抄録
In this study, the surface property of activated carbons (ACs) was modified by outgassing and ammonia gas treatment to remove the surface acidic functional groups and to introduce the basic sites into the carbon surface, respectively. Then, the nitrate ion adsorption was performed using the prepared ACs to examine the effect of surface charge of the ACs under various solution pH. The competitive adsorption experiment between nitrate ion and nitrogen-containing aromatic compound was also conducted to specify the effective functional groups for the adsorption of nitrate ion. The result showed that low equilibrium pH (pHe) of the solution enhanced the adsorption of nitrate ion, and the adsorption amount of nitrate ion at the same solution pHe was promoted according to the increase in the amount of basic sites on the ACs. When the pHe of the solution was lower than pKa of the aromatic compounds, the amount of nitrate ion adsorption was increased in the presence of aromatic compounds, and the significant adsorption was observed accompanying the increase in pKa value. Accordingly, it could be concluded that the basic groups possessing high pKa value could promote the adsorption of nitrate ion
