SORPTION OF HEXADECYLAMMONIUM IONS ON REDUCED CHARGE MONTMORILLONITE

Using lithium fixation, a series of montmorillonite samples were prepa red which had reduced negative layer charges. The sorption of hexadecy lammonium (HDA) ions was found to be controlled by the remaining layer charge. The relation between the amount of HDA sorbed by one gram of Li-treated montmorillonite and the cation-exchange capacity (CEC) of t he sample was found to be Q(HDA)/(mmol g-1) = 0.214 + 1.723 CEC for CE C values lower than 0.75 mmol g-1. This relation was valid if the HDA present was sufficient to reach the saturation point. The amount of ex changeable Ca2+ ions desorbed after HDA sorption was only 83 to 93 % o f the remaining CEC.