Sorption of cesium on illite: Non-equilibrium behaviour and reversibility

Journal Article · Fri Feb 01 04:00:00 EST 1991 · Geochimica et Cosmochimica Acta; (United States)

DOI:https://doi.org/10.1016/0016-7037(91)90002-M· OSTI ID:5551852

Comans, R N.J.; Haller, M ^[1]; De Preter, P ^[2]

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1. Univ. of Utrecht (Netherlands)
2. Katholieke Universitiet Leuven (Belgium)

Adsorption, desorption, and isotopic exchange have been used to investigate the kinetics and reversibility of cesium sorption on illite. Trace concentrations of cesium were used and experimental conditions were kept close to those to those of many freshwater environments. Initials adsorptions of cesium on illite was rapid but was followed by slower uptake process with time scales of weeks to months. The uptake proceeded faster and reached much higher K{sub d} values in a Ca{sup 2+} environment than in a K{sup +} environment. The apparent reversibility of sorption was affected by both the slow sorption processes and the nature of the competing cation. The desorption equilibration patterns indicate that cesium is released from rapidly accessible sorption sites but that the slow forward reaction continues. On time scales relevant for modeling its transport and retention in aquatic systems, cesium shows partially irreversible behavior. A mechanistic interpretation for the observed sorption and isotopic exchange behavior is proposed whereby cesium migrates slowly to energetically favorable interlayer sites from which it is not easily released.

• OSTI ID: 5551852
• Journal Information: Geochimica et Cosmochimica Acta; (United States), Journal Name: Geochimica et Cosmochimica Acta; (United States) Vol. 55:2; ISSN GCACA; ISSN 0016-7037
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
580000* -- Geosciences
ADSORPTION
ALKALI METALS
CESIUM
CHEMICAL REACTION KINETICS
CHEMICAL REACTIONS
CHEMISTRY
CLAYS
DESORPTION
ELEMENTS
GEOCHEMISTRY
ILLITE
INTERFACES
ISOTOPIC EXCHANGE
KINETICS
MATHEMATICAL MODELS
METALS
MOLECULAR MODELS
REACTION KINETICS
ROCK-FLUID INTERACTIONS
SEDIMENT-WATER INTERFACES
SEDIMENTS
SORPTION
SORPTIVE PROPERTIES
SURFACE PROPERTIES