This study focuses on the adsorption of Cu(II) ions using a novel magnetic adsorbent, which was synthesized by modifying a cellulose/Fe₃O₄/SiO₂ nanocomposite with 4-aminoantipyrine. The influence of pH, contact time and initial metal ion concentration on the adsorption capacity of the product was systematically investigated. Maximum adsorption efficiency was observed at pH 5. Equilibrium concentrations of Cu(II) ions in solution was set by using 1-phenyl-2- [2-hydroxy-3-sulfo-5-nitrophenylazo] 1,3-butadione (R) as reagent. During the study, several kinetic models parameters were evaluated. The equilibrium data were found to fit well with the pseudo-secondorder model, indicating that this model effectively describes the adsorption process. To analyze the adsorption behavior, several isotherm models including Langmuir, Freundlich, Temkin, and Redlich–Peterson were employed. Among them, the Langmuir model provided the best fit to the experimental data, indicating monolayer adsorption. The maximum adsorption capacity of the adsorbent for Cu²⁺ ions was calculated to be 138,9 mg/g. The present study also encompassed desorption experiments, revealing that a 0.5 mol·L-1 HCl solution exhibited the highest efficiency for desorbing Cu (II) ions.