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3728757 
Journal Article 
Encapsulation of a powdery spinel-type Li+ ion sieve derived from biogenic manganese oxide in alginate beads 
Koilraj, P; Smith, SM; Yu, Q; Ulrich, S; Sasaki, K 
2016 
1 
Powder Technology
ISSN: 0032-5910 
301 
1201-1207 
WOS:000384785300127 
A powdery lithium ion sieve (HMO) derived from biogenic birnessite was homogeneously integrated in sodium alginate (AL) beads. The composite beads were then characterized and their Li+ adsorption properties were investigated. Scanning electron microscopy-energy dispersive spectroscopy analysis showed that the HMO particles were homogeneously dispersed in the AL beads even after drying. The adsorption isotherm of Li+ adsorption to HMO encapsulated in AL beads (HMO-AL) was well fitted by the linear Langmuir model, and the beads showed a maximum adsorption capacity of 3.61 mmol/g based on HMO, which is comparable with the value of the original powdery HMO. Kinetic studies revealed that adsorption of Li+ follows a pseudo-second-order model with rate constant k(2) = 2.8-11.9 x 10(-3) g/(mmol min) for the initial Li+ concentration range 2.56-4.23 mM. Diffusion of Li+ from aqueous solution to the HMO particle through the Ca-AL network is the rate-limiting step for Li+ adsorption to HMO-AL beads. The HMO-AL beads enhanced the handling efficiency for Li+ adsorption and reused without significant reduction of Li+ adsorption efficacy. (C) 2016 Elsevier B.V. All rights reserved. 
Lithium ion sieve; Lithium manganese oxide; Alginate; Biogenic birnessite; Encapsulation