Abstract With the spread of hydrodesulfurisation in petroleum refining and increasingly strict regulations on the sulphur content of transport fuel, especially marine fuel, a global surplus of elemental sulphur has gradually appeared. There is now a surplus that will be used to improve high-volume infrastructure materials, such as asphalt binders. Sulfur-modified asphalt has the following advantages: it is less dependent on petroleum-based binders; sulfur polymerisation and inverse vulcanisation can be used to improve mechanical properties; and it is economically viable because sulfur is significantly cheaper than bitumen. Partial replacement of bitumen with sulfur can reduce binder costs and utilise the excess sulfur from the refinery productively at the same time. Meanwhile, the asphalt materials will also release various hazardous substances and other harmful factors over time. Emissions occur in binder production, mixture hauling, pavement application, and over the life of the pavement, and potential exposure routes for construction workers and nearby communities are created. Sulfur in the asphalt system can change the emission characteristics by promoting the production of sulfur-containing volatile compounds, such as sulfides and thiols, which are often highly odorous and may also be more toxic. Research has been conducted on the emissions of traditional asphalt; however, the impact of adding sulphur on the chemical structure of emissions and pathways for human health exposure remain unexplored. The three main knowledge gaps are as follows: (1) The effect of sulfur chemistry on the emission characteristics of asphalt and the generation of sulfur-containing volatile organic compounds have not been systematically studied; (2) Data on prolonged human exposure and the resulting health changes, especially neurological and respiratory problems, are scarce; and (3) How emissions from sulfur-containing asphalt are altered in the presence of environmental stress, such as heat ageing, UV degradation and oxidation, is poorly understood. At the same time, the following three new opportunities have appeared: (1) Stabilising sulphur through inverse vulcanisation and sulphur-based polymers; (2) Adding bio-derived additives and functional carbons to reduce volatile emissions; (3) Combining materials science, exposure assessment and toxicological modelling to better evaluate the health risks of sulphur-containing asphalt systems. The above deficiencies need to be rectified in order to promote the all-weather construction of roads with sulphur valorisation and safeguard the environment and public health.
Abstract Dissolved organic matter (DOM) is the most active form of organic carbon in rivers and plays a key role in biogeochemical processes. Understanding how land use change and seasonal hydrology regulate DOM dynamics is critical, particularly in monsoon regions with intensive human activities and hydrological variability. This study investigated the spatiotemporal variations in DOM composition and sources across different land use/land cover (LULC) types in representative rivers of the Three Gorges Reservoir (TGR) region during dry and wet seasons. In the dry season, DOM was dominated by protein-like, autochthonous components, whereas the wet season showed increased humic-like, terrestrial DOM with higher molecular weight and aromaticity. These seasonal variations were closely associated with changes in hydrological conditions. Rivers with higher forest cover exhibited more aromatic and allochthonous DOM signatures. In contrast, rivers influenced by urban and cultivated land use showed stronger signals of protein-like, autochthonous DOM, which were associated with higher nutrient levels and anthropogenic inputs. These results highlight the combined effects of monsoonal hydrology and land use on riverine DOM dynamics and provide insights for biogeochemical modeling and watershed management in the TGR region.
Abstract The large-scale decommissioning of lithium-ion batteries (LIBs) production is progressing rapidly, and the demand for environmentally friendly recycling and material recovery is rising. Collectively, this review has presented a series of studies on recent progress in using waste LIB black mass to synthesize various materials for water treatment, including synthesis methods, material structure and application performance of derived adsorbents, Fenton catalysts, persulfate-activating catalysts, etc. The above are based on rational material design and processing to create high-efficiency, multi-functional water treatment materials from black mass. Anode graphite-based adsorbents are a typical representative type with good heavy metal adsorption performance, and cathode-derived catalysts show fast degradation of organic pollutants via oxidative pathways. This review briefly introduces the shortcomings of the current state and provides some directions for further research to promote the construction of an effective pollution treatment model in the circular economy era.
Abstract The co-pyrolysis technology of agricultural and forestry waste and polluted soil has simultaneously achieved biomass resource utilization and soil remediation. However, the heterogeneity of raw materials, non-linear processes, and long ecological response cycles pose serious challenges to its precise regulation. This article systematically reviews the new paradigm of machine learning driven closed-loop design and its multi-scale improvement mechanism for soil health. Firstly, the key applications of machine learning in co-pyrolysis systems were elucidated: by integrating multimodal sensing data with deep neural networks, random forests, and other algorithms, a proxy model was constructed between raw material attributes, process parameters, product performance, and repair effects. Based on this, an intelligent control loop integrating perception, prediction, optimization, and feedback was formed. Secondly, the hierarchical mechanism of closed-loop system driving soil functional regeneration was revealed layer by layer from four scales: molecular/nano interface (quantum confinement catalysis and covalent bond orientation fixation), micro/millimeter structure (biomimetic topology reconstruction and dynamic pore regulation), in situ field (nutrient cycling activation and pollutant bioavailability reduction), and ecosystem (carbon sink function enhancement and microbial network reconstruction). Furthermore, the core bottlenecks such as path uncertainty caused by raw material fluctuations, quantum tunneling barriers within nanopores, physical limits of multifunctional performance of biochar, thermodynamic contradictions of system energy self-sustaining, unpredictability of long-term ecological response, and adaptation conflicts of current standard systems were summarized. Interdisciplinary integration directions such as quantum chemistry computing, ultrafast laser regulation, biomimetic reactors, synthetic biology biochar symbiotic systems, and blockchain trusted carbon management were also discussed. This review provides a systematic theoretical framework for the deep intersection of machine learning and thermochemical remediation technology, and also points out the technical path for achieving precise, intelligent, and sustainable remediation of polluted soil.
Abstract In this study, 3D BiOBr@hollow carbon sphere (BiOBr@C) hybrids were synthesized via template-assisted hydrothermal methods. The effect of BiOBr@C on the catalytic decomposition of phenol was investigated. Compared with BiOBr, the BiOBr@C hybrid exhibited a significantly increased specific surface area. Furthermore, the BiOBr@C hybrid also showed improved visible-light absorption capacity because of the synergistic effect between the carbon spheres and BiOBr. Phenol decontamination experiments demonstrated that the BiOBr@C hybrid achieved an optimal catalytic decomposition efficiency of 34% within 24 h, outperforming both pure BiOBr and carbon spheres alone. Kinetic analysis indicated that the phenol decontamination process on BiOBr@C fit the Weber‒Morris intraparticle diffusion model, suggesting that the catalytic decomposition mechanism involved multiple processes, including intramolecular diffusion and surface chemical adsorption, rather than simple physical adsorption. This study provides a promising strategy for designing efficient BiOBr-based photocatalysts for phenol decontamination applications.
Abstract The increasing concentration of atmospheric CO2 has accelerated the global demand for sustainable carbon mitigation technologies. The solar-energy-driven photocatalytic CO2 reduction provides an eco-friendly and effective method to transform CO2 to useful fuels and chemicals. However, conventional semiconductor photocatalysts often exhibit low efficiency owing to fast recombination of photogenerated electron and hole pairs along with its limited light absorption capability. In this context, Schottky heterojunctions formed by coupling metals with semiconductors have been recognized as an efficient solution to improve charge separation, light harvesting, and catalytic stability. This review comprehensively summarizes the fundamentals of Schottky heterojunctions, its synthesis strategies, and the charge transfer processes that facilitates effective photocatalytic CO2 reduction. Unlike previous reviews primarily focused on conventional semiconductor heterojunctions or generalized photocatalytic CO2 conversion systems, this review critically correlates Schottky barrier engineering, interfacial charge transfer, and product selectivity in metal-semiconductor photocatalysts. Particular emphasis is placed on structure-activity relationships, plasmonic enhancement, defect engineering, and mechanistic pathways governing formation of selective carbon-based products. Various metal-semiconductor systems including noble metal-based (Au, Ag, Pt) and earth-abundant metal-based (Cu, Ni, Co) heterostructures, are discussed with emphasis on its synthesis strategies, structural configurations, and performance enhancement factors. Furthermore, the role of plasmonic effects, barrier height modulation, and interfacial engineering in optimizing photocatalytic activity is elucidated. Finally, the article outlines the existing limitations and future perspectives in the design of cost-effective, stable, and scalable Schottky heterojunction photocatalysts, aiming to establish a robust foundation for next-generation solar-driven CO2 reduction technologies.
Contaminants of emerging concern (CECs) refer to various synthetic chemicalsu2014such as pharmaceuticals and personal care products (PPCPs), pesticides, per- and polyfluoroalkyl substances (PFASs), micro/nanoplastics, and nanomaterialsu2014that pose a threat to both environmental and human well-being. These pollutants primarily originate from industrial activities, wastewater effluents, household waste, and agricultural runoff. Anthropogenic CECs are recognized as a new class of micropollutants that contaminate aquatic environments and pose a threat to ecological and human health. Their continuous input from industrial, domestic, and agricultural sources results in chronic exposure and toxicity. Growing evidence of their health impacts calls for immediate and effective control measures to address CEC-induced hazards. This study outlines key sources, environmental implications, and innovative treatment solutions. Strengthening pollution control, treatment efficiency, and ecosystem protection helps governments resolve the water quality challenges of urbanization and move toward sustainable living. Yet, the removal of diverse and persistent CECs requires more advanced solutions, posing a significant challenge.
Ultrasound-assisted cavitation was used to synthesize BaZrO3 nanoneedles. Ultrasonic energy facilitated uniform mixing and anisotropic growth along the c-axis, resulting in a needle-like shape. The synthesized BaZrO3 nanoneedles were characterized using X-ray diffraction (XRD) for phase and crystallinity, Fourier-transform infrared spectroscopy (FTIR) for functional groups and chemical bonds, Ultraviolet-Visible diffuse reflectance spectroscopy (UV-Vis DRS) to assess optical absorption and estimate the band gap, photoluminescence (PL) spectroscopy to analyze charge-carrier recombination, and field-emission scanning electron microscopy (FESEM) along with dispersive X-ray spectroscopy (EDX) for elemental composition. TEM and FESEM images confirmed the needle-shaped morphology and size of the nanostructures. This morphology contributed to faster degradation under natural sunlight. Their high photocatalytic efficiency arises from the anisotropic nanoneedle shape, which provides a large active surface area and promotes rapid charge transport, along with advantageous optical properties such as strong sunlight absorption and reduced electronu2013hole recombination. Overall, these features enable faster reaction kinetics, making BaZrO3 nanoneedles a highly effective and durable photocatalyst for degrading both cationic and anionic pollutants. The photocatalytic performance was tested on two organic dyes: the cationic dye Rhodamine B (RhB) and the anionic dye Indigo Carmine (IC). The nanoneedles achieved 99.5% degradation of RhB in 50 min and 98% of IC in 60 min, demonstrating excellent photocatalytic activity. These results confirm that BaZrO3 nanoneedles are efficient photocatalysts for rapidly breaking down both cationic and anionic dye pollutants under sunlight.
Glyphosate is one of the most commonly used herbicides that is frequently observed in soil and water systems. Its persistence and toxicity pose serious concerns to human health and the environment. Conventional treatment methods such as adsorption and biological processes are often inadequate as these approaches either transfer the pollutant to another phase or show partial mineralization. In this work, MXene (Ti3C2Tx) and graphitic carbon nitride (g-C3N4) supported over activated carbon fibre (ACF) were integrated to create a Schottky-type heterojunction as a stable photoanode for photoelectrochemical (PEC) degradation of glyphosate. For single-chamber PEC operation, g-C3N4 served as the visible-light absorber, metallic MXene acted as an electron sink while ACF as a conductive and sustainable support. Strong interfacial coupling between MXene and g-C3N4 was established by structural and spectroscopic investigations that supported band bending at the interface and enabled effective charge separation. The hybrid system accelerated the oxidation of glyphosate by significantly increasing the production of reactive oxygen species. Under ideal conditions, glyphosate was degraded to around 100% in 270 min at a bias potential of 1.4 V. These findings highlight the potential of MXene-g-C3N4/ACF photoanode as a scalable, cost-effective, and visible light active platform for remediation of glyphosate and potentially other organic contaminants in water.
With the increasingly serious environmental pollution and gradual depletion of fossil fuels, the development of efficient green energy conversion technology has become an urgent global issue. Photocatalytic water splitting for hydrogen production has attracted extensive attention due to its ability to directly convert solar energy into hydrogen energy. However, it still faces bottlenecks such as low light utilization efficiency and low quantum efficiency. Cadmium sulfide (CdS) has become a research hotspot because of its suitable band gap, excellent band structure and low-cost advantages. Nevertheless, problems such as severe photocorrosion and high carrier recombination rate of CdS have seriously restricted its practical application. This paper reviews the research progress in the characteristics, preparation methods and performance improvement strategies of CdS-based photocatalysts in recent years. It elaborates on the basic properties of CdS photocatalysts and several common preparation methods. On this basis, various modification strategies for CdS photocatalysts in hydrogen production are emphatically discussed, including morphology regulation strategy, solid solution engineering strategy, heterojunction construction strategy and element doping strategy, focusing on the efficient utilization of charges, the preparation of CdS-based material composite systems and the improvement of photocatalytic activity. Finally, the development prospects and challenges of CdS-based photocatalytic materials in photocatalytic hydrogen production are prospected.
Background: Psychotropic drugs are contaminants of emerging concern, and some of them are also very toxic to aquatic organisms. Photodegradation is a major removal pathway for these compounds in sunlit surface waters. Psychotropic drugs are known to generate transformation products (TPs) upon direct photolysis, and the environmental impact of these TPs should be assessed. Methods: The software ECOSAR was used to assess acute and chronic toxicity of the compounds towards fish, crustaceans, and algae. Results: The TPs were often less toxic than their parent molecules, and in silico evidence of a toxicity increase was obtained in around 10% of the cases. However, comparison with available experimental data for carbamazepine suggests that the formation of just one or few toxic TPs should trigger concern, because of the potential to increase the overall toxicity of the irradiated mixture. Conclusions: The direct photolysis appears to often produce decontamination, but there are several cases where formation of at least one more toxic TP should raise concern. For the drugs considered here, it is the case of alprazolam, carbamazepine and diazepam, and also of dezipramine because of the formation of mutagenic acridine.
This article reviews recent engineering modifications and improvement methods that make natural diatomite an excellent, environmentally friendly catalyst for environmental protection and energy applications. In terms of regulation of the pore structure and surface properties for enhancing catalytic performance and expanding applications. Through physical alteration, chemical alteration or both types of modification on diatomite to make it actived and generate accessibile porosity and numerous active sites, thus enhancing its catalytic performance. Furthermore, at the same time as having adsorption and catalytic activity for pollutant conversion during pollution treatment by concentrating/degradating efficiency may rise. Recent studies show that such a connection can enhance pollutant adsorption efficiency simultaneously in gas-liquid and liquid-solid systems substantially. Representative cases of catalytic treatments: volatile organic compounds (VOCs), antibiotics residues, and heavy metal ions. Diatomite not only provides support but can also act as a mediator during the reaction process to enhance the reaction rate constants even more significantly. There is still difficulty in strictly controlling the microstructure to maintain a stable environment for active sites at different times and clarify interface reactions mechanisms. In the future, more research will be conducted on Diatomite-based materials for photocatalysis, advanced oxidation processes and energy conversion technologies.
Radioactive iodine constitutes a critical and persistent contaminant in nuclear waste management and environmental remediation. Nanoscale hierarchically porous metal-organic frameworks (NH-MOFs) exhibit considerable potential for iodine removal. However, the synthesis of NH-MOFs with tunable porosity and high stability remains an immense challenge. In this study, bimetallic nanoscale hierarchically porous Zn/Co-MOFs were synthesized via a reverse microemulsion method. The resulting nanoscale hierarchically porous Zn/Co-MOFs were characterized using a complementary combination of X-ray powder diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), nitrogen adsorption-desorption isotherms, and thermogravimetric analysis (TGA). These characterization results confirmed that the crystal size, pore size, and number of unsaturated metal sites in the nanoscale hierarchically porous Zn/Co-MOFs (Zn/Co-MOF_An) could be easily tuned by controlling the microemulsion parameters (e.g., the aqueous-to-oil ratio and surfactant concentration). The as-synthesized Zn/Co-MOF_An exhibited excellent iodine adsorption capacities (iodine vapor: 6.55 g/g; liquid-phase iodine: 585 mg/g) owing to the combined effects of shortened diffusion distances and hierarchical porosity. This work highlights the potential of Zn/Co-MOFs as high-performance and scalable adsorbents for radioactive iodine remediation.
In wastewater treatment, heterogeneous advanced oxidation processes (AOPs) are often evaluated by the degradation rate of pollutants, but this may overlook a problem: pollutants may not be completely mineralized but instead transfer and accumulate on the surface of the catalyst as degradation intermediates. Recently, the organic carbon transfer process (OCTP) proposed by Xing et al. in Nature Water indicates that partial degradation intermediates can mask active sites and lead to catalyst deactivation, but this deactivation is reversible. Based on this, we introduce OCTP as a question of where the carbon of heterogeneous AOPs goes, pointing out that the properties of the oxidant and the choice of the reaction path will determine whether the pollutants in the system move towards deep mineralization or surface accumulation, thereby affecting stability and long-term effectiveness. Based on this logic, we propose the index of catalyst regeneration extent (CRE) to quantify the recoverable effective life after cleaning and advocate designing corresponding strategies according to different situations.
Membrane fouling and wetting are the main challenges for membrane distillation (MD) that constrains its application especially in water recovery from saline oil-in-water emulsion. Herein, a novel covalent organic framework (COF) modified membrane was developed via facile in-situ growth of COF-LZU1 (synthesized by p-phenylenediamine and 1,3,5-benzenetricarboxaldehyde) on electrospun polyvinylidene uFB02uoride (PVDF) substrate (average pore size: 0.80 u03BCm, average porosity: 85.5%). This newly developed membrane exhibited high surface roughness (1.22 u03BCm), suitable porosity (57.3%), well-distributed pore size (0.67 u03BCm) and thin thickness (58.0 u03BCm). In addition, the hydrophilic COF-LZU1 layer (water contact angle 79.9u00B0) and hydrophobic PVDF substrate (water contact angle 140.5u00B0) endowed this Janus-like membrane with high fouling and wetting resistance. As a result, relatively higher water flux and milder conductivity increase were shown on COF-LZU1@PVDF-2 membrane during the treatment for saline oil-in-water emulsion with 0.0-4.0 g Lu22121 n-hexadecane and 50-80u00B0C feed temperature. The anti-fouling and anti-wetting mechanisms were also quantitatively investigated by the extended Derjaguinu2013Landauu2013Verweyu2013Overbeek (XDLVO) theory and liquid entry pressure (LEP) value. The relevant findings may pave the way in high performance COF modified membrane development with high water flux and high permeate quality for robust membrane distillation.
When treating wastewater, traditional AOPs mainly break down pollutants into harmless substances completely with radical chain reactions. However, the long-term use of these methods brings problems in sustainable development. They use too much energy and produce large amounts of carbon emissions. Researchers have carried out recent studies on oxidation-polymerization ways. These studies show that polymerization reactions work better than mineralization processes. They can remove organic pollutants effectively. They also cut down energy use greatly and help realize the reuse of resources. This paper summarizes the working principles and newest progress of polymerization reactions. These reactions are started by different active substances. The content includes radical ways like organic and inorganic radicals. It also includes non-radical ways such as high-valent metal oxides, electron transfer processes, complexes and singlet oxygen. Additionally, this paper puts forward methods to improve polymerization reactions. These methods come from two aspects. One is radical ways including concentration synergistic regulation, redox potential and nanoconfinement. The other is non-radical ways including electron regulation, microstructure regulation and composite carrier design. Finally, this paper talks about the difficulties and limits of polymerization ways in removing organic pollutants and lists future research directions in this area. It aims to offer reference and theoretical help for the later use of oxidative polymerization ways in resource recovery.
