Removal of Chromium (III) from drinking water using ash of bark of Terminalia arjuna

Drinking water samples of 27 sources of Chirang District of Assam, India have been analyzed. Ash bark of Terminalia arjuna was studied as adsorbent for adsorption of Cr³⁺ions from contaminated water based on these findings. Terminalia arjuna was characterized by X ray fluoresence spectroscopy for determining chemical composition, X ray diffraction to verify crystallinity, fourier transform infra red spectroscopy for residual organic species and N2 adsorption studies to find out surface area and pore volume. The adsorption experiments were applied to evaluate the adsorption performances of Terminalia arjuna. The maximum (99%) removal of Cr (III) can be obtained if 60 mL of water containing 0.8g L⁻¹of Cr (III) was passed through 5 g of Terminalia arjuna bark ash for 2 elutions. Langmuir's and Freundlich's adsorption isotherms gave satisfactory fitting to the adsorption isotherm data.