In this research, the MnO(2)NPs-AgX zeolite as a novel composite adsorbent was synthesized and identified via Scanning electron microscopy (SEM), Atomic adsorption spectrometry (AAS), X-ray diffraction (XRD) and Fourier transform infrared (FTIR) techniques. Furthermore, the removal of radioactive strontium-90 (Sr-90) from drinking tap water of Ramsar city was investigated via the synthesized MnO2NPs-AgX zeolite composite. A single radiometric technique, Ultra Low-Level Liquid Scintillation Counting (LSC), was also exerted to monitor the reaction progress. The obtained results revealed that the Sr-90 was perfectly removed after 8 h by the MnO(2)NPs-AgX zeolite composite. Also, the reaction kinetic information was studied applying pseudo first and second order kinetic Elovich and Intra particle diffusion kinetic models. The adsorption kinetics of Sr-90 was matched appropriately to the pseudo second order kinetic model. Further, the evaluation of the thermodynamic parameters such as AG, AH and AS, specified that the adsorption procedure of Sr-90 was spontaneous and illustrates physical adsorption properties and exothermic nature of the adsorption. It is emphasized that the MnO(2)NPs-AgX zeolite as a novel composite represents a high capacity and potential for the removal of radioactive Sr-90 from drinking water samples. (C) 2017 Elsevier B.V. All rights reserved.