Impregnation methods and Ra adsorption process in Mn-fibers and Mn-cartridges: A mini review

Mn-fibers and Mn-cartridges are chemically modified polymers used in treatment of water with levels natural or anthropogenic radiological activities and as pre-concentration media of elements such as Ra, Th and U. The adsorption property of these media, which occurs by eletrostatic interactions, is acquired by the pre-oxidation in specific parts of the polymer molecule with KMnO4, creating active sites with MnO2. Several methods of impregnation are shown in literature and were optimized to minimize the loss of MnO2, stages, time and degradation of the polymer and raise the extraction efficiency. This article discusses the aspects of the impregnation method that may influence the extraction efficiency of the Ra isotope. It includes, the stages of sampling and treatment of the sampling, chemical analysis in the RaDeCC, chemical and physical properties of the samples and the stages of fiber preparation of fibers and impregnated cartridges. Moreover, it covers a detailed discussion about the phenomenon of adsorption of Ra, reaction of impregnation, developments and optimizations of the impregnation methods of these polymers. (C) 2021 The Author(s). Published by Elsevier B.V.