexation with interlayer cation Ca2+. Due to strong affinity of TETA for Cu2+, significant amounts of Cu2+ uptake occurred on TETA-rectorite. Desorption of Ca2+ from TETA-rectorite confirmed the replacement of interlayer cation Ca2+ by Cu2+. However, the replacement of Ca2+ by Cu2+ in TETA-rectorite did not involved in removal of TETA. As such, TETA-modified clay minerals may serve as a type of sorbents for the removal of selected heavy metals via surface or interlayer via complexation.
AB - Uptake of metals, organics, and formation of metal-organic complexes on the surface or in the interlayer of clay minerals had been studied extensively over the last half century. In this study, we investigated the uptake mechanisms of Cu2+, triethylenetetramine (TETA), and Cu-TETA on rectorite and its use for metal removal via metal-TETA complexation. The uptake of Cu2+, TETA, and Cu-TETA by rectorite occurred on the external as well as in the interlayer space, resulting in a change of d001-spacing due to differences in sizes of interlayer cations or complexes. Although the uptake of Cu2+ and Cu-TETA by rectorite was via a cation exchange process as evidenced by the stoichiometric desorption of dominant interlayer cation Ca2+, the uptake of TETA alone on rectorite was via complexation with interlayer cation Ca2+. Due to strong affinity of TETA for Cu2+, significant amounts of Cu2+ uptake occurred on TETA-rectorite. Desorption of Ca2+ from TETA-rectorite confirmed the replacement of interlayer cation Ca2+ by Cu2+. However, the replacement of Ca2+ by Cu2+ in TETA-rectorite did not involved in removal of TETA. As such, TETA-modified clay minerals may serve as a type of sorbents for the removal of selected heavy metals via surface or interlayer via complexation.
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U2 - 10.1016/j.jhazmat.2019.03.085
DO - 10.1016/j.jhazmat.2019.03.085
M3 - Article
C2 - 30921569
AN - SCOPUS:85063196328
SN - 0304-3894
VL - 373
SP - 187
EP - 196
JO - Journal of Hazardous Materials
JF - Journal of Hazardous Materials
ER -