Removal of Cr (VI) and COD from Electroplating Wastewater by Corncob Based Activated Carbon

In the present work, hexavalent chromium and COD removal from electroplating wastewater was investigated using a low cost Corncob based activated carbon (CAC). 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 found 399.006 m2 /g and 0.23 cm3 /g respectively. The effect of various parameters such as temperature (T), adsorbent dose (w), pH and contact time (t) on adsorption of chromium ions by CAC was investigated. The optimum pH ≈3.0 is found for the removal of Cr (VI) and COD for optimum dose of CAC (15 Kg/m3 ). Various isotherm models were fitted for Cr (VI) and COD removal. Freundlich model well fitted to Cr (VI) adsorption while Redlich-Peterson is found to be fit for COD removal. Pseudo-second order kinetic model was well fitted for both Cr (VI) and COD removal.