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.

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.

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.

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.

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.

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.

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.

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.

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.

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.