Abstract: The invention relates to a composite solid material which fixes inorganic contaminants based on metal hexacyanoferrate comprising a solid support coated with a thin film of an anion-exchange polymer to which is fixed an insoluble metal hexacyanoferrate forming a thin layer, characterized in that said polymer is a noncrosslinked polymer which comprises, as anion-exchange groups, solely quaternary ammonium groups and in that it does not comprise primary, secondary or tertiary amine groups.

Abstract: The invention relates to a composite solid material fixing mineral contaminants, with a metal hexacyanoferrate basis, characterised in that it comprises a solid support coated with a pellicle of an anion-exchange polymer to which is fixed an insoluble metal hexacyanoferrate forming a thin layer. The present invention also relates to the method of preparing the said composite solid material fixing mineral contaminants with a hexacyanoferrate basis. The present invention finally relates to method of fixing, which can be carried out in a column and continuously, of at least one mineral contaminant contained in a solution, on the said composite solid material fixing mineral contaminants. The said solution is in particular a liquid or an effluent originating from the nuclear industry and installations.