Kinetic and Equilibrium Studies of Congo Red Adsorption on Adsorbent fromBambara Groundnut Hulls

Abstract

 Kinetics and equilibrium isotherms of Congo red adsorption on adsorbent derived from Bambara groundnut (Vigna
subterranea (L) Verdc.) hulls were investigated in a series of batch experiments. Using a one-factor-at-a-time
(OFAT) approach, optimum removal efficiency of Congo red by the adsorbent occurred at pH of 6.0 at lower
adsorbent dosage, attaining a peak value of 72.79% after 4 hours of agitating time. Findings also revealed that,
among the kinetic and isotherm models tested, the experimental data fitted best to pseudo-second order model ( =
0.957) and Freundlich adsorption isotherm ( = 0.981). This suggests that Congo red adsorption on Bambara
groundnut hulls involves chemisorption and the process is indicative of cooperative adsorption. The study
demonstrates that Bambara groundnut hulls can serve as an alternative low-cost adsorbent for removing Congo red
from industrial wastewater