Removal of Pb²⁺ and Cd²⁺ from Aqueous Solutions Using Plantain (Musa paradisiaca) Stem Sap Extract

This study explores the potential of Musa paradisiaca (plantain) stem sap extract as a sustainable biosorbent for the removal of Pb²⁺ and Cd²⁺ from aqueous solutions. The aim was to assess its feasibility for heavy metal removal through experimental and analytical approaches. The sap extract was obtained from fresh plantain stems and the biosorbent extracted from the plantain stem sap was subjected to characterization tests to determine its physicochemical properties. These included Fourier-transform infrared spectroscopy (FTIR), solubility analysis, pH measurement, and melting point determination. Adsorption experiments using the biosorbent on an aqueous solution were conducted by varying parameters such as contact time, solution pH, and extract dosage. These tests were used to evaluate the extract’s removal efficiency and adsorption behavior for Pb²⁺ and Cd²⁺ ions. Results showed the sap extract had 63.54% solubility in distilled water and a pH of 4.59. FTIR analysis revealed key functional groups such as hydroxyl, carbonyl, and amine present in the biosorbent. Maximum removal efficiencies were 98.29% for Pb²⁺ at 60 minutes and 93.59% for Cd²⁺ at 80 minutes. Pb²⁺ adsorption decreased beyond a dosage of 0.4 g, while Cd²⁺ removal improved with increasing dosage. Adsorption Isotherm modeling showed Pb²⁺ and Cd²⁺ fit the Freundlich model with R² of 0.9545 and 0.999 respectively, while Cd²⁺ fits the Langmuir model (R² = 0.9658), suggesting multilayer adsorption on heterogeneous sites. Conclusively, findings from the study demonstrated that Musa paradisiaca stem sap extract is an effective and eco-friendly biosorbent for removing Pb²⁺ and Cd²⁺ from aqueous solutions. The extract’s solubility, presence of key functional groups, and favorable adsorption performance indicates its potential for sustainable heavy metal remediation.