Groundnut shells (GS) was used as a precursor to study the workability of H3PO4 and ZnCl2 treated activated carbon. Dye absorption was found to fit into Freundlich and Langmuir isotherms models. The results revealed that thermally cracked groundnut shell at 600oC could serves as filter for the dye adsorption from water phase. Over 80 percent adsorption was reported by each adsorbent. Percentage of dye absorbed (%RE) by the absorbents, followed the trend: commercial > GS/ZnCl2 > GS H3PO4 > GS pyrolized. This follows that the adsorption by pyrolized sample is onto a surface of least heterogeneity. The same sample present least value of adsorption intensity (n = 1/1357 or 0.734). This evidently proves the role played by activation. Furthermore, the percentage burn off, effect of carbon dose and effect of initial concentrations were also estimated. It was generally proven that the sorted biomass could be a potential precursor for generating activated carbon used for waste dye affluent treatment.