ADSORPTIVE REMOVAL OF HEXAVALENT CHROMIUM (VI) FROM TANNERY WASTE WATER

Abstract

In the present work, hexavalent chromium removal from tannery wastewater was investigated using a low cost activated carbon, carbonized and prepared from corncobs. Corncob based activated carbon (CAC) was characterized to understand the adsorption characteristics of chromium (VI) ions and its physiochemical properties. The particle size of CAC was in the range of 450-850 μm. Proximate and ultimate analysis of CAC showed the presence of high carbon content. BET surface area and pore volume were 400.006 m2/g and 0.23 cm3/g respectively. The effect of parameters such as temperature (T), adsorbent dose (w), pH and contact time (t) on adsorption of chromium ions by CAC was investigated. The pH ≈4.0 is found to be optimum for the removal of Cr(VI) from waste water by CAC at an optimum dose of 15 Kg/m3. Optimum value of contact time is found as 5 hr. Various isotherm models were fitted for Cr(VI) removal. Freundlich model well fitted to Cr(VI) adsorption. Pseudo-second order kinetic model was well fitted for Cr(VI). Thermodynamic parameters represent the exothermic and spontaneous nature of adsorption