In this research work, new composite materials based on magnesium phosphate cement (MPC) were developed to evaluate the retention of fluorine from wastewater. This material was prepared with dead burned magnesia oxide (MgO), ammonium dihydrogen phosphate (NH₄H₂PO₄), and some retarding agents. We chose to synthesize with hydrogen peroxide instead of water; alumina and zeolite were also added to the cement. The obtained optimal conditions were studied and analyzed by X-ray diffraction (XRD) and scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), BET, and thermogravimetric analysis (TGA). The adsorbents showed a strong ability to remove fluoride from contaminated water, and the best defluoridation capacity was evaluated as 2.21 mg/g for the H₂O₂ cement. Equilibrium modeling was performed, and the experimental data were presented according to the isotherms of Langmuir, Freundlich, Temkin, and Dubinin–Radushkevich.

In this study, we used a novel composite material based on magnesium phosphate cement (MPC) to explore the retention of fluoride from used water. Dead-burned magnesium oxide (MgO), ammonium dihydrogen phosphate (NH₄H₂PO₄), and a few retarders were used to create this particular substance. Several studies have corroborated the performance of using aluminum in the capture of fluoride. From this perspective, we attempted to reinforce our matrix with different quantities of aluminum, which increased the resistance of the composite in water. The optimal conditions that were obtained were evaluated and scrutinized using a range of techniques, including scanning electron microscopy (SEM), X-ray diffraction (XRD), thermogravimetric analysis (TGA), Fourier transforms infrared spectroscopy (FTIR), and Brunauer–Emmett–Teller (BET). The adsorbents demonstrated a powerful ability to remove fluoride from contaminated water and the defluoridation capacity was evaluated at 4.84 mg/g. Equilibrium modeling was carried out, and the experimental data were expressed in accordance with the Langmuir, Freundlich, Temkin, and Dubinin–Radushkevich isotherms.

This work investigates the influence of spark plasma sintering (SPS) parameters on the microstructure and mechanical properties of consolidated aluminum powders processed by high-energy ball milling under an air atmosphere. Sintering was performed under vacuum at various temperatures ranging from 550 °C to 625 °C and under pressures between 50 and 100 MPa. The particle size, crystallite size, and microstructure of the powders and the consolidated pellets were analyzed using laser granulometry, X-ray diffraction (XRD), scanning electron microscopy (SEM), and Archimedes’ density measurements. Mechanical properties were evaluated via Vickers microhardness, nanoindentation, and tribological testing. For comparison, unmilled aluminum powders were also consolidated and characterized. After 46 h of milling, the aluminum crystallite size was reduced from 74 nm to 68 nm. The sample’s density increased with higher sintering temperature and pressure. The aluminum sintered at 600 °C and 100 MPa after 46 h of milling exhibited the highest microhardness (187.5 HV). Nanoindentation tests were conducted to characterize different microstructural regions formed after SPS, revealing two distinct zones: one hard and one soft. The tribology results revealed that the SPS-consolidated samples of milled powders exhibited a reduction of 50% in specific wear rate and a reduction of 20% in the coefficient of friction compared to the SPS-sintered samples of unmilled powders.

In the present study, we explore the synthesis and characterization of novel composite materials derived from magnesium phosphate cement by incorporating varying quantities of aluminum, iron oxide, or alumina. These composites demonstrate promising properties related to water resistance and significant specific surface areas. Furthermore, our investigations reveal that aluminum, iron oxide, and phosphate constituents exhibit an affinity for fluoride retention. Consequently, we apply these synthesized materials for fluoride adsorption. Our results indicate a noteworthy adsorption capacity, ranging from 2.35 mg/g for cement synthesized with 0.25 g of aluminum to 4.84 mg/g for materials synthesized with 1.5 g of aluminum. The influence of incorporating alumina or iron oxide into these matrices is thoroughly examined. Additionally, we investigated the optimal conditions utilizing a range of analytical techniques, including scanning electron microscopy (SEM) equipped with an energy dispersive spectrometer (EDS), the Brunauer–Emmett–Teller (BET) method, X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), and thermogravimetric analyses (TGA). To further elucidate this process, we perform equilibrium modeling and present experimental data in accordance with the Langmuir, Freundlich, Temkin, and Dubinin–Radushkevich isotherms.

A serious risk that harms the safe use of water and affects aquatic ecosystems is water pollution. This occurs when the water’s natural equilibrium is disrupted by an excessive amount of substances, both naturally occurring and as a byproduct of human activities, that have varied degrees of toxicity. Radiation from Cs isotopes, which are common components of radioactive waste and are known for their long half-lives (30 years), which are longer than the natural decay processes, is a major source of contamination. Adsorption is a commonly used technique for reducing this kind of contamination, and zeolite chabazite has been chosen as the best adsorbent for cesium in this particular situation. The purpose of this research is to investigate a composite material based on magnesium phosphate cement (MPC). Magnesium oxide (MgO), potassium dihydrogen phosphate (KH₂PO₄), and properly selected retarders are used to create the MPC. The optimal conditions for this composite material are investigated through the utilization of X-ray diffraction, scanning electron microscopy, BET surface area analysis, and atomic absorption spectroscopy. The principal aim is to enable innovations in the elimination of radioactive waste-contaminated water using effective cesium removal. The most promising results were obtained by using KH₂PO₄ as an acid, and MgO as a base, and aiming for an M/P ratio of two or four. Furthermore, we chose zeolite chabazite as a crucial component. The best adsorption abilities for Cs were found at Q_ads = 106.997 mg/g for S₂ and Q_ads = 122.108 mg/g for S₁. As a result, zeolite is an eco-friendly material that is a potential usage option, with many benefits, such as low prices, stability, and ease of regeneration and use.

Hot Consolidation (HC) was employed to prepare high-performance aluminum matrix composites reinforced with mechanically alloyed powders. Two different reinforcements, Al₆₅Cu₂₀Nb₁₅ and Al₆₅Co₂₀Nb₁₅, synthesized by high-energy ball milling, were incorporated into an Al₉₅(AlSi)₅ matrix at 20 wt% after homogenization in a Turbula WAB mixer for 2 h. Microstructural characterization using laser granulometry, scanning electron microscopy, and X-ray diffraction confirmed significant particle refinement and the formation of stable intermetallic phases during milling. The Al₆₅Cu₂₀Nb₁₅ system showed the formation of Al₂Cu and Nb-containing intermetallic compounds, while the Al₆₅Co₂₀Nb₁₅ reinforcement phases such as Al₃Nb, AlNb₂, and Al₁₃Co₄ were identified. The consolidated composite exhibited high densification levels, reaching relative densities of 99.6% and 96.77% for composite 1 and composite 2, respectively. In addition, the Vickers hardness increased significantly compared with the unreinforced aluminum matrix, attaining values of 96.34 HV and 68.28 HV for composite 1 and composite 2, corresponding to hardness improvement of approximately 182% and 100%, respectively. The superior densification and hardness of composite 1 were attributed to enhanced interfacial bonding, refined microstructure, and the effective strengthening effect of reinforcement phases. These results demonstrate that the combined use of high-energy mechanical alloying and Hot Consolidation proved to be an efficient approach for producing lightweight aluminum matrix composites with improved microstructural and mechanical properties suitable for advanced structural applications.