The influence of adsorbent dose, initial metal ion, pH, other ions, temperature and contact time were studied for the adsorption of ferrous ions on to acid activated carbon prepared from Albizia lebbeck bark. The results were analyzed in the light of Langmuir and Freundlich isotherms From this, the adsorption efficiency, ads orption energy, adsorption capacity, intensity of adsorption and dimensionless separation factor w ere calculated. From the kinetic studies the rate constant values for the adsorption process was calculated. F rom the effect of temperature thermodynamic parameters like ∆ G°, ∆ H°, and ∆ S° were calculated. The mechanism of adsorption for that ferrous ion onto carbon have in vestigated by using the experimental results and confirmed by IR spectra, XRD and SEM images.