Method of making an ion exchange material in which a ceramic material is ion-implanted with sulfur, carbon, phosphorus, or nitrogen, which is oxidized to sulfate, carboxylate or carbonate, phosphate, or nitrate, respectively, or the nitrogen is reduced to amine or amide. Alternatively, a mixture of ceramic powder and a binder containing sulfur, carbon, phosphorus or nitrogen is heated in a non-oxidizing atmosphere to a temperature up to 1000°C. The sulfur is then oxidized to sulfate, the carbon to carboxylate or carbonate, phosphorus to phosphate, and nitrogen to nitrate, or the nitrogen is reduced to amine or amide. Also a method of treating acidic aqueous solutions containing dissolved radioactive materials by passing them through an ion exchange column containing the ion exchange material made by the afore-mentioned methods.