TY - JOUR
T1 - Polyethylenimine functionalized halloysite nanotubes for efficient removal and fixation of Cr (VI)
AU - Tian, Xike
AU - Wang, Weiwei
AU - Wang, Yanxin
AU - Komarneni, Sridhar
AU - Yang, Chao
N1 - Funding Information:
We are grateful to the National Basic Research Program of China (Grant No. 2011CB933700 ) for the financial support. The project was also supported by the National Natural Science Foundation of China (Grant NO. 51371162 and NO. 51344007 ).
Publisher Copyright:
© 2015 Elsevier Inc. All rights reserved.
PY - 2015/5/1
Y1 - 2015/5/1
N2 - A typical nanoporous-geomaterial (halloysite nanotubes, HNTs) was functionalized by polyethyleneimine (PEI) grafting and the functionalized halloysite (PEI-HNTs) exhibited excellent performance for Cr (VI) removal from aqueous solution and immobilization by reduction. After PEI modification, the Cr (VI) uptake capacity of PEI-HNTs was about 64 times higher than that of the original HNTs and the maximum equilibrium removal capacity was found to be 102.5 mg g-1 at 328 K. Part of Cr (VI) was reduced to Cr (III) and then precipitated on the surface of adsorbent during the sorption process as determined by X-ray photoelectron spectroscopic analysis, suggesting that the PEI-HNTs are not only useful for Cr (VI) immobilization but also good for its reduction. The adsorption of Cr (VI) by the PEI-HNTs was fitted to Langmuir model and the kinetics of uptake could be described by a pseudo-second-order rate model very well. The results also demonstrated that PEI-HNTs could detoxify Cr (VI) at low pH value. The mechanism of uptake of Cr (VI) was postulated to be electrostatic interaction followed by its immobilization through reduction. The functionalized nano-geomaterial synthesized here could be a promising candidate of low cost for highly efficient Cr (VI) removal followed by its immobilization.
AB - A typical nanoporous-geomaterial (halloysite nanotubes, HNTs) was functionalized by polyethyleneimine (PEI) grafting and the functionalized halloysite (PEI-HNTs) exhibited excellent performance for Cr (VI) removal from aqueous solution and immobilization by reduction. After PEI modification, the Cr (VI) uptake capacity of PEI-HNTs was about 64 times higher than that of the original HNTs and the maximum equilibrium removal capacity was found to be 102.5 mg g-1 at 328 K. Part of Cr (VI) was reduced to Cr (III) and then precipitated on the surface of adsorbent during the sorption process as determined by X-ray photoelectron spectroscopic analysis, suggesting that the PEI-HNTs are not only useful for Cr (VI) immobilization but also good for its reduction. The adsorption of Cr (VI) by the PEI-HNTs was fitted to Langmuir model and the kinetics of uptake could be described by a pseudo-second-order rate model very well. The results also demonstrated that PEI-HNTs could detoxify Cr (VI) at low pH value. The mechanism of uptake of Cr (VI) was postulated to be electrostatic interaction followed by its immobilization through reduction. The functionalized nano-geomaterial synthesized here could be a promising candidate of low cost for highly efficient Cr (VI) removal followed by its immobilization.
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U2 - 10.1016/j.micromeso.2014.12.031
DO - 10.1016/j.micromeso.2014.12.031
M3 - Article
AN - SCOPUS:84922340633
SN - 1387-1811
VL - 207
SP - 46
EP - 52
JO - Microporous Materials
JF - Microporous Materials
ER -