The emission of volatile organic compounds (VOCs) significantly contributes to the atmospheric oxidative balance and secondary organic aerosol (SOA) formation, thereby influencing global climate. Reactive substances such as methane, non-methane hydrocarbons, dimethyl sulfide, and halocarbons in the ocean are important components of VOCs, primarily produced through biological and non-biological processes. To date, substantial research has been conducted on the source-sink processes of marine VOCs and their response mechanisms to environmental factors. However, much of this research has focused on biological processes, overlooking the contributions of photochemical processes involving dissolved organic matter (DOM) in the sea surface (micro) layer, which may result in an underestimation of their emissions. In recent years, marine photochemistry, particularly the photochemical processes of DOM in the sea surface micro-layer, has gained increasing attention. This review systematically examines the research progress on the sources and emission fluxes of marine VOCs, with a focus on the mechanisms of VOCs production via DOM photochemistry, their response to environmental factors, and their implications for climate change. Furthermore, future research directions are proposed from the perspectives of technological innovation, mechanism exploration, and environmental assessment. Long-term observation and simulation studies of photochemical processes of DOM in the sea surface micro-layer are highlighted as crucial for revealing the response of marine VOCs photochemical production to human activities and its impact on climate change.

The solid-phase extraction method and the thermal-optical method were combined to obtain different polar HULIS and the carbon content of HULIS (HULIS-C) in PM_2.5 with high temporal resolution during the heavy pollution event in Xi'an. The light absorption characteristics of HULIS were analyzed using a UV-Vis spectrophotometer equipped with a liquid waveguide capillary cell (LWCC), and the positive matrix factorization model (PMF) was used to analyze the sources of HULIS. At the same time, the source of HULIS is combined with the positive matrix factorization model (PMF). The results showed that the average mass concentration of neutral HULIS (HULIS-n) (6.6±2.6)µg/m³ was higher than that of acidic HULIS (HULIS-a) (3.7±3.5)µg/m³, accounting for approximately 30% and 18% of OC, respectively, indicating severe HULIS pollution during heavy pollution periods. The absorption coefficients (AAE, E₂/E₃, and MAE₃₆₅) of HULIS-n were all greater than those of HULIS-a, suggesting that HULIS-n contains more conjugated and aromatic structures and has stronger light-absorbing properties, with a more significant impact on atmospheric visibility. The source analysis revealed clear differences in the contributions of HULIS-n and HULIS-a. The primary sources of HULIS-n included secondary sources, coal combustion, motor vehicle emissions., while the contributions of secondary sources and coal combustion were higher for HULIS-a.

This study conducted sampling and testing on the waste gases generated from different processes in typical automobile manufacturing plant coating workshops located in northern and southern China. It meticulously analyzed the emission characteristics of volatile organic compounds (VOCs) and odor characteristics, and extensively explored odor characteristic prediction methods from multiple dimensions. The results revealed that OVOCs, alkanes, and aromatic hydrocarbons are the predominant components in the exhaust gases, with OVOCs constituting 73.80% to 99.03% of the odor activity value (OAV), thereby classifying them the most significant odor-contributing substance category. Acetaldehyde, n-butyl acetate, isobutyl acetate, and n-butyraldehyde all significantly contributed to the odor at both the inlet and outlet of the treatment equipment. Furthermore, electronic noses were used to classify waste gas samples, achieving 100% and 98.1% accuracy rates for inlet and outlet, respectively. Quantification of odour was achieved through regression analysis, which revealed a strong linear correlation between OVOCs substance concentration and OAV_max and OAV_sum. The electronic nose technology combined with BP neural networks was found to be an effective predictor of OAV_max and OAV_sum. Additionally, a logarithmic relationship was observed between OVOCs substance concentration, OAV_max, OAV_sum, and odor concentration.

To address the issue of biases in the representational capabilities of existing assessment methods for ozone pollution meteorological conditions, stemming from a lack of boundary layer indicators, this study utilized meteorological and environmental observation data collected from 2019 to 2023. By integrating ozone numerical simulations and incorporating source tracking along with process rate analysis techniques within the model framework, we developed a joint model and observation-based Tianjin Ozone Pollution Meteorological Condition Assessment Index (OWI). This index aims to accurately assess ozone pollution meteorological conditions in Tianjin. The research findings reveal a strong correlation between ozone concentrations and various meteorological factors. The OWI index was constructed based on parameters such as average temperature, maximum temperature, relative humidity, daily precipitation, daytime ultraviolet radiation, midday ultraviolet radiation, sunshine duration, average wind speed, and wind direction. It effectively characterizes the impact of these meteorological conditions on ozone levels. Notably, this index exhibits a correlation coefficient of 0.82 with O₃ concentration and demonstrates an ability to identify 82% of mild or more severe ozone pollution incidents. Furthermore, by analyzing the effects of daytime and nighttime boundary layer heights on precursor diffusion processes—such as near-surface nitrogen oxide titration and vertical exchange of ozone—the study addresses potential overestimations in O₃ concentrations by the OWI index under favorable vertical diffusion conditions. To optimize the OWI index further, we incorporated indicators for both daytime and nighttime boundary layer heights. Through ozone numerical simulations, the study calculated the effects of horizontal and vertical transport, convection, chemical generation, turbulent mixing, and regional transport on ozone levels. By combining simulation results with observations, the OWI index was oized under specific conditions, such as adjusting upwards when daytime vertical transport exceeds 15µg/(m³⋅h) or daytime ozone chemical generation exceeds 20µg/(m³⋅h); and considering surrounding meteorological conditions and ozone transport impacts when regional transport was too strong.

TiCeO_x bimetallic catalysts were prepared as catalyst carries. And the Ru-supported catalysts with different dispersions were synthesized by the methods of Ru³⁺ impregnation reduction (bottom to up) and Ru colloid solution thermal diffusion (top to down) methods. In the catalyst RuTiCeO_x-N prepared by Ru³⁺ immersion reduction method, Ru species exist in the form of RuO_x nanoclusters. In the catalyst RuTiCeO_x-A prepared by Ru colloid solution thermal diffusion, Ru species exist in the form of single-atom dispersion. The different dispersion states of Ru species lead to the difference of active oxygen species and acid sites involved in chlorobenzene (CB) oxidation. Chemisorbed oxygen and surface lattice oxygen could be the dominating active oxygen species for RuTiCeO_x-N and RuTiCeO_x-A, respectively. And due to the chemisorption of CB, that could be transformed into hydroxyl radical (-OH) to be involved in the catalytic reaction. Catalyst RuTiCeO_x-A performed better with the complete conversion of CB at 300℃ and 24h of durability test without deactivation. That could be attributed to the synergy between its resulted active oxygen species and multiple acid sites (strong and weak).

To investigate the spatial and temporal distribution characteristics of dust events in Inner Mongolia and their exogenous contributions, high-precision aerosol vertical distribution profiles were obtained using seven multi-band lidars deployed in Inner Mongolia. In addition, the three-dimensional dynamic evolution, atmospheric circulation and exogenous dust sources of summer dust storms in Inner Mongolia were further analyzed by combining ground station observations, atmospheric chemistry models, meteorological reanalysis data and backward trajectory models. It is found that the overall number of dust days in Inner Mongolia from 2014 to 2024 shows a fluctuating upward trend, and spring is the peak season for dust events, with the cumulative number of dust days reaching 117. In the past five years, the change of the number of dust days in spring was relatively stable, but since 2020, the number of dust days in summer began to show an increasing trend. During 20~25July 2024, a serious dust event occurred in Inner Mongolia. The dynamic evolution of the dust event from high altitude to near-surface was effectively monitored by the networked LiDAR in Inner Mongolia. on 20 July, the dust first appeared in the west-central part of Inner Mongolia and the China-Mongolia border, and then spread eastward under the combined effect of the northwesterly winds behind the low-pressure trough and the surface gales. The intensity of the dust weakened somewhat on 22 July. However, the low-pressure trough reappeared on 23 July, and the northerly flow behind the trough guided the cold air southward to form strong winds, which rapidly blew up the surface dust particles, leading to a general increase in dust uptake in west-central Inner Mongolia and transporting them downstream through the northwesterly wind behind the trough. During this dust event, the Sino-Mongolian border became the main potential source area of PM₁₀ during the dust event, contributing most significantly to the PM₁₀ mass concentration. This indicates that the Sino-Mongolian border area is gradually becoming an important source of dust in northern China.

The seasonal vertical distribution of aerosols in the southern margin of the Taklamakan Desert was analysed using aerosol LiDAR data from the Minfeng meteorological station from June 2023 to May 2024, and the HYSPLIT backward trajectory model was employed to identify the transport paths of aerosols at different altitude layers. Finally, the vertical distribution of aerosols and their transport paths at different stages of dust pollution are analysed by taking a dust pollution event as an example. The results show that: ①The dust aerosols can be lifted up to a maximum height of 3~4km (4.4~5.4km above sea level) above the ground surface, which is comparable to the average elevation of the Tibetan Plateau (>4km), and suggests the possibility of transport of dust aerosols from the study site to the outside of the Tarim Basin. ②The extinction coefficients of the four seasons show a decreasing trend with height in the vertical direction, and the maximum values are all located at the low altitude of 150m. The highest values are found in spring (0.69km^-1, 0.20), followed by winter (0.52km^-1, 0.18) and summer (0.40km^-1, 0.16), and the lowest values are found in autumn(0.25km^-1, 0.11). ③The dust aerosols are mainly affected by the east-west transport, except for the 1500 and 3000m altitude layers in winter which are affected by the westerly transport, the 500, 1500 and 3000m altitude layers in the rest of the seasons are affected by the northeasterly and westerly transport at the same time. ④The extinction coefficients carried by the northeasterly jet are significantly higher than those carried by the westerly jet at different altitudes in all seasons, making the northeasterly jet the main dust transporting jet. ⑤The study of a dust pollution event shows that the extinction coefficient of the near-surface aerosols is greater than 1km^-1, the depolarization ratio exceeds 0.3, and the vertical trend is decreasing with height during the dust pollution process. The northeastern airflow in the Tarim Basin is the main transport airflow for dust aerosols during this dust event.

Based on the ozonesonde data in Guangdong, Hong Kong, and Macao regions from 2022 to 2023, the vertical distribution characteristics of O₃ concentration were analyzed, and the applicability of Aqua satellite AIRS O₃ vertical profile product and ERA5 reanalysis O₃ vertical profile product were evaluated by using self-organizing map neural network (SOM) method. The vertical distribution of O₃ in the Greater Bay Area exhibited significant seasonal variations. In spring, summer, and winter, the ozone vertical distribution displayed a unimodal structure, with peak concentrations located near 700, 950, and 300 hPa, respectively. In contrast, the vertical distribution in autumn showed a bimodal structure, with peaks near 925 and 400hPa. The vertical differences in O₃ between stations were relatively small, with deviations between Guangdong and Hong Kong stations ranging from -3.2% to 11.0%. The quality of AIRS and ERA5 data in autumn and winter within the troposphere was better than that in spring and summer. At 850~200hPa, both AIRS and ERA5 data showed relatively good quality, with seasonal relative average deviations (Rad) ranging from 16.5% to 25.8% for AIRS and 15.1% to 25.7% for ERA5. The average correlation coefficients (r) for the seasons ranged from 0.47 to 0.75 for AIRS and 0.23 to 0.74 for ERA5. Below 850 hPa, the quality of AIRS and ERA5 data was relatively bad, with average value of r were 0.34 and -0.15. The vertical distribution of O₃ was categorized into 5 types. Among these, the data quality of AIRS and ERA5 was best under the type 1distribution structure, while it was worst under the type 2 and type 3 structures. Type 1 occurred more frequently in autumn (43%) and winter (61%), whereas type 2 and type 3 were more common in summer (66%). Type 4 and type 5 occurred more frequently in spring (85%).

In this study, the components of dissolved organic matter (DOM) during the anaerobic-anoxic-aerobic (A²O) biological wastewater treatment process was analyzed by using fluorescence emission excitation matrix combined with parallel factor analysis(3D EEMs-PARAFAC), and the generation of nitrous oxide (N₂O) in each unit was also quantified. Additionally, machine learning model was employed to further predict the response relationship between DOM components and N₂O generation. Results showed that DOM in the influent of the wastewater treatment plants (WWTP) was primarily composed of four components, including tryptophan (C1), fulvic acid (C2), humic acid (C3), and tyrosine (C4), while C1 and C4 being the dominant components. The concentration of DOM decreased progressively throughout the treatment process, while the removal efficiency of readily biodegradable DOM (such as C1and C4) were significantly higher than that of C2 and C3. N₂O emission was the major component of direct carbon emissions and showed significant spatial heterogeneity. The N₂O emission amount of each unit ranked from high to low were observed in the following order: oxic tank, secondary sedimentation tank, anoxic tank, anaerobic tank, grille, and primary sedimentation tank. Shapley Additive exPlanation (SHAP) analysis revealed that C1 and C2 would significantly affect the N₂O generation process, while the effects of C3 and C4 were negligible. Specifically, C1would enhance N₂O generation, while C2 had an adverse effect. High-throughput sequencing results indicated that Methylotenera and Terrimonas, which could utilize readily biodegradable organic matter for denitrification, were the dominant bacterial genera in the sludge of WWTP. Overall, this study revealed disparate response between N₂O generation and different DOM components during the A²O process, which would help to improve the current carbon emission accounting method of WWTPs and provide theoretical support for optimizing their low-carbon operation processes.

As a common pollutant in water, nitrate has nonnegligible harmful effects on human health and the ecological environment. Faced with an increasingly severe energy crisis, the development of green, clean and sustainable nitrate removal technologies to replace the conventional resource-intensive denitrification process is urgently needed. Photoelectrochemical nitrate reduction powered by sunlight has become a research hotspot at home and abroad. Based on the way photogenerated electrons being transferred from semiconductor to nitrate, this technology can be categorized into photocatalytic reduction, photoelectrocatalytic reduction, and microbial photoelectrotrophic reduction. In this review, the mechanisms of three photoelectrochemical nitrate reduction technologies were discussed. With a focus on improving system performance, the selection and design strategies of photocatalysts, photoelectrodes and microbial photosensitizers were also summarized. Moreover, the technical difficulties of photoelectrochemical nitrate reduction are clarified and the future directions of research are proposed, such as regulating the pathway of microbial absorption and utilization of photogenerated electrons through genetic engineering and other methods. The insights provided will serve as a reference for the development of new nitrate removal and reutilization technologies.

Varieties of non-noble metal catalysts were prepared and screened by hydrothermal deoxidation of stearic acid for the purpose of efficiently catalyzing the conversion of waste oil into green diesel. The experimental results demonstrated that the nano-Ni-Cu alloy exhibited a significant catalytic effect on stearic acid, with its catalytic performance and product distribution being the most comparable to those of the Pt/C catalyst. Furthermore, the optimization of reaction conditions, stability analysis, catalyst characterization, reaction mechanism exploration and broad-spectrum analysis were carried out for nano Ni-Cu alloy. The characterization results revealed that the structure of nano-Ni-Cu alloy remained stable, and no significant structural changes were observed after continuous cyclic use. Under the optimum reaction conditions of 330℃, 120min, with the addition of 20µL methanol,30mg catalyst and 80µL water in a 1.67ml micro reactor, stearic acid was primarily converted into heptadecane through catalytic hydrodeoxygenation and decarbonylation. Additionally, the broad-spectrum analysis indicated that the yield of C8-C18 alkanes from various fatty acids and fatty acid esters catalyzed by nano-Ni-Cu alloy could exceed 95%, conforming its excellent catalytic performance.

In order to address the issues of complex processes and high infrastructure and operational costs in simultaneous nitrogen and phosphorus removal, a heterotrophic nitrifying strain NP3 exhibiting simultaneous nitrogen and phosphorus removal capabilities was isolated from activated sludge in this study. Strain NP3 was identified as Pseudomonas stutzeri by 16S rRNA sequence analysis, and its nitrogen and phosphorus removal characteristics and mechanisms were investigated. It was showed that strain NP3 was able to utilize ammonium, nitrate, and nitrite as the sole nitrogen source for efficient nitrogen and phosphorus removal under aerobic conditions. The accumulation of intermediate products during the reaction process was minimal, and nitrogen and phosphorus were primarily removed through assimilation. The growth and metabolic rates followed the order: NH₄⁺-N >NO₂⁻-N >NO₃⁻-N. Under the optimal growth conditions of sodium citrate as the carbon source, C/N=10, T=30℃, pH =7, and r=160r/min, the maximum removal rates of ammonia nitrogen and phosphate were almost 100%. Furthermore, successful amplification of denitrification and polyphosphate genes (nosZ, nirS, ppk) further confirmed the simultaneous nitrogen and phosphorus removal capability of strain NP3. X-ray Photoelectron Spectroscopy (XPS) analysis demonstrated that the functional groups on the extracellular polymeric substances(EPS) surface could adsorb different forms of phosphorus such as C-PO₃/P-C, PO₄^3-/HPO₄^2-, acting as phosphorus transfer stations.³¹P nuclear magnetic resonance (NMR) results further indicated that there was a large effect of EPS on phosphorus fugitive morphology, with pyrophosphate being the main phosphorus species in the presence of EPS, whereas orthophosphate and orthophosphate diester were the major phosphorus forms after EPS extraction.

Advanced oxidation processes (AOPs) represent a widely adopted approach for eliminating organic pollutants from water bodies. Nevertheless, conventional AOPs grapple with several challenges, notably including inadequate electron interactions, interference from macromolecular substances, constrained mass transfer processes, and moderate efficiency levels. To overcome these limitations, the employment of a spatial confinement strategy, which entails the construction of tailored nanoscale reactors, has emerged as a promising solution to substantially bolster oxidation efficiency. The spatial confinement strategy offers several key advantages: (1) optimize the migration of protons and charges; (2) alter molecular structures and molecular dynamics; and (3) create new active sites. This strategy is commonly integrated into processes such as Fenton oxidation, persulfate oxidation, photocatalytic oxidation, ozonation, and electrochemical oxidation. This paper summarizes the implementation and analytical methods of spatial confinement, outlines its three major functions, reviews its applications in various oxidation processes, and evaluates its effects at both microscopic and macroscopic levels. Furthermore, future directions for the development of spatial confinement in advanced oxidation are discussed.

Based on field data from 2019 to 2022 in the South Tiaoxi River Watershed in the upper reaches of the Taihu Lake Basin, redundancy analysis (RDA) and non-parametric breakpoint analysis (nCPA) were employed to analyze the relationships between riverine nitrogen (N) concentrations and landscape pattern indices at different buffer scales, and identity the critical landscape threshold ranges affecting the river nitrate (NO₃^--N) concentration. The results showed that the total nitrogen (TN) concentration in the South Tiaoxi River exceeded the Class V surface water quality standard, with NO₃^--N as the predominant N pollutant. During the wet season, the concentrations of TN, dissolved total nitrogen (DTN), NO₃^--N, and dissolved organic nitrogen (DON) were significantly higher than those in the dry season, whereas ammonium nitrogen (NH₄⁺-N) concentrations were lower. N concentrations were lower in the upstream compared to downstream. The landscape pattern indices in the buffer zones of 400m and 200m explained the largest variance in river N concentrations during the wet and dry seasons, respectively (89.49% and 90.97%). Based on the identified key thresholds of landscape pattern indices for significantly reducing the risk of NO₃^--N pollution in the watershed, the following suggestions are provided: the proportion of farmland, construction land, and Shannon diversity index (SDHI)in the buffer zone of 400m should be controlled within 0.25%, 1.75%, and 0.77, respectively; and the proportion of farmland and edge density (ED) in the buffer zone of 200m should be kept within 0.5% and 39m/hm², simultaneously with the proportion of forest area exceeding 91.0%.

In the present study, Manganese oxide octahedral molecular sieve (OMS-2_PS) was synthesized using K₂S₂O₈ and(CH₃COO)₂Mn·4H₂O via a solid-phase method. The physicochemical properties of OMS-2_PS were analyzed via X-ray diffraction(XRD), Fourier-transform infrared spectroscopy (FT-IR), and X-ray photoelectron spectroscopy (XPS). The performance of persulfate activation by OMS-2_PS for degrading organic contaminants was examined. This study also investigated the effect of various parameters, including dosage of OMS-2_PS, PS concentration, and initial pH, on AO7 removal efficiency. Moreover, the mechanism of PS activation by OMS-2_PS was explored. The results showed OMS-2_PS was successfully synthesized via a solid-phase method, which exhibits a nanorod structure. OMS-2_PS could activate PS to degrade organic contaminants. The use of 50mg/L AO7,1.0g/L OMS-2_PS, and 2.0mmol/L PS led to the AO7 removal and mineralization rates of 97.4% and 50.1%, respectively. Ion coexistence experiments demonstrated that AO7 removal was considerably inhibited by Cl⁻, NO₃⁻, and CO₃²⁻, while HA had almost no effect on it. The free radical quenching experiments and electron paramagnetic resonance (EPR) analysis indicated ·OH and SO₄^•−were the primary active oxygen species in the OMS-2_PS/PS system, and ·OH played the dominant role in the AO7 degradation. XPS analysis revealed Mn(IV) and lattice oxygen on the surface of OMS-2_PS were the main active sites for PS activation. Based on experiment results, a potential activation mechanism of PS by OMS-2_PS was proposed that PS combined with OMS-2_PS through the hydroxyl groups on the surface of OMS-2_PS, and then PS reacted with the active sites on the surface of OMS-2_PS to produce active oxygen species. In addition, The OMS-2_PS/PS system effectively removed AO7 from different water bodies, and also degraded efficiently other pollutants including bisphenol A, naphthalene, and tetracycline, indicating that the OMS-2_PS/PS system have a bright application prospect in environmental pollution control.

This study applied umbrella-shaped modified basalt fiber (MBF) bio-carrier to an integrated fixed-film activated sludge system to investigate the performance of MBF bio-nest in wastewater treatment and N₂O emission reduction. The effect of dissolved oxygen (DO) on N₂O reduction in the bio-nest was investigated by changing the DO concentration. The results showed that under the same operating conditions, TN removal efficiency was increased by 63.87% and N₂O emission was reduced by 77.76% in the bio-nest system compared with the sequencing batch activated sludge bioreactor. According to the 16sRNA sequencing results, a variety of functional microregions existed within MBF bio-nests, with a high diversity of microbial populations. Saccharibacteria genera incertae sedis were the main carbon-removing bacteria in the reactor, and heterotrophic nitrification-aerobic denitrification(HN-AD) genera were the main nitrifying bacteria, which did not emit N₂O during the nitrification process. Denitrification genera were dominated by conventional heterotrophic denitrification bacteria (HDN) in the inner and middle layers of the bio-nest (17.42%,23.02%), and HN-AD bacteria in the outer layer of the bio-nest and suspended sludge (29.70%, 27.53%). Aerobic/anoxic/anaerobic genera were distributed in all layers of the bio-nest, and denitrification genera had higher relative abundance in the MBF bioreactor than in the SBR, which facilitated denitrification and mitigated the accumulation of intermediate products, reducing N₂O emissions. The MBF bio-nest reactor had the highest TN removal rate of 86.64%±1.14% and the lowest N₂O emission of (0.78±0.83) mg N₂O/g TN when the DO concentration was 2.5mg/L (M2). The bio-nest microbial genus categories were basically the same in each DO gradient, but differed in their relative abundance. In M2, HN-AD bacteria were the main nitrifying functional bacteria in the reactor(the relative abundance of the layers from inside to outside was 44.24%, 61.34%, and 36.16%), which was conducive to N₂O reduction; HDN were the main functional bacteria in the M2reactor, with moderate relative abundance of 20.17%, 12.00%, and 21.20% from inside to outside layers; the concentrations of NO₂^--N and NO₃^--N in the effluent were (0.011±0.002) and (1.65±0.46)mg/L; denitrification was carried out completely, which was conducive to the reduction of N₂O emissions.

To address the issue of insufficient polarization of auxiliary electrodes (AEs) in magnetically assembled electrodes, five types of magnetically assembled electrodes were constructed using five different AEs: CNT/Fe₃O₄、Fe₃O₄/MnO₂、Fe₃O₄/Co₃O₄、Fe₃O₄/RuO₂, and ferrocarbon particles (FC). This study examined the effects of tourmaline on the electrochemical performance of each electrode and its impact on wastewater treatment efficiency. The results demonstrate that tourmaline can significantly enhance the polarization process of AEs, increase the active surface area of the electrodes by up to 28.47%, improve the degradation efficiency of simulated acid red G wastewater by up to 108.06%, and enhance the mineralization efficiency of real petrochemical wastewater by up to 10.61%.

To investigate the impact and mechanisms of the "23·7" heavy rainstorm event on groundwater quality in the Mentougou Plain area, the area at the foothills of the Yongding River was selected as the study area. By comparing the alterations in groundwater and surface water quality before and after the rainstorm, and integrating hydrogeochemical modeling with microbial characterization, we analyze the underlying causes. The results showed that the average concentrations of Ca²⁺ and HCO₃^- in the groundwater increased by 9.75% to 14.68%, while those of Cl^-, SO₄^2-, F^-, total Fe, and total Mn decreased by 26% to 86.92% after the rainstorm, consistent with the trend in surface water. It suggested that the variation in groundwater chemistry was primarily driven by the infiltration of affected surface water. However, the trends in K⁺, dissolved oxygen (DO), redox potential (Eh), and NO₃^--N in groundwater are opposite to those in surface water, indicating that groundwater chemistry changes were not solely the result of simple physical mixing with surface water. The reverse simulation results using PHREEQC indicate that under the influence of the rainstorm, the evolution of groundwater chemistry is regulated by a combination of physical mixing and dilution, mineral dissolution and precipitation, denitrification, and sulfate reduction. Specifically, physical mixing and dilution account for 15.82% of the alterations. Based on it, the silicate minerals dissolution increases the Ca²⁺ concentration, while the dissolution of silicate and evaporite minerals, in combination with cation exchange, helps maintain Na⁺ balance. The infiltration of rainwater and the decomposition of organic matter increase the HCO₃^- concentration. The denitrification and sulfate reduction decrease NO₃^- and SO₄^2- concentrations. Notably, the heavy rainstorm exacerbated the dilution and diffusion of high-concentration Fe contamination around the Shougang Industrial Park. Although dilution reduced the peak concentration of Fe exceeding the standard from 89.5mg/L to 25.4mg/L, the number of locations where Fe exceeded the standard increased from one to four, accounting for 66.67% of the total. Meanwhile, this process significantly promoted the enrichment of Fe(Ⅱ)-dependent autotrophic denitrifying bacteria in the groundwater, enhancing the denitrification rate and significantly reducing the concentration of NO₃^--N in the groundwater.

This study aimed to explore the accumulation of MGEs by wetland plants in the treatment of rural sewage using a soil ecological infiltration system. Thus, the changes in the integrase gene intI1and transposase gene tnpA-04 in the vegetative parts of the wetland plant Iris were investigated before and after treatment. The results showed that, over a 60d operational period, the soil ecological infiltration system achieved average removal rates of ammonia nitrogen and chemical oxygen demand from rural sewage of 88.50% and 75.17%, respectively. The average height and fresh weight of the Iris increased by 3.63% and 43.45%, respectively. The concentration of MGEs in the plant increased by 1.67ng/g, with intracellular accounting for 68.26%. Forthermore, the abundance of the tnpA-04 gene was found to be 37.86% higher than that of the intI1gene, which demonstrated a higher propensity for transfer within the vegetative parts of Iris. The bioconcentration ability for MGEs in the plant's vegetative parts followed the order: stem >root > leaf. Moreover, variations in soil properties significantly influenced the plant's ability to accumulate MGEs (P < 0.05). This study suggests that wetland plants can effectively accumulate MGEs from rural sewage, thereby reducing the risk of antibiotic resistance gene dissemination.

This study aimed to investigate the mitigating effect and regulatory mechanism of humic acid (HA) on the physicochemical properties and pollutant treatment performance of aerobic granular sludge (AGS) under prolonged stress induced by graphene (G) and oxide graphene (GO). The results demonstrated that the optimal dosage of HA (10mg/L) significantly enhanced the physicochemical characteristics of AGS, and improved the pollutant treatment performance of the AGS reactor (R2 (1.0mg/L G) and R3 (1.0mg/L GO)). At the 75^th day, in R3, there was an obviously increase in average particle size of AGS from 1224.1µm to 1407.5µm, while in R2it increased from 1313.0µm to 1461.3µm. Simultaneously, the enhancement of AGS physicochemical properties led to a respective increase of 2.3% and 7.6% in TN removal efficiency for R2 and R3. The introduction of HA resulted in a significant reduction in the levels of reactive oxygen species (ROS), lactate dehydrogenase activity, catalase activity, and superoxide dismutase activity in R2 and R3. This suggested that HA can effectively bind with accumulated ROS within cells to further mitigate oxidative stress levels induced by G and GO. The addition of HA also effectively alleviated the excessive secretion of extracellular polymeric substances (EPS) in AGS, resulting in a decrease in the content of aromatic proteins and tyrosine-like substances within EPS. Consequently, this led to a more compact and denser AGS particle structure in R2 and R3. Ultimately, the changes in Zeta potential of G and GO (before and after the addition of HA) indicate that the incorporation of HA can enhance the initial potential values of G and GO, thereby augmenting the repulsive effect between G/GO and microorganisms, reducing direct contact between microorganisms and G/GO, thus effectively mitigating the toxic effects exerted by G and GO on microorganisms.

To clarify the temporal and spatial variation patterns of methane emissions from landfills and their influencing mechanisms, a case study was conducted at a municipal solid waste landfill in Qingdao. The static chamber method was used to measure the diurnal dynamics of methane emission fluxes across different seasons. The results indicate significant seasonal variations in methane emission fluxes from the landfill, with the highest emissions occurring in winter at (115.67±65.34) mmol/(m²·h) and the lowest in summer at (61.51±74.57) mmol/(m²·h). The diurnal methane emission fluxes also varied markedly between seasons, with summer fluxes exhibiting a bimodal curve and autumn and winter fluxes showing a unimodal curve. Correlation analysis revealed that methane emission fluxes were significantly related to atmospheric pressure, air temperature, relative humidity, wind speed, soil temperature, and soil relative humidity. In summer and autumn, methane emission fluxes showed a significant positive correlation with atmospheric relative humidity and a negative correlation with air temperature, whereas the opposite was true in winter.

The co-pyrolysis of biomass/sewage sludge was demonstrated to facilitate efficient resource utilization, harmless treatment, and sludge volume reduction. Due to the complexity of co-pyrolysis reactions, it was deemed essential that the thermodynamic properties and product distribution of this process be systematically evaluated. The pyrolysis characteristics, synergistic effects, and product distribution of municipal sludge-peanut shell mixtures were investigated using thermogravimetric analysis and a fixed-bed reactor. It was observed that significant synergistic interactions were exhibited during municipal sludge/peanut shell co-pyrolysis, primarily during the volatile release stage, where the synergistic effect was found to accelerate mixture pyrolysis. When the conversion rate (α) was below 0.7, the apparent activation energy was progressively reduced with increasing sludge mass ratio(SMR). Conversely, when α exceeded 0.7, the apparent activation energy sharply increased with higher SMR. The gas yield was enhanced with elevated pyrolysis temperatures, while liquid and solid yields were significantly diminished. Elevated temperatures were also shown to promote H₂ and CH₄ generation. Product yields and synergistic effects were strongly influenced by SMR, with the most pronounced co-pyrolysis synergy observed at an SMR of 40wt.%.

A new block filter material with well-developed pores and stable chemical properties was prepared from a biomass ash by short-term and high-temperature sintering. The phosphorus adsorption properties, as well as the kinetics and thermodynamic behaviors, of this material were investigated in this paper. The results of the static adsorption experiments show that the biomass ash filter achieved higher phosphorus adsorption per unit under conditions of higher initial phosphorus concentration, higher reaction temperature, longer adsorption time, or lower solid-liquid ratio. Among these parameters, the solid-liquid ratio was the primary controlling parameter affecting phosphorus adsorption by the filter material. The maximum adsorption per unit of the filter material reached 7.72mg/g, when the initial concentration of phosphorus was 90mg/L, the reaction temperature was 55℃, the adsorption time was 1250min, the pH was 3, and the solid-liquid ratio was 1:200(g:mL). The surface of the material exhibited a heterogeneous structure, and its phosphorus adsorption was primarily driven by multilayer physical endothermic adsorption, supplemented by monolayer or multilayer spontaneous chemical adsorption. Under the dynamic adsorption conditions, the phosphorus adsorption capacity of this filter material per unit was 9.8, 22.27 and 27.22 times that of three common commercial filter materials, including coconut shell biochar, ceramsite and natural zeolite, respectively. This indicates excellent adsorption properties, enabling water purification while achieving biomass ash disposal and recycling, making it highly valuable for promotion.

To promote the reduction and recycling of construction and demolition (C&D) waste in housing, a dynamic material flow model was established to simulate the evolving characteristics of housing flow-stock in both urban and rural areas of Beijing from 1949 to 2100. The amount of urban and rural housing C&D waste generated was predicted. The results showed that from 1949 to 2100, cyclical fluctuations were observed in the volume of new construction and demolition of housing in Beijing’s urban and rural areas, with the housing stock following an S-shaped curve. The area of new housing construction in urban and rural regions peaked at 31.456million m² in 2012 and 7.887 million m² in 2015, while the demolition area reached its maximum of 15.008 million m² in 2094 and 4.535 million m² in 2016. The saturation values of housing stock in urban and rural areas were 800 and 1.247 million m², respectively. By the mid-to-late 21 st century, Beijing was anticipated to experience a surge in C&D waste generation, which will reach its peak and then persist at elevated levels with periodic fluctuations. The apex of C&D waste generation was projected to occur in 2094, with an estimated total output of 23.964 million tons. Cement, brick, sand, and gravel were the predominant components of C&D waste by weight, accounting for 90.2%~95.5% of the total weight of housing C&D waste in urban areas and 92.2%~94.1% of that in rural areas, while the weight proportion of iron and steel ranged from 0.1% to 4.5% and 0.1% to 3.0%, respectively. The long-lifetime scenario could defer the peak of C&D waste, with a maximum reduction potential of 72.0%. Additionally, recycling C&D waste as urban minerals could lead to a dramatic decrease in future demand for primary steel, with a reduction of up to 98.5%.

Earthworm (Pheretima guillelmi) was selected as the model animal. Combination of in situ determination, high-throughput sequencing and biochemical analysis, the results indicated that the production of Fe(Ⅱ) was highest in the glucose treatment group and lowest in the amino acid setup. During the iron(Ⅲ) reduction process, the content of surface-adsorbed Fe(Ⅱ) was the highest, ranging from 0.6 to 24.38mmol/L;whereas the content of ionic Fe(Ⅱ) was the lowest, ranging from 0.02 to 2.21mmol/L. The community structure of iron(Ⅲ)-reducing bacteria was significantly influenced by the type of organic matter, and the dominant iron(Ⅲ)-reducing bacteria in different treatment groups were diverse. Additionally, the iron(Ⅲ) reduction process was accompanied by the generation of reactive oxygen species (ROS). The content of hydrogen peroxide (H₂O₂) was the highest, ranging from 0.32 to 0.73mmol/L, and be show a significant positive correlation with the contents of ionic Fe²⁺, surface-adsorbed Fe(Ⅱ), and high-crystalline iron, while exhibiting a significant negative correlation with the content of iron in organic complex state. Hydroxyl radical (^•OH) has a significant positive correlation with ionic Fe²⁺, adsorbed Fe(Ⅱ), and high-crystalline iron. Superoxide anion (O₂^•−)has a significant positive correlation with low-crystalline iron and a significant negative correlation with adsorbed Fe(Ⅱ) and high-crystalline iron. The research results provide a new perspective for understanding the role of earthworms gut microbiota in soil iron cycling and ROS formation, which can be applied for pollutant control and degradation.

The weathered soil profiles were taken as the research objects from paddy and upland fields, which are typical agricultural lands in the carbonate rock regions of South China. The sources of soil heavy metals were traced via Pb isotope composition, and the vertical distribution and influencing factors of eight common types of heavy metals in the farmland soil profiles were systematically analyzed. The results revealed that the weathering of parent rocks was the main source of soil heavy metals in the study area, and the contents of heavy metals in the two profiles were found to be higher than the soil background value (0.056mg/kg). The enrichment of Cd tended to occur in the surface layer (0.49~2.15mg/kg) and the middle layer(0.75~1.87mg/kg) of the soil profiles, while that of the other elements tended to occur in the middle layer. The physicochemical properties and the mineral compositions of the soils, as well as the changes in the redox conditions exerted important impacts on the migration of heavy metals. The secondary enrichment of heavy metals in the soil profiles from the study area was attributed to the weathering process of carbonate rocks, while the impact of the leaching process on the migration and enrichment of heavy metals was more significant in the profile from the paddy field.

The Net Anthropogenic Nitrogen Input (NANI) model was utilized to estimate nitrogen inputs to Quzhou for the period from 2003 to 2022, and its spatial and temporal patterns, variations in components, and determining factors were examined. The results indicated that the average NANI for Quzhou over the past two decades was 12925kg/(km²·a), with a peak of 15698kg/(km²·a)in 2011. The spatial distribution was found to demonstrate an east-high and west-low pattern, which was consistent with land-use configurations. The predominant component of NANI was nitrogen fertilizer, which contributed 27% to 41%, followed by net nitrogen input from food/feed at 22% to 42%, atmospheric nitrogen deposition at 21% to 33%, and nitrogen fixation at 7% to 11%. The variations in NANI were primarily driven by nitrogen fertilizer application between 2003 and 2008, food/feed inputs between 2009 and 2014, and atmospheric deposition in recent years. Strategies were proposed to mitigate NANI, including promoting new energy vehicles, reducing nitrogen fertilizer application to align with standards of agriculturally advanced nations, and regulating livestock and poultry farming to match local demand. It was anticipated that these measures would decrease NANI by approximately 833, 893, and 896kg/(km²·a), respectively, achieving a cumulative reduction of about 2622kg/(km²·a), positioning it among the lower levels globally.

With the gradual depletion of shallow coal resources in mines and the continuous advancement of structural reforms on the supply side of national energy, the number of abandoned mines has increased, drawing growing attention to the environmental issues left behind in these areas. This study focuses on the abandoned mine in the Wansheng Economic Development Zone, Chongqing City. We collected five types of samples, including water (n=7), sediments (n=4), soil (n=8), coal gangue (n=2), and plants (n=10). The concentrations of the 16priority polycyclic aromatic hydrocarbons (PAHs) identified by the United States Environmental Protection Agency (USEPA) were analyzed using gas chromatography-mass spectrometry (GC-MS). Positive matrix factorization (PMF) and Monte Carlo simulation were employed to analyze the sources of PAH pollution and the carcinogenic risks in various environmental media within the abandoned mine. The results showed that the concentrations of PAHs in river, leachate, sediments, surface soil, coal gangue, and dominant plants were (45.6±12.4), (97.8±89.4)ng/L, (3640±2520), (6400±2650), (18600±1120), and (801±1110)ng/g, respectively. In the river, leachate, coal gangue, and dominant plants, the 2-3 ring PAHs are dominant, accounting for 83%,71%, 39%, and 54%, respectively. In the sediment and surface soil, the 5-6 ring PAHs have a relatively high proportion, accounting for 37% in both. The PMF source apportionment results indicated that diagenetic sources and petroleum source (49%) and traffic sources (32%) were the main contributors to PAHs in water. Traffic sources (48%) and coal combustion sources (35%) were the primary sources of PAHs in surface soil, while traffic sources (46%) and petroleum source and coal combustion sources (38%) were the major sources of PAHs in dominant plants. Monte Carlo simulations revealed potential carcinogenic risks to local residents from soil, coal gangue, and self-cultivated vegetables in the abandoned mine, with adults facing higher health risks than children. Over 96% of the carcinogenic risks were attributed to dermal contact.

An Approximate Homogeneous Turbulence Simulation system was employed to systematically explore algal responses to the interactive effects of turbulence and salinity by integrating the regulatory roles of these interactions on photosynthesis, nutrient metabolism, extracellular polymeric substances secretion, and grazing activities. It was demonstrated that at the biomass level, the damage to algae caused by turbulence was enhanced at 1‰ salinity, with Chl-a content in the low- and high-turbulence groups being 0.37 and 1.41 times that of the still-water group, respectively. At 4‰ salinity, damage was mitigated, with Chl-a content in these groups being 0.82 and 2.29 times that of the still-water group. This phenomenon was attributed to the regulation of algal photosynthetic efficiency and nutrient utilization rate by salinity. At the community structure level, the energy metabolism was enhanced by the increased salinity, which resulted in a lower water pH, thereby providing a competitive advantage to diatoms and leading to their dominance within the phytoplankton community. However, gas exchange and the shift in zooplankton composition were intensified by the elevated turbulence, mitigating the competitive advantage of diatoms caused by increased salinity. Consequently, the proportion of cyanobacteria increases, reinstating them as the dominant phylum.

Taking Huaihai Economic Zone as an instance, the spatio-temporal evolution of land use were analyzed from 2003 to 2023. On this basis, the spatio-temporal heterogeneity and spatial agglomeration of landscape ecological risk were identified for different historical periods and scenarios by combining PLUS model, spatial statistical method and ecological risk assessment model. The results indicate the following: (1) The land use types in Huaihai Economic Zone were mainly cultivated land and construction land. The overall land use pattern has not changed much in the past 20years. Concretely, it mainly manifested as the transformation of cultivated land into construction land. (2) The landscape ecological risk index (LERI) firstly increased and then decreased. In addition, the index was high in the east but low in the west of the study area. Furthermore it was relatively high in the north but low in the south. (3) The Moran's I index of the LERI decreased first and then increased. However, the local spatial agglomeration were mainly 'high-high' and 'low-low' patterns. (4) The LERI under the three scenarios of natural development, economic priority and ecological protection were 0.2470, 0.2451 and 0.2489, respectively. Under the ecological protection scenario, high ecological risk area accounts for the largest proportion across the whole regions. In contrary, the area of low ecological risk area accounts for the largest proportion in the scenario of economic development.

In order to explore the effect of biodegradable polylactic acid microplastics (PLA-MPs) on nitrogen conversion in sediments, a laboratory experimental sediment system was constructed, and 0 (control), 0.05%, 0.5% and 5% (W/W) PLA-MPs were added to freshwater sediments, then the incubation experiment was performed for 45d at 25℃ and light intensity of 40µE/(m²·s). The concentration of dissolved organic carbon (DOC) decreased significantly and the concentration of dissolved organic carbon (DOC)increased significantly (P<0.05), and the formation of CO₂ and CH₄ was promoted. At the end of the experiment, the concentration of NH₄⁺-N was reduced by the addition of PLA-MPs, and the concentrations of NO₃^--N and TN in the 0.05% and 0.5% PLA-MPs treatment group were lower than those in the control group (compared with the control group, the TN concentrations of the overlying water decreased by 68.44% and 61.83%, respectively). On the contrary, the TN accumulation in the 5% PLA-MPs treatment group was recorded (the TN concentration in the overlying water was 5.71mg/L at the end of the experiment) and was significantly higher than that in the control group (P<0.05). The NO₂^--N concentration in the 0.5% and 5% PLA-MPs treatment groups decreased and the release of N₂O was reduced, while the concentration of NO₂^--N in the 0.05% and 5% PLA-MPs treatment groups was increased. The addition of PLA-MPs promoted the expression of nitrogen-fixing genes nifH and nitrification genes amoA, and the denitrification genes nirS and nosZ were enriched in the 0.05% and 0.5% PLA-MPs treatment groups. However, the abundance of denitrification gene narG was only up-regulated in the 0.5% PLA-MPs treatment group. The abundance of narG and nirS genes in the 5%PLA-MPs treatment group was down-regulated, and the expression of nosZ gene was inhibited but then promoted. The results show that PLA-MPs changes the properties of the overlying water and sediment, promotes nitrogen fixation and nitrification, and provide carbon source to enhance denitrification and denitrification under 0.05% and 0.5% PLA-MPs treatments, but the reduction of NO₃^--N and NO₂^--N is inhibited due to low pH in 5% PLA-MPs treatment, resulting in TN accumulation.

To explore the patterns of forest carbon storage evolution influenced by the implementation of dual-carbon policies, This study selects Jiangmen City, a key ecological barrier in the Guangdong-Hong Kong-Macao Greater Bay Area, as a case study. Using land cover and carbon density data from five periods between 2000 and 2020, the study employs the InVEST model to quantitatively assess the area's carbon storage, in conjunction with the Policy Modeling Consistency (PMC) index model and the Least Absolute Shrinkage and Selection Operator (Lasso) regression model to analyze the quality of forestry policies and their impact on carbon storage. The results indicate that forest and agricultural lands were the principal contributors to carbon storage changes in Jiangmen City. From 2000 to 2015, these lands was significantly converted to built-up areas, causing carbon storage to decrease from 34.22×10⁶t to 33.59×10⁶t, accounting for 72.8% of the decrease in the Greater Bay Area's carbon storage during the same period, which represented a 14.35% reduction. After 2015, the implementation of subsidy policies related to forest city development resulted in an increase in the area of carbon storage exceeding areas of loss from 2015 to 2020, with a net increase of 0.5% in carbon storage. The “incentive safeguard” variable was identified as a principal factor in this increase. Spatially, the areas of increased and decreased carbon storage in Jiangmen City exhibited clustered distributions, reflecting the “forest surrounding cities and trees entering cities”policy. Based on the joint spatial distribution characteristics of carbon storage density and building density, the study proposes carbon sequestration enhancement strategies for different functional zones, including forest protection in ecological conservation areas, carbon planning in wilderness areas, spatial transformation in central old urban areas, and garden construction in newly developed urban areas. These recommendations provide theoretical support and practical examples for formulating sustainable urban development policies.

This study used the urban sprawl index and InVEST model to analyze the spatiotemporal changes of urban sprawl and its impact on ecosystem services in 19 provincial capital cities along the main and tributary streams of the Yangtze River Basin from 2000 to 2020. It also explored the factors influencing ecosystem services in the urban sprawl areas. This study found that: (1) 47.37%and 73.63% of cities experienced urban sprawl during 2000~2010 and 2010~2020, respectively. (2) From 2000 to 2020, the average habitat quality, total food and meat production services, and total carbon storage of provincial capital cities in the Yangtze River Basin (central urban area) decreased by 4.25%, 7.03%, and 4.53%, respectively, while the total water production increased by 12.10%. (3) The loss of ecosystem services due to urban sprawl was the most significant in terms of habitat quality, with a loss of 71.56% from 2010 to 2020 compared to 2000. (4) A correlation analysis was conducted on the impact of land-use conversion, socio-economic factors, and climate on ecosystem services, and it was determined that land-use and use conversion and socio-economic factors were the most influencing factors.

We used the PLUS model to predict the land use pattern under different development scenarios in 2030 in the Loess Plateau, an important ecological barrier in China, and applied the InVEST-Geodector model to analyze the spatiotemporal changes and driving factors in ecosystem carbon storage from 2020 to 2030. The findings were as follows: (1) The area of cropland will decrease under the natural development and ecological protection scenarios; the area of grassland decreases significantly under the cropland protection scenario, and forests and waters are effectively protected under all three scenarios. (2) The ecosystem carbon storage under the natural development, ecological protection, and cropland protection scenarios is 4.922, 5.021, and 4.922Pg, respectively. Compared with those in 2020, carbon storage will increase by 8.07, 37.22, and 8.07Tg, respectively. Carbon storage has obvious spatial heterogeneity, with high carbon density in the northern Qinling Mountains, Taihang Mountains, and Lvliang Mountains and low carbon density in Erdos City and its surrounding areas. Changes in carbon storage are closely related to the changes in the number of land classes and conversion of land use types. In conclusion, the ecological protection scenario is more in line with the future development needs of the study area. (3) The core determinants of ecosystem carbon storage are slope and precipitation, and the dominating combinations of factors driving regional differences and changes in carbon storage are the interactions of slope, soil type, or average annual temperature content with other variables.

The spatiotemporal evolution of water quality in the Yangtze River Basin since the impoundment of the Three Gorges Reservoir is critical for formulating comprehensive basin management strategies. Using stepwise multiple linear regression analysis, key water quality indicators influencing the basin from 2003 to 2024 were identified as total phosphorus (TP), permanganate index(COD_Mn), ammonia nitrogen (NH₃-N), lead (Pb), and dissolved oxygen (DO). Evaluations via the single-factor method and the WQI_min index demonstrated that the average water quality across the entire Yangtze River Basin has reached an excellent level. However, secondary basins—including the Wu River Basin, Min-Tuo River Basin, and Taihu Lake water system—exhibited relatively severe pollution, with TP and NH₃-N being the most prominent contaminants. Significant spatial heterogeneity in water quality was observed. Linear regression and seasonal Kendall tests indicated a statistically significant upward trend in the overall water quality of the Yangtze River Basin. All secondary basins, except the Han River Basin, demonstrated significant improvements. Following the Three Gorges Reservoir impoundment, TP concentrations in the upper reaches of the Yangtze River (specifically the Jialing River Basin, Wu River Basin, and the mainstream section from Yibin to Yichang) initially increased and subsequently declined. Similarly, NH₃-N concentrations in the middle reaches (e.g., Dongting Lake and Poyang Lake water systems) and the Wu River Basin located in the upper Yangtze River exhibited comparable trends of initial rise followed by reduction. Conducting research on the spatiotemporal evolution characteristics of water quality across the entire Yangtze River Basin, incorporating secondary tributaries through multi-scale, long-term time series, and multi-indicator analyses, provides critical scientific support for precise pollution mitigation strategies in the region. Such an integrated approach enables a comprehensive understanding of water quality dynamics, identifies pollution hotspots, and informs spatially differentiated management actions, thereby enhancing the efficacy of basin-wide environmental governance.

As a typical arid oasis in northwest China, economic development in the Turpan Basin is heavily dependent on groundwater. In this study, hydrogeochemical mechanisms controlling groundwater boron (B) enrichment and associated health risks through an integrated approach combining hydrochemical analysis, isotopic tracing, and UNMIX receptor modeling were systematically investigated based on 6 river water and 49 groundwater collected in the study area. The results indicated that: (1)surface water in the study area was neutral to slightly alkaline, while groundwater ranged from slightly acidic to slightly alkaline;groundwater B existed in a mixed form of H₃BO₃ and B(OH)₄^-, with H₃BO₃ being the dominant species. (2) Groundwater B concentrations ranged from ND to 4.26mg/L, with 24.5% exceeding China's drinking water standard (1.0mg/L, GB5749-2022). High-B groundwater (mainly Cl·SO₄-Na·Ca type) exhibited significant spatial heterogeneity, clustering in the Gaochang District downstream of B-bearing river. (3) Groundwater B enrichment originated from mountain rock weathering (dominant source), supplemented by anthropogenic inputs (wastewater/fertilizers), with surface water infiltration being the principal transport pathway. Key controlling processes included pH-dependent speciation, cation exchange, competitive adsorption, dissolution of evaporite, and the mixing, with significant variations between aquifers. (4) The UNMIX model identified four factors: surface water infiltration recharge (36.6%), carbonate-silicate dissolution (21.8%), evaporite dissolution (21.6%), and industrial/agricultural activities (20.0%), with boron primarily originating from surface water infiltration recharge (56.0%). (5) The order of vulnerable segments of the population in terms of risk posed by B in groundwater was: infants > adult men > adult women > children. in the arid region of Northwest China.

Accurately assessing the degradation status of seagrass bed ecosystems was essential for formulating effective protection and restoration decisions However, existing assessments of seagrass bed ecological degradation were primarily conducted from the health perspective, neglecting the endpoint of degradation and its critical levels during the degradation process. This study took ecosystem collapse as the endpoint of degradation and, from an ecological risk perspective, the assessment framework of the Red List of Ecosystems was drawn upon. Three main criteria—habitat range degradation, abiotic environmental degradation, and biological process degradation—were integrated to establish an assessment framework for seagrass bed ecosystem degradation. Fourteen seagrass bed distribution areas along the South China coast were selected for empirical study. The assessment results showed that the seagrass bed in Tangjiawan had reached an extremely degraded level. Eight seagrass beds, such as Zhelin Bay, were severely degraded (57%); the seagrass bed in Li'an Port was moderately degraded; and four seagrass beds, such as Liusha Bay, were slightly degraded (29%). Among the three major assessment criteria, biological processes were identified as the main manifestation of seagrass bed degradation along the South China coast. From the perspective of ecosystem collapse risk, a framework for assessing seagrass bed ecosystem degradation was constructed, providing a new perspective for evaluating the degradation status of seagrass beds and other ecosystems, and offering important decision-making support for ecosystem conservation and restoration.

This paper reviewed the occurrence characteristics and abundance of microplastics (MPs) in disinfection processes of water treatment plants both inside and outside China, and analyzed the MPs removal effectiveness of chlorine, ozone and ultraviolet disinfection, followed by an in-depth discussion of the effects of MPs presence on disinfection and its secondary pollution. The results showed significant differences in the abundance of MPs across different water treatment plants, primarily existing in the forms of fibers and fragments, predominantly composed of polyethylene terephthalate (PET), polyethylene (PE), and polypropylene (PP), with most sizes less than 1.0mm and colors mostly black, white, or transparent. The removal rate of the chlorine disinfection unit ranged from 0% to 71.38%; but part of the water treatment plants had seen a rise in MPs abundance after the ozone and ultraviolet disinfection. The removal mechanisms of MPs by disinfection processes remained required further research. Additionally, the trihalomethane formation potential (THMFP) of microplastic-derived dissolved organic matter (MP-DOM) in the chlorine disinfection process could reach as high as 453.3µg/mg, higher than the formation potential of typical aquatic natural organic matter and algae organic matter, pointing to greater health risks.

Microplastics (MPs) pollution has become a hot research topic in the environmental field, while few studies have reported the MPs pollution in the gastrointestinal tract of river fish in Hainan Island. In the present study, 222 freshwater fish specimens belonging to 35 species with different feeding habits were collected from 11 sampling sites located in the upper, middle, and lower reaches of the Nandu River. The pollution characteristics of MPs in the gastrointestinal tract of fish samples were analyzed. The results showed that MPs were detected in 94.5% of the fish gastrointestinal tracts, with an average abundance of (4.85±3.51)MPs per fish. The MPs in fish gastrointestinal tract were dominated by <1.0mm (73.3%) transparent (38.9%) fibers (60.6%), and were mainly composed of polypropylene (53.3%) and polyethylene (34.2%). The highest abundance of MPs was recorded in the gastrointestinal tract of filter-feeding planktivorous fish (7.00 per fish) and the lowest abundance was recorded in the gastrointestinal tract of insectivorous fish (2.57 per fish). From the upper to the lower reaches, the percentage of blue fragment MPs with size <1.0mm in the fish gastrointestinal tract was increasing, while the percentage of yellow/red fiber/film MPs with size >1.0mm was decreasing. This could be attributed to the increase of aquacultural activities, the usage of agricultural films, and a large amount of sewage and industrial wastewater in the lower reaches.

The study investigates the spatio-temporal dynamics of anthropogenic emissions in China under a carbon-neutral scenario, with a focus on synergistic reductions in carbon dioxide (CO₂), volatile organic compounds (VOCs), and nitrogen oxides (NO_x). Using the Dynamic Projection model for Emissions in China (DPEC), emissions trends were analyzed and compared with two Shared Socio-economic Pathway (SSP) scenarios (SSP1-1.9 and SSP1-2.6). The findings reveal that under the DPEC carbon-neutral scenario, CO₂ emissions will peak by 2030 and decrease by 91% by 2060 relative to 2020 levels. Emissions of VOCs and NO_x show continuous reductions since 2020, with declines of 65% and 88%, respectively, by 2060. Compared to the two SSP scenarios, the DPEC scenario shows a weaker reduction in VOCs but a stronger reduction in NO_x. Sectoral analysis highlights that CO₂ reductions primarily stem from the energy and industrial sectors, whereas the transportation sector drives notable decreases in VOCs and NO_x. By 2060, the industrial sector will remain the dominant source of emissions for CO₂, VOCs, and NO_x. The results suggest that the DPEC carbon-neutral scenario aligns closely with China's future emission reduction trends, demonstrating significant potential for synergistic emission reductions. Achieving these targets on schedule will require robust policy implementation and sectoral commitment, offering substantial improvements in air quality and environmental outcomes.

This study collected the surface soil samples (0~10cm) from the freshwater (salinity: 0) and mesohaline (salinity:10~15) P. australis marshes in the six main estuaries in China, which are the Liao River Estuary, Yellow River Estuary, Yangtze River Estuary, Oujiang River Estuary, Minjiang River Estuary, and Pearl River Estuary. The production rates of soil CH₄ and CO₂ were measured using laboratory anaerobic slurry incubation method, and the extracellular enzyme activity and abundance of methanogen functional genes (mcrA) were also measured. Mean CH₄ production rate in the freshwater and saltwater P. australis marshes was (2.69±1.63) and (2.97±1.71) ng CH₄/(g·d), respectively. Mean CO₂ production rate was (7.64±4.94)and (10.28±6.84)µg CO₂/(g·d), respectively. CO₂ production rate in the freshwater P. australis marshes was significantly lower than that in mesohaline P. australis marshes, but no significant difference in CH₄ production rate was observed between freshwater and mesohaline marshes. Soil pH and soil organic carbon (SOC) content were identified as the main factors influencing extracellular enzyme activity and methanogen abundance. A decrease in pH led to a significant reduction in the production rates of CH₄ and CO₂. Total carbon, total nitrogen, SOC, activity of five extracellular enzymes, and abundance of mcrA were identified as the key factors influencing CH₄ and CO₂ production. Our research results suggest that across the Chinese coastal estuarine freshwater and mesohaline P. australis marshes, salinity is not a main factor controlling CH₄ production, however, the increase in salinity perhaps raise soil anaerobic mineralization rates, which indicates that sea level rise and saltwater intrusion will cause carbon emission increase from estuarine P. australis marshes.

This research addressed the issue of low-carbon development in hydropower, provided a review of the key factors influencing the carbon footprint of hydropower and the regional variations in these footprints. The findings of this research indicated an increasing global focus on research into the carbon footprint of hydropower. Case studies revealed that the primary contributors to the hydropower carbon footprint were the manufacture of construction materials and engineering activities during the construction phase, as well as energy consumption by equipment during the operation and maintenance phase. This research identified key factors affecting hydropower carbon emissions, including the type of hydropower, installed capacity, water storage volume, reservoir area, and life cycle stages. Furthermore, from a geographical perspective, it explored the regional variation in hydropower carbon emissions, highlighting the impact of differences in climate, precipitation, and ecological environment due to geographical location on the hydropower carbon footprint.

To investigate the impact of organochlorine pesticides (OCPs) exposure during pregnancy on neonatal sex hormone levels and birth physique, this study recruited 271 mother-infant pairs from Guangzhou and collected meconium samples within 24hours postpartum. The levels of ten OCPs and seven sex hormones in meconium were analyzed. The generalized linear model (GLM) was employed to explore the association between OCP exposure and birth physique scores. Additionally, the mediation effect model was utilized to assess the mediating role of sex hormones in the relationship between OCP exposure and birth physique scores. The results indicated that the predominant OCPs in neonatal meconium was p,p'-DDE, with concentration range of not detected (nd) to 0.25nmol/g (median 0.05nmol/g). The median levels of progesterone (P4), androstenedione (AED), testosterone (T), estrone (E1), estradiol (E2), and estriol (E3) in meconium were 1.80, 0.24, 0.13, 0.15, 0.38, and 8.24nmol/g respectively. For each unit increase in p,p'-DDE exposure level, AED, T, and E3 in meconium increased by 1.82 (95% CI: 0.34, 3.29), 1.31 (95% CI: 0.03, 2.60), and 211(95% CI: 120, 302), respectively. In male newborns, for each unit increase in p,p'-DDE concentration was associated with an increase of 9.12 (95% CI: 3.11, 14.9) in E3leevels. Conversely, in female newborns, for each unit increase in Σ₁₀OCPs concentration resulted in a decrease of 11.8 (95% CI: - 22.8, - 0.84) in the E2/T ratio. Exposure to p,p' - DDE may influence the birth length-Zscore (BLZ) in male neonates through the regulation of E3, with an indirect effect of 0.73 and a mediation effect percentage of 25.3%. Exposure to Σ₁₀OCPs may impact head circumference-Zscore (HCZ) in female neonates via regulating E2/T ratio, with an indirect effect of - 0.18 and a mediation effect percentage of 19.4%. Exposure to OCPs during pregnancy may affect the changes in birth physique scores of neonates by regulating their sex hormone levels.

A systematic study on antibiotic resistance genes (ARGs) and resistant pathogenic bacteria in the air and corresponding sewage of the sewage treatment plant was conducted. Their enrichment rate in the air and influencing factors were analyzed, and daily respiratory exposure was assessed. A divergence in the distribution of predominant ARGs in ambient air and sewage was revealed, with Sul1 and tetW being identified as the most abundantly detected genetic markers. The taxonomic composition of the dominant pathogenic bacteria was found to be similar across both matrices, with Bacteroides, Klebsiella, and Enterococcus genera being identified as the most prevalent in sequential order. Enrichment of certain ARGs and pathogenic bacteria was observed in the air of wastewater treatment plants, with the highest enrichment rates being attributed to the tetW gene and Megamonas genus, respectively. The transfer process of ARGs and pathogenic bacteria from wastewater to air was influenced by factors such as water quality and aeration processes. Tracing analysis indicated that approximately 73.59%±3.61% of the bacteria in the air of wastewater treatment plants originated from the sewage. Methicillin-resistant Staphylococcus aureus (MRSA) was successfully isolated from both air and sewage samples, with MRSA in the air being observed to exhibit an antibiotic resistance index (0.24) that was significantly higher than that in sewage (0.077±0.045). Furthermore, MRSA's resistance to vancomycin in the air was also found to be greater than that of the corresponding isolates from sewage. The daily inhalation exposure to bacteria for workers at the wastewater treatment plant was estimated to be (1.9±1.5)×10⁵ copies/d, with average exposure to ARGs and mobile genetic elements(MGEs) being calculated as (7.4±7.5)×10⁴ copies/d and (0.8±1.0)×10⁴ copies/d, respectively. The findings of this study were expected to provide scientific data for a comprehensive assessment of health risks associated with air quality in wastewater treatment plants and for the development of corresponding control strategies.

A controlled experiment was conducted to investigate temperature-induced alterations in serum biochemical indices and gut microbiota of endemic fish (Procypris rabaudi) in Jinsha River, a cascade hydropower development river in southwest China. Three temperature treatments (16℃, 20℃, 24℃) were established with exposure durations of 24h and 10d. Results showed that compared to the ambient temperature group, the serum antioxidant enzyme activity was promoted in the low temperature group after 24h but inhibited after 10d. The decrease in lysozyme (LZM) activity in the low temperature group of 10d (67.12%) was more significant than that of 24h group (52.04%) relative to the ambient temperature group. And the concentrations of glucose (GLU) and CORTISOL were increased significantly in the low temperature groups both 24h and 10d compared with those in the ambient temperature groups. The Chao1index of the low temperature group at 24h were 23.22% and 26.36% lower than those of the ambient temperature and high temperature groups, respectively. The alpha diversity was found to stabilize in the low temperature group after 10d. Compared to 24h, the difference in gut microbiota community structure under different temperature conditions after 10d was smaller, and the low temperatures significantly affected the community composition of the gut microbiota. Co-occurrence network analysis revealed that microbial interactions were simplified and weakened in the low temperature group (24h), whereas prolonged thermal adaptation (10d) was associated with network stabilization. Significant correlations were established between Proteobacteria, Bacteroidetes, and Firmicutes with antioxidant enzymes and LZM activity.

The catalytic degradation mechanism of petroleum hydrocarbons by Ferripyochelin (FerriPCH), formed by the combination of pyochelin (PCH) from the extracellular fluid of P. aeruginosa NY3 and Ferri, was investigated. The results showed that two chiral PCHs were produced by strain NY3. The purified PCH could degrade both alkanes and polycyclic aromatic compounds of petroleum hydrocarbon after combining with Ferri. A certain ratio of hexadecane, anthracene, as well as phenanthrene could be degraded by FerriPCH which formed by PCH and Ferri in the ratio from 2:1 to 1:1. In addition, degradation efficiency of aromatic hydrocarbons with low bio-availability was significantly higher than that of alkanes. Further studies showed that strongly oxidizing free radicals of •OH and •O₂^- produced after the binding of Ferri and PCH degraded petroleum hydrocarbons into carbon dioxide and water step by step.

N-methyl-2-pyrrolidone (NMP) was selected as the sole carbon and nitrogen source, and a strain NCSL-HH10 that could efficiently degrade NMP was isolated from the cleaning wastewater of lithium-ion battery cathode slurry mixer. 16S rDNA sequencing and phylogenetic affiliation analysis showed that this strain belonged to Burkholderia contaminans. The results showed that 100% NMP removal and 94.3% TOC removal could be obtained in 1500mg/L NMP wastewater within 48h using this strain. Such a high mineralization degree indicated that the strain possessed a relatively complete NMP degradation pathway. In addition, the strain could completely degrade NMP with a concentration as high as 15000mg/L, which displayed the highest NMP degradation concentration with a high mineralization degree (63.2%) compared to the publicly available literatures. Finally, 10000mg/L NMP wastewater was treated by Burkholderia contaminans NCSL-HH10 and activated sludge under open environment, respectively. It was found that 95.7% NMP and 76.5% TOC were removed within 60h by NCSL-HH10, which was significantly higher than activated sludge (only 39.0% NMP and 30.2% TOC were removed within 84h).

Based on the ISfinder database and reference meta-analysis, this study conducted a systematic study of the diversity of 5812 insertion sequences (ISs) and their co-occurrence with functional genes. The study found significant differences in the distribution of different IS families among hosts, as well as in their co-occurrence with functional genes. DDE-type ISs are predominant, with the IS5 and IS3 families containing the most ISs, while the ISH6 family contains the fewest. ISs are widely found in bacteria and archaea, and several IS families show host specificity, being found only in either bacteria or archaea. The study demonstrated that IS co-occur with various functional genes, such as antibiotic resistance, heavy metal resistance, and stress resistance, indicating their significant role in environmental adaptation and the spread of antibiotic resistance genes among pathogens. Some IS exhibited co-occurrence with multiple functional genes, suggesting broader ecological adaptability, while others showed functional specificity. Future research should focus on experimentally validating the mechanisms through which IS mediate gene transfer and host adaptation, to reveal the mechanism of microbial evolution and ecological adaptation.

Owing to high-cost concerns, contractors dispose the construction spoils predominantly through landfilling or dumping at present. How to motivate them to adopt recycling is a challenge. A novel contingent valuation method named HCVM was proposed in this study. Taking the survey data of 585 construction employees in Changsha City, Hunan Province as a sample, the contractors’willingness to pay (WTP) and their influencing factors were analyzed. The unclear pricing principle of non-recycling disposal charge was clarified, and the incentive mechanism for contractor's construction spoils recycling was proposed accordingly. The results show that: 1) the average WTP of contractors is 73.69 yuan/t, which is higher than the current landfilling charge of 20 yuan/t, and the expected penalty cost for dumping of 16.70~25 yuan/t. It is suggested that the government should increase the landfilling cost over 73.69 yuan/t by pricing or tax, and raising the penalty for dumping from 5000 to 15000 yuan per truck. 2) The average disposal cost for construction spoils recycling is 137 yuan/t, and the average price of recycling products selling is 40 yuan/t. Even if including contractors' WTP, it remains lower than the total recycling cost. The government can address this discrepancy with direct monetary subsidies, rewards developing new technologies to reduce the recycling costs or issuing policies to promote the market demand and selling price of recycling products.3) 74.35% of the respondents were willing to pay for the construction spoils recycling. Factors such as the ownership attribute of contractors, pressure from the public, awareness of environmental protection, and satisfaction with current disposal method positively influence their WTP. However, the respondents' construction project experience negatively affected their WTP. The government's guidance, the higher subsidies, rewards of construction spoils recycling and stricter penalties for dumping can also effectively motivate contractors to adopt recycling behaviour.

Against the backdrop of China entering a new stage of development, implementing new development concepts, and building a new development pattern, how to pursue healthy industrial development while controlling water energy consumption and reducing carbon emissions has become an important and urgent practical task. On the base of exploring deep level industrial economic connections, the theoretical framework of the three-dimensional full footprint stereoscopic correlation of industry water energy carbon was constructed. Then the article designed an input-output calculation model for industrial factor footprints and created a function correction input-output table to solidify the data foundation. Selecting Chinese industries from 2002 to 2022 as the research object, the three-dimensional full footprint of industrial water, energy, and carbon were calculated. Based on the three dimensional full footprint stereoscopic correlation network of water energy carbon in Chinese industries, the evolution characteristics of network attributes and relationship structures have been compared and analyzed by combining dynamic and static methods. The results showed that:(1) During the research period, the average annual growth rate of China's industrial water, energy, and carbon total carbon footprint had decreased, but the total amount had increased significantly. The increase in water footprint was mainly due to the increase in industrial direct footprint, while the increase in energy footprint and carbon footprint were due to the increase in industrial indirect footprint. (2) There were significant differences in the three-dimensional footprint of water energy carbon and dual factor among various industries, and it was necessary to integrate the characteristics of industries and footprint characteristics to improve the efficiency of factor utilization. (3) During the research period, various indicators and coupled performance of the industrial water energy carbon network had improved, but the circular sustainability, symbiosis and mutual benefit, and correlation had not reached the ideal state.

Lrovincial panel data from 2011 to 2021 were leveraged in this study to examine the effectiveness and underlying mechanisms of digitalization in promoting the coordinated development of mineral resources and ecological conservation from the perspective of regional development disparities. It was indicated by the findings that, overall, a moderate upward trajectory had been shown in the level of coordinated development of mineral resources and the environment in China. However, significant geographical heterogeneity persisted, with the southeastern coastal regions being outperformed by the central and western areas. This coordinated development was significantly promoted by digitalization, a conclusion that was remained robust even after addressing endogeneity and conducting sensitivity analyses. Furthermore, industrial structure upgrading and improvements in green innovation capabilities were identified as key mediating factors through which coordinated development was facilitated by digitalization. It was also revealed by this study that the impact of digitalization varied across different regions, with China’s southeastern regions being benefited more substantially. Based on this analysis, several recommendations were proposed, including investments in digital infrastructure and technologies being enhanced; the pivotal role of digitalization being reinforced; the green transformation of the industrial structure being advanced; and targeted regional development strategies being developed.

Based on the STELLA platform, a system dynamic model was constructed based on technology iteration, service life, and other influencing factors. This model systematically analyzed and simulated wind turbine waste generation under various scenarios, while quantifying the recycling scale of wind turbine waste and its potential carbon emission reduction effects. The results showed that: (1) Under the design lifetime scenario, the new-installed capacity of wind turbines in China were found to be increasing rapidly from 2006 to 2038, reached a trough in 2047, and then increased again. The scale of wind turbine scrapping was rising rapidly, and the peak time of wind turbines wastes with different unit capacities gradually occurred later as the unit capacity increased. (2) Under the design lifetime scenario, the amounts of waste generation components of wind turbines in 2060 were identified as follows: steel(13.67 million tons), aluminum (197200 tons), copper (762300 tons), plastic (137700 tons), fiberglass (1.7644 million tons), electronic devices (162300 tons), permanent magnets (27700 tons), lubricating oil (11000 tons), and concrete (34.76 million tons), respectively. (3) From 2025 to 2060, the cumulative closed-loop recycling of decommissioned wind turbine materials could meet 49.46%, 41.13%, and 32.67% of the total material demand under the short lifetime, design lifetime, and the long lifetime scenario, respectively. The cumulative carbon emission reductions from 2025 to 2060 with 100% resource utilization of steel, aluminum, copper and permanent magnets in scrapped wind turbines under the short lifetime, design lifetime, and the long lifetime scenario were calculated as 246.54 million tons, 175.95 million tons and 122.18 million tons respectively. Extending the wind turbine lifespan, establishing and improving the recycling system for wind power equipment, strengthening the resource recycling capabilities, and promoting advanced recycling technologies such as steel remanufacturing would reduce greenhouse gas emissions effectively. These efforts are considered significant in achieving China’s goals of peak energy production before 2030 and carbon neutrality by 2060.