Search Results (919)

Per- and polyfluoroalkyl substances (PFAS) are a diverse group of synthetic fluorinated compounds widely used in industrial and consumer products due to their exceptional thermal stability and hydrophobicity. However, these same properties contribute to their environmental persistence, bioaccumulation, and potential adverse health effects, including hepatotoxicity, immunotoxicity, endocrine disruption, and increased cancer risk. Traditional water treatment technologies, such as coagulation, sedimentation, biological degradation, and even advanced membrane processes, have demonstrated limited efficacy in removing PFAS, as they primarily separate or concentrate these compounds rather than degrade them. In response to these limitations, photoassisted processes have emerged as promising alternatives capable of degrading PFAS into less harmful products. These strategies include direct photolysis using UV or VUV irradiation, heterogeneous photocatalysis with materials such as TiO₂ and novel semiconductors, light-activated persulfate oxidation generating sulfate radicals, and photo-Fenton reactions producing highly reactive hydroxyl radicals. Such approaches leverage the generation of reactive species under irradiation to cleave the strong carbon–fluorine bonds characteristic of PFAS. This review provides a comprehensive overview of emerging photoassisted technologies for PFAS removal from water, detailing their fundamental principles, degradation pathways, recent advancements in material development, and integration with hybrid treatment processes. Moreover, it discusses current challenges related to energy efficiency, catalyst deactivation, incomplete mineralization, and scalability, outlining future perspectives for their practical application in sustainable water treatment systems to mitigate PFAS pollution effectively. Full article

Acrylonitrile–butadiene–styrene (ABS) has been widely used as an engineering thermoplastic, and the increasing post-consumer waste of ABS plastics calls for efficient and sustainable recycling technologies. The recent advances in ABS recycling technologies were investigated to enhance material recovery, purity, and environmental performance. Thermo-oxidative degradation compromises mechanical integrity during reprocessing, while minor reductions in molecular weight increase melt flow rates. Surface modification techniques such as boiling treatment, Fenton reaction, and microwave-assisted flotation facilitate the selective separation of ABS from mixed plastic waste by enhancing its hydrophilicity. Dissolution-based recycling using solvent and anti-solvent systems enables the recovery of high-purity ABS, though some additive losses may occur during subsequent molding. Magnetic levitation and triboelectrostatic separation provide innovative density and charge-based sorting mechanisms for multi-plastic mixtures. Thermochemical routes, including supercritical water gasification and pyrolysis, generate fuel-grade gases and oils from ABS blends. Mechanical recycling remains industrially viable when recycled ABS is blended with virgin resin, whereas plasma-assisted mechanochemistry has emerged as a promising technique to restore mechanical properties. These recycling technologies contribute to a circular plastic economy by improving efficiency, reducing environmental burden, and enabling the reuse of high-performance ABS materials. Full article

This study systematically explores the mechanisms and application potential of biochar in remediating heavy metal-contaminated soils. Particular emphasis is placed on the role of raw materials and pyrolysis conditions in modulating key physicochemical properties of biochar, including its aromatic structure, porosity, cation exchange capacity, and ash content, which collectively enhance heavy metal immobilization. The direct remediation mechanisms are categorized into six pathways: physical adsorption, electrostatic interactions, precipitation, ion exchange, organic functional group complexation, and redox reactions, with particular emphasis on the reduction in toxic Cr⁶⁺ and the oxidation of mobile As³⁺. In addition to direct interactions, biochar indirectly facilitates remediation by enhancing soil carbon sequestration, improving soil physicochemical characteristics, stimulating microbial activity, and promoting plant growth, thereby generating synergistic effects. The study evaluates combined remediation strategies integrating biochar with phytoremediation and microbial remediation, highlighting their enhanced efficiency. Moreover, practical challenges related to the long-term stability, ecological risks, and economic feasibility in field applications are critically analyzed. By synthesizing recent theoretical advancements and practical findings, this research provides a scientific foundation for optimizing biochar-based soil remediation technologies. Full article

The ethanol oxidation reaction (EOR) is a key process for direct ethanol fuel cells (DEFCs), offering a high-energy-density and carbon-neutral pathway for sustainable energy conversion. However, the practical implementation of DEFCs is significantly hindered by the EOR due to its sluggish kinetics, complex multi-electron transfer pathways, and severe catalyst poisoning by carbonaceous intermediates. This review provides a comprehensive and mechanistically grounded overview of recent advances in EOR electrocatalysts, with a particular emphasis on the structure–activity relationships of noble metals (Pt, Pd, Rh, Au) and non-noble metals. The effects of catalyst composition, surface structure, and electronic configuration on C–C bond cleavage efficiency, product selectivity (C1 vs. C2), and CO tolerance are critically evaluated. Special attention is given to the mechanistic distinctions among different metal systems, highlighting how these factors influence reaction pathways and catalytic behavior. Key performance-enhancing strategies—including alloying, nanostructuring, surface defect engineering, and support interactions—are systematically discussed, with mechanistic insights supported by in situ characterization and theoretical modeling. Finally, this review identifies major challenges and emerging opportunities, outlining rational design principles for next-generation EOR catalysts that integrate high activity, durability, and scalability for real-world DEFC applications. Full article

Laccases, a class of multicopper oxidases found in diverse biological sources, have emerged as key green biocatalysts with significant potential for eco-friendly pollutant degradation. Their ability to drive electron transfer reactions using oxygen, converting pollutants into less harmful products, positions laccases as promising tools for scalable and sustainable treatment of wastewater, soil, and air pollution. This review explores laccase from a translational perspective, tracing its journey from laboratory discovery to real-world applications. Emphasis is placed on recent advances in production optimization, immobilization strategies, and nanotechnology-enabled enhancements that have improved enzyme stability, reusability, and catalytic efficiency under complex field conditions. Applications are critically discussed for both traditional pollutants such as synthetic dyes, phenolics, and pesticides and emerging contaminants, including endocrine-disrupting chemicals, pharmaceuticals, personal care products, microplastic additives, and PFAS. Special attention is given to hybrid systems integrating laccase with advanced oxidation processes, bioelectrochemical systems, and renewable energy-driven reactors to achieve near-complete pollutant mineralization. Challenges such as cost–benefit limitations, limited substrate range without mediators, and regulatory hurdles are evaluated alongside solutions including protein engineering, mediator-free laccase variants, and continuous-flow bioreactors. By consolidating recent mechanistic insights, this study underscores the translational pathways of laccase, highlighting its potential as a cornerstone of next-generation, scalable, and eco-friendly remediation technologies aligned with circular bioeconomy and low-carbon initiatives. Full article

Achieving ultra-low-sulfur diesel is a crucial objective in modern fuel refining, driven by increasingly stringent environmental regulations. This study presents the development of a highly efficient oxidative–adsorptive desulfurization process utilizing a nanocatalyst synthesized from biowaste eggshell-extracted calcite. The oxidation reaction was conducted in a digital basket reactor (DBR), an advanced reactor system designed to enhance mass transfer and catalytic efficiency. To further augment the catalyst’s performance, the calcite was modified with eco-friendly MnO₂, while activated carbon was employed as an adsorbent to effectively capture oxidized sulfur compounds, ensuring compliance with ultra-low-sulfur fuel standards. The synthesized nanocatalyst underwent comprehensive physicochemical characterization using SEM, EDX, BET, and FTIR, confirming its high surface area, structural integrity, and superior catalytic activity. The MnO₂/P–calcite catalyst achieved a sulfur removal efficiency of 96.5% at 90 °C, 80 min, and 600 rpm, demonstrating excellent oxidative–adsorptive performance for real diesel fuel. The integration of this innovative nanocatalyst with the DBR system presents a sustainable, cost-effective, and industrially viable approach for deep desulfurization, offering significant advancements in clean fuel production and environmental sustainability. Full article

Despite the immense potential in environmental remediation, the translation of magnetic nanomaterials (MNMs) from laboratory innovations to practical, field-scale applications remains hindered by significant technical and environmental challenges. This is particularly evident in soil environments—which are inherently more complex than aquatic systems and have received comparatively less research attention. Beginning with an outline of the fundamental properties that make iron-based MNMs effective as adsorbents and catalysts for heavy metals and organic pollutants, this review systematically examines their core contaminant removal mechanisms. These include adsorption, catalytic degradation (e.g., via Fenton-like reactions), and magnetic recovery. However, the practical implementation of MNMs is constrained by several key limitations, such as particle agglomeration, oxidative instability, and reduced efficacy in multi-pollutant systems. More critically, major uncertainties persist regarding their long-term environmental fate and biocompatibility. In light of these challenges, we propose that future efforts should prioritize the rational design of stable, selective, and intelligent MNMs through advanced surface engineering and interdisciplinary collaboration. Full article

Advancing catalysts for low-temperature NH₃-SCR enhances their viability as a terminal flue gas denitration solution across diverse operating regimes. A high-performance, hydrothermally stable catalyst for low-temperature SCR was synthesized by depositing MnO_x onto MgAlO_x composite oxide supports. These supports, featuring varied Mg/Al ratios, originated from layered double hydroxide (LDH) precursors. The obtained catalyst with the Mg/Al ratio of 2 (Mn/Mg₂AlO_x) possesses relatively high concentrations of active oxygen species (O_α) and Mn⁴⁺ and exhibits remarkable catalytic performance. The Mn/Mg₂AlO_x catalyst exhibits a wide operating temperature range (100–300 °C) for denitration, achieving over 80% NO_x conversion, along with robust water resistance. The temperature-programed surface reactions and NO oxidation reactions are performed to elucidate the promoting effect of water on N₂ selectivity, which is not only due to inhibition of catalyst oxidation capacity at high temperature but also is related to the competing adsorption of water and NH₃. In situ DRIFTS analysis confirmed that the NH₃-SCR mechanism over Mn/Mg₂AlO_x adheres to the Eley–Rideal (E–R) pathway. These findings highlight the significant promise of Mn/MgAlO_x catalysts for deployment as downstream denitration units within exhaust treatment systems. Full article

Per-polyfluoroalkyl substances (PFASs) are a class of persistent organic pollutants that have been detected in several environmental matrices. Photoelectrocatalysis (PEC) was employed to remove PFASs contained in natural groundwater collected in the Veneto region (Italy), where a massive PFAS contamination was present. Nine PFASs were detected and monitored throughout the process. By varying the magnitude of the applied cell voltage (no bias and 4, 6, and 8 V) the optimal condition was assessed to be 4 V, resulting in a total PFAS removal of about 87%. The presence of H₂O₂ was ineffective on the reaction kinetic, while NaCl inhibited the oxidation of PFASs. The E_EO (Electrical Energy per Order of Magnitude) analysis revealed that PEC is more energy-efficient than both traditional photolysis and most advanced oxidation techniques discussed in published research. Full article

Tryptophan (Trp) and tryptamine (Tryp), critical biomarkers in mood regulation, immune function, and metabolic homeostasis, are increasingly recognized for their roles in both oral and systemic pathologies, including neurodegenerative disorders, cancers, and inflammatory conditions. Their rapid, sensitive detection in biofluids such as saliva—a non-invasive, real-time diagnostic medium—offers transformative potential for early disease identification and personalized health monitoring. This review synthesizes advancements in electrochemical sensor technologies tailored for Trp and Tryp quantification, emphasizing their clinical relevance in diagnosing conditions like oral squamous cell carcinoma (OSCC), Alzheimer’s disease (AD), and breast cancer, where dysregulated Trp metabolism reflects immune dysfunction or tumor progression. Electrochemical platforms have overcome the limitations of conventional techniques (e.g., enzyme-linked immunosorbent assays (ELISA) and mass spectrometry) by integrating innovative nanomaterials and smart engineering strategies. Carbon-based architectures, such as graphene (Gr) and carbon nanotubes (CNTs) functionalized with metal nanoparticles (Ni and Co) or nitrogen dopants, amplify electron transfer kinetics and catalytic activity, achieving sub-nanomolar detection limits. Synergies between doping and advanced functionalization—via aptamers (Apt), molecularly imprinted polymers (MIPs), or metal-oxide hybrids—impart exceptional selectivity, enabling the precise discrimination of Trp and Tryp in complex matrices like saliva. Mechanistically, redox reactions at the indole ring are optimized through tailored electrode interfaces, which enhance reaction kinetics and stability over repeated cycles. Translational strides include 3D-printed microfluidics and wearable sensors for continuous intraoral health surveillance, demonstrating clinical utility in detecting elevated Trp levels in OSCC and breast cancer. These platforms align with point-of-care (POC) needs through rapid response times, minimal fouling, and compatibility with scalable fabrication. However, challenges persist in standardizing saliva collection, mitigating matrix interference, and validating biomarkers across diverse populations. Emerging solutions, such as AI-driven analytics and antifouling coatings, coupled with interdisciplinary efforts to refine device integration and manufacturing, are critical to bridging these gaps. By harmonizing material innovation with clinical insights, electrochemical sensors promise to revolutionize precision medicine, offering cost-effective, real-time diagnostics for both localized oral pathologies and systemic diseases. As the field advances, addressing stability and scalability barriers will unlock the full potential of these technologies, transforming them into indispensable tools for early intervention and tailored therapeutic monitoring in global healthcare. Full article

Ozonized vegetable oils are gaining attention for their antimicrobial and therapeutic potential, yet the lack of standardized ozonation protocols and incomplete characterization of their chemical profiles hinder clinical translation. In this study, we standardized the ozonation process of sunflower oil and investigated the chemical evolution and antimicrobial efficacy of the resulting products. Ozonation proceeded through a classical three-step mechanism involving the formation of primary ozonides, their decomposition into carbonyl compounds and carbonyl oxides, and subsequent recombination into stable secondary ozonides capable of sustained ozone release with reduced toxicity. Time-course analysis at 100, 240, and 480 min revealed key reaction products, including the appearance of azelaic acid after 240 min, progressive depletion of linoleic acid, and the emergence of 2,5-furandione exclusively after 480 min—indicative of advanced oxidative processes. The formation of hydroperoxides and their secondary degradation into ketones, acids, and epoxides was also observed, with implications for both biological activity and sensory properties. Importantly, the ozonized oil demonstrated potent antimicrobial activity against Staphylococcus aureus, Escherichia coli, Salmonella choleraesuis, Pseudomonas aeruginosa, Candida albicans, and Aspergillus brasiliensis. These findings provide a comprehensive chemical and functional characterization of ozonized sunflower oil and support its development as a standardized antimicrobial agent for therapeutic use. Full article

Nano zero-valent iron (nZVI) particles have received much attention in environmental science and technology due to their unique electronic and chemical properties. While sulfate radical-based advanced oxidation processes (SR-AOPs) activated by nZVI show promise for mono-chlorobenzene (MCB) degradation, their efficiency is severely limited by surface oxidation of nZVI and Fe³⁺ accumulation. This study aims to enhance the nZVI/persulfate (PS) system using L-cysteine (Cys) to achieve effective MCB removal. The work involved synthesizing nZVI via borohydride reduction, followed by comprehensive characterization and batch experiments of the Cys/nZVI/PS degradation system of MCB were carried out to evaluate the key influencing factors and analyze the reaction mechanism of Cys-enhanced MCB degradation. Under optimal conditions (0.1 g/L nZVI, 3 mM PS, 0.1 mM Cys, pH 3), 92.6% of MCB was degraded within 90 min—an 18.7% improvement compared to the Cys-free system. Acidic pH promoted Fe²⁺ release and significantly enhanced degradation, while HCO₃⁻ strongly inhibited the process. Mechanistic studies revealed that sulfate radicals (SO₄^•−) played a dominant role, and Cys served as an electron shuttle that facilitated the Fe³⁺/Fe²⁺ cycle and enhanced Fe⁰ conversion, thereby sustaining PS activation. This study demonstrates that Cys effectively mitigates the limitations of nZVI/PS systems and provides valuable insights for implementing efficient SR-AOPs in treating chlorinated organic contaminants. Full article

Rechargeable aqueous Zn-MnO₂ batteries are positioned as a highly promising candidate for next-generation energy storage, owing to their compelling combination of economic viability, inherent safety, exceptional capacity (with a theoretical value of ≈308 mAh·g⁻¹), and eco-sustainability. However, this system still faces multiple critical challenges that hinder its practical application, primarily including the ambiguous energy storage reaction mechanism (e.g., unresolved debates on core issues such as ion transport pathways and phase transition kinetics), dendrite growth and side reactions (e.g., the hydrogen evolution reaction and corrosion reaction) on the metallic Zn anode, inadequate intrinsic electrical conductivity of MnO₂ cathodes (≈10⁻⁵ S·cm⁻¹), active material dissolution, and structural collapse. This review begins by systematically summarizing the prevailing theoretical models that describe the energy storage reactions in Zn-Mn batteries, categorizing them into the Zn²⁺ insertion/extraction model, the conversion reaction involving MnO_x dissolution–deposition, and the hybrid mechanism of H⁺/Zn²⁺ co-intercalation. Subsequently, we present a comprehensive discussion on Zn anode protection strategies, such as surface protective layer construction, 3D structure design, and electrolyte additive regulation. Furthermore, we focus on analyzing the performance optimization strategies for MnO₂ cathodes, covering key pathways including metal ion doping (e.g., introduction of heteroions such as Al³⁺ and Ni²⁺), defect engineering (oxygen vacancy/cation vacancy regulation), structural topology optimization (layered/tunnel-type structure design), and composite modification with high-conductivity substrates (e.g., carbon nanotubes and graphene). Therefore, this review aims to establish a theoretical foundation and offer practical guidance for advancing both fundamental research and practical engineering of Zn-manganese oxide secondary batteries. Full article

Advanced oxidation processes (AOPs) utilising a hydroxyl radical (•OH), a strong oxidant, are seen as a promising solution for removing hazardous and recalcitrant pollutants from waste streams. Among AOPs, non-thermal plasmas, especially pulsed corona discharge (PCD), enable the abatement of hazardous volatile organic compounds (VOCs) with high energy efficiency. This study demonstrates the viability of upscaling PCD technology with water sprinkling in degrading the VOC toluene using a semi-pilot scale plasma reactor. A toluene–air mixture was treated with varying gas-phase toluene concentrations (30–100 ppm) and pulse repetition frequencies (25–800 pps), achieving toluene removal of 5–55% in PCD and an additional 10–18% in PCO, as well as excellent toluene removal energy efficiencies from 9.0 to 37.1 g kW⁻¹ h⁻¹. The process design with water sprinkling provides additional advantages compared to dry reactors—the water surface serves as a source of hydroxyl radicals and scrubs the air from degradation by-products resulting from the incomplete oxidation of target pollutants. Transformation products of toluene were identified, and an oxidation pathway via hydroxylation of the aromatic ring was suggested as the major route towards ring-opening reactions. A photocatalytic oxidation reactor with TiO₂ catalyst plates, following PCD as a post-treatment, enabled additional removal of residual contaminants, also converting residual ozone to oxygen. The PCD reactor with water sprinkling and post-plasma photocatalysis shows promising results for upscaling the process. Full article

Waste lithium-ion batteries (LIBs), which usually contain dangerous organic electrolytes and transition metals, including nickel, cobalt, iron, and manganese, can hurt the environment and human health. Substantial advancements have been achieved in employing high-efficiency, economical, and environmentally sustainable techniques for the recycling of spent LIBs. Converting exhausted LIBs into efficient energy conversion catalysts straightforwardly is a good strategy for addressing metal resource constraints and clean energy concerns. This transforms waste cathodes, anodes, binders, and separators from depleted LIBs into electrocatalysts free of platinum group metals for the oxygen evolution reaction (OER) and the oxygen reduction reaction (ORR). The composite, including transition metal oxide, graphene oxide, and carbon mass, will be synthesized from spent LIBs, demonstrating enhanced electrocatalytic activity. Utilizing “waste-to-energy” methods for used LIBs as catalysts would provide substantial benefits in environmental preservation and the effective production of functional materials in metal–air batteries. Full article