Adsorption of caesium ions by some materials used in the manufacture of PVC-based surface coatings

Abstract

An attempt was made to establish the nature of and some of the factors influencing the adsorption of caesium ions in solution on to a range of solid materials; polyvinyl chloride (PVC), barytes, china clay, whiting, carbon black, titania, asbestos, chosen since they are all used in the manufacture of a range of products used for surface coatings and storage vessels. Particular attention was paid to the use of products containing these compounds which are recommended for use in radioactive areas, both for the storage of radioactive materials and the protection of surfaces, where contamination can present problems. The adsorption processes were investigated by preparing and analysing the characteristics of the adsorption isotherms of caesium ions on to powder samples using a batch equilibration technique, and as was to be expected the predominant mechanism appeared to be one of ion exchange. It was confirmed that titania, and to a lesser extent china clay, whiting and carbon black, played a major part in the adsorption process. It is clear that the quality of any final product will depend on the process used in its manufacture, which in turn can be related to its potential for contamination in a radioactive facility.