Mikiko KAWANAKA
Preferential Adsorption of Heavy Metal Ions on the Surface of Manganese Oxide Particles in an Aqueous Environment
Kazunori SATO
It has been reported that manganese oxide has a high ability of Pb(II) adsorption, but the adsorption mechanism was not clear. In this research, I focused on the crystal structure of manganese oxides, ¦Ã-MnOOH and ¦Á-MnO2. I investigated the ability of preferential adsorption of Pb(II) ions on these manganese oxides. An adsorption experiment for the heavy metal ions (Pb(II), Cu(II), and Zn(II)) was conducted. ¦Ã-MnOOH and ¦Á-MnO2 showed a preferential adsorption of Pb(II) ions in an aqueous mixture of Pb(II), Cu(II), and Zn(II) ions. It was found that the affinity of manganese oxides for of heavy metal ions does not depend on the crystal structure of manganese oxides. The experimental results of adsorption isotherms and pH dependency indicate that Cu(II) ions adsorb to the surface of the manganese oxides by the proton exchange. As for Pb(II) ions adsorption of ¦Á-MnO2, the pH dependency was low and the Pb(II) ions adsorption did not compete with the Cu(II) ion adsorption; the adsorption sites are different for Pb(II) and Cu(II) ions. From these results, it is concluded that ¦Á-MnO2 has a specific adsorption site for Pb(II) ions
Please use "previous botton" to return the previous page