抄録
In order to explain the role of humic acid in the behavior of metal ions in aqueous environments, such as rivers and estuaries, portions of Zn, Cd and Ni combined with humic acid in dilute aqueous solutions were determined using ultrafiltration. The portions of these ions combined with humic acid increase with pH, and decrease with concentration of NaCl in solution. In solution containing less than 50 ppm NaCl, Cd is distinguished in portions of ions linked to humic acid from Zn and Ni, while the combination of Cd with humic acid is most remarkably influenced by NaCl. Some trace metals can be removed from the aqueous phase during the coagulation process of humic acid. When river water is mixed with sea water, the combination of humic acid and the metal ions such as Zn++, Cd++ and Ni++ is responsible for the removal of these ions only when the concentration of humic acid is high.
