Large-scale mining of graphite, a crucial strategic mineral, generates substantial amounts of graphite tailings (GT). The stockpiling of this solid waste occupies vast land resources and poses persistent environmental risks due to potential heavy metal leaching. Repurposing GT into construction materials presents a promising solution, with its use as a partial replacement for fine aggregates in cementitious composites being one of the most effective methods. This review systematically consolidates current research on graphite tailings cement mortar (GTCM) and graphite tailings concrete (GTC). Due to its physicochemical properties comparable to natural sand, GT is suitable for producing building materials. Studies consistently demonstrate that a substitution level of 10% to 20% optimizes overall performance. This optimal range enhances particle packing, promotes cement hydration via pozzolanic activity, and refines the microstructure, leading to improved workability, superior mechanical strength, and enhanced durability, including resistance to permeability, freeze–thaw cycles, and chemical attacks. Moreover, the inherent carbon content imparts electrical conductivity to GTC, enabling functional applications like de-icing and structural health monitoring. The successful utilization of GT also extends to lightweight foamed and autoclaved aerated concrete. However, research on the structural behavior of GTC components remains limited. Preliminary findings on beams and columns are encouraging, but comprehensive studies on their seismic performance and design methodologies are urgently needed to facilitate the widespread engineering application of this sustainable material and mitigate the environmental impact of tailings accumulation.

Green solvents for the extraction and bioutilisation of metals from coal fly ash by Magnetospirillum gryphiswaldense MSR1.

Phosphogypsum, the primary solid waste from the wet-process phosphoric acid industry, poses significant environmental and health risks due to large-scale stockpiling. To promote its resource utilisation, this study systematically evaluated the solidification and stabilisation performance of phosphogypsum–coal fly ash cementitious material (PAC) for Cr(VI)-contaminated soil under high-chloride conditions. Phosphogypsum reactivity was enhanced via mechanical activation and high-temperature calcination. An orthogonal experimental design was employed to analyse the effects of multiple factors—including calcination temperature and duration—on compressive strength and heavy metal leaching behaviour. Results show that PAC prepared from coal ash calcined at 600 °C for 3 h exhibits excellent mechanical properties and Cr(VI) stabilisation efficacy under high-chloride conditions, achieving a maximum compressive strength of 28.75 MPa and a Cr(VI) leaching concentration as low as 15.69 μg/L. Microstructural characterisation revealed the synergistic formation of a dense framework between C–S–H gel and calcium aluminate, conferring superior mechanical strength. Substitution and chelation mechanisms of Cl− ions played a key role in enhancing corrosion resistance. This study provides theoretical support and technical guidance for the high-value utilisation of phosphogypsum-based materials in remediating saline–alkali-contaminated soils.

Emerging catalysts for catalytic ozone advanced oxidation in water purification: Metal-organic frameworks and their derivatives.

Silver ion-catalyzed ammonium persulfate oxidation enhances low-temperature sulfuric acid curing and water leaching of valuable metals in copper slag: Experimental and mechanistic analysis

A synergistic enhancement strategy for CuS oxidation performance: polyvinyl pyrrolidone modification and bimetallic charge reconstruction.

Peroxymonosulfate activation by Co-doped chlorella biochar for destructing antibiotic resistance: Targeting the degradation of free DNA bases and inactivation of resistant bacteria.

Enhanced activation of peroxymonosulfate using Y3+ substituted magnetic nanostructured ZnFe2O4 for carbamazepine degradation.

Despite the growing public health threat of electronic cigarettes (e-cigs), the cell-specific immune responses to differently flavored e-cig exposure remain poorly understood. To bridge this gap, we characterized the lung immune landscape following acute nose-only exposure to flavored e-cig aerosols in vivo using single-cell RNA sequencing (scRNA seq) in mice. Metal analysis of daily generated aerosols revealed flavor-dependent, day-to-day variation in metal (Ni, Cu, K, and Zn) leaching. scRNA seq profiling of 71,725 lung cells from control and exposed mice revealed pronounced dysregulation of myeloid cell function in menthol (324 differentially expressed genes, DEGs) and tobacco (553 DEGs) flavors, and lymphoid cell dysregulation in fruit-flavor (112 DEGs) e-cig aerosol exposed mouse lung, compared to air controls. Flow cytometry corroborated these findings, showing increased neutrophil frequencies and reduced eosinophil counts in menthol- and tobacco-exposed lungs. Flavored e-cig exposure also increased CD8+ T-cell proportions, upregulated inflammatory gene expression (Stat4, Il1b, Il1bos, Il1ra, and Cxcl3), and enriched terms like 'Th1 cytokine signaling' and 'NK cell degranulation'. Notably, tobacco-flavored e-cig aerosol exposure increased immature (Ly6G⁻) neutrophils and reduced S100A8 expression, suggesting altered neutrophil activation in vivo. Overall, this study identifies flavor-dependent immune alterations in the lung following acute e-cig aerosol exposure and provides a foundation for future mechanistic studies.

The oxidation of alcohols to aldehydes is a key transformation in industrial chemistry, as aldehydes are vital intermediates in the synthesis of pharmaceuticals and fine chemicals. Conventional oxidation routes typically employ stoichiometric and corrosive oxidants, generating significant environmental concerns. Greener oxidants such as molecular oxygen (O2) offer a more sustainable alternative to stoichiometric oxidants; however, their efficient utilization requires activation by catalysts (e.g., Cu-, Pd-, Au-, or Ti-based systems). Homogeneous photocatalysts such as CuCl2 exhibit promising activity under light irradiation but are limited by challenges in separation and recycling. This study investigates the immobilization of CuCl2 and TiO2 (P25) within sodium alginate beads to facilitate photocatalyst recovery and minimize metal leaching. Under UV irradiation for 4 h, benzyl alcohol conversions of 54% (P25) and 49% (CuCl2) were achieved. Catalyst encapsulation markedly reduced activity due to internal mass transport limitations, as restricted diffusion of O2 and benzyl alcohol within the bead matrix limited access to active sites and suppressed overall reaction rates. Co-immobilization of P25 and CuCl2 partially restored conversion (22%), while maintaining high benzaldehyde selectivity (≈1 after 4 h) across all systems. These findings highlight oxygen depletion and mass transfer resistance as key constraints in bead-based photocatalysts. To guide further optimization, a MATLAB-based reactor model incorporating species transport, interfacial mass transfer, and kinetics was developed.

To facilitate the large-scale recycling of phosphogypsum (PG) as a construction material and mitigate the environmental safety concerns associated with its stockpiling or discharge, this study proposes an innovative approach. The method employs modified (acid-treated) basalt fibers (MBF) synergistically combined with microbially induced carbonate precipitation (MICP) technology for PG solidification. This synergistic MBF–MICP treatment not only enhances the strength and further improves the toughness of the solidified PG but also effectively immobilizes heavy metals within the PG matrix. Bacterial attachment tests conducted on fibers subjected to various pretreatment conditions revealed that the maximum bacterial adhesion occurred on fibers treated with a 1 mol/L acid concentration for 2 h at 40 °C. However, MICP mineralization experiments performed on these pretreated fibers determined the optimal pretreatment conditions for mineralization efficiency to be an acid concentration of 0.93 mol/L, a treatment duration of 0.96 h, and a temperature of 30 °C. Unconfined compressive strength (UCS) tests and calcium carbonate content measurements identified the optimal reinforcement parameters for MBF–MICP-solidified PG as a fiber length of 9 mm and a fiber dosage of 0.4%. Furthermore, comparative analysis demonstrated that the UCS and toughness of MBF–MICP-solidified PG were superior to those of bio-cemented PG specimens treated with unmodified fibers or without any fiber reinforcement. It was found by scanning electron microscopy that there was an obvious phosphogypsum particle-fiber-calcium carbonate precipitation interface in the sample, and the fiber had a bridging effect. Finally, heavy metal leaching tests conducted on the solidified PG confirmed that the leached heavy metal concentrations were below the detection limit, complying with national discharge standards.

The development of heterogeneous catalysts for liquid-phaseaerobicoxidation is of great interest. Herein, we report the synthesis of3D porous graphitic carbon spheres incorporating Mn+1Cn-type MXenes (M = Ti, V, Nb),prepared by delaminating MXene nanosheets in chitosan-based aerogels,followed by pyrolysis. In the case of Nb2C, a heterojunctionwith a NaNbO3 perovskite forms within the carbon matrix,leading to the highest catalytic performance. This 3D Nb2C/NaNbO3 structure achieved a 100% yield in the aerobicoxidation of cyclohexanone oxime to cyclohexanone within 6 h, withnegligible metal leaching. Structural analysis revealed the partialoxidation of Nb2C to NaNbO3 during synthesis,leading to a Nb2C–NaNbO3 heterostructure.Control experiments confirmed that this interface is essential forthe high activity, as neither Nb2C nor NaNbO3 alone on the porous carbon matrix reached a similar performance.Mechanistic studies based on hot filtration tests, quenching experiments,and EPR spectroscopy demonstrated that the reaction involves reactiveoxygen species, mainly superoxide and hydroperoxyl radicals, generatedand acting on the catalyst surface. This work provides a promisingstrategy for designing efficient and robust MXene-based catalystsfor sustainable oxidation processes.

ABSTRACT Municipal solid waste incineration (MSWI) fly ash is a hazardous waste, and traditional landfill disposal lacks sustainability. Resource utilization offers a viable pathway for its future management. Heavy metals are key hazardous components in fly ash, and their stabilization is essential for resource utilization. However, traditional high-temperature treatments are energy-intensive and costly, limiting large-scale application. This study proposed an energy-efficient, medium-temperature treatment method for fly ash and evaluated its environmental risks. Molecular dynamics simulations were conducted to elucidate the underlying mechanisms of heavy metal stabilization. The study revealed that co-sintering fly ash with clay at 750°C and 950°C led to a significant reduction in heavy metal leachability, with Pb and Zn concentrations decreasing by 97.4% and 61.7%, respectively. The sintered products developed new fibrous mineral phases, predominantly wollastonite and rankinite, within which heavy metal ions were incorporated through isomorphic substitution for Ca2+ in the crystal lattice, leading to stable immobilization. Sequential extraction analysis showed that the chemical forms of heavy metals shifted from acid-soluble to more stable reducible and oxidizable fractions after treatment. Consequently, the environmental risk levels of Zn and Pb decreased from moderate to negligible, while that of Cd was reduced from high to negligible. Long-term leaching tests under simulated acid rain conditions confirmed that the sintered products maintain high stability during prolonged environmental exposure.

Cookware manufactured through informal processes often uses unregulated raw materials and lacks quality control, which may result in elevated toxic metal levels. This study assessed the concentrations of manganese (Mn), lead (Pb), chromium (Cr), cadmium (Cd), and nickel (Ni) in informally manufactured cookware from Saki, southwest Nigeria. It also evaluated metal leaching into water during cooking and examined associated moulding materials and soils to identify potential sources of contamination. Four cookware samples, six moulding materials, and seventeen soil samples (including one background sample) were analyzed using flame atomic absorption spectrophotometry. Metal concentrations in cookware samples were generally high, with mean values (mg/kg) of Mn (375), Pb (136), Cr (26.9), Cd (1.70), and Ni (181), exceeding FAO/WHO acceptable limits for food-contact materials. Moulding materials showed extremely elevated Mn concentrations, while soils near manufacturing sites contained Pb and Cd above NESREA guideline values. Leaching tests conducted by boiling water for up to three hours showed metal concentrations below detection limits (0.01mg/L), suggesting minimal short-term exposure risks. However, the high total metal content in cookware and production materials indicate potential public health concerns. This study provides baseline data linking informal manufacturing practices to cookware quality and site contamination in Nigeria.

Integrating water electrolyzers with intermittent renewable energy poses critical durability challenges from dynamic load fluctuations inducing catalyst degradation. We report a zinc-mediated sacrificial protection strategy enhancing NiMo catalyst stability through in situ dendritic passivation. Zinc-decorated NiMo on nickel felt (Zn-NiMo/NF) exhibits considerable hydrogen evolution activity (94.6mV overpotential at 50mA cm-2) comparable to Pt/C. Under stringent load fluctuation cycling protocols (-500/50mA cm-2), the zinc overlayer spontaneously reconstructs into laterally oriented, NiMo-enriched dendrites providing dual protection: physical barriers suppressing dissolution (order-of-magnitude reductions in metal leaching) and sacrificial buffering wherein zinc preferentially oxidizes to zincate, shielding nickel from irreversible hydroxide formation. Zn-NiMo/NF maintains stable performance while pristine NiMo/NF degrades substantially. Anion exchange membrane electrolyzer validation confirms minimal voltage escalation over 100 h cycling (1.645- 1.667V), outperforming Pt/C (1.7028-1.857V). This establishes sacrificial interface engineering as an effective paradigm for robust earth-abundant electrocatalysts in renewable energy-integrated hydrogen production.

Synergistic electrochemical multi-resources recovery from spent LiFePO4 and etching solvents.

Sustainable upcycling of solid waste into heterogeneous peroxymonosulfate activators for degrading emerging organic contaminants in wastewater.

A double Z-scheme ternary heterojunction FeNi2S4@MoS2/g-C3N4: Interfacial synergistic mechanism of charge carrier dynamics-accelerated adsorption-photocatalysis for efficient pollutant degradation and hydrogen evolution.

Ce doped Bi-MOF derived hollow Bi2O3/CeO2: Abundant oxygen vacancies to efficiently enhance catalytic ozonation of 4-Nitrophenol.

Dual-functional Mn-single atom catalysts for synergistic H2O2 generation and activation: Toward efficient refractory organic wastewater treatment.