Microbial community structures, functional characteristics, and their relationships with hydrochemical environmental factors in arid areas of oasis area of the Hotan River Basin with fluoride-containing groundwater were investigated. Three groups of groundwater were analyzed: the LF group (ρ(F^-) ≤ 1.0mg/L), MF group (1.0mg/L<ρ (F^-) ≤ 2.0mg/L), and HF group (ρ (F^-)>2.0mg/L). The diversity, structural composition, and functional characteristics of the bacterial communities in the groundwater of the three groups were investigated using high-throughput sequencing. The results showed that ① While the diversity of the bacterial communities in the three groups was less affected by F contents, significant differences in community compositions were observed. ②Proteobacteria represented the dominant phylum in all three groups, with relative abundance of 67.61% (LF group), 52.02% (MF group), and 41.43%(HF group). The dominant bacterial genus in the HF group was Sphingobium, which had relatively low abundance in the LF and MF groups. The relative abundance of Gallionella, Hydrogenophaga, Nitrospira, and Ferritrophicum was markedly higher in the LF or MF groups compared with the HF group. ③ F^-, HCO₃^-, Ca²⁺, NO₃^-, and Cl^- were key indicators that affected bacterial community structures in F-containing groundwater. ④ PICRUSt2 functional prediction indicated that metabolic functions dominated in all three groups, while bacteria in the HF group showed reduced activities in pathways involved in co-factor abundance and vitamin metabolism compared with the LF group. ⑤ Gallionella, Hydrogenophaga, Nitrospira, and other chemoautotrophic carbon-fixing microorganisms, which had relatively high abundance in the HF group were significantly negatively correlated with the F^- and HCO₃^- contents, and significantly positively correlated with the Ca²⁺content (P<0.01). At the same time, Nitrospira was also positively correlated with NO₃^- and negatively correlated with NH₄⁺(P<0.01). The structural and functional differences in microbial communities in the groundwater of the oasis area of the Hotan River Basin, as well as their correlations with environmental factors, reflect the bidirectional relationship between chemoautotrophic carbon-fixing microorganisms and groundwater F^- contents in arid areas.

Based on the Global dataset of solar-induced chlorophyll fluorescence (GOSIF) and the Optimal Parameters-based Geographical Detector (OPGD) model, systematically analyzed the spatio-temporal patterns and driving mechanisms of vegetation photosynthesis on the Loess Plateau (LP) and its six ecological subregions from 2002 to 2022. The results indicated that: (1) On the temporal scale, the annual mean SIF across the LP region demonstrated significant growth with spatial heterogeneity. The hilly-gully region (Subregion B2) showed the highest increase rate[0.0024W/(m²·μm·sr·a)], while sandy and irrigated agricultural areas displayed the lowest [0.0006W/(m²·μm·sr·a)]. (2) On the spatial scale, the spatial distribution of annual SIF on the LP was significantly different, Notable degradation was observed in localized areas, particularly within the high-plain-gully Subregion A1 (central Qinghai Province) and the Guanzhong Plain. 11.36% of the region (southern rocky mountain and valley plain areas) exhibited SIF changes that deviated from the regional trend. (3) Anthropogenic factors dominated human activities and climate change exerted dual influences on vegetation photosynthetic evolution, with the former acting as the dominant driver and the latter governing spatial divergence. Precipitation primarily regulated SIF variations in the high-plain-gully Subregion A1, while solar radiation dominated the evolution in Subregion A2, hilly-gully regions, and rocky mountain-valley plain areas. Factor interactions synergistically amplified SIF spatial heterogeneity.

Analyzed the changes in vegetation cover (FVC) in the arid and semi-arid regions of northern China from 2000 to 2023, the impacts of FVC changes on ecosystem services were evaluated, and the impact thresholds were identified. The results showed that the FVC in these regions was characterized by a spatial pattern of being low in the west and high in the east, and low in the north and high in the south. Areas with increasing FVC accounted for 40.01% of the total study area. Overall ecosystem services were observed to decrease gradually from south to north, with high-value areas mainly distributed in southern Gansu Province and northwestern Xinjiang, while low-value areas were concentrated in central and western Inner Mongolia and northern Ningxia. The overall trend of ecosystem services was found to be increasing, with 85.01% of the area showing an upward trend. The FVC level was positively correlated with carbon fixation, soil conservation, and water production services, with significantly positive correlation areas accounting for 54.56%, 7.9%, and 11.43%, respectively. The increase in FVC was found to promote the comprehensive ecosystem services index (CIES) from 0.09 to 0.23. The FVC impact threshold in forest and farmland areas was not significant, and the positive effect of increasing FVC tended to weaken when grassland vegetation coverage reached 0.87.

The zero-valent iron-activated persulfate (ZVI-PS) method was used for sludge dewatering. The dewatered sludge was then mixed with humic carbon (HC) and carbonized to successfully prepare a hybrid biochar catalyst. When applied to levofloxacin (LVFO)-containing wastewater treatment in a photofenton system, the catalyst exhibited excellent performance under circumneutral conditions. It effectively addressed the traditional Fenton system's dependence on acidic environments, thereby significantly broadening the applicable pH range. This study systematically investigated the effects of catalyst dosage, H₂O₂ concentration, xenon lamp power, and pH on LVFO degradation efficiency. The results showed that under optimal conditions (catalyst dosage: 1g/L, H₂O₂ dosage: 0.6mL/L, xenon lamp power: 300W, pH 7), the LVFO degradation rate by the hybrid biochar reached 92.58%—far higher than the 55.86% achieved by humic carbon. This superior performance was primarily attributed to the abundant iron species on the hybrid biochar surface, which facilitate iron cycling and thus enhance catalytic activity. Active species quenching experiments revealed that the system degrades LVFO mainly through the non-radical pathway of singlet oxygen (¹O₂), which explained its excellent degradation capacity under circumneutral conditions. After five cycles of reuse, the catalyst's iron leaching rate was below 0.56%, and it retained high catalytic efficiency. A potential LVFO degradation pathway was proposed based on three-dimensional fluorescence spectroscopy and intermediate product detection.

Microplastics (MPs) are emerging contaminants of global concern, posing a potential and serious threat to ecosystems and human health due to their small size, ease of migration, and slow degradation. MPs pollution control is urgently needed. Artificial intelligence (AI) is becoming increasingly integral to MPs pollution management, leveraging its superior data processing, pattern recognition, and predictive power. This paper presents a comprehensive review of recent advances in AI applications across the MPs management lifecycle, including collection and detection, source apportionment, impact assessment, and strategic intervention. The AI models utilized in each phase are comparatively evaluated, with a focus on their accuracy and limitations. This paper critically examines the extant challenges and outlines prospective development pathways, ultimately aiming to facilitate more informed and effective strategies for the scientific and intelligent management of MPs pollution.

To quantitatively assess fiber microplastic emissions and their spatial distribution resulting from household laundering, a release and transport flux model was developed. This model, which integrates global textile consumption data with microplastic emission factors from laundering, was used to evaluate how variations in washing behaviors and wastewater treatment capacities across different countries and regions influence fiber microplastic release patterns. The simulation results indicated that the global emission of fiber microplastics from household washing reached approximately 2298.8kt in 2022. India, China, and the United States were identified as the top three contributors, with estimated emissions of 624.5kt, 471.4kt, and 332.8kt, respectively. Following wastewater treatment, significant regional differences in microplastic removal efficiency were observed. North America exhibited the highest removal rate at 78%, while removal efficiencies in Asia and Africa below the global average. Ultimately, fiber microplastics not retained during wastewater treatment entered the marine environment via river systems. The Ganges River (16.5kt), the Yangtze River (12.4kt), and the Indus River (5.1kt) were identified as the rivers with the highest annual fluxes of fiber microplastics into the ocean.

Toxicity thresholds (ECx) forCd, and in combination with tetracycline and imidacloprid, were determined based onthe soils collected from six typical greenhouse vegetable farms in China. Three toxicity endpoints includingthe growth of Brassica napus, the growth of the red earthworm Aedes aegypti and the soil microbial substrate-induced respiration (SIR) were applied, and the quantitative relationships and prediction models were established between the toxicity of the pollutants and key soil properties. The results showed that the toxicity dose-effect relationships of the pollutantsacross different soils and test endpoints typically followed a distinct S-shaped curve. For example, the toxicity thresholds forCd alone on B. napuswere 0.6~8.5mg/kg (EC₁₀) and 4.3~14.7mg/kg (EC₅₀), respectively. For the combined pollution of Cd and tetracycline, the corresponding values were 0.1~2.2mg/kg (EC₁₀) and 1.2~6.9mg/kg(EC₅₀). For the combination of Cd and imidacloprid, the values were 0.1~3.7mg/kg (EC₁₀) and 1.4~10.0mg/kg(EC₅₀). The toxicity thresholds of pollutants varied significantlydepending on the test endpoints, e.g., the sensitivity order for Cd and tetracycline was Chinese cabbage > earthworm > microorganisms, the toxicity thresholds for the combined pollutants were consistently lower than those for the single pollutants, indicating a synergistic effect. Additionally, a low-dose stimulation effect (hormesis) on the growth of B. napus was observed, with a maximum stimulation rate of 103% to 110%. Soil pH was identified as the primary factor controlling and predicting the toxicity thresholds. A comprehensive prediction model based on soil pH, cation exchange capacity (CEC), and organic carbon (OC) content was developed, which can effectively predict the toxicity thresholds and assess the ecological risks associated with the combined pollution of Cd and emerging contaminants in greenhouse vegetable soils.

To compare their capture efficiency, four types of iron (hydro)oxide-loaded biochar functionalized with ferrihydrite, goethite, hematite, or magnetite were synthesized via co-precipitation method at a consistent iron-to-biochar mass ratio. The modification significantly improved electrostatic attraction between the biochar and aged microplastics, thereby increasing retention capacity. Among these materials, magnetite-loaded biochar demonstrated the highest removal efficiency exceeding 90% and maximum adsorption capacity of 25.02mg/g, representing a 5.53-fold improvement over unmodified biochar. This superior performance is likely attributed to its highest iron oxide loading (4.15wt%). Adsorption data followed both the Langmuir monolayer model and pseudo-first order kinetics. Notably, magnetite-loaded biochar maintained over 95% retention under varying ionic strengths, cation valences, and pH conditions. It also preserved greater than 90% of microplastics in multi-bed volume tests and real-water samples. Moreover, after multiple alkaline washing regeneration cycles, the material remained stable adsorption performance, demonstrating its excellent reusability potential.

The sedimentation behavior of microplastics (MPs) in water bodies is synergistically regulated by the intrinsic properties of the particles, the photoaging degree, and the chemical conditions of the solution. Existing studies have overlooked the sedimentation behavior for different types of aged MPs in karst small water bodies. Through simulation experiments, the sedimentation behavior of three types of MPs (polystyrene (PS), polyamide 6 (PA6), and polyethylene terephthalate (PET)) with different photoaging degrees wasinvestigated in weakly dynamic water bodies and environments with different concentrations of CaCl₂. The results showed that the sedimentation ratios of the three types of MPs exhibited a decreasing trend with the deepening of photoaging under pure water conditions, while the opposite result was observed in the CaCl₂ environment. Compared with pristine MPs, the sedimentation ratios of MPs aged for 1000h decreased by 38.8% to 56.0% in pure water. In contrast, the sedimentation ratios increased by 23.8% to 93.3% and 66.1% to 357.1% in 10mmol/L and 100mmol/L CaCl₂ solution, respectively. Ca²⁺ can compress the electrical double layer of MPs, reducing the electrostatic repulsion between particles. Simultaneously, It can also bridge with the oxygen-containing functional groups on the surface of aged MPs. These effects facilitate the homogeneous aggregation of particles, therebypromoting their sedimentation. The results of Pearson correlation analysis and DLVO theory calculations indicated that bridging of Ca²⁺ was an important external factor regulating the aggregation and sedimentation of MPs before and after aging. Although the photoaging degree and salt ions influenced the sedimentation process of MPs, the fact that Peclet values of the three polymer MPs were below 1demonstratedthat material densitywas the dominantfactor governing their sedimentation behavior. the sedimentation of MPs is primarily governed by polymer density. Photoaging regulates interparticle interactions by changing the oxygen-containing functional groups and size distribution of MPs. While the compression of the electrical double layer and bridging effects induced by Ca²⁺ further influence their aggregation and sedimentation behavior of MPs.

This study constructs a comprehensive framework for assessing regional carbon inequality by integrating and extending the logarithmic mean Divisia index (LMDI) with production-theoretical decomposition analysis (PDA). Based on panel data from 273 Chinese cities (2006~2019), we examine the dynamic evolution and drivers of per capita carbon emission inequality from structural, technological, and efficiency perspectives. Results indicate significant carbon inequality in China, with the inequality index first decreasing from 15.18 (2006) to 14.51 (2008) before fluctuating upward to 22.59 (2019). Rising potential carbon intensity and shifts in regional economic structure were the main drivers of increased inequality, while regional economic growth, production efficiency improvements, and narrowing inter-city technology gaps helped mitigate it—though carbon reduction technologies showed no significant equalizing effect. Dynamic analysis reveals that potential carbon intensity fluctuations had the strongest impact on inequality changes, while technological progress and efficiency gains effectively curbed its rise. Regionally, the southern coast exhibited the highest carbon inequality, while the northwest had the lowest, with drivers varying in direction and intensity across regions.