Isothermal, kinetic, and thermodynamic studies for solid-phase extraction of uranium(VI) via hydrazine-impregnated carbonbased material as efficient adsorbent

The current study describes the application of a new extraction method for efficient uranium adsorption via cost-effective hydrazine-impregnated activated carbon.Various experimental parameters such as time, adsorbent weight, temperature(°C), and uranium concentration were thoroughly investigated. The synthesized adsorbent was characterized via X-ray diffraction, Fourier transformation infrared spectroscopy(FT-IR), scanning electron microscopy, and thermogravimetric analysis. The results showed86% uranium extraction under optimized conditions(20% P2O5 at 25 °C, 120 min). The obtained findings fit well with thermodynamic and isothermal(Langmuir and Freundlich isotherms) models and pseudo second-order kinetics. In thermodynamic studies, the negative sign of(DG°) specified the spontaneity of process, the negative sign of(DH°) revealed endothermicity, and the positive sign of(DS°) showed high randomness after adsorption.