抄録
The effects of carbon dioxide on neutralization process of acid precipitation by soil have been investigated. In order to estimate the contribution of carbon dioxide contained in soil on the neutralization, a soil sample and an acid solution were shaken in an atmosphere of high concentration of carbon dioxide. Higher concentration of carbon dioxide was, larger amounts of cations were liberated from soil phase. Thus, it was suggested that both oxonium ions originated from dissolution of carbon dioxide in aqueous solution and originally existed in an acid solution might contribute to the cation exchange reaction. Furthermore, in order to estimate the amounts of cation to be liberated by ion-exchange from soil, a constant ‘γ’ was presented instead of the conventional lime-potential. By using ‘γ’, it was able to simply and quantitatively express a cation exchange potential for cations of any oxidation states. Based on both equilibria for cation exchange reaction and for dissollution of carbon dioxide into the solution, the changes of pH value of the solution was simulated under high concentration of carbon dioxide in gas phase, and the simulated values agreed well with the measured ones.
