We conducted experiments for the humic acid adsorption by allophane, ferrihydrite, activated charcoal and micro charcoal to clarify the mechanisms involved in the accumulation of humic substances in Andisols. Adsorption envelopes indicated that: 1) the adsorption patterns of humic acid on these materials from equilibrium pH 4 to 6 showed that the amount of humic acid sorbed was the largest for allophane folowed by activated charcoal, ferrihydrite and micro charcoal; 2) there were many differences between activated charcoal and micro charcoal in regards to their humic acid adsorption properties; and 3) many researches indicated that the amount of active Al was much larger than that of micro charcoal in Andisols. From these results, we concluded that active Al plays an important role in the accumulation of humic substances in Andisols, as indicated by Kobo and Oba, Wada and Higashi, Shoji, and Inoue and Higashi.
|Translated title of the contribution||Comparison of Humic Acid Adsorption on Allophane, Ferrihydrite, Micro Charcoal and Activated Charcoal|
|Number of pages||8|
|Journal||日本土壌肥料学雑誌 = Japanese journal of soil science and plant nutrition|
|Publication status||Published - Feb 5 2000|