**16. Polyorgs ion exchangers**

Polyorgs type chelating ion exchangers [58, 99–103] are used for separation, concentration and removal of palladium(II) ions and other noble metals from deposits, rocks, ores, minerals and industrial waste waters. The Polyorgs sorbents were prepared by introducing e.g. imidazole, pirazole, mercaptobenzothiazole, amidooxime groups to the macroporous copolymers (polystyrene, polyvinyl, polyacrylonitrile) and other matrices. Sorbents of this type are characterized by high chemicals stability in strong acid and alkaline solutions as well as high thermal resistance and can be applied in the whole pH range. The sorbents of Polyorgs type (11-n, 15-n, 17-n and 33-n) were also used for filling fibres e.g. polyacrylonitrile (PAN), cellulose, polyvinyl (PVA) ones. In the literature, such sorbents are called filled fibrous sorbents (FFS) [99, 102, 103]. Main advantages of FFS are good kinetics of sorption and ease in their separation from solution which make them more attractive than sorbents in the form of powder or grains.
