Removal Of Lead And Cadmium Ions From Aqueous Solution Using Vigna subterrenea Seed Shells Carbon

Abstract

Carbon derived from Vigna subterrenea seed shells (CVSS) was employed for the effective removal of Pb (II) and Cd (II) by adsorption. CVSS was prepared via the chemical activation method using the nitric acid solution as activating agent. The effects of operational parameters such as pH, adsorbent dosage and contact time were studied. Adsorption isotherms and kinetics experiments were performed at 25 ^oC and 30 ^oC. The metal ions uptake increases with an increase in solution pH for the carbon for both Pb (II) and Cd (II) ions. Across the temperatures, equilibrium removal efficiencies of CVSS for Pb (II) and Cd (II) were 89.77≤ and≤ 73.81) respectively. Maximum adsorption capacity Q_max of CVSS for Pb (II) and Cd (II) were 9.25 and 8.56mg/g respectively. Langmuir's model provides the best fit for both lead and cadmium. Adsorption kinetics obeyed the pseudo-second-order model.