INTERACTION OF NICKEL COPPER AND CADMIUM WITH SOIL MANGANESE IN SALINE SOLUTIONS

The sorption of heavy metals in soil may result in the release of protons or other metal cations. Manganese release to soil solution has been observed with the addition of certain heavy metals to soil. In this study Ni, Cu, and Cd in Na salt solutions of Cl−and ClO4−were leached through soil, and the effluents analyzed. Peak or pulse increases in the Mn concentration were coincidental with appearance of Ni, Cu, or Cd in the effluent. Increased Na salt concentrations resulted in increased Mn release, even though the amount of heavy metal sorbed decreased. Copper treatments produced a decreased effluent pH, which probably accounted for some of the released Mn. Nickel and Cd treatments, on the other hand, resulted in slight or no significant effluent pH decrease. Several possible mechanisms are introduced that could account for Mn release. It is most probable that proton release with Ni, Cu, or Cd sorption accounts for most of the Mn release.