Monitoring nanoplastic (NP) aggregation in bidisperse systems under environmentally relevant ionic conditions remains a significant challenge. Conventional techniques such as dynamic light scattering and transmission electron microscopy are hindered by matrix interference, low sensitivity, and difficulties in resolving polydispersity. Here, we addressed this gap by using a coupled system including hollow fiber flow field-flow fractionation (HF5), ultravioletvisible detector (UV), and point-discharge optical emission spectroscopy (PD-OES) to investigate aggregation behavior of bidisperse polystyrene NPs (PSNPs, 50 nm and 100 nm) at ionic conditions below 1 mM, representative of freshwater ecosystems. We demonstrated that bidisperse PSNPs exhibit enhanced aggregation compared to monodisperse counterparts by using the HF5-UV/PD-OES platform for purification, separation, and carbon-specific quantification. This platform elucidated the critical roles of cation valence (Na+ vs. Ca2+) and low concentration ion gradients (0.01-1 mM) in modulating aggregation over extended scales (i.e., 24 h). Finally, toxicity assessments on Microcystis aeruginosa revealed that aggregation reduces PSNP ecotoxicity depending on cation valence, thereby alleviating growth inhibition, oxidative stress, and impairment of chlorophyll biosynthesis. These findings elucidate how environmentally relevant ionic conditions govern NP fate and effects in freshwater ecosystems, providing a critical link between physicochemical transformations and biological responses for ecological risk evaluation.

This study evaluates the accuracy of various Geographic Information System interpolation methods in predicting the stratified spatial distribution of organic pollutants (Benzene, Total Petroleum Hydrocarbons [TPH], and Methyl Tert-butyl Ether [MTBE]) in groundwater at a petrochemical-contaminated site. Given the limitations of traditional monitoring methods in predicting spatial distribution, this study focuses on the spatial computational prediction of volatile organic compound concentrations at a former petrochemical industrial site. Three interpolation methods-Inverse Distance Weighting (IDW), Radial Basis Function (RBF), and Ordinary Kriging (OK)-were applied and evaluated. Prediction accuracy was assessed using leave-one-out cross-validation, with performance quantified through key metrics: Root Mean Square Error, Coefficient of Determination, and Spearman's Rank Correlation Coefficient. Results demonstrate significant variations in optimal prediction methods depending on pollutant type and depth stratum. For pollutants predominantly enriched in shallow and middle layers (Benzene, TPH), OK yielded the highest accuracy and stability. Conversely, for predictions of pollutants primarily concentrated in deeper layers, RBF achieved superior performance. IDW consistently underperformed across all strata and pollutants. All interpolation methods generally exhibited systematic overestimation of pollutant concentrations (mean cross-validation error > 0). Through a hierarchical evaluation of the accuracy and interpolation effectiveness of these methods, this study develops a more accurate modeling framework to describe the composite groundwater contamination patterns at petrochemical sites. This study systematically evaluates the spatial prediction accuracy of various non-aqueous phase liquid species under differing groundwater-table depths, identifies the most robust interpolation method, and thereby provides a benchmark for enhancing predictive fidelity in subsurface contaminant mapping.

Abstract Dissolved organic sulfur (DOS) in acid mine drainage (AMD) has attracted widespread attention due to its potential metal-complexation capacity. Given the little knowledge about DOS in AMD environments, this study employs high-resolution mass spectrometry and metagenomics to investigate its occurrence, synthesis pathways, and influencing factors. The results indicate that DOS exists at a mass spectrometry intensity-weighted relative abundance of 15.8–36.0% in AMD environments, mainly in CHOS and CHONS forms, with both levels higher than those found in soil, marine, and groundwater environments. DOS is dominated by highly unsaturated compounds, with highly oxygenated and unsaturated DOS being more stable and exhibiting greater mobility. Assimilatory sulfate reduction is the primary pathway for DOS synthesis, exhibiting gene abundance 4.5 times higher than dissimilatory sulfate reduction. Iron (hydr)oxides reduce the DOS content in AMD environments by adsorbing and immobilizing highly unsaturated compounds in sediments and inhibiting assimilatory sulfate reduction and organic carbon degradation involved in DOS synthesis. Overall, this study clarifies the molecular occurrence and fate of DOS and reveals a microbial–mineral synergistic regulation mechanism, providing a fundamental basis for understanding its molecular characteristics and potential metal-complexation relevance in AMD systems.

Microplastics (MPs), a pervasive environmental pollutant, present a significant and growing threat to human health. Metabolomics has emerged as a powerful tool for deciphering pollutant toxicity by sensitively detecting metabolic perturbations. This review outlines metabolomic methodologies and their application in environmental toxicology. Meanwhile, evidence of the multisystem toxic effects of MPs revealed by metabolomics is synthesized, and progress in integrating metabolomic data with multiomics to elucidate underlying mechanisms is summarized. Results indicate that MPs induce systemic toxicity through organ-specific metabolic disruptions. In the intestinal tract, MPs compromise barrier integrity, induce amino acid and lipid metabolic reprogramming, and cause microbial dysbiosis, impacting distal organs via the gut-organ axes. Upon entering the nervous system, they disrupt neurotransmitter metabolism and impair cognitive function. Concurrently, MPs impair reproductive function by altering testicular phospholipid metabolism, reducing sperm quality, and disrupting placental lysine and glucose homeostasis, restricting fetal growth. Furthermore, MPs inhibit central energy metabolism pathways, including glycolysis and the tricarboxylic acid cycle across diverse species, resulting in impaired growth and development. Future research should leverage spatial metabolomics, causal validation techniques, and advanced computational algorithms to systematically map MP-induced metabolic disruptions, establish definitive mechanistic links, and reconstruct toxicity networks. Our study provides scientific basis for further clarifying the MP toxicity and identifying molecular targets of metabolic reprogramming to develop interventions that mitigate the health risks of MPs.

Acquiring life cycle inventory (LCI) data has been a major challenge for life cycle assessment (LCA), which not only affects results accuracy, but also consumes significant time and effort. LCI data can be classified into primary and secondary data. There is broad consensus that secondary data are more readily obtainable than primary data, albeit with higher inherent uncertainty. This study employs soil washing technology as a case system to examine the substitutability of secondary for primary data across seven LCI data categories. Data substitutability determinations were made based on comprehensive uncertainty-sensitivity profiling. Across all three impact categories, water data demonstrated strong substitutability, eliminating the need for on-site collection, whereas concrete showed limited substitutability. This study provides new insights into harmonizing the use of primary and secondary data to achieve a balance between data collection costs and the accuracy of LCA results, thereby maximizing the efficiency of LCA.

Soil cadmium (Cd) pollution is becoming more serious and poses a strong threat to ecological safety and human health. Biochar (BC) can fix heavy metals and store carbon, but its long-term stability and its interaction with environmental factors are still not clear. In this study, the effects of BC on Cd fixation and the formation of organic-mineral complexes (OMCs) in aged soil under different environmental conditions were further investigated by combining aging experiments including wet-dry cycle, freeze-thaw cycle and ultraviolet irradiation, combined with soil physical fractionation and 13C isotope tracking. The results demonstrated that BC could improve soil stability. BC also increased the resistance of dissolved organic matter to decomposition and reduced the continuous loss of soil organic matter. BC significantly reduced the content of available Cd and increased the proportion of residual Cd. Therefore, the potential environmental risk of Cd is decreased. BC also increased soil carbon content. A 5% BC addition reduced organic carbon loss during aging. Organic carbon in OMCs smaller than 2 mu m was more stable. 13C tracing showed that after aging, the proportion of BC increased in OMCs larger than 200 mu m. The results showed that carbon moved from fine particles to coarse particles. Correlation analysis shows that soil organic carbon was positively related to residual Cd. Biochar increased the number of large OMCs, improved soil stability, and promoted organic-mineral reactions. This process strengthened the costabilization of Cd and carbon, providing a support for the combined control of Cd and organic matter in soil.

The rapid expansion of coastal dredging projects has resulted in the accumulation of large volumes of dredged sediments, creating significant environmental and land-use challenges. Conventional disposal methods, such as landfilling and marine dumping, not only waste valuable resources but also pose risks, including heavy metal contamination and excessive salinity. In this study, dredged sediment from the former sedimentation area of Huanghua Port was systematically examined for its potential reuse as greening soil through a three-stage approach: desalination, amendment with additives, and composting. Water-washing experiments were conducted to optimize desalination parameters, with a focus on the effects of solid-to-liquid ratios and washing solution concentrations on electrical conductivity reduction. Biochar, fly ash, and wood vinegar were then applied as amendments to evaluate their impacts on soil properties, including pH, organic matter, electrical conductivity, and cation exchange capacity. In addition, co-composting experiments with dredged sediment and crop straw were designed to investigate composting dynamics and changes in physicochemical characteristics under different mixing ratios. The results showed that two washes with a 0.3% NaCl solution effectively reduced electrical conductivity to acceptable levels. Subsequent amendment and composting treatments markedly enhanced soil fertility and ecological suitability. In particular, the combination of 1000-fold diluted wood vinegar and straw-to-sediment composting at a 1:3 weight ratio enabled the amended sediment to meet the Chinese standards for Planting Soil Green. Overall, this study establishes a scientific basis and practical strategy for the sustainable recycling of dredged sediments, supporting their application in urban greening and ecological restoration.

Assessing soil quality is crucial for guiding ecological restoration, mitigating land degradation, and promoting ecological sustainability in coal mining areas. However, the understanding of soil quality recovery across reclamation years and microtopographies and the applicability of different assessment methods remain insufficient. In this study, three minimum data set (MDS) methods were used to evaluate soil quality, which were based on the investigation and analysis of a reclamation chronosequence (0, 1, and 5 years) and two microtopographies (platforms and slopes). The MDS constructed by principal component analysis, hierarchical cluster analysis, and random forest model methods all showed acceptable reliability. Nonlinear scoring exhibited higher evaluation accuracy compared to the linear method. Cation exchange capacity, soil organic matter, alkali-hydrolyzable nitrogen, available phosphorus, and sucrase activity were retained across all three MDS methods. These indicators reflect crucial soil functions related to nutrient retention and microbial activity. Soil quality improved with increasing reclamation age, and recovery trajectories diverged between microtopographies. The 5-year reclaimed slope achieved better soil quality recovery than the platform, while 1-year reclaimed soil remained below undisturbed wasteland levels. Microbial biomass carbon and microbial biomass nitrogen (MBN) were the major limiting factors in initial reclamation. MBN remained the main limiting factor for the platforms after 5 years of restoration, while sand content became the main limiting factor for the slopes. These results could provide insights into microtopography-based reclamation strategies and recovery trajectory prediction in mining areas.

Emerging contaminants (ECs) have raised worldwide concerns due to their potential environmental and ecological risks. ECs in sediments from the Yangtze River, Poyang Lake, and its tributaries were analyzed to investigate river-lake interaction and assess their hazard and risk. A total of 166 chemicals were identified by nontargeted screening, and their ToxPi hazard scores ranged from 0.0527 to 0.6559. The chemical compositions of different sections in Poyang Lake were dominated by seasonal water exchange, limited hydrological connectivity, and tributary inputs. The spatial distributions of nine representative ECs exhibited halo-like patterns according to targeted and interpolation analysis. The distributions of their hot spots were also influenced by inflows from tributaries and backflow from the Yangtze River. These ECs were mainly sourced from domestic wastewater, industrial emissions, and agricultural non-point source pollution. Netilmicin and mesulfenfos exhibited high risks to aquatic organisms by risk quotient assessment. Insight of ECs behaviors will provide fundamental information to propose potential monitoring management strategies in similar river-lake interaction water bodies.

The design of efficient, low cost and recyclable photocatalyst is of great significance for disposing organic wastewater. In this work, η-Fe2O3/g-C3N4 heterostructure was constructed by in-situ cyclic voltammetry codeposition and calcination on nickel foam (NF). The microstructural and morphological characterization of the sample confirmed that spherical η-Fe2O3/g-C3N4 nanocomposites were co-deposited on three-dimensional porous NF to form Fe2O3/g-C3N4/NF photoelectrode under 50 cycles of 50 mV/s electric field. The removal rate of as-prepared η-Fe2O3/g-C3N4/NF photoelectrode for 10 mg·L−1 Rhodamine B solution reaches 95.2 % in 1h, which is 5.6 times of g-C3N4/NF and 5.3 times of η-Fe2O3/NF, respectively. According to the electrochemical test results, the enhanced photocatalytic activity of η-Fe2O3/g-C3N4/NF was principally due to efficient photogenerated charge separation and transfer ability of the photoelectrode. The results of active species capture experiments indicate that superoxide radical, hydroxyl radical and hole almost equivalently participated in photodegradation of η-Fe2O3/g-C3N4/NF, and its possible photodegradation mechanism was proposed on the basis of Z-scheme charge transport path. The η-Fe2O3/g-C3N4/NF nanocomposites would be expected to become a promising photoelectrode for large-scale applications.

Self-assembled FeOX/MnOX-synthetic humic-like acid composites (FeOX-SHLA or MnOX-SHLA) synthesized via in situ abiotic humification offer an alternative to conventional Fe/Mn-modified humic acids, addressing key limitations including structural variability and secondary pollution from metal salt-containing effluents. However, their synthesis, heavy metal immobilization mechanisms, and domain-specific microbial responses remain poorly understood. Herein, FeOX-SHLA and MnOX-SHLA amendments were synthesized and evaluated through a 90-day soil microcosm experiment. MnOX-SHLA achieved superior immobilization efficiency, reducing DTPA-extractable Cd and Pb by 74.8 % and 98.1 %, respectively, compared with 43.9 % and 40.5 % for FeOX-SHLA. Spectroscopic analysis revealed that both amendments immobilized metals through surface complexation, precipitation, electrostatic attraction, and cation-π interactions, with MnOX-SHLA facilitating stronger alkalinization and more stable metal-phosphate precipitate formation. Notably, bacteria and fungi exhibited distinct adaptive strategies to both amendments. Under both treatments, bacterial communities demonstrated greater sensitivity to environmental perturbations than fungi, while both domains shifted from deterministic to stochastic assembly, with drift dominating fungal assembly (86.7-93.3 %). FeOX-SHLA induced higher complexity and robustness in both bacterial and fungal networks than MnOX-SHLA. In both treatments, bacterial networks reorganized into modular structures, enabling functional specialization, whereas fungal networks favored integrated cooperation. Both amendments shifted stability maintenance from competition to cooperation, evidenced by decreased cohesion indices and increased positive interactions. Enrichment of key taxa such as Rhodanobacter (FeOX-SHLA) and Methylobacterium (MnOX-SHLA) potentially contributed to synergistic metal immobilization and soil health recovery. These findings provide mechanistic insights into immobilization performance and amendment- and domain-specific microbial impacts of FeOX-SHLA and MnOX-SHLA, guiding development of synergistic chemical-biological soil remediation strategies.

The design of efficient, low cost and recyclable photocatalyst is of great significance for disposing organic wastewater. In this work, q-Fe2O3/g-C3N4 heterostructure was constructed by in-situ cyclic voltammetry codeposition and calcination on nickel foam (NF). The microstructural and morphological characterization of the sample confirmed that spherical q-Fe2O3/g-C3N4 nanocomposites were co-deposited on three-dimensional porous NF to form Fe2O3/g-C3N4/NF photoelectrode under 50 cycles of 50 mV/s electric field. The removal rate of as-prepared q-Fe2O3/g-C3N4/NF photoelectrode for 10 mg & sdot;L- 1 Rhodamine B solution reaches 95.2 % in 1h, which is 5.6 times of g-C3N4/NF and 5.3 times of q-Fe2O3/NF, respectively. According to the electrochemical test results, the enhanced photocatalytic activity of q-Fe2O3/g-C3N4/NF was principally due to efficient photogenerated charge separation and transfer ability of the photoelectrode. The results of active species capture experiments indicate that superoxide radical, hydroxyl radical and hole almost equivalently participated in photodegradation of q-Fe2O3/g-C3N4/NF, and its possible photodegradation mechanism was proposed on the basis of Z-scheme charge transport path. The q-Fe2O3/g-C3N4/NF nanocomposites would be expected to become a promising photoelectrode for large-scale applications.

Public health and ecological security are seriously threatened by hexavalent chromium [Cr(VI)], whereas bioreduction of Cr(VI) to trivalent chromium [Cr(III)] presents a far lesser risk to the environment. The study examined the performance and removal mechanisms of Cr(VI) by Alcaligenes faecalis S1, known for its strong reducing capacity, and Lysinibacillus macrolides S2, which shows tolerance to Cr(VI). The results indicated that the extracellular secretions of strains S1 and S2 were the main sites of Cr(VI) reduction, primarily in the form of extracellular reduction of hexavalent chromium to trivalent chromium. The genomic findings of bacteria substantiated this idea, as both strains S1 and S2 possessed chromate reduction genes, concurrently demonstrating chromate transporter proteins and DNA repair proteases, among others, that function in reducing Cr(VI) toxicity to themselves. The construction of bacterial consortium S3 was further pursued in order to investigate the synergistic resistance mechanism of strains S1 and S2 against Cr(VI). It was found that S1 and S2 synergistically enhance the Cr(VI) resistance of the bacterial consortium S3 through the expression of reduction and resistance genes, endowing it with broader pH adaptability and excellent Cr(VI) reduction capabilities. This complementary effect allowed S3 to have multiple biological reduction mechanisms: enzyme-mediated reduction of Cr(VI), DNArepaired enzymes, detoxification enzymes, and Cr(VI) efflux, significantly reducing Cr(VI) toxicity damage. In conclusion, this study has deepened the understanding of the fundamental characteristics of strains S1 and S2, as well as the remediation synergistic mechanisms of Cr(VI), providing a molecular basis and scientific guidance for future bioremediation.

As a vital measure for promoting the green transformation of agriculture, the analysis of the impact of government support and farmers’ internal perceptions (subjective norms, attitudes toward behaviour, behavioural intention) on the adoption of conservation tillage technology is essential for optimizing policy design and promoting sustainable agricultural development. Based on the Stimulus-Organism-Response (SOR) theoretical model, this study constructs a relational model involving government support, farmers’ internal perceptions, and conservation tillage technology adoption behaviour. Most existing studies have examined internal or external factors in isolation, thus lacking an understanding of how government support influences farmers’ adoption of conservation tillage through psycho-institutional interactions. This study addressed this gap by using the integrated SOR framework and Structural Equation Model. An empirical analysis was conducted using survey data from 245 farmers in Enshi City, Hubei Province. The effective questionnaire rate was 94.23%. The results show that both government support and farmers’ internal perceptions significantly positively influence conservation tillage technology adoption behaviour. Furthermore, bootstrap analysis with 2000 replicates demonstrated that internal perceptions serve both as individual and chain mediators between government support and conservation tillage technology adoption behaviour. Therefore, in promoting conservation tillage technology, the role of government support should be effectively utilized. By strengthening farmers’ internal perceptions, their awareness, familiarity, and satisfaction with conservation tillage technology can be increased, thus encouraging its adoption and dissemination. This will contribute to implementing the rural revitalization strategy and achieving the green transformation of agriculture.

Studying the effects of microplastics (MPs) on plant-derived carbon and microbial-derived carbon in soil is of great significance for understanding how polluted soil affects plant productivity, water quality maintenance, human health and climate change. This study compared the effects of various concentrations (0.5 %, 1.0 %, 1.5 %, 2.0 %, and 2.5 %, w/w) of polyethylene (PE) and biodegradable polylactic acid (PLA) MPs on soil plant- and microbial-derived carbon through a 35-day soil pot experiment and biomarker method. PLA MPs promoted phospholipid fatty acids (PLFAs). PE MPs significantly reduced PLFAs. PLA and PE reduced total amino sugars, glucosamine, galactosamine and muramic acid. PLA and PE MPs reduced microbial, bacterial, and fungal necromass carbon contents, which may be due to the promotion of rhizosphere priming effect by MPs, thereby accelerating the decomposition of microbial necromass carbon. PLA had a promoting or reducing effect on V-type phenols, S-type phenols, C-type phenols, and total lignin phenols, while PE had a reducing effect on them. The reason may be that PE indirectly leads to a decrease in plant derived carbon by reducing soil total nitrogen, hydrolytic nitrogen, cation exchange capacity, etc. In general, PLA promoted the contribution of plant residual carbon to soil organic carbon (SOC), and decreased the contribution of microbial necromass to SOC. PE decreased the contribution of plant residual and microbial necromass to SOC.

Biochar has increasingly attracted the attention of researchers owing to its excellent stabilization effect on heavy metals and resource recycling properties. To better describe the stabilization process of heavy metals under the action of biochar, this study combined literature data integration and soil culture experiments, constructed a conceptual model of As and Cd stabilization under different biochar additions through the conditional probability theory, investigated the effects of biochar on soil properties and key components, identified the factors influencing the model parameters, and analyzed As and Cd stabilization by biochar and their mechanisms. Biochar addition improved soil particle size distribution and pore structure and increased soil pH and organic matter content but decreased cation exchange and total reducing substances. When the amount of biochar was 5

Agricultural soil contamination by cadmium (Cd) is a globally recognized concern, with biochar presenting considerable potential for remediation. However, the response of various crop components to biochar application for Cd pollution mitigation remains insufficiently understood. A literature review covering publications from 2017 to 2023 compiled 364 datasets from 60 studies to evaluate the responses of different parts of three crops to biochar treatment in Cd‐contaminated soil. Findings indicated that biochar application reduced soil Cd bioavailability by 30.5% and decreased Cd accumulation in roots, shoots, leaves and grains by 31.3%, 34.0%, 25.3% and 43.1%, respectively, with the most pronounced reduction observed in grains. The efficiency of biochar in Cd remediation is influenced by its characteristics and application rates. Composite biochar, synthesized through co‐pyrolysis of biomass with other materials, demonstrated the highest effectiveness in reducing Cd concentrations in crops. Pyrolysis conducted at 400–600°C for 2–4 h significantly enhanced biochar's remediation potential, while biochar with a pH range of 6.5–8.5 and application rates above 2% notably decreased Cd absorption in crops. These results contribute valuable insights into the applicability of biochar materials in agricultural soil–crop systems, offering guidance on their anticipated effectiveness in mitigating Cd contamination.

Straw biochar (BC) and four innovative biochar environmental materials (AFFA/BC) were synthesized via oxygen-limited pyrolysis at different ratios and applied for the remediation of lead (Pb)-contaminated soils. Accelerated aging, which mimics the effects of natural aging on heavy metal fixation properties, was induced through alternating dry and wet conditions. Two models, which are based on conditional probability-induced failures, were developed to characterize the aging process more effectively. The results indicated that the novel biochar material presented elevated Si, Al, and Na contents, increased specific surface area, pore volume, and yield, and the formation of chemical bonds such as T-O-T and T-O (T = Si or Al). Simultaneously, synchronous and asynchronous spectral analysis methods were used to demonstrate that fly ash leads to the formation of new chemical bonds and protects the functional groups of biochar from the destructive effects of high temperatures. Compared with the original biochar, the application of the new biochar material to Pb-contaminated soil increased the soil pH, cation exchange capacity (CEC), and soil organic matter (SOM) content while reducing toxic Pb leaching, resulting in conversion to a more stable residual state. Throughout wet–and–dry cycles, the Pb leaching concentration from the soil gradually increased, with AFFA/BC-2 resulting in a lower aging rate. This study provides a method for preparing low-cost and green soil amendments, which have great potential for repairing HM-contaminated soil and achieving value-added utilization of coal-based solid waste and agricultural waste.