Abstract: Granular activated carbon was modified with nitric acid of different concentration.The surface chemical characteristic of pre-modified and post-modified activated carbon was analyzed by BET specific surface area test and Boehm functional group titration.The treatment effects of simulated wastewater containing copper by pre-modified and post-modified granular activated carbon were compared.The results indicated that specific surface area and the total quality of acid functional group increased in the process of nitric acid oxidation，which lead to the increase of the Cu²⁺ removal rates considerably.On the conditions of normal temperature，natural pH，equilibrium time of 180 min，absorbent dosage of 5 g/L，the Cu²⁺ removal rates was above 70% by the granular activated carbon which was modified with nitric acid of 10% concentration，and about 90% by the granular activated carbon which was modified with nitric acid of 70% concentration respectively.The Cu²⁺ adsorption behavior of nitric acid-modified granular activated carbon conformed to Langmuir adsorption equation.

Key words: Activated carbon, Modification, HNO₃, Cu²⁺, Adsorption