<p>A solution to the environmental issues is the valorisation of the agro-industrial residues as an association is made between the waste management and the resource recovery. Spent coffee grounds (SCG) have received special concern as a potentially good source of adsorbent, because of their comparably large supply, naturally formed carbon based, and desirable surface performance. However, the low porosity, surface area, adsorption capacity and functional groups such as including hydroxyl (–OH), carboxyl (–COOH), and carboxyl (C=O) do not allow the direct utilization of Spent coffee grounds. In order to address these limitations, chemical activation through pre and post treatment techniques with chemical activating reagents such as alkaline, acidic, metal oxide, and carbonate (H₃PO₄, KOH, K₂CO₃, Fe₂O₃, ZnO, MgCO₃) have been studied to improve structural and chemical properties of spent coffee grounds. The results from the mechanism of activations have been elaborated in present study in concern with enhanced surface area, formation of clear and distinct microporous and mesoporous pore structures, functional group modification (such as forming P₄O₁₀, and forming alcohol, hydroxyl, saturated hydrocarbon, unsaturated hydrocarbon, aromatic ring and ether groups) are improvement in the result among adsorption capacity. This paper has focused on the activation techniques of SCG using different activating agents and their influence on the development of the pore, surface modification, and adsorption capability for different types of pollutant in waste water.</p>