The surface sorption nature of the activated carbon derived from Achyranthes aspera plant (ACAA) towards an anionic dye, Alizarin red S has been investigated by adopting batch modes of extraction using simulated water. The influence of various physicochemical parameters like pH, sorbent concentration, agitation time, temperature and initial concentration of the dye have been probed and the conditions have been optimized for the maximum removal of the dye. The effect of the presence of fivefold excess of co-ions on the % removal of the dye has been investigated. The adsorption data is analyzed for understanding the nature of adsorption using Langmuir and the Freundlich isotherms and found that the Langmuir model has better describes the adsorption process indicating the homogenous mono-layer nature of the adsorbate (Dye) layer on the adrsorbent, ACAA. The RL= 0.48 of the Langmuir model indicates that the adsorption of the dye is onto the surface of the active carbon, ACAA and further, the sorption of the dye is confirmed using FTIR data. The kinetics of adsorption has been analyzed using pseudo first order and pseudo second order models and observed that the adsorption kinetics follows pseudo second order as it has R2 vale: 0.9757 which approaches to 1. The thermodynamics parameters namely; ΔH, ΔS and ΔG revealed the spontaneous and endothermic nature of adsorption process. The procedures developed in this investigation have been applied to the samples collected from the effluents of textile industries and found to be successful.