This study focused on the high-hydrodynamic sandy shoal Sanba Tan and the slow-flow sedimentary clay shoal Wugui Zhou in the Jingjiang section of the Yangtze River. The response mechanisms between the composition of SDOM and phosphorus forms were analyzed using EEMs-PARAFAC and sequential extraction methods. Significant compositional differences were observed between the SDOM from Sanbatan and Wuguizhou. Sanbatan was dominated by protein-like components, whose high biological activity, coupled with a high proportion of Fe/Al-P, was found to jointly govern the distribution of phosphorus forms. In contrast, the SDOM from Wuguizhou was primarily characterized by humic-like components, whose high aromaticity and strong chelating capacity were identified to promote the accumulation of organic phosphorus, which was significantly higher than that in Sanbatan. A significant negative correlation was observed between protein-like components and Fe/Al-P (P<0.05), while the humification index was significantly positively correlated with organic phosphorus (P<0.05). These results suggested that SDOM influences phosphorus forms through two primary pathways: competition with metal oxides for adsorption sites and alteration of microbial metabolism. At Sanba Tan, SDOM was more readily precipitated with iron-aluminum oxides, thereby retaining more Fe/Al-P. Conversely, the low-to-medium molecular weight protein-like SDOM in Wuguizhou accelerated the decomposition and mineralization of organic phosphorus. The influence of SDOM on phosphorus forms in sandbars of the mid-Yangtze River was elucidated for the first time in this study, providing theoretical support for the phosphorus trapping function associated with the hydrological regulation of large rivers.

Given high concentrations of chemical oxygen demand (COD), ammonium nitrogen (NH₄⁺-N), suspended solids (SS), and poor biodegradability of concentrated swine farm wastewater, a combined treatment process of "pretreatment-biochemical treatment- advanced treatment" was employed in this study, specifically designed as "solid-liquid separation → anaerobic fermentation → A/O → MBR." By comparing influent characteristics and pollutant removal efficiency between summer and winter, the energy consumption and greenhouse gas (GHG) emission profiles of the system were systematically analyzed. The average effluent COD and TN in the summer were significantly lower than those in the winter (711.21mg/L and 61.78mg/L, respectively), indicating that low temperature significantly inhibit the treatment efficiency. The A/O unit dominated energy usage, with a consumption of 7.65 (kW·h)/m³, accounting for 56.48% of total energy demand. The annual GHG emissions totaled 1364.41t CO₂-eq, with an emission intensity of 15.53kg CO₂-eq/m³. The emission intensities per unit COD and TN removed were 1.33kg CO₂-eq/kg COD_removed and 10.89kg CO₂-eq/kg TN_removed, respectively. Further analysis revealed that external electricity consumption contributed to 72.98% of total GHG emission, followed by nitrous oxide (N₂O) release (25.99%). Through the regulation of seasonal process parameters, the development of multi-mode operation strategies, and the integration of online monitoring technologies, the precise control of the treatment process is optimized to achieve the goals of energy saving, consumption reduction, and low-carbon operation.

The soil-water partition coefficient (K_d) of per- and polyfluoroalkyl substances (PFAS) was predicted using machine learning (ML) models, and their partitioning behavior in soils was elucidated. A dataset comprising 1,227 samples of 47 PFAS was employed, with 16 PFAS physicochemical properties and soil parameters used as input features. It was demonstrated that the lgK_d values ranged from -1.40 to 3.95. When the number of CF₂ groups exceeded 5and the molecular weight (MW) was greater than 400g/mol, significant linear relationships were observed between lgKd and both the CF₂ number and MW, with R² values of 0.96 and 0.94, respectively. The influence of soil properties on PFAS adsorption was found to be dependent on the type of PFAS: non-zwitterionic PFAS were mainly affected by organic carbon content and silt content, whereas zwitterionic PFAS were primarily influenced by silt and sand content. After parameter optimization, the ML model exhibited good predictive performance, achieving an R² of 0.85, an RMSE of 0.35, and an MAE of 0.26. MW, organic carbon content, water solubility (lgS), and net charge density were identified as the most important features, with contribution rates of 31.6%, 29.8%, 19.7%, and 10.0%, respectively. Three-dimensional interaction analysis indicated that when soils with high organic carbon content, high cation exchange capacity (CEC), and low pH were combined with PFAS of large MW, lgK_d exceeded 0.40, reflecting strong adsorption. Conversely, under conditions where CEC was below 8.00 cmol/kg, organic matter content was less than 1.00%, and MW was below 380g/mol, lgK_d was lower than 0.40, indicating weaker adsorption and higher potential for environmental migration. The findings provide a reliable tool for predicting the adsorption behavior of PFAS.

To uncover the underlying mechanism through which government behavior shapes the evolving relationship between economic growth and environmental protection, panel data from 284 Chinese cities over the period 2003~2022 were employed. After verifying the existence of the Environmental Kuznets Curve (EKC), a moderated mediation model was constructed to systematically examine the moderating effect of government environmental attention on the EKC and its underlying mechanisms, and the heterogeneity of this effect was further empirically analyzed. The results indicated that a significant inverted U-shaped EKC relationship was observed at the urban level in China, and that government environmental attention exerted a significant negative moderating effect on this relationship, which was shown to be robust. Industrial structure upgrading and green technological innovation were found to play partial mediating roles in the moderating mechanism, with the mediating effect of green technological innovation being more pronounced. The moderating effect of government environmental attention exhibited heterogeneity and was not statistically significant in high-income regions. In light of the “dual carbon” goals, local governments should be guided to allocate attention resources in a more rational and efficient manner, with emphasis placed on the synergistic effects of technological progress and industrial transformation, and to formulate differentiated regional development policies tailored to local conditions, so as to effectively promote China’s low-carbon economic transition and high-quality development.

Based on the statistical data of environmental emergencies directly dispatched by the Ministry of Ecology and Environment from 2005 to 2022, this study used the standard deviation ellipse and mean center to explore the spatiotemporal variability of environmental emergencies, the results showed that the total quantity of environmental emergencies in China exhibited a downward tendency. The spatial mean center of environmental emergencies moved to the southwest of China, spanning a total distance of 734 kilometers in the past 17years, Hubei and Shanxi provinces had replaced Zhejiang, Guangdong and Jiangsu provinces as new high-incidence regions. Through the analysis of the characteristics of environmental emergencies, including the causes, pollution media and pollutants, it is found that production safety accidents were the primary cause of environmental emergencies, accounting for 45.12% of the total, followed by traffic accidents, which had surpassed production safety accidents in proportion over the past two years. Water pollution incidents were the most frequent environmental emergencies, and among the particularly major and the major environmental emergencies, water pollution incidents accounted for about 77.55%. Petroleum and heavy metals were two common pollutants in environmental emergencies, accounting for 16.31% and 5.88% of the total incidents, respectively. In the major and above level environmental emergencies, the proportion of heavy metals was higher than that of petroleum.

To investigate changes in the emission characteristics of key pollutants following the transition from household coal-burning to biomass clean heating in the Fenwei Plain, field measurements were conducted in rural areas of Xianyang using a variety of residential biomass-burning devices. Results showed that, in automatically fed pellet stoves, particulate emissions were dominated by PM_2.5, with emission factors for PM_2.5 and PM₁₀ of 1.14g/kg and 1.28g/kg, respectively, significantly lower than those of traditional stoves. Water-soluble ions in PM_2.5 were dominated by K⁺ and Cl^-, accounting for 81.5 %~94.3 % of total ionic mass, which was 25.9 %~69.6 % higher than that in traditional stoves. Due to the use of cleaner fuels and more efficient combustion, the total carbon (TC) emission factor in PM_2.5 from pellet stoves ranged from 0.1to 0.4g/kg, in contrast to 0.6~3.6g/kg for traditional stoves. Levoglucosan (LG) in PM_2.5 from pellet stoves showed the lowest emission factor, with a lower LG/OC ratio than that of traditional stoves, indicating a reduced contribution of advanced stoves to organic carbon aerosol emissions. By integrating the experimentally derived LG emission factors into an established empirical model, we estimated that the clean-heating transition had reduced the contribution of residential biomass burning to organic carbon aerosol by approximately 6.4 %.

In view of the characteristics of Ultisols (red soils) in southern China, this study developed two types of rice-specific biochar-based fertilizers (BBOF: bio-organic-inorganic biochar-based fertilizer; BBF: inorganic biochar-based fertilizer) using rice straw biochar as the base and coating technology. Pot and field experiments were conducted to evaluate their effects on soil chemical properties, microbial communities and rice yield under different pH value, nutrient statuses, and cadmium (Cd) pollution levels. Conventional fertilizer (CF) was used as the control, with three carbon treatments for experiments: direct biochar application (BC), BBOF, and BBF. The results showed that both BBF and BC improved rice yield under field conditions, with BBF enhancing the three key yield components; however, BBF had limited effects on soil improvement. BBOF and BC significantly increased soil pH and soil organic carbon contents(SOC) in the weakly acidic (WA) soil and the strongly acidic soil (SA) with Cd pollution(P<0.05), demonstrating effective acid regulation and carbon sequestration, but had limited effects in low-nutrient acidic (LN) soils. The impact of carbon treatments on soil nutrients varied with soil type: in WA soils, all three treatments significantly increased available phosphorus (AP), available potassium (AK), and dissolved organic carbon (P<0.05); in SA soil, AK was significantly reduced (P<0.05); and in LN soil, ammonium nitrogen(NH₄⁺-N) and nitrate nitrogen levels were notably altered, with BC also significantly increasing AK content (P<0.05). Other soil properties showed no significant response to biochar treatments. Compared with BC, biochar-based fertilizers reduced the amount of exogenous biochar applied and thereby decreased soil Cd input, indicating higher environmental safety. Microbial community analysis revealed that none of the biochar treatments had significant effects on fungal communities (P>0.05), but all affected bacterial communities, with an impact intensity order of BC>BBOF>BBF and a soil bacterial communities response order of LN>SA>WA. Both BC and BBOF regulated bacterial communities in a similar way by significantly increasing the relative abundances of key phyla (Myxococcota, Methylomirabilota, and Acidobacteria) and important functional families (Rokubacteriales_unclassified, Anaeromyxobacteraceae, Bradyrhizobiaceae, and Nitrospiraceae), while significantly decreasing the relative abundances of Planctomycetota (phyla level) and Subgroup_7_unclassified and Isosphaeraceae (family level) (P<0.05). Correlation and redundancy analyses indicated that shifts in soil bacterial communities were closely related to changes in soil chemical properties, with different driving factors identified across soils: AP in WA, SOC in SA, and NH₄⁺-N in LN. This suggests that the regulatory effects of carbon treatments are highly soil-dependent. In conclusion, the bio-organic-inorganic biochar-based fertilizer demonstrated advantages in improving soil environmental conditions and regulating microbial communities in rice-growing red soils, showing potential to replace direct application of biochar. However, its yield enhancement effects and application strategies require further study and optimization.

The research progress of high background of soil heavy metals related to carbonate rocks was systematically reviewed from the aspects of spatial distribution, element combination, spatial coverage, controlling factors, formation process, and risk characteristics. At present, it was generally believed that the main causation for the formation of this type of high background was the “secondary enrichment” of elements in the weathering process of parent rock, that is, the leaching of major elements, e.g. Ca, caused the relative enrichment of trace elements, e.g. Cd. In this process, iron and manganese minerals played an important role in the in-situ concentration of these elements. From the geographical perspective, the hot and humid climate was conducive to the formation of a higher background content. In general, Cd and other elements in soil developed from carbonate eluvium had the character of “high background with low activity”, while in the alluvial areas formed by carbonate weathered materials, high acid soluble state of Cd might have occurred with risks of activation under conditions such as soil acidification. With high spatial variation of soil heavy metals in such areas, especially in the medium and small spatial scales, problems such as differentiation between natural background and anthropogenic pollution, quantitative recognition of relative risks, and development of control measures for environmental management, were required to be solved in the future study.

Using meteorological station observations, ERA5-L and reanalysis data, and Landsat remote sensing imagery from 2010 to 2023, we analysed the spatiotemporal characteristics of dust storms in the Ebinur Lake Basin of Xinjiang Uygur Autonomeus Region, northwest China. The generalized grey correlation model was applied to quantitatively assess the influence of surface wind speed, soil moisture, and vegetation coverage on the frequency of dust storm occurrences. The results showed an overall upward trend in dust storm days during 2010~2023 (+0.08d/a). In particular, there was a significant increase from 2010 to 2014 (+0.60d/a), followed by a short decline from 2014 to 2017 (−0.70d/a), and a rise after 2018(+0.31d/a). Spring was identified as the peak season for dust storm occurrences, with a lower frequency observed in summer and autumn, and no recorded events in winter. Spatially, the Jinghe meteorological station emerged as the high-frequency centre over the past 14 years. Compared with the late 20th century, the standard deviation of annual dust storm days across the five meteorological stations decreased by 88.42%, indicating a substantial reduction in regional disparities. It revealed that surface wind speed was the most critical driver of dust storms. Soil moisture was the second most influential factor, showing a distinct seasonal lag effect, while vegetation coverage exerted a comparatively minor influence on dust storm occurrence.

Analyzing the spatiotemporal variation and influencing mechanisms of dry deposition is crucial for identifying pollution sources, atmospheric pollution control, soil environmental management, and agricultural pollution prevention. Focusing on the Xiangjiang River Basin, a vital grain producing region in China, this study estimated PM_2.5 dry deposition fluxes using empirical parameterization formulas and multi-source data, including remote sensing PM_2.5 concentrations, ERA5 reanalysis meteorological data, and ground-based monitoring. The long-term spatiotemporal characteristics of dry deposition across the basin and three zones delineated by three lines for land use (agricultural zones, ecological preservation zones, and urban development zones) were investigated. Furthermore, the random forest model was employed to quantify the contributions of influencing factors and elucidated the dominant mechanisms driving dry deposition. Results show thatthe dry deposition fluxes presented a spatial pattern of high in the north and central areas, low in the south and periphery. Urban development zones had the highest dry deposition flux (1.42g/m²), followed by agricultural zones (1.06g/m²) and ecological preservation zones (0.80g/m²). Since 2000, dry deposition fluxes have shown a declining trend at a rate of -0.017g/(m²·a), with significant decreases in high PM_2.5 concentration areas. Residential emissions (2.43±0.04), air temperature (0.71±0.01), industrial emissions (0.69±0.02), and relative humidity (0.59±0.01) were identified as dominant factors influencing PM_2.5 dry deposition. Considering the spatial heterogeneity of mechanisms in influencing factors, tailored atmospheric pollution control measures are recommended to achieve targeted pollution mitigation.

This study applied the IPCC methodology to estimate carbon emissions in Shanxi Province from 2010 to 2022. A Kaya-LMDI model was employed to identify the key drivers influencing carbon emissions in the region. Using 2022 as the baseline year, the LEAP-Shanxi model was developed to forecast carbon emissions from 2023 to 2060. Economic development acted as the primary driver of carbon emission growth, whereas energy intensity emerged as the dominant restraining factor; By 2060, under four specific scenarios—industrial energy efficiency improvement, low-carbon transportation transition, accelerated new energy adoption, and optimized power structure—energy conservation and carbon reduction effects would become particularly pronounced, these measures could reduce sectoral emissions by 42.16, 3.21, 1.38 and 31.73Mt respectively; Both baseline and integrated scenarios indicate that Shanxi Province could reach its carbon peak by 2030, with projected emissions of 764.33 and 742.34Mt respectively; The comprehensive scenario demonstrates a potential reduction of 107.42Mt in carbon emissions compared to the baseline projections for 2060. These findings can offer a robust theoretical foundation for Shanxi Province to develop targeted low-carbon strategies and implement effective emission reduction measures.

This study employed a partial denitrification-Anammox biofilm system (PDA-Bf) to treat simulated municipal wastewater, with a focus on exploring its nitrogen removal performance under mesophilic conditions (34℃). After 317 days of operation, the results indicated that under an influent carbon-to-nitrogen ratio (C/N) of 2.1, the total nitrogen (TN) concentration in the effluent was reduced to 10.94mg/L, with an average TN removal rate of 82.6%. Moreover, the contribution of the Anammox pathway to TN removal significantly increased over time. The study found that the abundances of the denitrifying genus Thauera and the anammox genus Candidatus Brocadia in the biofilm significantly increased with operation time. Thauera increased from 0.37% on day 250 to 4.11% on day 305, and Ca. Brocadia rose from 0.27% to 3.51%. The two genera worked well in synergy. The outer layer of the biofilm had a high abundance of genes encoding nitrate reduction, such as narG (55152hits), narH (35866hits), and narI (16506hits), indicating that this area was suitable for the growth of denitrifying bacteria and provided nitrite for the Anammox reaction. In contrast, the inner layer of the biofilm had a higher abundance of the Anammox-related hdh gene (1174hits), and lower abundances of nitrite reduction genes nirK (13400hits) and nirS (3954hits), maintaining a higher nitrite concentration and creating a suitable environment for Anammox bacteria (AnAOB). This stratified microbial community structure suggests that the outer and inner layers of the biofilm are respectively suitable for the growth of Thauera and Ca. Brocadia, jointly promoting the efficient nitrogen removal performance of the system.

The study focused on the spatiotemporal distribution characteristics of retired power batteries and critical metal resources in China. It used the LSTM neural network model to predict the sales volume of electric vehicles. It also estimated the stock of retired power batteries and critical metal resources by applying the Weibull distribution model, and further analyzed their spatial distribution characteristics. The research found that from 2012 to 2035, there were significant regional differences and spatial agglomeration in the cumulative retirement volume of power batteries and the cumulative stock of critical metal resources in China. Currently, Guangdong, Zhejiang, Shandong, Beijing, Shanghai, and Henan had the highest cumulative retirement volume of power batteries and the highest cumulative stock of critical metal resources, while Tibet, Qinghai, Ningxia, Heilongjiang, Xinjiang, and Inner Mongolia had the lowest. By 2035, Jiangsu was projected to replace Beijing as one of the six provinces with the highest cumulative retirement volume, with a cumulative retirement volume of 2.2546 million tons. Gansu was projected to replace Inner Mongolia as one of the provinces with the lowest cumulative retirement volume, with a cumulative retirement volume of 153,600 tons. In terms of spatial agglomeration, the high-high agglomeration area was found to be Jiangsu, while the low-low agglomeration areas included Xinjiang, Qinghai, Sichuan, Gansu, Inner Mongolia, and Jilin. It was projected that the scope of high-high agglomeration would expand further in the future (with Anhui and Shanghai being added), while the scope of low-low agglomeration would contract (with Sichuan no longer being part of this category). Regarding the distribution of processing capacities of the white-listed enterprises for the comprehensive utilization of retired power batteries, it was found that although China had an overall surplus in processing capacity, there was a spatial misalignment. It was anticipated that in the future, the recycling and regeneration capacities in Shanghai, Jiangsu, Hebei, Guangxi, Tianjin, Guangdong, Zhejiang, Yunnan, and Henan would not be sufficient to meet their own demands, and it was necessary to further optimize the layout of recycling and processing capacities.

To investigate the causes of ozone (O₃) pollution in the Pearl River Delta (PRD) region under non-high-temperature conditions, this study analyzed differences in O₃ pollution characteristics between high-temperature days (daily maximum temperature ³28°C) and non-high-temperature days (daily maximum temperature <28°C) using air quality and meteorological data from 2015 to 2023. The key findings are as follows: O₃ pollution in the PRD primarily occurred on high-temperature days, yet 17.2% of total polluted cities were observed during non-high-temperature days. High-temperature pollution was concentrated in central and southwestern PRD, while non-high-temperature pollution predominantly occurred in the southwest. Non-high-temperature O₃ pollution typically occurred under conditions of daily maximum temperature (25.0~27.2°C), relative humidity (44.9%~56.8%), and sunshine duration (7.7~9.8h). Compared to high-temperature pollution days, non-high-temperature pollution days exhibited 6.0% lower relative humidity and a more concentrated distribution of sunshine duration in higher intervals. The SHAP method demonstrated that relative humidity is the most influential meteorological factor affecting O₃ concentrations. On high-temperature days and non-high-temperature days, the contribution of relative humidity to the O₃_8h concentration can reach up to 30 and 60μg/m³, respectively. Low relative humidity (<65%) paired with prolonged sunshine duration synergistically promoted O₃ formation, whereas high relative humidity (>65%) combined with reduced sunshine suppressed it. Additionally, the pronounced impact of sunshine duration under non-high-temperature conditions highlights sufficient solar radiation as a prerequisite for O₃ generation. Under non-high-temperature conditions, NO₂ exerts a weaker influence on O₃ concentrations compared to high-temperature days, with its contribution to O₃ concentration variations quantified at approximately 15 μg/m³.

Based on panel data from 30 provinces in China from 2011 to 2021, this paper uses the coupling coordination degree model, local spatial autocorrelation analysis, and system GMM regression method to systematically examine the spatiotemporal evolution characteristics and influencing factors of the coupling coordination level between China's new quality productivity and carbon emissions. The study found that the annual average of the new quality productivity index increased from 0.1 to 0.23, and the carbon emission intensity decreased from 2.548 to 1.942, indicating a continuous improvement in the synergy level between the two. The coupling coordination degree shows a gradient differentiation of "high in the southeast and low in the northwest". Eastern coastal provinces have risen to high-quality coordination based on digital economy and green technology innovation, while northern energy bases have long been in low value agglomeration due to the "high carbon low efficiency" path dependence. Economic development, opening up to the outside world, and innovation levels significantly promote the improvement of coordination, while environmental regulations have a restraining effect due to the "compliance cost squeeze". Regional heterogeneity analysis shows that the eastern region strengthens technology spillover through global value chain embedding, the northeast is constrained by structural contradictions in heavy industry, and the western region suppresses innovation diffusion due to geographical decline and lagging infrastructure.

This study focused on the protective mechanism of astaxanthin (AST) against arsenic-induced mitochondrial-dependent apoptosis in mouse hippocampal neuronal cells (HT-22). An in vitro sodium arsenite (NaAsO₂) exposure model was established in HT-22cells, including control, NaAsO₂-exposed (4, 6, 8, 10μmol/L), AST-treated (2μmol/L), and AST-intervened (2μmol/L AST + 10μmol/L NaAsO₂) groups, so as to evaluate the effects of AST intervention on arsenic-induced neural lesions. DCFH-DA was used to detect the level of reactive oxygen species (ROS). An ATP kit was used to assess the energy metabolism of mitochondria via ATP production. The levels of protein, including PGAM5 and signaling pathways of mitochondrial dynamics (fission/fusion), autophagy, and apoptosis, was analyzed by Western blot. Results showed that NaAsO₂ exposure significantly induced increased generation of ROS (P<0.05), decreased synthesis of ATP (P<0.05), activation of PGAM5, up-regulation of p-Drp1-Ser616, and down-regulation of p-Drp1-Ser637 and mitochondrial fusion proteins (OPA1, MFN1), leading to excessive mitochondrial fission. Intervention by AST effectively reversed these effects (P<0.05), which were demonstrated by the inhibition of PGAM5-mediated mitochondrial fission, alleviation of oxidative stress, and reversion of energy metabolism. It is supposed that AST plays a role in AMPK-mTOR-dependent autophagy and mitochondrial apoptosis. On one hand, AST inhibited AMPK phosphorylation which subsequently activated mTOR and down-regulated LC3II/LC3I ratio (autophagy marker); on the other hand, AST down-regulated pro-apoptotic proteins (Bax, cleaved-caspase-3), and upregulated anti-apoptotic Bcl-2 (P<0.05), thereby regulating AMPK-mTOR-dependent autophagy and mitochondrial apoptosis. This study suggests that AST protects against NaAsO₂-induced neurotoxicity by targeting PGAM5through the recovery of mitochondrial dynamics, improvement of energy metabolism, and regulation of AMPK-mTOR-autophagy-apoptosis axis, providing highlights on potential therapeutic strategies for arsenic-related neuronal damage.

By integrating network toxicology, transcriptomics, and in vivo zebrafish assays, this study systematically investigated the differential toxicities and underlying molecular mechanisms of an alkyl phosphate (TiBP), a brominated phosphate (TDBPP), and a chlorinated phosphate (TCPP), with the aim of elucidating structure-dependent toxic effects of organophosphate flame retardants (OPFRs). The results showed that the halogens affected the accuracy and comprehensiveness of network toxicology predictions. Zebrafish experiments further confirmed that combining network toxicology with transcriptomic analysis provided a more comprehensive characterization of OPFR-induced toxic mechanisms. In terms of acute toxicity, TDBPP exhibited the lowest LC₅₀ (922.3μg/L), followed by TiBP (21.14mg/L) and TCPP (37.56mg/L). Mechanistically, the three compounds elicited toxicity through distinct gene-pathway networks. Owing to their halogen substituents, TDBPP and TCPP showed stronger metabolic and endocrine disruption, as evidenced by a 1.6-fold and 2-fold increase in lipid accumulation, respectively, compared with the control group under medium-dose exposure. In contrast, TiBP predominantly induced neuroimmune toxicity. At low doses, the non-halogenated structure of TiBP rendered zebrafish more sensitive to neuroconductive inhibition, resulting in the strongest inhibition of locomotor ability, with approximately 50% reductions in both swimming speed and distance. At high doses, the presence of chlorine atoms in TCPP enhanced receptor binding ability, resulting in predominant toxicity across the neural, metabolic, and immune systems. Although the brominated structure of TDBPP conferred the highest acute toxicity, its comprehensive effect at equitoxic doses was weaker than that of TCPP, potentially due to a delayed manifestation of metabolism-associated carcinogenicity. Overall, this study employed a multi-dimensional integrative strategy to elucidate how molecular structural features of OPFRs govern their biological effects.

A novel efficient phosphate adsorbent (CF-La) was synthesized by treating activated carbon fibers using lanthanum with impregnation method. The adsorption isotherms, adsorption kinetics, one-way experiments, and actual water sample tests were carried out. The adsorption isotherm studies demonstrated that the adsorption process conforms to the Langmuir model, indicating monolayer adsorption, with the maximum adsorption capacity of 5.78mg/g at 333K. Kinetic analyses revealed that the adsorption process follows the pseudo-second-order kinetic model, involving both physical and chemical adsorption mechanisms. The pH and competitive ions experiments indicated that the best adsorption effect was achieved under neutral environment, and the best adsorption result was achieved under neutral condition. The effects of five anions on CF-La were in the following order: S^2-＞ SO₄^2- ＞CO₃^2-＞ Cl^-≈NO₃^-. The recyclability assessment through five adsorption-desorption cycles showed that CF-La retained ＞80% adsorption and desorption efficiency. By conducting characterization with SEM and BET on the modified material before and after, it is confirmed that lanthanum has been successfully loaded onto the surface. Analysis of the materials before and after adsorption using XPS and FTIR indicates that the synthesized material features a mesoporous structure, and the presence of lanthanum in two different oxidation states on the surface is beneficial for enhancing the adsorption efficiency. The experiment on sample water verified that CF-La showed excellent adsorption performance on inorganic phosphorus and organic phosphorus in Chaohu Lake, Anhui Province, and the water samples from Chaohu Lake in summer and winter could be reduced to within the threshold of cyanobacterial bloom after adsorption for 10h.

With the rapid development of the renewable energy industry, the usage of lithium iron phosphate batteries has soared. Therefore, the recycling of spent batteries has become a social focus. The selective leaching method can effectively extract lithium, reduce impurities, and improve recycling efficiency. This paper systematically reviews various selective lithium leaching techniques, including chemical oxidation, acid-assisted leaching, electrochemistry, high-temperature roasting, mechanochemistry, and so on, which further compares their respective advantages and disadvantages from the aspects of technical economy and environmental benefits. The results indicate that the chemical oxidation method has advantages in cost control and operational flexibility, while the electrochemical method is more and environmentally friendly and green. For the selective recycling of spent lithium iron phosphate batteries, more efficient, environmentally friendly, and economical recycling solutions should be developed in the future. This will provide new ideas for exploring selective recycling strategies for lithium iron phosphate batteries, which can promote comprehensive and coordinated development of the economy, environment, and technology, and thereby build a virtuous cycle system of new quality productivity.

Taking Xingtai, a typical industrial city, as the study object, the pollution characteristics of O₃ were analyzed based on air quality monitoring and meteorological data from 2018 to 2022. The geographical detector method was employed to investigate the individual and combined impacts of meteorological factors and precursors on O₃ pollution. An air quality model was used to assess the sensitivity of O₃ generation, and EKMA curves were adopted to determine optimal emission reduction ratios in different control areas. The research revealed that the monthly average O₃ concentrations in Xingtai exhibited an inverted V-shaped pattern, with peak values observed in June (199.28μg/m³) and trough values recorded in January and December (37.16μg/m³). The hourly O₃ concentrations and their variation ranges across seasons followed the order: summer ＞ spring ＞ autumn ＞ winter. Significant seasonal differences were identified in the driving factors affecting surface O₃ concentrations. On an annual scale, meteorological factors were found to exert greater influence on O₃ pollution than precursor pollutants. Temperature and solar radiation were identified as the main positive driving factors for O₃ concentration increases, while humidity and precipitation served as primary negative drivers. CO and NO₂ were positive drivers in spring and summer but showed opposite effects in autumn and winter. The central urban area with surrounding counties, along with Qinghe and Linxi counties, were classified as VOCs control areas. The northwestern and central-eastern counties were designated as synergistic control areas for both VOCs and NO_x. The optimal emission reduction ratios for between VOCs and NO_x were determined to be 1.5:1and 1:1, respectively, in the different control areas.

Sediment cores from two major estuarine regions in the Maowei Sea were analyzed for grain size, total organic carbon (TOC), total nitrogen (TN), total phosphorus (TP), and carbon and nitrogen stable isotopes (δ¹³C and δ¹⁵N) to investigate the distribution characteristics of biogenic elements and organic matter sources. The results showed that the contents of TOC, TN, and TP in core sediments of the Maolingjiang River Estuary (MRE) were 0.09%~0.61%, 0.01%~0.05%, and 0.006%~0.018%, respectively, whlie those in core sediments of the Qinjiang River Estuary (QRE) were 0.63%~0.91%, 0.05%~0.09%, and 0.034%~0.060%, respectively. The vertical distributions of TOC, TN, and TP in core sediments of the MRE showed an increasing trend from surface to sub-surface layer, and then gradually decreased with depth, which exhibited minimal the vertical variability. In core sediments of the QRE, the vertical distributions of TOC, TN, and TP exhibited a biphasic pattern with initial decreases followed by increases with depth. The TOC, TN and TP contents in core sediments of the MRE showed significant positive correlations with fine particles (silt and clay) (P < 0.01), while the TN content in core sediments of the QRE exhibited significant positive correlation with fine particles (silt and clay) (P < 0.05), demonstrating that fine particles play a key role in controlling the distributions of biogenic elements in estuarine sediments of the Maowei Sea. The three-end-member mixing model revealed that terrestrial input dominated sedimentary organic matter in both the MRE (48.2 ± 26.0%) and QRE (48.0 ± 13.0%), with marine plankton contributing (32.0 ± 18.5)% and (40.1 ± 9.8)%, respectively, and mangrove litter accounting for (19.8 ± 8.3)% and (11.9 ± 3.7)%, respectively. Terrestrial input was the primary source of organic matter in core sediments from the main estuarine areas of the Maowei Sea.

To investigate the variation rules, pollution characteristics, and their regional transport of fine particulate matter (PM_2.5) components in different seasons from Hohhot and Wuhai cities. In this study, the concentration of PM_2.5 and its chemical components, such as water-soluble ions, organic carbon (OC), elemental carbon (EC), and metallic elements, and meteorological data, were obtained from the atmospheric super station in June-August and December of 2022, and January-February of 2023 from Hohhot and Wuhai. The sources and transport paths were also analyzed according to the Positive Definite Matrix Factor Decomposition (PMF) model and the Backward Trajectory (HYSPLIT) model. PM_2.5 mass concentration in winter was higher than that in summer in both cities. PM_2.5 mass concentration in Wuhai was higher than that in Hohhot in the same season. PM_2.5 in both cities is alkaline in winter and summer. The alkalinity of PM_2.5 in Hohhot was stronger than that in Wuhai during summer, and weaker than that in Wuhai during winter. The content of K, Mn, Cu, Ba, Ti, K⁺, and Cl^- in PM_2.5 in winter was higher than that in summer in the two cities. The two cities were more affected by biomass combustion, coal-fired emissions, and motor vehicle emissions in winter. PM_2.5 in Hohhot during summer mainly came from combustion sources, secondary inorganic sources, industrial sources, soil dust sources, and mixed sources motor of vehicle and road dust, while in winter it mainly came from coal combustion sources, biomass combustion sources, secondary inorganic sources, soil dust sources, mixed sources of motor vehicle and road dust, and mechanical wear sources. PM_2.5 in Wuhai during summer mainly came from combustion sources, secondary inorganic sources, industrial sources, soil dust sources, motor vehicle sources, road dust sources, while in winter it mainly came from combustion sources, secondary inorganic sources, industrial sources, soil dust sources, mixed sources of motor vehicle and road dust, and mechanical wear sources. Hohhot city was dominated by secondary sources in both summer and winter. Wuhai city was dominated by the mixture of motor vehicle and road dust in summer, while by secondary inorganic sources in winter. Hohhot City was mainly affected by air currents from southern Shanxi Province, northern Shaanxi Province, and southern Mongolia in summer, with potential source areas being southern Shanxi Province, southern Hebei Province, and northern Henan Province. Wuhai was mainly affected by air currents from eastern Xinjiang, Alxa League, southern Shaanxi Province, and Bayannur City in summer. Hohhot and Wuhai were affected by air currents from Alxa League and southern Mongolia in winter, with the difference that PM_2.5 transport in Wuhai in winter was also affected by air currents from northern Xinjiang. The potential source areas for winter in Hohhot are local, Baotou., Bayannur, Ordos, northeastern Alashan League, and the southern region of Mongolia, while that in Wuhai City during summer and winter were the eastern part of Xinjiang, Hexi Corridor region, Alashan League, Ordos City, Ulanqab City, and Wuhai City. The research results provide data support for the prevention and control of air pollution in typical cities along the Yellow River Basin.

In order to investigate the impact of future climate change on high temperatures and ozonepollution, summer temperatures and O₃ concentrations for different years in the 21st century were simulated using downscaling based on the CMIP6-WRF/Chem model. The results of the study indicated that, in comparison with 2014, the rate of temperature increased in typical cities within the Beijing-Tianjin-Hebei region would slow down by 2100 under the SSP2-4.5 scenario with peak warming rates of 0.29°C/decade, 0.46°C/decade, and 0.33°C/decade for Beijing, Tianjin, and Shijiazhuang respectively. Under the SSP5-8.5 scenario, warming accelerated markedly, with rates of 0.63°C/decade, 0.80°C/decade, and 0.72°C/decade for the three cities. Under both scenarios, daily average O₃ concentrations and MDA8O₃ concentrations in Beijing, Tianjin, and Shijiazhuang all exhibited increasing trends, with growth rates of 1.1μg/(m³·decade), 1.5μg/(m³·decade) and 0.9μg/(m³·decade), and 1.2μg/(m³·decade), 1.3μg/(m³·decade) and 1.1 μg/(m³·decade), respectively. However, the number of days exceeding O₃ standards exhibited differing patterns, potentially linked to variations in O₃ concentrations between hot and non-hot days. Non-hot-day O₃ concentrations exhibited an increasing trend across all cities, with the largest increment occurring in Beijing under the SSP5-8.5scenario by 2035, rising by 12.9μg/m³. Conversely, O₃ concentrations decreased to varying degrees on high-temperature days, with the largest reduction occurring in Tianjin under the SSP2-4.5 scenario by 2100, decreasing by 13.9μg/m³. Under all scenarios, Tianjin's temperature penalty factor was lower than in 2014, indicating a consistent high-temperature suppression effect on O₃ across scenarios and years. The influence of air temperature on O₃ is non-linear, and relative humidity may modulate the relationship between high temperatures and O₃ concentrations.

This study investigated triclosan (TCS) and its environmental derivative 2,4,6-trichlorophenol (2,4,6-TCP) using zebrafish as a vertebrate model for a comprehensive, multi-level assessment that included morphological, physiological, biochemical, neurobehavioral, and molecular endpoints. Acute exposure of zebrafish embryos to gradient concentrations of TCS and 2,4,6-TCP induced pronounced developmental malformations, including shortened somites, yolk sac edema, spinal curvature, and delayed or absent swim bladder inflation, with clear dose-response relationships. Benchmark dose (BMD) analysis revealed compound-specific teratogenic sensitivities: pericardial edema was the most sensitive endpoint for TCS, accompanied by significant inhibition of body length and eye size, whereas yolk sac area was the most sensitive indicator for 2,4,6-TCP. The differences in morphological teratogenicity may be attributed to distinct target organs and modes of action. The LC₅₀ values for 120 hpf zebrafish larvae were 0.591mg/L for TCS and 1.137mg/L for 2,4,6-TCP, respectively. Both ECOSAR predictions and experimental results consistently indicated that TCS exhibited significantly higher developmental toxicity and lethality than 2,4,6-TCP for fish, Daphnia, and green algae. Behavioral analyses demonstrated that both TCS and 2,4,6-TCP significantly suppressed spontaneous locomotor activity of zebrafish larvae and disrupted light-dark response behaviors, indicating potential neurotoxic effects. Mechanistic investigations revealed that both TCS and 2,4,6-TCP induced oxidative stress, resulting in excessive accumulation of reactive oxygen species (ROS) in the brain, pericardium, and spine regions. This oxidative damage led to reduced neuronal proliferation, excessive neuronal apoptosis, and abnormal neurodevelopment. Neurobiochemical indicators further demonstrated impaired neurotransmitter transmission and cholinergic system dysfunction, characterized by decreased serotonin (5-HT) levels and inhibited acetylcholinesterase (AChE) activity.Target gene prediction and bioinformatics analyses identified 441 and 173 potential target genes for TCS and 2,4,6-TCP, respectively.Pathway enrichment analysis revealed that TCS primarily affected embryonic development by activating oxidative stress, inflammatory response, and endocrine disruption-related signaling pathways, whereas 2,4,6-TCP regulated developmental abnormalities by interfering with neurotransmitter transport, synaptic formation, and structural differentiation. Further analysis identified the top ten hub genes involved in the associated regulatory pathways, among which only three genes (hsp90aa1, esr1, and gfra) were shared between the two compounds. Approximately 70% of the identified hub genes were compound-specific. Protein-protein interaction (PPI) network analysis revealed that TCS was primarily enriched in the mitophagy, p53signaling, NOD-like receptor signaling, and necroptosis pathways, mediated by key regulators such as pparg, bcl2l1, casp3a, stat3, mmp9, src, and stat1a. In contrast, 2,4,6-TCP predominantly regulated the MAPK signaling pathway, cell cycle pathway, and progesterone mediated oocyte maturation pathway through cdc25b, top2a, cdk1, ptpn11a, pdgfrb, flt1, and erbb2. Four neurodevelopment-related hub genes were further screened and validated by RT-qPCR, confirming the mechanistic differences between TCS and 2,4,6-TCP.

Accurate estimation of CO₂ emissions at the regional scale, particularly in large urban agglomerations, is essential for effective greenhouse gas mitigation. In this study, the WRF-STILT model, combined with three prior anthropogenic CO₂ emission inventories (EDGAR v6.0, an improved version of EDGAR v6.0 integrated with GCG v1.0, and the ODIAC inventory) was used to simulate atmospheric CO₂ concentrations in the Yangtze River Delta during winter 2018. Observational data from a 70-meter tower in Quanjiao, Anhui province, served as the reference. A scale factor Bayesian inversion method was applied to optimize the simulation results, allowing estimation of anthropogenic CO₂ emission fluxes in the region. The results indicate that the CO₂ concentrations simulated by the WRF-STILT model effectively reflect the emission characteristics of the Yangtze River Delta. In winter, simulations based on the improved inventory aligned more closely with observations than those using EDGAR v6.0alone. The posterior CO₂ emission fluxes estimated using the EDGAR and improved inventories were (0.199 ± 0.005) and (0.200 ± 0.007) mg/(m²·s), respectively—representing decreases of 0.02 and 0.01mg/(m²·s) compared to the prior flux estimates. The Bayesian inversion method significantly optimized the prior emissions from the EDGAR inventory. When calculating total CO₂ emissions for the region using the improved inventory, power generation and industrial sectors were identified as the primary sources of uncertainty. Additionally, due to the low nocturnal boundary layer height, the model tended to overestimate the contribution of elevated emission sources near the observation site. Future simulations should ensure the WRF model accurately captures hourly boundary layer heights, and that vertical emission profiles of point sources are incorporated into emission inventories.

The persulfate-based advanced oxidation process demonstrates significant advantages in the removal of refractory organic pollutants. However, traditional activation methods are associated with high energy consumption and the potential generation of secondary pollution, which restricts the widespread application of this technology. Based on the photosensitive properties of dissolved organic matter (DOM) in secondary effluent, a practical self-activation peroxymonosulfate (PMS) reaction system using solar radiation was established. Systematic investigations were conducted on the effects of different persulfate types, initial pH conditions, and common inorganic anions on PMS decomposition efficiency, accompanied by comprehensive characterization of physicochemical properties and structural transformations in DOM before and after the reaction. The results indicated that the all fractions of secondary effluent could effectively activate PMS, with the hydrophilic (HI) fraction exhibiting the most efficient activation, achieving a PMS decomposition rate of up to 26.7% under neutral conditions. During the decomposition process, reactive oxidative species generated from PMS interacted with DOM, leading to the gradual degradation of its aromatic structures and a reduction in molecular weight. The intensity of fluorescent substances, such as humic-like compounds, significantly decreased, while the proportions of lignin, lipids, tannins, and other compounds had notable changes. These observations indicated that the DOM in secondary effluent achieved self-degradation through effective activation of PMS. Humic-like compounds and lignin in secondary effluent DOM served as the primary electron donors. Upon excitation by sunlight, they transferred photogenerated electrons to PMS, thereby activating it and triggering the self-degradation of DOM. The self-catalytic system of using the DOM in actual secondary effluent in this study without the need for external catalysts, avoiding high energy consumption and secondary pollution.

This study takes the Huaihe River Basin as the research area, integrates ecosystem service assessment, biodiversity analysis, and landscape connectivity analysis, and identifies ecological sources by combining nature reserves. Eight key resistance factors were selected, including landscape ecological risk, MSPA (Morphological Spatial Pattern Analysis) landscape types, vegetation coverage, topographic relief, land use types, night-time light index, distance to rivers, and distance to roads. A comprehensive resistance surface was constructed using the entropy weight method. Based on circuit theory, ecological corridors were built and their grades were determined. Furthermore, key areas for ecological restoration were identified by recognizing ecological pinch points and barrier points. The results showed that a total of 24 ecological sources were identified in the Huaihe River Basin, with a total area of 23,590.30km², mainly distributed in cities such as Lu'an and Xinyang. There were 41ecological corridors, among which 19 were key ecological corridors. A total of 781 ecological pinch points and 142 ecological barrier points were identified. The main land use types of ecological pinch points were cultivated land, water areas, and forest land. Xuzhou City had the largest area of ecological pinch points, while Chuzhou City had the largest number of ecological pinch points. The total area of ecological pinch points requiring priority protection and restoration was 405.76km², and the total area of ecological barrier points was 948.99km². The Huaihe River Basin presents a spatial pattern of "three cores, four belts, and multiple points". Guided by the principle of prioritizing natural ecology and supplementing with artificial measures, this study proposes scientific protection and restoration strategies for key areas of different land types, aiming to enhance the integrity and connectivity of the ecosystem in the Huaihe River Basin. The findings provide a scientific basis and practical guidance for ecological protection and restoration in the Huaihe River Basin and other river basins.

This study investigated the advection and diffusion patterns of hydrogen sulfide (H₂S) in a prototype sewer network of a residential area in Xi'an, using Ventsim to simulate both natural and forced ventilation conditions. The results show that the simulated and measured values are within 10% difference, which confirms the reliability of the Ventsim simulation method. Forced ventilation increased the air velocity in sewer pipes by 8.8% compared to natural ventilation conditions. It was further found that utilizing only an intake or exhaust fan required 108s and 105s, respectively to completely expel hazardous gases from the sewage network. Simultaneous operation of both intake and exhaust fans significantly enhanced the migration rate of harmful gases, reducing the expulsion time to 55s. Nevertheless, using only an intake fan may cause H₂S to escape through small openings on manhole covers. These findings provide technical support for predicting and controlling hazardous gases within sanitary sewer networks, contributing to infrastructure safety and operational maintenance.

This review summarizes the extracellular electron transfer mechanisms in anaerobic ammonium oxidation (anammox) systems and strategies for their enhancement, categorizing the influence mechanisms of carbon-based materials on anammox bacteria into three aspects: conductivity of carbon-based materials, functional groups on their surfaces, and interactions between microbial communities and extracellular polymeric substances. Studies have demonstrated that biochar, activated carbon, carbon nanomaterials, and iron-carbon composites can regulate the anammox process by mediating extracellular electron transfer. Carbon-based materials primarily enhance anammox performance through shortening reactor start-up periods, improving nitrogen removal efficiency, and alleviating pollutant inhibition effects. These materials not only effectively enrich microorganisms but also promote the stability enhancement of granular sludge, demonstrating significant application potential in anammox systems. Future research should focus on material modification to further improve the sustainability of carbon-based materials in practical applications.

Polydimethylsiloxane (PDMS) is widely applied in daily-use products, medical treatment and power industry. In order to achieve its harmless disposal, the microbial green degradation approach was explored, and the pyrolysis characteristics, composition, production mechanism and surface hydrophobicity (CSH) of microbial cell membrane during the degradation process were analyzed. Results demonstrated that CGMCC 0452 strain exhibited strong tolerance to high-viscosity PDMS when polydimethylsiloxane (PDMS) was treated with Pseudomonas aeruginosa strain (CGMCC 0452). With the extension of degradation days, the CSH increased to 16%, and the CO stretching vibration of the carbonyl group in the chemical structure of the rhamnolipid chain was detected at 1712 cm^-1 by Fourier transform infrared spectroscopy. Gel permeation chromatography analysis revealed that the weight-average molecular weight and number-average molecular weight of PDMS decreased by 29130 Da and 21701 Da, respectively. Based on the above results, combined with comprehensive analysis of gas chromatography-mass spectrometry, it was determined that the long chain of polysiloxane was mainly degraded into cyclosiloxane oligomers (D5, D6, D8, D9), and the degradation products did not appear toxic and harmful substances. Finally, the CSH enhancement mechanism (rhamnolipid adsorption and cell membrane lipopolysaccharide loss) and cyclosiloxane oligomer formation mechanism were revealed from the micro level. This paper provides a novel research idea for the efficient and harmless treatment of polysiloxane, and offers a valuable reference for investigating the biodegradation mechanism of polymers.

This study investigates the relative contributions of anthropogenic and meteorological factors to ozone (O₃) variations in major cities on the northern slope of the Tianshan Mountains (Urumqi, Changji, Shihezi, Wujiaqu) from 2018 to 2023 using a stepwise multiple linear regression (MLR) model. Based on OMI satellite data (HCHO and NO₂ tropospheric column concentrations) and ground-based observation data (O₃ and NO₂), the fractional nucleation rate (FNR) threshold for the northern slope of the Tianshan Mountains was determined. The study highlights regional differences, seasonal patterns, and variations in the sensitivity of precursor substances. The results indicate that O₃ on the northern slope of the Tianshan Mountains generally exhibited a fluctuating upward trend, with an annual average concentration of 86.97μg/m³, and the O₃ concentration in the warm season (107.63μg/m³) was higher than that in the cold season (66.31μg/m³). The O₃ concentration decreased to its lowest level (86.71μg/m³) in 2020 attributed to the decreased emissions resulting from the pandemic. The annual growth rates varied significantly among the cities, with Changji at 3.87μg/(m³·a) and Shihezi at 1.51μg/(m³·a). Meteorological factors have a significant impact on O₃ concentration variations, with temperature and humidity as key factors. The contribution rates of meteorological factors in Urumqi and Wujiaqu were higher (50% and 60%, respectively), while those in Changji and Shihezi were lower (29% and 44%, respectively). The NO₂ column concentration showed a downward trend (annual decrease rate of 0.22 × 10¹⁵ molec/(cm²·a)), while the HCHO column concentration remained relatively stable, indicating that VOCs emissions may have increased. FNR analysis indicates that the ozone formation sensitivity (OFS) threshold was as follows: when FNR < 1.75, ozone formation was controlled by VOCs; when FNR > 3.67, ozone formation was controlled by NO_x; and when 1.75 < FNR < 3.67, it is in a transitional state. During the warm season (April to September), the sensitivity of O₃ photochemical production was mainly controlled by NO_x. This study reveals the spatiotemporal variation characteristics of O₃ formation and precursor sensitivities in the northern slope area of the Tianshan Mountains, providing scientific guidance for the development of more precise O₃ pollution control strategies.

This study investigated the characteristics of O₃ and its precursors in Dongguan during the autumns of 2018 and 2022. By integrating observational data, backward trajectory analysis, and box model simulations, we examined the changes in O₃ and precursor concentrations, O₃ formation pathways, and the evolution of control regimes during both polluted and clean periods, which provided insights into ozone pollution mitigation. The average O₃ concentration in Dongguan was higher in autumn 2022 than in 2018, whereas both the average concentrations of nitrogen oxides (NO_x) and volatile organic compounds (VOCs) decreased in 2022. Alkanes accounted for the largest proportion of total VOCs (TVOCs) in both autumn periods, while aromatics and alkenes contributed the most to ozone formation potential (OFP). Notably, the contribution of biogenic VOCs (specifically isoprene) to OFP increased from 6.0% in 2018 to 12.1% in 2022. Comparative studies between polluted and clean periods revealed that TVOC concentrations during polluted periods in 2018 (73.7×10^-9) and their growth rates (148.5%) were significantly higher than those in 2022 (26.1×10^-9 and 67.0%), driven primarily by alkanes and aromatics. In 2018, the OFP growth rate of alkanes was highest during the polluted periods, whereas aromatics dominated in 2022. Box model simulations revealed that the enhancement of O₃ formation rates (16.6×10^-9/h) was notably higher in the polluted periods of 2018 than in 2022 (1.8×10^-9/h), mainly due to increased production of RO₂ and HO₂ radicals from high concentrations of alkanes and aromatics. Additionally, the marked decline in TVOC concentrations during the polluted periods of 2022 suggests a shift in O₃ formation from a VOC-limited regime to a transitional regime, highlighting the need for joint control of TVOCs and NO_x. The results of VOCs emission reduction indicated that O₃ was most sensitive to reductions in the top 10 OFP-contributing species, with relative incremental reactivities (RIR) of 0.85%/% in 2018 and 0.81%/% in 2022, which was more effective than reducing alkenes (0.74%/% in 2018 and 0.37%/% in 2022), aromatics (0.44%/% in 2018and 0.49%/% in 2022), and the top 10species with the highest concentrations (0.20%/% in 2018and 0.37%/% in 2022).

A total of 24 sediment samples were collected from the Yellow River Zhengzhou Section to explore the influence of confluence on the distribution and pollution of microplastics in the sediments of the middle and lower reaches of the Yellow River. To investigate the pollution distribution characteristics of microplastics, quantitative and qualitative analysis were conducted by using stereomicroscopy and fourier transform infrared spectroscopy method. Subsequently, cluster analysis was performed to examine the relationship of the microplastics pollution distribution between the main and tributary streams. The results showed that the mean values of microplastic abundance in the sediments were (1340.97 ± 314.84) n/kg and (2372.22 ± 604.17) n/kg during the wet season and dry season, respectively. Overall, the abundance of microplastics showed a trend of higher tributary than main stream, and higher downstream than upstream. Among them, fibrous microplastics accounted for the highest proportion, and dominated by blue, black, and transparent, with the majority of the particle size less than 2mm. The main polymer type was polyethylene terephthalate (PET), and the waste water discharges from washing and household waste disposal were identified as the major sources. Moreover, increased diversity in shapes and types of microplastic were observed after confluence, with a reduction in the fraction of the dominant colours (blue, black, clear) and an expansion in the proportion of small particle sizes (＜2mm). This indicates that the tributaries, as the source, contributed to the composition and distribution of microplastics in the main stream sediments after confluence, even affecting their migration.

In this study, nighttime light intensity was adopted as a proxy for economic activity, and a random forest model was constructed to integrate both anthropogenic and meteorological factors for O₃ concentration prediction. Panel data from the Beijing-Tianjin-Hebei region and surrounding areas (the "2+26" cities) during 2014~2022 were employed to empirically examine the differential contributions of economic activity intensity across various temporal scales, spatial regions, and pollutant types. The findings showed that:①economic activity intensity consistently exhibited significant predictive power across different temporal scales. On the annual scale, its importance reached 0.7053, surpassing all meteorological variables and becoming the dominant predictor. In contrast, on the daily scale, temperature and other meteorological factors were found to be more influential, with the contribution of economic activity reduced to 0.0869. ②Marked spatial heterogeneity was observed between high- and low- O₃ concentration areas. Temperature and economic activity had stronger impacts in high- O₃ regions, while low-concentration regions displayed irregular and spatially discontinuous patterns of predictor relevance. ③ Over long time horizons, economic activity was identified as a decisive factor in explaining both PM_2.5 and O₃ concentrations. However, on shorter time scales, although economic activity was the second most important factor for PM_2.5 prediction after temperature, its contribution to O₃ prediction remained relatively limited.

Ammonia (NH₃), a cornerstone chemical for sustaining modern society, is traditionally produced via the energy-intensive and carbon-emissive Haber-Bosch process. In light of growing sustainability demands, the electrocatalytic nitrate reduction reaction (NO₃RR), powered by intermittent renewable energy, has recently emerged as a multidisciplinary research frontier. This reaction not only enables ammonia synthesis under ambient conditions but also offers the dual benefit of wastewater remediation and value-added chemical production. This Review highlights recent advances in single-atom site catalysts for NO₃RR. We first discuss the reaction mechanisms underlying nitrate-to-ammonia conversion, with an emphasis on in situ characterization techniques essential for mechanistic insights. We then provide a comprehensive overview of atomically dispersed catalysts in NO₃RR, focusing on the structure–activity relationships that inform the rational design of efficient systems. Finally, we summarize key findings and offer perspectives on current challenges and future directions. This Review aims to inform the development of environmentally benign ammonia synthesis strategies and nitrate valorization technologies, contributing to the advancement of green catalysis in the context of carbon neutrality.

To investigate the distribution and associated risks of residual pollution after five years of sudden river pollution incident happened, this study conducted sampling and analyzed phenol contents in sediment. By integrating geostatistical methods with risk assessment approaches, the spatial distribution of phenol as well as its ecological and human health risks were evaluated. The results showed that residual phenol contents ranged from 2.3 to 26.6μg/kg, with an average of 5.46μg/kg and an average pollution increment of 3.28μg/kg. A statistically significant difference in phenol contents was observed between the survey area and the control area (P<0.05). Among the ten survey sections, A, C, and D represented peak content zones. Of the twenty sampling sites, D1exhibited the highest pollution level(I_geo=2.699), classified as moderate to strong pollution. Spatial interpolation indicated that the midstream C~D section (7.6~26.6μg/kg) was the area with the highest predicted phenol contents, followed by the section A near the leakage site (6.2~10.7μg/kg). Moran’s I analysis revealed a significantly positive spatial clustering of pollution (I>0, z=2.395, P<0.05), with D1 and D2 identified as polluted zones, while B2 was categorized as a clean zone. The risk quotient method suggested that daphnid faced the highest potential ecological risks (0.237~2.759), followed by fish (0.083~1.019), whereas algae exhibited no high-risk values (0.051~0.773). Health risk assessment results indicated that the non-carcinogenic health risk of phenol exposure through drinking water intake was low, with a maximum hazard quotient of 3.47×10^-3. This study identified the existence and distribution pattern of residual pollution and analyzed its health risks to the ecosystem and human population. The study results can provide a scientific basis for formulating environmental supervision strategies for key areas.

This study investigated the accumulation and translocation characteristics of emerging short-chain per- and polyfluoroalkyl substances (PFAS) in a typical submerged macrophyte Aquarius uruguayensis through controlled exposure experiments. The target pollutants included six short-chain PFAS (three perfluoroalkyl carboxylic acids (PFCAs) and three perfluoroether acids (PFEAs)). A. uruguayensis demonstrated bioaccumulation capability of all six short-chain PFAS from water, with whole-plant bioconcentration factors (BCF_total) ranging from 3.0 to 46.0L/kg, primarily detected in leaves with average shoot bioconcentration factors (BCF_shoot) of 2.5~62.2L/kg; In addition to roots and stems, A. uruguayensis leaves were also proven capable of accumulating PFASs independently, with stronger absorption capacity than roots and stems; A. uruguayensis showed selective accumulation of the six short-chain PFAS, preferentially concentrating hydrophilic small-molecule PFASs, with plant BCF showing significant negative correlations with logK_ow and molecular mass(ρ₁= -0.62,ρ₂= -0.81, P＜0.05), and its BCF decreases with the increase of logK_ow and molecular mass; Short-chain PFAS underwent translocation within the plant, with a high contribution from roots to leaves, and a low contribution from leaves to roots.

This study investigated the spatiotemporal variations of ozone (O₃) pollution and O₃ formation sensitivity in the Yangtze River Delta (YRD) with the air quality model CAMx and an optimized photochemical indicator (PH₂O₂/PHNO₃). The critical years of emission reduction strategies (2013, 2017, 2020, and 2030) were selected to simulate and predict changes in ozone concentration and formation sensitivity under different emission scenarios. The results revealed a north-south gradient in O₃ concentrations, with higher levels in northern areas and lower levels in southern areas. The ozone formation sensitivity regimes were divided by an Anqing-Nanjing-Suzhou-Jiaxing line. The northern aeras of the line were governed by a VOCs-limited regime (occupying 43.3% of the total area) and the southern areas were predominantly NO_x-limited (45.3%), with transitional zones covering the remaining area. Under fixed meteorological conditions, continuous reduction in anthropogenic emissions during 2013~2020led to a sustained decline in the daily maximum 8-hour average (MDA8) O₃ concentration, and a shift of the ozone formation regime from VOCs-limited to NO_x-limited. In 2030, O₃ levels in urban hotspots such as Shanghai are likely to increase, despite an overall reduction in regional O₃ levels. The shift towards the NO_x-limited region will continue, increasing by 30.2% from 2013 levels. Only specific cities along the Yangtze River and areas with heavy traffic emissions will remain VOCs-limited. In summary, excluding the impact of climate change, the emission mitigation strategies can effectively decrease the ozone levels in the YRD. Meanwhile it is still necessary to coordinate the reduction rates of NO_x and VOCs in VOCs-limited cities to prevent increases in O₃ levels.

To clarify the concentration characteristics and sources of volatile organic compounds (VOCs) in a typical northwestern petrochemical park during summer, continuous monitoring of 116 VOCs was conducted from June to July 2024. The measured VOC (MVOCs) concentrations were obtained, and the initial VOC (InVOCs) and consumed VOC (CVOCs) concentrations were calculated. Whereafter, the positive matrix factorization (PMF) was used to analyze the sources of MVOCs and InVOCs, the principal component analysis (PCA) was employed to identify the sources of CVOCs, and the contribution of the major factors of each VOC source to ozone (O₃) formation was also calculated. The results indicated that during the observation period, oxygenated VOCs (OVOCs) and alkanes exhibited the highest concentration contributions among both the measured total VOCs (M-TVOC) and the initial total VOCs (In-TVOC), with a diurnal variation characterized by bimodal peaks in the morning and evening. The consumed total VOCs (C-TVOC) exhibited a strong correlation (r = 0.89) with the diurnal variation of O₃ concentrations, with alkenes and OVOCs being the dominant contributing species. Among the top ten ozone formation potential (OFP) species for all three VOCs categories, alkenes and aldehydes were predominant. .The sources of MVOCs and InVOCs were ranked as follows: petrochemical sources > combustion sources > vehicle emissions > biogenic emissions > solvent utilization sources.. As for CVOCs, the sources were identified aspetrochemical sources (51.1%) > gasoline evaporation (26.0%) > biogenic emissions (18.2%) > solvent utilization sources (4.8%). Among these, petrochemical sources were identified as the largest contributor to O₃formation. The results indicated that reducing emissions from petrochemical sources, combustion sources, and vehicle emissions is an effective strategy for controlling summer VOCs around the park. Additionally, cutting emissions from petrochemical sources and solvent utilization sources can significantly decrease the contribution of VOCs to O₃ formation.

Based on the environmental statistics data and departmental survey data of Shaanxi Province in 2022, the emission inventory of atmospheric pollutants and CO₂ of Shaanxi Province in 2022 was established by a combination method of bottom-up and top-down. The results indicate that the total emissions of SO₂, NO_x, CO, VOCs, NH₃, PM₁₀, PM_2.5, BC, OC and CO₂ were 64.0x10³, 31.2x10⁴, 19.3x10⁵, 21.5x10⁴, 34.0x10⁴, 67.9x10⁴, 20.8x10⁴, 11.7x10³, 24.0x10³, 33.1x10⁷ tons, respectively. The primary source of SO₂ was electricity generation and heating supply; the primary source of NO_x and BC was diesel vehicles; the primary source of CO was the iron and steel industry; the primary source of VOCs was the coking industry; the primary source of NH₃ was livestock and poultry farming; the primary source of PM₁₀ and PM_2.5 was the road dust; and the primary source of OC was biomass stoves. Yulin, Xi’an and Weinan were the major cities with SO₂ and PM₁₀ emissions; Yulin, Xi’an and Hancheng were the major cities with PM_2.5 emissions; Xi’an, Yulin and Xianyang were the major cities with NO_x emissions; Xi’an, Yulin and Yan’an were the major cities with VOCs emissions; Hancheng, Yulin and Xi’an were the major cities with CO emissions; Yulin, Weinan and Baoji were the major cities with NH₃ emissions; Yulin, Xi’an and Xianyang were the major cities with BC emissions; Yulin, Xi’an and Weinan were the major cities with OC emissions. On this basis, the pollution and carbon reduction effects of air pollutants and CO₂ emission reduction measures were analyzed, and it was found that the cleanification of civil energy, the electricity generation of cleaner power energyin power plants and the renovation of coal-fired boilers all have pollution and carbon reduction effects,while the electricity generation of cleaner power energyin power plants have the highest synergistic effect.