Boron sorption in Na-montmorillonite

Chen, Y.; Sawaguchi, Takuma 

Sorption of boron in compacted Na-montmorillonite was studied for a better understanding of the boron migration behavior. Boron adsorption at various pH and ionic strength conditions was investigated by batch studies. Sorption distribution ratio value (K [m/kg]) was found to be at the order of magnitude of -3. At fixed pH, sorption can be described using Freundlich isotherm expressions. Boron sorption generally increased with pH. Above about pH 8, however sorption decreased. It was assumed that adsorption was via ligand exchange with aluminol groups at clay surfaces. Both charges of adsorbent and adsorbate were taken into account to explain the pH effects.