Blast furnace slags (BFSs), significant by-products of the steel industry, represent a valuable, underutilized resource for environmental applications, particularly in adsorption. While raw BFSs have inherent limitations, their reactivity and performance as adsorbents can be substantially enhanced through mechanical, thermal, or chemical activation processes. This study delves into understanding the microstructural and compositional changes induced by various activation methods and their direct impact on the adsorption capacity of the slags. To comprehensively evaluate and quantify these transformations, the main objective of this research is to investigate the effect of local materials, specifically co-products from the El-Hadjar steel company (Annaba steel plant). We employed advanced characterization techniques such as X-ray Diffraction (XRD) for physical and chemical characterization, and used Scanning Electron Microscopy (SEM), Thermogravimetric Analysis (TGA), and specific adsorption tests for the identification of different chemical bonds. The primary objective is to demonstrate how activation transforms a material often considered waste into an efficient and cost-effective adsorbent. This valorization of BFSs not only contributes to the circular economy but also offers sustainable solutions for pollution control and environmental remediation. Future prospects for this research include further optimizing activation processes and exploring novel high-value applications for BFSs, such as the removal of emerging pollutants or the recovery of valuable resources