Removal of Bi (III) with Adsorption Technique Using Coconut Shell Activated Carbon

In present study, we report the preparation of coconut shell activated carbon as adsorbent and its application for Bi (III) removal from aqueous solutions. The developed adsorbent was characterized with scanning electron microscope (SEM), Fourier Transform Infrared (FTIR), C, H, N, S analyzer, and BET surface area analyzer. The parameters examined include agitation time, initial concentration of Bi (III), adsorbent dose and temperature. The maximum adsorption of Bi (III) (98.72%) was observed at 250 mg.L-1 of Bi (III) and adsorbent dose of 0.7 g when agitation was at 160 r.min(-1) for 240 mm at (299 +/- 2) K. The thermodynamic parameters such as Gibb's free energy (Delta G(circle minus)), enthalpy (Delta H-circle minus) and entropy (Delta S-circle minus) were evaluated. For the isotherm models applied to adsorption study, the Langmuir isotherm model fits better than the Freundlich isotherm. The maximum adsorption capacity from the Langmuir isotherm was 54.35 mg-g(-1) of Bi (III). The kinetic study of the adsorption shows that the pseudo second order model is more appropriate than the pseudo first order model. The result shows that, coconut shell activated carbon is an effective adsorbent to remove Bi (III) from aqueous solutions with good adsorption capacity.