Equilibrium studies and modeling on the removal of .sup.56Mn by alumina and kaolinite

The removal of manganese from aqueous solutions on synthetic alumina and natural kaolinite was investigated in batch experiments as a function of pH. Experiments were carried out by using the radiotracer .sup.56Mn, produced by neutron activation. Theoretical analysis of manganese removal was performed considering the existence of a single type of surface sites, denoted as [identical to] SOH°. The uptake of manganese on kaolinite is similar to that on alumina, indicating that adsorption occurred on the variable-charged aluminol sites. Adsorption experiments suggest that [identical to] AlOH° group is the most probable edge site for complexing manganese cations through mononuclear surface complexes ([identical to] AlOMn.sup.+) and ([identical to] AlOMnOH).