Mostafa A. Masoud

For the first time, this study explores the valorization of graphite schist (GS), a metamorphic rock, as a novel supplementary cementitious material (SCM) in concrete. Portland cement (PC) was partially replaced with GS at 0, 10, and 15% by mass to prepare CC (control), GC10, and GC15 mixes, respectively. Physical, mechanical, hydration, microstructural, and radiation shielding properties were investigated. GS showed superior particle fineness, higher surface area, notable antifungal activity, and remarkable thermal stability up to 800 °C, outperforming PC in several aspects. Unlike GC15, GC10 achieved sustained compressive strength, closely related to that of CC. Microstructural analysis revealed that GS functioned mainly as a filler with limited pozzolanic reactivity, contributing moderately to particle packing. However, unhydrated cement particles and weakened interfacial transition zones were more prevalent at 15% GS. The improved performance of GC10 over curing periods reflected the more favorable influence of 10% GS on hydration and microstructure. Moreover, GS incorporation slightly improved fast neutron attenuation but reduced gamma-ray shielding due to increased porosity and reduced density. Overall, GS can be a promising multifunctional SCM, offering antifungal potential, acceptable neutron shielding, balanced strength, and reduced PC usage at 10% replacement.

This study explores the potential of utilizing weathered basalt waste, discarded from basalt stone quarrying, as a resource for producing efficient adsorbents to remove Fe (III) and Zn (II) from aqueous and real wastewater. Raw weathered basalt (RWB), and its calcined derivatives at 750 °C for 3 h (CWB-750) and at 950 °C for 1 h with activated carbon impregnation (CWB/AC-950), were prepared and characterized. Characterization using XRD, FTIR, SEM, and surface area analyzer revealed that calcination improved porosity and surface area with some privilege for CWB/AC-950. CWB/AC-950 revealed remarkable removal efficiency for Fe (III) at a pH value of 5, achieving 98.30%, closely matching that of RWB (98.00%), and outperforming CWB-750 (96.20%). In contrast, RWB exhibited the highest removal capacity for Zn (II) at a pH value of 6, with an efficiency of 55%, surpassing both CWB-750 and CWB/AC-950, which achieved approximately 36%. For both contaminants, Pseudo-2nd-order equation (R ² > 0.98) provided a superior fit, showcasing favorable sorption process by all the addressed materials. The Fe(III) sorption data for all the investigated materials were better described by the Freundlich (FL) model compared to the Langmuir (LM) model. Similarly, the Zn(II) sorption data for the calcined derivatives (CWB-750 and CWB/AC-950) were well-explained by the FL model. These findings are supported by the very high determination coefficients (R ² > 0.96) and significantly lower average relative error (ARE) values (8.66 and 13.69) compared to those obtained from the LM model (55.99 and 189.25, orderly). In contrast, for RWB, despite the very high R ² values (> 0.98) for both models, neither adequately captured the Zn(II) sorption behavior, as evidenced by the exceptionally high ARE values (52.67 and 161.19 for LM and FL, respectively). These findings are supported by the very high determination coefficients (R ² > 0.96) and significantly lower average relative error (ARE) values compared to those obtained from the LM model. In contrast, for RWB, despite the very high R ² values (> 0.98) for both models, neither adequately captured the Zn(II) sorption behavior, as evidenced by the exceptionally high ARE values (52.67 and 161.19 for LM and FL, respectively). The remediation mechanism of both Fe (III) and Zn (II) by all adsorbents was not exclusively governed by inter-particle diffusion. Eventually, these findings highlight the sustainable potential of repurposing RWB waste and its calcined derivatives for water remediation applications.

The rapid expansion of textile industries has contributed significantly to non‐biodegradable waste generation, presenting a global environmental challenge. Additionally, waste from the mining industry, such as chrysotile serpentine, contributes to this environmental issue. Therefore, this study investigates the possibility of recycling polyamide 6 waste combined with chrysotile serpentine waste to produce nanotextile fabric‐based composite (NTF‐BC). This study highlights the environmental significance of sustainable techniques in waste management specifically within the textile industry. The chrysotile serpentine waste was intensively pulverized into nanoscale particles to eliminate its hazardous fibrous nature and facilitate the electrospinning process. Comprehensive characterization was conducted using various analytical techniques including XRD, XRF, FT‐IR, SEM, BET, and DMA, to explore the properties of prepared fabrics as a function of electrospinning parameters (Ctl.Sp concentration, spinning distance, applied voltage, and flow rate.). SEM analysis indicated optimal fabrication conditions for smoother and more homogeneous NTF‐BC at Ctl.Sp concentration of 7.5%, voltage of 20 kV, spinning distance of 15 cm, and flow rate of 1 mL/h. XRD and FT‐IR analyses showed that increasing the Ctl.Sp ratio, distance, and voltage negatively affected sample crystallinity and favored the α‐form over the γ‐form. In terms of DMA characteristics, the Ctl.Sp ratio and applied voltage positively impacted the E′ values, with minimal influence from spinning distance and rate. Notably, the highest geometric properties (i.e., S_BET and V_t) of the fabricated NTF‐BC were attained at the lowest Ctl.Sp ratio of 5%.

This study comprehensively evaluates the radiation attenuation efficiencies of hematite and barite, commonly used materials in radiation shielding, using theoretical and simulation investigations. The MCNP-5 code was used to obtain the linear attenuation coefficient (LAC) within the energy range of 0.015–15 MeV, with validation by the XCOM program. Based on these LAC values, various gamma-ray shielding parameters were determined: mass attenuation coefficient, half-value layer, radiation protection capacity, mean free path, transmission factor, and equivalent thickness to lead (ET_Pb). Additionally, effective atomic number (Z_eff) and electron density (N_eff) were calculated, including both single-energy and energy-dependent forms for photon absorption and interaction. Furthermore, MCNP-5 simulations and NGCal program calculations were used to assess thermal neutron attenuation, while the NXcom program determined fast neutron behavior. This analysis revealed superior γ-ray shielding for barite compared to hematite. Similarly, the NXcom program indicated better fast neutron shielding for barite. However, interestingly, simulations validated a 210% higher effectiveness in thermal neutron attenuation for hematite. Finally, comparing the studied materials with other shielding materials demonstrated promising potential as environmentally friendly alternatives for effective shielding against various radiation types.