Due to their low permeability and their high sorption properties, clay materials rich in smectite are often used as geochemical barrier in the case of waste landfill or waste water treatment. If these materials are well-known to adsorb cationic contaminants through ion exchange or by surface complexation, they appear to be less efficient to retain neutral or anionic compounds, such as pharmaceutical products (PP). Organoclays, hybrid materials based on clay materials and cationic surfactants, were proposed as realistic alternatives for the sorption of organic compounds and pharmaceuticals [1-3]. If their efficiency was highlighted in batch experiment conditions, no study stressed out the sealing performance of organoclays during percolation experiments, where the solution is constantly renewed. Thus, the aim of this work was first to characterize, through percolation experiments by using an œdometric cell coupled with an injection system under controlled pressure [4], the hydromechanical properties (swelling and hydraulic conductivity) of different organoclays prepared with various cationic surfactants. The hydromechanical properties determined by using pure water as injected solution and compared to the sodium exchanged smectite from Wyoming (Na-SWy2) appeared to be closely related to the nature of surfactant and its organization. The incorporation of surfactants within the interlayer space of the layered materials increases the hydraulic conductivity of about 100 times to that of the Na-SWy2 (k = 10-12 m.s-1). This significant increase of permeability will unfortunately lead to a lower interaction duration between organoclays and contaminants in solution, a disadvantage for sorption mechanism which was more particularly studied in the case of the amoxicillin, one of the most useful antibiotic for the treatment of several bacterial infections. [1] Akcay G., Kilinc E., Akcay M. (2009). The equilibrium and kinetics studies of fluorbiprofen adsorption onto tetrabutylammonium montmorillonite (TBAM). Colloid Surface A, 335, 189-193 [2] De Oliveira T., Guégan R. (2016) Coupled organoclay/micelle action for the adsorption of diclofenac. Environmental Science and Technology, 50, 10209-10215 [3] De Oliveira T., Guégan R., Thiebault T., Le Milbeau C., Muller F., Teixeira V., Giovanela M., Boussafir M. (2017). Adsorption of diclofenac onto organoclays: effects of surfactant and environmental (pH and temperature) conditions. Journal of Hazardous Materials, 323, 558-566. [4] Le Forestier L. Muller F., Villiéras F., Pelletier M. (2010). Textural and hydration properties of a synthetic montmorillonite compared with a natural Na-exchanged clay analogue. Applied Clay Science, 48, 18-25