Multi-metal sorption by spent animal bones

The multi-component metal sorption by animal bones was examined using single, binary, and ternary systems composed of Cu²⁺, Zn²⁺, and Ni²⁺. Four isotherm models, namely Freundlich, Langmuir, Sips, and Ideal Adsorption Solution Theory (IAST) were used in this study to predict the equilibrium uptake for Cu²⁺, Zn²⁺, and Ni²⁺ in binary solutions using the single adsorption constants, obtained by the single isotherm experimental data. Sorption was suppressed by the presence of other metal ions in the binary or ternary sorption processes. The Langmuir, Freundlich, and Sips isotherm models were found to represent the experimental data of a single isotherm sorption process. Whereas, the predictions of binary sorption isotherm systems, Cu²⁺-Ni²⁺, Zn²⁺-Cu²⁺, Ni²⁺-Zn²⁺, showed good agreement with experimental data when using all models except Langmuir.