CC-BY-NC-NDGorgievski, MilanMarković, MiljanŠtrbac, NadaGrekulović, VesnaZdravković, Milica2023-12-262023-12-262023978-86-6305-137-9https://eco.tfbor.bg.ac.rs/download/Zbornici/2023.pdfhttps://repozitorijum.tfbor.bg.ac.rs/handle/123456789/2459Langmuir, Freundlich, and Temkin isotherm models were used to study the equilibrium and mechanism of biosorption of copper ions onto onion peels under batch conditions. Isotherm parameters were calculated from the line graphs according to each model. The results obtained on the basis of correlation coefficients, show that the Freundlich isotherm model (R2 = 0.964) is in good agreement with the analyzed experimental data. This model assumes that the surface energy of the adsorbent is heterogeneous, strong binding sites are occupied first, and that the binding energy decreases as the number of occupied adsorbent sites increases.enadsorption isothermscopper ionsonion peelsbiosorptionconferenceObject