Adsorption Isotherm, Kinetics and Thermodynamics Study of Cr (VI) ions onto Modified Activated Carbon from endocarp of Canarium schweinfurthii

Isothermal, kinetics and thermodynamics studies of Cr (VI) from simulated solution onto modified activated carbon from endocarp of Canarium schweinfurthii (African Elemi) was studied. The effect of process parameters such as, contact time, pH, adsorbent dosage, initial metal ion concentration and temperature were investigated. Process optimization was carried out at pH of 2 and contact time of 30 min. Pseudo second order kinetics gave best correlation coefficient with calculated adsorption capacity close to experimental value. The initial rate of reaction for Cr (VI) is 6.74 x 10-4 mg/g.min. Result obtained from isothermal studies showed KF > qd, and >1. Gibbs free energy investigated from thermodynamic study, showed the adsorption process is spontaneous and endothermic as enthalpy change is positive. The adsorbent is recommended for use for removal of Cr (VI) ions in industrial effluents.