Study on adsorption properties of coconut shell activated carbon modified by HNO₃ and γ-Fe₂O₃

The modification by nitric acid and loaded γ-Fe₂O₃ catalyst was performed to the commercially available coconut shell activated carbon to improve the adsorption performance of activated carbon. The iodine adsorption and methylene blue adsorption experiments were carried out on the coconut shell activated carbon before and after modification. The results show that, the iodine adsorption value of the coconut shell activated carbon by nitric acid and loaded γ-Fe₂O₃ catalyst increases by 16.1% and 39.3%, respectively. The methylene blue adsorption value of activated carbon increases by 10.7% after the nitric acid modification, and this value decreases by 3.5% after the loaded γ-Fe₂O₃ catalyst modification. Both of the two modification methods enhance the overall adsorption capacity of coconut shell activated carbon. The total adsorption capacity of coconut shell activated carbon modified by γ-Fe₂O₃ catalyst is stronger than that of nitric acid modification. The research results can provide the reference for the treatment of SO₂ and NO_x in the sintering flue gas of iron and steel enterprises by activated carbon.