The characteristics of the activated carbon and the changes in that of the modified activated carbon were verified by SEM, EDX, XRD, XPS, BET and FT-IR analyses;·The SEM studies indicate the formation of regular structure with net thin fibrils of AC; and spherical shape and smaller than 18nm in size of porous surface created in AC-MnO2-NC. The EDX studies show the presence of the elements, Carbon, Oxygen, Sodium, Magnesium, Phosphorous, Sulphur, Chlorine, Potassium and Calcium in AC. In case of AC-MnO2-NC in addition to these elements, the capping Manganese is proved. The XRD studies indicate the formation of short range crystalline structure and abundance of amorphous structure of the activated carbon and the modified activated carbon. The presence of Carbon and Oxygen in the activated carbon and in addition to these elements, the presence of Manganese in the modified activated carbon are also revealed by XPS studies. The BET studies show that the surface area of AC is 83.54m2/g and that for AC-MnO2-NC is 147.76m2/g. The FT-IR study suggest that the capping of MnO2 in modified activated carbon and the presence of the functional groups viz., -OH, -C=O, -C=C, -C-H, -CH2, -CH3 in the two adsorbents. The percentage of dye removal increases with increasing agitation time and adsorbent dose and decreases with increasing initial dye concentration. An increase in the time of agitation was found to be directly proportional to the amount of dye adsorbed per unit weight of the adsorbent. The adsorption of dyes from aqueous solutions attain equilibrium at different agitation time which depend on initial dye concentrations and initial pH of the dye solutions.