Groundnut shells (GS) was used as a precursor to st udy the workability of H 3 PO 4 and ZnCl 2 treated activated carbon. Dye absorption was found to fit into Freundlich and Langmuir isotherms models. The results revealed that thermal ly cracked groundnut shell at 600 o C could serves as filter for the dye adsorption from water phase. Over 80 percent adsorption was reported by each adsorbent. Percentage of dye absor bed (%RE) by the absorbents, followed the trend: commercial > GS/ZnCl 2 > GS H 3 PO 4 > GS pyrolized. This follows that the adsorption b y pyrolized sample is onto a surface of least heterog eneity. The same sample present least value of adsorption intensity (n = 1/1357 or 0.734). This ev idently proves the role played by activation. Furthermore, the percentage burn off, effect of car bon dose and effect of initial concentrations were also estimated. It was generally proven that t he sorted biomass could be a potential precursor for generating activated carbon used for waste dye affluent treatment.