adsorbents were prepared from silica and metakaolin in different Al and Si components
and applied for removal of metal ions, Cs+ and Pb2+, from
other heavy metal ions mixture. The geopolymer was optimized at Si/Al = 2 as
adsorbent, targeting to Cs+ and Pb2+ separation. The
binding behavior was well fitted to Langmuir model, which proved that the
metakaolin-based geopolymer had multibinding to adsorb ions. The effective
adsorption was also observed independent of NaCl concentration for the Cs+ and Pb2+. This meant that the ion adsorption of geopolymers occurred
under non-electrostatic mechanism.