BTEXs are prevalent contaminants at petrochemical sites, posing significant environmental and health risks due to their toxicity and mobility in soil and groundwater. This thesis examines the use of a commercial colloidal activated carbon (CAC) as an injectable reactant in the form of a water-based colloidal suspension, which is injected into the contaminated aquifer forming a treatment zone, and acts by adsorbing the BTEX present in groundwater, immobilizing them. The applications of CAC in environmental remediation are increasing in number thanks to its high surface area and strong adsorptive capacity. Conducted under the supervision of the Groundwater Engineering Group at Politecnico di Torino and Arcadis in Germany, this research included laboratory tests aimed at assessing the CAC colloidal stability and mobility in porous media, identifying 1 g/l as the optimal concentration for testing.