Competitive metal binding to a silicate-immobilized humic material.

The investigation of the competitive binding of metal ions to a biogenic material comprised of organic peat immobilized in a polysilicate matrix was undertaken. This material was packed into 5.0mL bed-volume columns using 40-60mesh size particles. Two separate mixtures of metal ions were studied by monitoring the solution pH and the concentration of each metal in the effluent as a function of the volume of influent introduced to the material. These mixtures contained either the metal ions Ca(2+), Mg(2+), and Cu(2+) or the ions Cu(2+), Hg(2+), and Pb(2+). A general order of binding affinities was determined to be Mg(2+)