TY - JOUR
T1 - Halloysite/alginate nanocomposite beads
T2 - kinetics, equilibrium and mechanism for lead adsorption
AU - Chiew, Christine Shu Ching
AU - Yeoh, Hak Koon
AU - Pasbakhsh, Pooria
AU - Krishnaiah, Kamatam
AU - Poh, Phaik Eong
AU - Tey, Beng Ti
AU - Chan, Eng Seng
N1 - Funding Information:
The authors would like to thank the Ministry of Higher Education Malaysia for supporting this research under the FRGS/1/2013/TK04/MUSM/02/1 scheme and the School of Engineering, Monash University Malaysia for providing the Ph.D. studentship to Christine Chiew.
Publisher Copyright:
© 2015 Elsevier B.V..
Copyright:
Copyright 2015 Elsevier B.V., All rights reserved.
PY - 2016/1/1
Y1 - 2016/1/1
N2 - This study highlights the potential of Hal/alginate nanocomposite beads for the removal of Pb2+ in aqueous solutions. This is based on comprehensive physicochemical-mechanical characterizations involving adsorption equilibrium, adsorption kinetics, diffusion studies, FTIR, EDX, FESEM, zeta potential, and compression tests. Results show Langmuirian adsorption isotherms and reasonably rapid second order adsorption kinetics. The Hal/alginate nanocomposite beads have high adsorption capacity for Pb2+ (i.e. 325mg/g) compared to that of free Hal nanotubes (i.e. 84mg/g). The overall process was diffusion limited, well described by the shrinking core model. The Hal/alginate beads removed Pb2+ through ion exchange with Ca2+ followed by coordination with carboxylate groups of alginate, in addition to physisorption on Hal nanotubes. Vital for industrial applications, the Young's modulus of the nanocomposite beads was strengthened by Hal nanotubes loading as well as Pb2+ uptake. As such, this adsorbent incorporates distinctive merits of both Hal nanotubes and alginate, which include the high affinity towards Pb2+, strong mechanical properties, and easy separation from the treated solution.
AB - This study highlights the potential of Hal/alginate nanocomposite beads for the removal of Pb2+ in aqueous solutions. This is based on comprehensive physicochemical-mechanical characterizations involving adsorption equilibrium, adsorption kinetics, diffusion studies, FTIR, EDX, FESEM, zeta potential, and compression tests. Results show Langmuirian adsorption isotherms and reasonably rapid second order adsorption kinetics. The Hal/alginate nanocomposite beads have high adsorption capacity for Pb2+ (i.e. 325mg/g) compared to that of free Hal nanotubes (i.e. 84mg/g). The overall process was diffusion limited, well described by the shrinking core model. The Hal/alginate beads removed Pb2+ through ion exchange with Ca2+ followed by coordination with carboxylate groups of alginate, in addition to physisorption on Hal nanotubes. Vital for industrial applications, the Young's modulus of the nanocomposite beads was strengthened by Hal nanotubes loading as well as Pb2+ uptake. As such, this adsorbent incorporates distinctive merits of both Hal nanotubes and alginate, which include the high affinity towards Pb2+, strong mechanical properties, and easy separation from the treated solution.
KW - Alginate
KW - Clay polymer nanocomposite adsorbent
KW - Halloysite nanotubes
KW - Mechanical properties
KW - Pb removal
UR - http://www.scopus.com/inward/record.url?scp=84949451135&partnerID=8YFLogxK
U2 - 10.1016/j.clay.2015.10.032
DO - 10.1016/j.clay.2015.10.032
M3 - Article
AN - SCOPUS:84949451135
SN - 0169-1317
VL - 119
SP - 301
EP - 310
JO - Applied Clay Science
JF - Applied Clay Science
ER -