Kinetic and equilibrium study of pyrolyzed sugarcane bagesse as adsorbents for Pb²⁺ and Cd²⁺ in an aqueous medium

ABSTRACT

Sugarcane bagesse was utilised as a low-cost adsorbent for the removal of metal ions. The study was done at a temperature of 35°C, and the maximum adsorption capacities for Pb(II) and Cd(II) ions were 3.02 and 2.90 mg/g, respectively, for sugarcane bagasse. These results were determined using the following optimum conditions: initial metal ion concentration of 100 mg/dm³, adsorbent weight of 0.5 g, time of 30 min and pH of 6. The adsorption of the metal ions by the adsorbents decreased with an increase in the initial concentration of the metal ions in an aqueous solution. The rate of adsorption also increased with temperature. The adsorption showed a good fit to the Langmuir model compared to the Freundlich adsorption model. The Langmuir dimensionless constant (R_L) for the adsorption of Pb(II) ion and Cd(II) ion ranged from 0.081 to 0.123 and 0.115 to 0.172, respectively, which confirms favourable adsorption. The adsorption process showed that the pseudo-second-order kinetics was a better fit than the pseudo-first-order kinetics. The result of this work showed a low-cost and efficient potential of sugarcane bagasse to be employed as a good adsorbent for metal ion removal.

KEYWORDS:

• Equilibrium
• adsorption
• aqueous solution
• sugarcane bagasse

Disclosure statement

No potential conflict of interest was reported by the author(s).