The adsorption of Cu2+ and Ni2+ on synthesized tripolyphosphate-crosslinked-chitosan-modified montmorillonite (TPP-crosslinked-CTS-modified MMT) was examined by kinetic and equilibrium studies. The adsorption followed a pseudo-second order kinetics. Based on the activation energies, chemisorption due to electron transfer between TPP-crosslinked-CTS-modified MMT and the Cu2+ and Ni2+ cations was concluded to be the rate-determining step. Equilibrium analysis for the adsorption of each cation shows a good fit to the Langmuir equation. The adsorption of metal cations onto TPP-crosslinked-CTS-modified MMT proceeds because of the cation adsorption capacity of MMT, complexation with CTS, and complexation with the crosslinking agent (TPP). The selectivity toward Cu2+ was high because of the selective adsorption of this cation by CTS.
- Chitosan-modified montmorillonite
- Heavy metal ions