An innovative cost-effective and lead-free polymer nanocomposite of polyvinyl alcohol/ polyvinyl pyrrolidone was developed. PVA/PVP nanocomposite film contained spherical AgCl and SnO₂ nanoparticles was facilely prepared via a one-pot synthesis method. The synthesis route affords uniform dispersion of the both nanoparticles and unique features of polymer nanocomposite of insoluble, dense, and nonporous properties. The new nanocomposite achieved an efficient gamma radiation attenuation capability. The attenuation capacity for gamma photons was investigated in terms of linear and mass attenuation coefficients (µ) and (µ_m), respectively, at low and high energies (using ⁶⁰Co and ¹³⁷Cs sources). Other parameters such as half value layer (HVL), tenth value layer (TVL), and mean free path (MFP) were used to evaluate the shielding capacity. Theoretical calculation (XCOM program) results were consistent with the obtained experimental results. The results revealed that the essential thickness of the polymer nanocomposite to reduce the γ-ray intensity to 50% is 6.6, 8.9, and 9.8 cm for 662, 1173, and 1332 keV γ-ray energies, respectively. The physio-chemical properties of the polymer nanocomposite were evaluated using spectroscopic, microscopic, and thermal analysis tools. Additionally, the formation of spherical nanoparticles was elucidated using TEM. FTIR and leachability were used to confirm the stability, good durability, and chemical resistivity of the synthesized polymer nanocomposite. The nano-filler AgCl and SnO₂ formation mechanism was discussed in detail. Graphical abstract

Natural radioactivity, radiological hazard, and petrological studies of Homrit Waggat granitic rocks, Central Eastern Desert, Egypt were performed in order to assess their suitability as ornamental stone. On the basis of mineralogical and geochemical compositions, Homrit Waggat granitic rocks can be subdivided into two subclasses. The first class comprises granodiorite and tonalite (I-type) and is ascribed to volcanic arc, whereas the second one includes alkali-feldspar granite, syenogranite, and albitized granite with high-K calc alkaline character, which is related to post-orogenic granites. ²³⁸U, ²²⁶Ra, ²³²Th, and ⁴⁰K activities of natural radionuclides occurring in the examined rocks were measured radiometrically using sodium iodide detector. Furthermore, assessment of the hazard indices—such as: annual effective dose (AED) with mean values (0.11, 0.09, 0.07, 0.05, and 0.03, standard value = 0.07); gamma radiation index (Iγ) with mean values (0.6, 0.5, 0.4, 0.3, and 0.14, standard value = 0.5); internal (Hin) with mean values (0.6, 0.5, 0.4, 0.3, and 0.2, standard value = 1.0); external (Hex) index (0.5, 0.4, 0.3, 0.24, and 0.12, standard value = 1.0); absorbed gamma dose rate (D) with mean values (86.4, 75.9, 53.5, 43.6, and 20.8, standard value = 57); and radium equivalent activity (Raeq) with mean values (180, 154, 106.6, 90.1, and 42.7, standard value = 370)—were evaluated with the knowledge of the natural radionuclides. The result of these indices falls within the acceptable worldwide limits. Therefore, we suggest that these rocks are safe to be used in industrial applications.

Bioleaching, in the scope of biotechnology, is one of the promising technologies, which can be utilized for extracting valuable radioactive metal (uranium) from other radioactive ones. Also, it considered as an economical way to recover uranium from low-grade ores after the depletion of high grade uranium deposits. The aim of the work is to explore the formation and composition of the bioprecipitate from low-grade uraniferous rock sample through the bioleaching process using fungi. Furthermore, to identify the radionuclides distribution during work stages using the Hyper Pure Germanium detector. The results showed that; Aspergillus niger accomplished 71.4% of uranium recovery, as well as, formation of stable organo-uranyl complex. The obtained bioprecipitate, composed of uranyl acetate hydrate, asserted that the uranium is nearly free from other radionuclides present in the original sample without any subsequent purification processes, whereas could not achieved by the conventional process of uranium recovery.

Ferruginous sandstone considered as a one of the economically significant uranium mineralized areas in the southwestern part of the Sinai that located at the lower member of Um Bogma Formation in Abu Thor area. The studied sample was characterized geologically as a sandstone rock contain 450 mg/kg of uranium. This work is aimed to compare between eco-friendly bioleaching and conventional leaching processe. The uranium bioleaching efficiency achieved 80% by using a native fungal strain; Aspergillus nidulans as a green technology with the optimimum conditions as; 3 pH value, 3% pulp density, 7 days incubation period, and 30 °C incubation temperatures. Whereas the traditional technique using alkaline and sulphuric acid leaching attained 68.5% and 95% respectively at the best condition. Finally, the shrinking core model was represented the layer diffusion process by acquiring apparent activation energy 18.28 and 16.82 kJ/mol for carbonate and sulphuric acid leaching, respectively.