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.

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.

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.

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.

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.

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.

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.

This research aims to analyze the influencing factors of aquifer recharge management in the Sanjiang Plain, China, by utilizing Geographic Information System（GIS）and Analytic Hierarchy Process（AHP）to construct a suitability evaluation system for Agricultural Managed Aquifer Recharge（Ag-MAR）. The results indicate that areas with deeper groundwater levels are more suitable for recharge, accounting for approximately 20.2% of the total study area, while the region's dense river network provides substantial surface water resources. Additionally, the optimal recharge period is identified as spanning from mid-October to early November. This study provides a scientific basis for groundwater management and presents specific recharge recommendations to address the issue of groundwater over-extraction, thereby ensuring the sustainability of both agricultural production and ecological systems. The findings underscore the importance of Ag-MAR in promoting sustainable groundwater management practices in agricultural regions.

This study utilizes panel data from 30 Chinese provinces from 2000 to 2021. We treat the carbon trading policy as a quasi-natural experiment, and apply a multi-period difference-in-differences method to systematically evaluate its impact on carbon emissions. The results indicate that: after the introduction of the carbon trading policy, the total carbon emissions in the pilot regions decrease by 13.2%, while carbon intensity and per capita carbon emissions fall by 21.3% and 17.2%, respectively. The carbon trading policy significantly reduces carbon intensity in the pilot regions; however, the impacts on total carbon emissions and per capita emissions are not significant. Carbon reduction through trading primarily relies on improvements in industrial structure, with weaker mediation effects from carbon trading prices, market activity, and low-carbon technology. There may be complementary and synergistic effects among different policies. Although carbon trading plays a positive role in promoting carbon reduction, its synergistic effects on SO₂, NO_x and PM_2.5 still need to be enhanced. These results provide important empirical support for understanding carbon trading policies and offer a scientific basis for refining the carbon trading system as well as guiding future adjustments and optimizations of carbon market policies.

The migration behavior of microplastics in aquatic environments is governed by complex interactions among hydraulic, physical, and material-specific factors. This study integrates hydraulic experiments and force analysis to identify the critical hydraulic parameter thresholds influencing state transitions of different microplastic types in freshwater systems. A Lagrangian particle tracking method is then employed to develop a migration model grounded in well-defined physical principles. This model simulates microplastic trajectories, predicting their ultimate movement states and environmental fate. The model is validated using field data from the urban section of the Jialu River in Zhengzhou, China. Results indicate that 66.79% of microplastics in this section have particle sizes smaller than 0.5mm, with fragmented（31.1%）and fibrous（29.2%）shapes being predominant. Polypropylene（PP）migrates as floating debris with the highest velocity, while polystyrene（PS）and polyamide（PA）particles smaller than 0.5mm migrate as suspended load. In contrast, polyethylene terephthalate（PET）and PA particles larger than 0.5mm migrate as bedload or remain stationary on the riverbed. Under flow rates of 14m³/s and 20m³/s, retention rates of microplastics over 36hours were 43.79%and 47.85%, respectively, with PA and PET constituting the major retained microplastic types. These findings provide valuable insights into the hydrodynamic behavior and environmental fate of microplastics, offering guidance for pollution management in freshwater systems.