Cadmium ions constitute a major threat to human health and the environment owing to their toxicity, bioaccumulation, and persistence in water bodies, causing renal dysfunction, cancer, and cardiovascular diseases. Hence, this study reports the facile fabrication of a novel sodium iron oxide silicate@amorphous sodium iron silicate product (S1) and its chitosan composite (S1@chitosan) for the high-performance separation of Cd(II) ions from aquatic environments. The Brunauer-Emmett-Teller surface area, total pore volume, and mean pore diameter of S1 were 94.97 m2/g, 0.5853 cm3/g, and 25.65 nm, respectively, while those for S1@chitosan were 30.94 m2/g, 0.09518 cm3/g, and 12.31 nm, respectively. The reduction in pore diameter, pore volume, and surface area confirms the successful functionalization of S1 with chitosan, as the chitosan coating partially blocks and fills the pores, reducing the available surface area and porosity. Also, scanning electron microscope (SEM) images revealed an uneven surface morphology for S1 and a more textured and rougher surface for S1@chitosan, supporting the incorporation of chitosan. Besides, energy-dispersive X-ray spectroscopy (EDX) and CHN analyses affirmed the existence of chitosan in the composite through the detection of carbon and nitrogen elements, characteristic of chitosan. The optimum conditions for the removal of Cd(II) ions were determined to be a contact time of 70 min for S1 and 50 min for S1@chitosan, a pH of 7.50, and a temperature of 298 K. The maximum sorption capacities were 284.09 mg/g for S1 and 389.11 mg/g for S1@chitosa. The removal mechanism for S1 primarily involves ion exchange, while S1@chitosan utilizes both ion exchange and complexation through the amino and hydroxyl groups of chitosan. Regeneration using HCl confirmed the effective reusability of both adsorbents over five successive cycles. The adsorption process was found to be chemical, exothermic, and best described by the pseudo-second-order kinetic model and Langmuir isotherm.

This study assessed the kinetics of natural gas hydrate (NGH) formation using N-benzyl-N, N-dimethyldodecan-1-aminium chloride (Benzalkonium chloride, Bzc) at concentrations ranging from 500 to 3000 ppm. It investigated its effects on the hydrate formation. These experiments were compared with pure water and sodium dodecyl sulfate (SDS) solutions at 298.15 K and 6.5 MPa. The findings indicate that the Bzc significantly enhances the formation kinetics and gas consumption of NGH. The 2500 ppm of Bzc notably reduced the induction time for hydrate nucleation up to 9.9 min. In contrast, it was 41.3 min with the SDS. The hydrate formation began at the gas/liquid interface and spread upward into the gas phase and downward into the liquid phase. The NGH dissociation and recovery were slower by the SDS among the Bzc solutions (smooth and fast). This observation indicates that the Bzc improves the formation and dissociation kinetics, making it a promising NGH formation and storage reagent. The results show that the Bzc significantly boosts the kinetics of NGH formation and dissociation at a small time and pressure. Providing valuable insights for optimizing hydrate technology.

Water scarcity and pollution pose significant challenges worldwide, necessitating innovative solutions for sustainable water supply. Traditional desalination methods have limitations in terms of energy consumption, fouling, and environmental impact. This study focuses on the synthesis and characterization of zinc-based metal-organic frameworks (Zn-MOFs) as advanced fillers for desalination techniques. Zn-MOFs were synthesized using a simple precipitation technique and characterized using techniques such as scanning electron microscopy, transmission electron microscopy, X-ray diffraction, and Fourier-transform infrared spectroscopy. The performance of Zn-MOFs was evaluated in terms of scale deformation experiments. The findings revealed that Zn-MOFs not only significantly reduce the concentration of Ca2⁺ ions responsible for scale (e.g., calcium carbonate scale) formation but also exhibit superior fouling resistance and high salt rejection capabilities. At a dosage of 3000mg/L and pH 7.5, a remarkable 99% removal efficiency was achieved for half-scale concentration (synthetic water was prepared by the following scale concentrations: 3665mg/L CaCl2, 685mg/L NaHCO3, and 12,000mg/L NaCl), while a 91.6% efficiency was obtained at normal scale concentrations (synthetic water was prepared by the following scale concentrations: 7330mg/L CaCl2, 1370mg/L NaHCO3, and 24,000mg/L NaCl). These results highlight the Zn-MOFs' advantages over conventional fillers and traditional techniques by offering improved stability, superior adsorption capacity, and enhanced scale management for desalination applications. This work contributes to advancing water treatment technologies by providing a more sustainable and effective approach for mitigating fouling and enhancing desalination efficiency.

This study focused on the synthesis of six bio-based zwitterionic surfactants derived from oleic acid to assess their applicability in different petroleum fields. The final bi-zwitterionic surfactants were synthesized from oleic acid, utilizing the double bond and carboxylic group. Friedel–Crafts alkylation, sulfonation, chlorination, amidation, and quaternization were performed to synthesize six bi-zwitterionic surfactants. The bi-quaternary surfactants derived from benzene are represented by the general formula Bi Q 10, BOAS (Amide), with the symbols BE, BP, and BPh. In contrast, those derived from naphthalene are represented by Bi Q 10, NOAS (Amide), with the symbols NE, NP, and NPh. The structures of these surfactants were confirmed using FT-IR and H1-NMR techniques. The surface activity and thermodynamic properties of the synthesized surfactants were analyzed through surface tension measurements conducted at various temperatures (30, 40, 50, and 60°C). Additionally, CMC, γCMC, πCMC, Γmax, Amin, and Pc20 were measured. The thermodynamic variables for micellization and adsorption were also measured. The structural effect of the obtained surfactants was assessed. The maximum value of the structural effect was 4.33 KJmol-1, corresponding to BE. The results indicated that the negative values of ΔGads were greater than the negative values of ΔGmic, indicating that these surfactants are absorbed in the interface prior to the formation of micelles. The more negative values of ΔGads suggest that these surfactants are strongly adsorbed onto solid particles, such as sands and rocks, indicating their potential utilization in oil production in different petroleum fields.

AbstractIn this study, we successfully synthesized gold nanoparticles (AuNPs) using an extract derived from Saudi chive. The synthesized AuNPs exhibited isotropic properties, with a consistent size distribution ranging from 12 to 26 nm and an average size of 19 nm, as confirmed by transmission electron microscopy (TEM) analysis. Ultraviolet–Visible (UV–Vis) spectroscopy revealed a strong surface plasmon resonance (SPR) band characteristic of isotropic AuNPs, further validating their formation. Additionally, X‐ray diffraction (XRD) analysis confirmed the crystalline nature of the synthesized nanoparticles, with diffraction peaks corresponding to the face‐centered cubic structure of gold. The growth of isotropic AuNPs suggests a homogeneous dispersion of the mold in the aqueous environment, a slower reduction rate of AuCl₄− ions, and the mold's capability to facilitate the internal formation of gold seeds. Remarkably, these AuNPs demonstrated potent bactericidal activity against antibiotic‐resistant Staphylococcus aureus, effectively inhibiting its growth. In contrast, the Escherichia coli bacterial strain remained unaffected by the presence of AuNPs.

Bimetallic nanoparticles (BMNPs) combine the desirable properties of two distinct metals that outperform conventional monometallic nanoparticles (NPs). This work presents a novel ecofriendly silver-copper (Ag-Cu) BMNPs synthesis using sunlight as a green reducing agent, enableing rapid Ag-Cu BMNPs formation at room temperature within 10min. This methodexploiting the facile reduction of Ag⁺ to Ag⁰, which subsequently mediates the reduction of Cu2⁺ to Cu⁰ via water radiolysis-generated species. The Ag-Cu BMNPs were integrated into two reusable catalytic membranes: PTFE@Ag-Cu, formed by immobilizing Ag-Cu BMNPs onto a polytetrafluoroethylene (PTFE) syringe filter, and ACF@Ag-Cu, synthesized via in-situ growth of Ag-Cu BMNPs on activated carbon fiber (ACF) cloth. PTFE@Ag-Cu displays exceptional performance and reusability, converting 2100mL of 0.15 mM p-nitrophenol to p-aminophenol over 105 cycles at a flow rate of 20mLmin-1. The Ag-Cu BMNPs also exhibit peroxidase-mimic activity, enabling colorimetric H2O2 detection with a range of 0-200 mM and a limit of detection (LOD) of 13.3 µM in solution. Further, the Ag-Cu nanoenzyme demonstrates strong potential for electrochemical glucose detection, achieving an LOD of 0.1 µMand sensitivity of 5221µA × 10-6 m⁻1 cm⁻2.

This work introduces a novel synergistic approach for enhanced scale formation inhibition in desalination processes by employing a PVC-PVA@Chitosan Quantum Dot (PVA-PVC@CS QD) membrane, advancing sustainable water purification technologies further. The membrane's unique composition surpasses conventional membranes by fusing the exceptional properties of chitosan quantum dots with the robustness of polyvinyl alcohol (PVA) and polyvinyl chloride (PVC). The study investigates the mechanical, thermal, and electrical properties of the membrane in order to completely understand its behavior in desalination applications, as well as how well it inhibits the formation of scale, particularly calcite scale. In water purification systems, the membrane's durability and fouling resistance, which are assessed mechanically, are critical to long-term performance. Ion transport is facilitated by the membrane's capacity to maintain selectivity and its ability to support efficient desalination processes is assessed by examining its electrical properties. Experimental results demonstrate that the PVA-PVC@CS QD membrane outperforms conventional membranes in terms of scale inhibition due to the synergistic interactions among its constituents.