The ability of concrete to remove silver from its aqueous solutions was studied. Silver removal is favored by low concentration and high pH at room temperature. The intrinsic acidity constants, average pKa1int and average pKa2int were determined. The calculated pHPZC (5.4) is in agreement with the pHPZC values determined from zeta potential measurements, indicating that the concrete particulate behaves amphoterically. The total acidity capacity for the negative and positive surface was 0.5 mC/cm2. A surface complex formation model (SCFM) was used to describe the adsorption of silver onto concrete particles. In general the equilibrium constants, the pKSi values, decrease as the silver loadings increase.

The ability of concrete to remove silver from its aqueous solutions was studied. Silver removal is favored by low concentration and high pH at room temperature. The intrinsic acidity constants, average pKa1int and average pKa2int were determined. The calculated pHPZC (5.4) is in agreement with the pHPZC values determined from zeta potential measurements, indicating that the concrete particulate behaves amphoterically. The total acidity capacity for the negative and positive surface was 0.5 mC/cm2. A surface complex formation model (SCFM) was used to describe the adsorption of silver onto concrete particles. In general the equilibrium constants, the pKSi values, decrease as the silver loadings increase.