FIELD: adsorption of radioactive materials or iron ions from aqueous solutions. SUBSTANCE: tannic acid is dissolved in source solution wherefrom mentioned material is to be adsorbed, aldehyde and then ammonia are added to solution obtained up to pH of at least 7. Resulting insoluble sediment incorporating tannic acid as basic component adsorbs mentioned materials. Source solution primarily contains nuclear fuel extracted from uranium or thorium. Polyacrylamide may be added to mentioned sediment to improve its settling down. Adsorbents should not be prepared in advance; this procedure and adsorption occur simultaneously. Upon treatment, adsorbents can be easily burned because no toxic gases are emitted in the process. EFFECT: improved safety and facilitated procedure. 3 cl
