The performances of binderless FAU-X monoliths (0.5 x 3 cm) build of nanocrystals featuring hierarchical trimodal porosity (micro-/meso-/macroporosity) in decontamination Cs-containing effluents have been evaluated. They have been compared to those obtained with newly synthesized FAU-X particles (1 mm) build with nanocrystals. Data have been confronted to those recently reported for a benchmark reference Cs + adsorbent Sorbmatech®, based on copper hexacyanoferrate nanoparticles (15 nm) immobilized into mesoporous silica particles (250-500 µm) (Cu-HCF@SiO 2 ). FAU-X monoliths show high rate of adsorption in batch in less than 2 min, much faster than Cs + adsorption in FAU-X particles (60 min). This result highlights the importance of a homogeneous macropore network in adsorbents to enhance mass transport and access to the zeolite active sites. FAU-X monoliths with 20 µm macropore diameter have been used in continuous flow experiments for sequestering Cs + (0.5 mmol/L) in mineral drinking water containing competing cations (Ca 2+ , Mg 2+ , Na + , K + ) with flow rates of 0.5 to 1 mL/min, corresponding to Darcy rates of 1.5 -3 m/h. FAU-X monoliths are very efficient for Cs + removal and show ideal steep breakthrough curves characteristic of fast diffusion. FAU-X monoliths are as excellent as Cu-HCF@SiO 2 and could represent an alternative adsorbent for safer processes, avoiding the handling of powders or particles. Above all, this study reveals the unique hydrodynamic behavior of FAU-X monoliths and opens the route for process intensification using FAU-X in continuous flow.