Regeneration of Hexamminecobalt(Ⅱ) Under the Catalysis of Activated Carbon Treated with K_2S_2O_8 Solution

摘要

The combined elimination of NO and SO_2 can be realized by hexamminecobalt(Ⅱ) solution. Activated carbon is utilized to catalyze the reduction of hexamminecobalt(Ⅲ) (Co(NH_3)_6~(3+)) to hexamminecobalt(Ⅱ) (Co(NH_3)_6~(2+)), so as to maintain a high NO removal efficiency for a long time. K_2S_2O_8 solution has been tried to modify coconut activated carbon to enhance its catalytic capability in the reduction of hexamminecobalt(Ⅲ). The experiments have been performed in a stirred cell to investigate the effects of K_2S_2O_8 concentration, impregnation temperature, and impregnation time on the catalytic ability of activated carbon. The results showed that the best K_2S_2O_8 concentration for the improvement of activated carbon is 0.3 mol L~(-1). The optimal impregnation temperature was 40℃. The optimum impregnation duration was 9 h. After treated with K_2S_2O_8 solution, the surface area of activated carbon decreased. But the acidity on its surface was enhanced, which played a crucial role in improving the catalytic capacity of activated carbon in the reduction of Co(NH_3)_6~(3+). The experimental results showed that the modified carbon could obtain a higher NO removal efficiency than the original carbon.