The Kinetic and Thermodynamic Study of the Removal of Selected heavy Metals from a Nigerian Brewery Wastewater Using Activated Carbon From Cheese Wood (alstonia boonei)

Abstract

An adsorbent was developed from the bark of Alstonia boonei for removing Pb, Ni and Fe ion from brewery wastewater using a batch adsorption process. Various process parameters that include adsorbent dosage, contact time, solution pH and temperature were studied. For the effect of temperature, Pb had its highest percentage removal of 80.48% at 40°C, for Ni 90.26% at 60°C, and Fe 98.76% at 50°C. The effect of solution pH shows the highest percentage removal of 98.39% and 99.85% for Fe and Ni respectively at solution pH of l0 while Pb had its highest percentage removal of 79.9% at the solution pH of 2 The result also shows highest percentage removal of 76.01% and 99.19% at adsorbent dosage of 1.5g for Pb and Fe respectively, and 96.8 % at 0.5g for Ni. Also, the highest percentage removal of Pb and Ni was at 60 minutes indicating 82.48% and 96.l9% respectively while Fe showed the highest percentage removal of 99.12% at contact time of 30 minutes. Negative values of entropy change ΔS° and Gibbs free-energy change ΔG° indicate that this adsorption process is spontaneous. The adsorption process follows pseudo-second-order kinetics. The surface functional groups and surface area of theadsorbent was examined by Fourier Transformed Infrared Technique (FT-IR) and BrunauerEmmett Teller (BET).