Adsorption and removal of Cu (II) ions from aqueous solution using pretreated fish bones

Pretreated fish bones obtained from engraulis European anchovy (Engraulis encrasicolus), European anchovy (Sardine pilchardus), bogue (Boops boops), bluefish (Pomatomus saltatrix) and gilthead seabream (Sparus aurata) were used as natural, cost-effective, waste sorbents for the adsorption and removal of copper from aqueous systems. The removal efficiency of the adsorbent was investigated as a function of pH, contact time, initial metal concentration, temperature, cleaning process, fish species and adsorbent dose. The maximum adsorption capacity was 150.7 mg/g at optimum conditions. The kinetic results of adsorption obeyed a pseudo-second-order model. Copper adsorption fitted the Langmuir isotherm. ΔH0 value was 12.9 kJ/mol indicating that the adsorption mechanism was endothermic. The activation energy, Ea, was determined as 52.9 kJ/mol. Weber–Morris and Urano–Tachikawa diffusion models were also applied to experimental equilibrium data. The fish bones were effectively used as a sorbent for the removal of Cu ions from aqueous solution.