In this work, the adsorption of copper ions onto activated carbons that oxidatively modified with H₂O₂ and HNO₃ was studied. The prepared sorbents with the surface area of 275–780 m²/g contain 0.53–3.77 mmol/g of oxygen-containing groups. It was found that the oxidized activated carbon effectively adsorbs Cu²⁺ ions from aqueous solutions. For the most efficient activated carbon–HNO₃–30 sorbent, the percentage removal of copper ions from solutions of varying concentration is high. In the concentration range from 1.5 to 6 × 10⁻⁴ M of Cu²⁺, it reaches >55%. At the concentrations lower than 1.5 × 10⁻⁴ M, the expected removal is above 80%. The experimental equilibrium adsorption data were modeled with 2- and 3-parameter isotherms. The analysis of adsorption modeling results accounting for the surface heterogeneity effect was provided. The data fit well to the Dubinin–Radushkevich model. Presumably, the complexation of Cu²⁺ with oxygen-containing groups passes within micropores. We found the correlation between the sorption capacity for Cu²⁺ and the concentration of surface groups. The presence of the carboxyl, anhydride, and lactone groups make a major impact on the adsorption.

Nanoporous activated carbon fibers (Busofit^TM, BACF) showed effective adsorption of carbon tetrachloride (CTC) vapors. About 2.50 mmol × g⁻¹ of chlorine, in the form of trichloromethyl and chlorine groups, can be grafted onto BACF surface by thermal decomposition of CTC at 450 °C. To obtain solid acids, this chlorinated BACF, the brominated and pristine BACFs, taken for comparison, were subjected to progressive sulfidation, hydrolysis and oxidation reactions for grafting sulfonic groups. By this wet route, sulfonic groups can substitute only 1.1–1.4 mmol × g⁻¹ of the grafted chlorine groups. Nevertheless, solid acids obtained in this way have high catalytic performance in the 2-propanol dehydration to propene. For these catalysts, in the range from 180 to 220°C, a 100% alcohol conversion with 100% selectivity to propene could be reached. Thermoprogrammed desorption and thermal analysis revealed that the pyrolytic chlorination triggers the highest thermal stability of grafted sulfonic groups, and, they can repeatedly act in the dehydration reaction.