Removal of cobalt(II) ion from water by adsorption using intact and modifiedFicus caricaleaves as low-cost natural sorbent

Abstract

AbstractA series of experiments were carried out in a batch system to assess the removal of cobalt ion (Co2+) by intact and modified Ficus carica leaves (FCLs) from the aqueous solutions in laboratory experiments. Adsorption kinetics and thermodynamic parameters, as well as equilibrium adsorption isotherms, were examined. The effects of pH, initial concentration of metal ions, biosorbent dose, and the treatment of biosorbent on the biosorption process were also studied. Results showed that the optimum uptake (20.2 mg/g with the removal efficiency of 31.02%) was reached at pH 4. It was also found that the FCLs treated with MgCl2 caused an increase in the uptake capacity, 33.9 mg/g (qexp) at pH 6, and removal efficiency was 57.15%. The biosorption data followed the Freundlich (R2 = 0.974), Langmuir (R2 = 0.978), Dubinin–Radushkevich (R2 = 0.982), and Temkin (R2 = 0.915) isotherms. Langmuir, Freundlich, and Dubinin–Radushkevich models exhibited a higher and better fit of the data. The Freundlich constants Kf...