Biosorption of Cd(II) From Aqueous Solution by Cocoa Pod Husk Biomass: Equilibrium, Kinetic, and Thermodynamic Studies

Cocoa pod husk biomass proved to be an effective biosorbent for the removal of Cd(II) from aqueous solution. The biosorbent was characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, surface structural parameters, and proximate analysis. The effects of operational parameters were investigated. Equilibrium was reached after 120 min at 303 K and optimum biosorption capacity was obtained at pH 6. The biosorption kinetics was best predicted by the Avrami model. The results showed that the biosorption equilibrium was best described by the Freundlich isotherm model. From the thermodynamic parameters determined, the biosorption was spontaneous and endothermic.