Characterization of technically enhanced- naturally occurring radioactive materials waste and removal of some of their radionuclides / Hanan Mohamed Abdelbary Abdelaziz ; Supervised Gehad Genidy Mohamed , Moustafa A. Hilal

Thesis (M.Sc.) - Cairo University - Faculty of Science - Department of Inorganic Chemistry

In this thesis, TE-NORM waste associated with oil and gas production from Ras Shukeir in Egypt, has been characterized in terms of chemical and radiological analysis. The obtained results indicated that, scale of the TENORM waste were mixture of carbonate, silicates and others. All TE-NORM samples, were found to contain enhanced radioactivities due to presence of the primordial radionuclides of the three naturally occurring decay series, namely uranium, thorium and actinium decay series with radium isotopes present in all of them as well as K-40. TE-NORM waste was separated for seven particle size from 112 to 1000 om and each fraction was measured using XRD, XRF and Þ- spectroscopy techniques. The radioactivity concentrations of the different TENORM samples were determined by Þ-ray spectrometer with HPGe-detector. The radioactivity of Ra-226, Th-232 and K-40 ranged from 14.1±0.4 to 28.9±0.9 kBq/kg, from 5.0±0.2 to 9.5±0.4 and 0.25±0.02 to 0.43±0.02 kBq/kg, respectively, in scale waste. Since the concentrations of Ra-226 and Th-232 were found to exceed the permissible levels by the international regulations. Leaching of radium from scale TE-NORM waste by different aqueous reagents (water, mineral acids, organic acids and inorganic salts) has been performed. The studies showed that the optimum conditions were 2 hours, 2±0.1 and 35±1{u00BA}C for contact time, pH and temperature, respectively. It was found that the maximum leachability percentages of radium were 40, 90, 27.4, 31.4, 30.9, 25.3 % using 7 M of hydrochloric acid, 7 M nitric acid, 5 M acetic acid, 0.05 M salicylic acid, 0.2 M citric acid and (15% acetic acid + 2% KMnO₄) solutions at the optimum conditions, respectively

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