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In this study, a porous adsorbent was synthesized hydrothermally from a molar composition gel of 10Na2O:Al2O3:100SiO2:2000H2O:20TPABr. X-ray diffraction confirmed the presence of a ZSM-12 zeolite phase, and nitrogen adsorption analysis revealed a Brunauer–Emmett–Teller specific surface area of 343.7 m2/g for the synthesized material. The ZSM-12 zeolite was then used for the recovery of uranium(VI) from aqueous solutions with initial uranium concentrations of 10 and 150 mg/L. Operating parameters such as pH, contact time, solid/liquid ratio, and temperature were systematically investigated. The optimum conditions were found to be consistent for both concentrations, with a pH value of 3, a contact time of 60 min, and a temperature of 20 °C. However, the solid/liquid ratio varied from 5 g/L for 10 mg/L uranium concentration to 8 g/L for 150 mg/L concentration. The Langmuir isotherm was well matched by ZSM-12, and its kinetics were consistent with the pseudo-second-order model. The adsorption of uranyl ions by ZSM-12 material is spontaneous, and both chemisorption and physisorption processes occur simultaneously during the adsorption. The thermodynamic parameters indicate that the adsorption of U(VI) on ZSM-12 is exothermic. The negative value of ΔS° indicates that the system disorder and randomness decrease as the adsorption proceeds and the liquid phase adsorbate components are immobilized on the surface of the adsorbent material.

The present work deals with the investigation of the use of the elaborated aluminophosphate (AlPO$_{4}$-5) and silico-aluminophosphate (SAPO-5) materials, in uranium sorption from aqueous solution and real effluents obtained from Nuclear Research Center of Draria, Algiers, Algeria. The surface charge and acidic–basic character of AlPO$_{4}$-5 and SAPO-5 is investigated by the determination of point of zero charge. Batch adsorption experimental studies are carried out to evaluate the influence of initial uranium concentration, final solution pH, contact time, solid-to-liquid ratio and temperature. A maximum adsorption capacity of 61.96 and 74.10 mg/g was obtained for AlPO$_{4}$-5 and SAPO-5 respectively, at pH 7 with an adsorbent ratio of 0.1/150 g/ml and an equilibrium time of 120 min. Kinetic models (pseudo-first order, pseudo-second order and Weber–Morris) are applied to find the mechanism for the removal of uranium ions, experimental data are analyzed by equilibrium models (Langmuir, Freundlich, Dubinin–Radushkevich and Temkin). Modeling sorption results show that uranium sorption is a chemical and endothermic process. The results showed that AlPO$_{4}$-5 and SAPO-5 are effective materials for the removal of uranium (VI) ions.