Decontamination of actual radioactive wastewater containing 137 Cs using bentonite as a natural adsorbent: equilibrium, kinetics, and thermodynamic studies.

Autor: Muslim WA; Iraqi Geological Survey/Ministry of Industry and Minerals, Baghdad, Iraq., Albayati TM; Department of Chemical Engineering, University of Technology-Iraq, 52 Alsinaa St., PO Box 35010, Baghdad, Iraq. Talib.M.Naieff@uotechnology.edu.iq., Al-Nasri SK; Radiation and Nuclear Safety Directorate Al-Tuwaitha Nuclear Site/Atomic Energy Authority, Baghdad, Iraq.
Jazyk: angličtina
Zdroj: Scientific reports [Sci Rep] 2022 Aug 16; Vol. 12 (1), pp. 13837. Date of Electronic Publication: 2022 Aug 16.
DOI: 10.1038/s41598-022-18202-y
Abstrakt: Batch adsorption treatment using Iraqi bentonite as a natural adsorbent was adopted in this study to decontaminate actual 137 Cs radioactive wastewater from the Al-Tuwaitha Nuclear Research Center, located south of Baghdad. The bentonite characterization was applied before and after treatment, using chemical compositions analyses, X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), Brunauer-Emmett-Teller (BET) surface area analysis and Fourier-transform infrared spectroscopy (FT-IR). The batch adsorption mode was applied with the initial radioactivity concentration (1440.5 Bq/L), solid/liquid ratio (1 g/L), pH (6-8), contact time (1.5 h), and temperature (298°K). The adsorption experiments showed a decontamination removal efficiency of about 95.66% of 137 Cs. A Freundlich adsorption isotherm model was approved for the adsorption of 137 Cs, with a coefficient of determination R 2  = 0.998. A pseudo-second-order model fitted well with the adsorption of 137 Cs, with R 2  = 0.983. The positive value of ΔH° in the thermodynamic results indicated that the adsorption process was endothermic physisorption (ΔH° = 15.01 kJ mol -1 ), spontaneous and favorable (ΔG° = -7.66 kJ mol -1  K -1 ), with a very low degree of disorder (ΔS° = 0.076 kJ mol -1  K -1 ).
(© 2022. The Author(s).)
Databáze: MEDLINE
Externí odkaz:
Nepřihlášeným uživatelům se plný text nezobrazuje