Isothermal Adsorption Behavior of Cesium Ions in a Novel Chitosan‐Prussian Blue‐Based Membrane

Abstract

Prussian blue (PB) particles were successfully immobilized on a novel chitosan membrane. Morphological observations confirmed that the PB particles were densely immobilized within the membrane. From isothermal adsorption analysis, an increase in the mass fraction of PB contained within the membrane (MFPB) assisted the improvement of the initial adsorption rate as well as the adsorption uptake of cesium ions. A high MFPB led to a decrease in the effective diffusion coefficient of cesium ions in the membrane. Adsorption equilibrium data were found in good agreement with the Langmuir model. The maximum adsorption capacity of the membrane immobilizing PB as well as the adsorption constant in the Langmuir model increased with higher MFPB.

Innovative Separation Technology Utilizing Marine Bioresources: Multifaceted Development of a Chitosan-Based System Leading to Environmentally-Friendly Processes

“…Chitosan have been focused as the media immobilizing various adsorbents since it is able to form stable gel structure through pH responsible [15,20,24,71,80]. From the advantages in both the adsorption process with selectivity and filtration with continuous operation, the membrane-type adsorbents have been recently developed to adopt the flow process.…”

“…For a large portion of such studies, adsorption abilities are evaluated from isothermal adsorption in batch process to reveal adsorption mechanisms [24,72]. As a typical case of an adsorption membrane immobilizing adsorbent particles, chitosan membrane incorporating Prussian Blue (PB) was developed for cesium removal from the aqueous phase [20]. The maximum adsorption capacity can be evaluated from the equilibrium adsorption amount of absorbate on absorbent (q e [mol g À1 ]) and the equilibrium concentration of absorbate in aqueous phase (C e…”

“…The structure of the membrane consisting of a chitosan polymer chain and PB were observed to suppress the diffusion of cesium ions into the membrane. The diffusion of cesium ions was inhibited considerably by the immobilized PB, which became dominant in comparison to the mass transfer resistance by the chitosan polymer chain [20].…”

“…In such case, the behavior of mass transfer into the chitosan hydrogel is complicated to quantitatively evaluate. The present chapter shows the determination of effective diffusion coefficient of cesium ions in chitosan membrane immobilizing Prussian Blue particles [20]. Furthermore, the chitosan aerogels with macro-porous structure is proposed for selective separation for anionic dye from aqueous phase.…”

“…In particular, the notable impacts of DD on the mass transfer mediated by chitosan membrane, the mechanical property, and the antibacterial activity, are introduced based on our previous research [17 -19]. Separation media prepared from chitosan are often combined with various adsorbents [20,21], carbon nanotubes [22,23], or other functional materials [24,25]. In such case, the behavior of mass transfer into the chitosan hydrogel is complicated to quantitatively evaluate.…”