Decolorization of Dye Wastewater by Activated Carbons Produced from Peanut Shell using ZnCl2 Impregnation Method

Abstract

This study assessed the adsorption capacity of different activated carbons produced from peanut shell for S3B dye (Sunfix Red 150%) present in dye wastewater under different contact conditions. The pre-impregnation of input material by ZnCl2 (weight ratio 1:1) increased surface charge of produced activated carbon to positive value; While activated carbons produced from non-impregnation and post-impregnation procedures had negative charge. The optimal adsorption conditions were at pH 5 with 10 g/L activated carbon in original dye wastewater ,  for 180 minute contacting time. Under the optimal conditions, pre-impregnated activated carbon had highest adsorption capacity, corresponding to80.2% S3B dye removal; while the two other types of activated carbons obtainedabout 40% dye removal. The adsorption process suited to Freundlich isotherm model (multilayer adsorption) with KF adsorption constants being 0.0377, 0.3314 and 0.0523 for non-, pre- and post-impregnated activated carbons, respectively.