In this work, the functional density theory calculations were performed to investigate the interaction mechanism (adsorption) of Cu2+, Cr(3+)and Cd(2+)metal ions in cellulose (CE) and cellulose acetate (AC). After the optimization of the structures at their energy minima, the following analyses were performed: molecular electrostatic potential (MEPs), reactivity indexes, frontier molecular orbitals (FMOs), structural parameters, interaction energy and QTAIM analysis. The study of MEPs, FMOs and reactivity indexes showed that it is possible to predict the site of interaction. Structural analyses have proven that the interactions occur. The calculated electron interaction energies showed that all ions interact with the matrix of CE and AC, and among them, the Cr(3+)ion was the one that interacted most effectively. Finally, the QTAIM analysis allowed to characterize the nature of the interaction, in which the interactions of cellulose acetate-Cr(3+)and cellulose-Cu(2+)presented electrostatic character, and the other interactions were partially covalent.