Abstract

Optimization of Adsorption Parameters for Effective Removal of Lead (II) from Aqueous Solution

Author(s): Jonas Bayuo, Kenneth Bayetimani Pelig-Ba and Moses Abdullai Abukari

In this study, groundnut shell was used as an adsorbent to remove lead (II) ions in an aqueous solution. Response Surface Methodology (RSM) was employed for the modeling and optimization of adsorption of lead (II) ion onto groundnut shell. The effects of three adsorption variables (contact time, pH as well as initial metal ion concentration) on two response variables (removal efficiency and adsorption capacity) were investigated using Central Composite Design (CCD), which is a subset of the Response Surface Methodology. Numerical optimization applying desirability function was used to identify the optimum conditions for a maximum removal efficiency and adsorption capacity of lead (II) ions onto the groundnut shell. The optimum operating condition for the adsorption of Pb (II) was found to be contact time of 90 min, pH of 8 and initial concentration of 75 mg/L with the desirability of 0.966. The maximum removal efficiency and adsorption capacity of Pb (II) ions under this operating condition were found to be 90.26% and 3.428 mg/g respectively. The equilibrium adsorption isotherm and kinetic studies showed that Langmuir isotherm and pseudo-second-order kinetic model fitted well to the experimental data. The characterization studies were performed using Fourier Transform Infrared Spectrometer (FT-IR) and Scanning Electron Microscope (SEM).