ARSENIC-ADSORBING ION EXCHANGER

The invention relates to a method for producing an ion exchanger carrying carboxyl groups and containing iron oxide/iron oxyhydroxide, said method being characterised in that a) a bead-type ion exchanger containing carboxyl groups in an aqueous suspension is brought into contact with iron-(III)-salts, or a`) an aminomethylated, cross-linked polystyrol bead polymer in an aqueous suspension is brought into contact with iron-(III)-salts and chloroacetic acid, and b) the pH values of the suspensions obtained in steps a) or a`) are adjusted to between 3 and 14 by adding alkali hydroxides or alkaline-earth hydroxides, and the obtained ion exchangers containing iron oxide/iron oxyhydroxide are isolated according to known methods. The invention also relates to such ion exchangers, and to the use thereof for the adsorption of heavy metals, especially arsenic.