Effectiveness of a cassava peel adsorbent on the absorption of copper (Cu2+) and zinc (Zn2+) metal ions

Abstract

Cassava peel waste can be used as an adsorbent to remove heavy metal pollution from industrial liquid waste. This study aims to determine the effect of the mesh size and operational temperature of a cassava peel adsorbent on the adsorption of heavy metal ions of copper (Cu2+) and zinc (Zn2+). This study concerns on the ability to absorb the heavy metals copper (Cu2+) and zinc (Zn2+), the characteristics of the adsorbent (functional group), and the adsorption capacity for isothermal adsorption using the Langmuir and Freundlich models. The cassava peels were crushed, dried, ground and sieved with 80, 100 and 120 mesh sieves. The cassava peel powder was activated with HNO3 and used to absorb metal ions from the model liquid waste at different temperatures of 35°C, 45°C and 55°C. The cassava peel adsorption process was analyzed using AAS, SEM and FT-IR analyses. The results of the study showed that the optimum conditions for the cassava peel adsorbent to absorb copper (Cu2+) and zinc (Zn2+) metal ions are 120 mesh in size and an operating temperature of 35°C to obtain adsorption values of 55.19% for copper (Cu2+) and 41.7% for zinc (Zn2+). Functional groups present in the cassava peel adsorbent include O-H, N-H, C=O, and C-N. Among the two widely used isotherms tested (i.e., Langmuir and Freundlich models), the experimental data were found to mostly closely resemble the Freundlich isotherm.