This study taken Wuliangsuhai Lake as the research object to reveal the microbial community structure of lake sediments, elucidated the representative iron-reducing microorganisms and their abundance, investigated the seasonal differences in the impact of iron-reducing microorganisms on As-P migration and transformation during the ice-bound period and the summer, and the impact of P on As migration and transformation, with the aim of providing a basis for deepening the understanding of the environmental geochemical behavior of As in cold and arid regions and As pollution remediation, and providing reference for the water environmental protection of As pollution and eutrophication risks in dual-risk lakes. The results showed that the relative abundance of iron-reducing microorganisms during the ice-bound period was higher than that in summer. There were seasonal differences in the representative iron-reducing microorganisms. Bacillus and Geobacter were the dominant genera of iron-reducing microorganisms during the ice-bound period and summer, but Geothrix was also one of the representative iron-reducing microorganisms in summer, and Shiwanella was one of the representative iron-reducing microorganisms during the ice-bound period. The correlation analysis and PLS-SEM model results showed that the representative iron-reducing microorganisms that play a major driving role in As-P migration and transformation and their impact on As-P migration and transformation exist significant seasonal differences. In summer, although the abundance of Thermoanaerobium was small, the iron-reduction process driven by Thermoanaerobium（path coefficient=0.178）would affect the release of As and P from sediments to water to a certain extent. In addition, Bacillus could also promote the iron-reduction process（Path coefficient=0.115）and was the main driver of As-P mobility and transformation. During the ice-bound period, the more abundant Geobacter was an important driver（path coefficient=0.530）of As mobility, which had an important effect on the mobility and transformation of As-P, and the effect of Thermoanaerobium on iron reduction (Path coefficient=0.284）and As-P mobility and transformation was greater than in summer（path coefficient=0.178）.

This study focuses on regions characterized by complex traffic environment area and its background environment, exploring the contamination profiles of six heavy metals（As, Hg, Cu, Ni, Pb, and Cd）at two spatial scales. Through modeling analysis, this study examined the patterns of dust resuspension and the associated health risks resulting from the movement of a single traffic source. The results indicate that the levels of Cd, Pb, and Cu contamination in traffic intensive area, as well as their ecological risks, exceed those found in background area, with Cd showing the highest contamination, 70% of which poses a high ecological risk. During the movement of a single traffic source, the severity of changes in dust concentration is positively correlated with velocity, with dust accumulation occurring at heights of 0.3m and 0.6m above ground level. The primary exposure pathway for key heavy metals is hand-to-mouth ingestion; although both non-carcinogenic risk and carcinogenic risks are generally low, at a vehicle speed of 60km/h and a height of 0.6m, the non-carcinogenic hazard quotient for inhalation（HQ-inh）is elevated. Therefore, protective measures are recommended for individuals active within this range.

In this study, zebrafish were used as a model organism to investigate the effects of combined exposure to polyamide microplastics（PA MPs）and triclosan（TCS）on lipid metabolism in larval zebrafish. The findings demonstrated that PA exhibited a strong adsorption capacity for TCS, with an adsorption rate reaching 74% at 168h. Exposure to PA and TCS from 6hpf to 120hpf resulted in pronounced morphological abnormalities in larval zebrafish, including pericardial edema, swim bladder closure, yolk sac edema, and spinal curvature, with a malformation rate of 13%. Moreover, combined exposure induced the accumulation of reactive oxygen species within the larvae, triggering oxidative stress responses. In the hepatic region, significant lipid accumulation was observed, accompanied by elevated levels of T-CHO and TG. These changes were further correlated with aberrant expression of genes involved in lipid metabolism, confirming that combined exposure to PA and TCS disrupted lipid metabolic processes in zebrafish. Mechanistic investigations revealed that combined exposure led to a reduction in mitochondrial membrane potential and decreased expression of ATP synthase genes, resulting in impaired energy supply and subsequent energy metabolism disruption. Notably, the presence of PA significantly amplified the disruptive effects of TCS on lipid and energy metabolism compared to exposure to either PA or TCS alone.

In order to identify the pollution characteristics and carcinogenic risk of oxygenated polycyclic aromatic hydrocarbons（OPAHs）in the environmental media in the coking plants, vegetation, soil and ambient air samples were collected in JD and PF coking plants. Four species of OPAHs, including 1-acenaphthenone（1-ANO）, 9-fluorenone（9-FLU）, 9, 10-anthraquinone（9, 10-ATQ）, and benzanthrone（BZO）, were detected using gas chromatography-mass spectrometry detector（GC-MSD）. The results showed that the concentrations of Σ₄OPAHs in vegetations, soils, and ambient air in PF plant were higher than those in JD plant, respectively, and 9-FLU and 9, 10-ATQ were dominated in the environmental media in both plants. The fugacity of ambient air-soil showed that 9-FLU was in equilibrium between the air and soil, and 9, 10-ATQ released from soil into the air in PF plant. Human health risks were assessed for adults through ingestion, dermal contact and inhalation. The carcinogenic risks of OPAHs in the soils in JD and PF plants were acceptable for adults, and the carcinogenic risks of OPAHs in the ambient air in both plants were also acceptable for adults. The results provide a basis for the formulation of OPAH prevention and control measures.

Based on the panel data of 2383 counties in China from 2003 to 2022, the composite system synergy model and super-efficient SBM-DEA model were initially employed to quantify the synergistic reduction of pollution and carbon emissions. Subsequently, the spatiotemporal evolution patterns of synergistic reduction of pollution and carbon emissions in counties were explored by kernel density estimation, spatial autocorrelation analysis, and standard deviation ellipse. Ultimately, the XGBoost algorithm and SHAP value interpretation algorithm were combined to identify the main influencing factors of synergistic reduction of pollution and carbon emissions. The results show that. the level of synergistic reduction of pollution and carbon emissions in Chinese counties has been gradually rising, with a marked acceleration observed after 2020. The synergistic reduction of pollution and carbon emissions exhibits a “high in the east, low in the west” pattern, accompanied by a significant spatial positive correlation. The distribution center of synergistic reduction of pollution and carbon emissions in counties generally migrates to the southeast, reflecting a north-south centripetal trend and an east-west spatial divergence. Energy intensity is the main influencing factor of synergistic reduction of pollution and carbon emissions, and has a negative impact on the synergistic reduction. Technological innovation and industrial structure generally promote the synergistic reduction. The impact of economic development, population density and financial development on the synergistic reduction shows complex nonlinear characteristics. Compared with the eastern region, the impact of energy intensity on the synergistic reduction of pollution and carbon emissions in the central and western regions is more significant.

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.

This paper takes the period from 2005 to 2022 as the examination period, and discusses the dynamic evolution law and spatial correlation characteristics of China's animal husbandry on the basis of re-measuring its carbon emissions and analyzing its current characteristics. The results show that the total amount of carbon emissions from China's animal husbandry in the study period has fluctuated, but the overall trend is declining, the carbon emission intensity has been in a continuous downward trend, only the inter-annual rate of decline is different, cattle and hog feeding is the key driver of carbon emissions from the animal husbandry. In 2022, the carbon emissions of the animal husbandry in each province and region were significantly different, and the top 10regions were mainly identified as core livestock production areas or grain production areas. The carbon emissions intensity of the animal husbandry in the interprovincial area was characterized by a distribution pattern of 'high in the northwest and low in the southeast'. The 30 provinces and regions were categorized into four types, such as those driven by cattle feeding and those driven by hog feeding, based on the composition of the carbon emissions of the animal husbandry in each region. During the study period, the carbon emission intensity of the animal husbandry as a whole, as well as that of cattle and sheep rearing, showed an obvious downward trend and the inter-provincial gap narrowed significantly; while the carbon emission intensity of hog rearing also declined, but the inter-provincial gap widened significantly. During the study period, the carbon emission intensity of China's animal husbandry has always had a significant spatial dependence, with low-low agglomeration as the main focus and high-high agglomeration as the secondary focus, and showing the characteristic of “the low is always low and the high is always high”.

This study creates four scenarios for the employment of carbon emission reduction policy tools, depending on whether the two emission reduction policies of carbon trading and carbon tax are engaged. During this process, evolutionary game theory is applied. The stability analysis of the game system has provided a thorough explanation of the influence mechanism and action mechanism of the combination of carbon emission reduction policies on enterprise carbon emission reduction. On this premise, we conduct sensitivity analysis to discover the primary sensitivity elements that influence the game system's path. In the empirical analysis section, we take the case of national carbon trading market construction as the empirical object, simulate the evolution trajectory of the main body of carbon trading and mixed carbon policy use scenario game, deeply analyze the influence degree of key factors on the system, and put forward the dynamic increasing tax rate and dynamic reward and punishment strategy, optimize the carbon emission reduction efficiency improvement strategy of mixed carb. The study found that: when compared to no carbon trading without carbon tax, carbon trading without carbon tax, and no carbon trading with carbon tax, the mixed carbon policy use scenario has the highest carbon emission reduction efficiency. Second, the current construction of China's carbon trading market need further strengthening. The government and businesses have not achieved the optimal state（supervision, carbon emission reduction）. The cost and penalty elements have a clear impact on the game system, however the direction of subsidy factors is unknown. Third, dynamic incentive and punishment schemes are combined with dynamic incremental tax rates in the mixed carbon policy scenario. The system spirals upward and reaches a stable equilibrium position（carbon emission reduction, supervision）, where the optimal reward and punishment scheme is dynamic subsidy-dynamic punishment.

This study analyzes provincial panel data from China covering the period from 2014 to 2022 to measure the level of industrial digitalization across three sectors: agriculture, industry, and services. Additionally, it accounts for the input of data factors and various undesired outputs while evaluating green total factor productivity, thereby exploring the interaction effects and mechanisms between the two. The research findings are demonstrated as follows: Significant disparities exist in the levels of industrial digitalization among provinces, demonstrating a spatial pattern of “East >Central >West.”Moreover, green total factor productivity shows a consistent upward trend, indicating a progressive improvement in regional multi-level differentiation. Robustness tests reveal that industrial digitalization across Chinese provinces significantly enhances green total factor productivity, with impact effects characterized by the order of agriculture < industry < services. Regarding transmission pathways, the development of industrial digitalization in each province predominantly boosts green total factor productivity by reducing the mismatch between capital and labor and facilitating industrial structure upgrades; In provinces characterized by high public environmental awareness and lower industrialization levels, the effect of industrial digitalization on enhancing green total factor productivity is comparatively pronounced; The impact of industrial digitalization on green total factor productivity exhibits a single threshold characteristic, contingent upon the intensity of various forms of environmental regulation, with threshold values of 0.4582 for command-and-control regulation and 0.0096 for market-based regulation. Consequently, the government should formulate differentiated regional industrial policies and marketing strategies to more effectively promote the development of industrial digitalization and bolster green total factor productivity, thereby achieving sustainable green development.

In the context of the comprehensive advancement of the green water protection campaign, guiding river chiefs to effectively assume inter-generational responsibilities and promote the ecological sustainability of urban inland rivers is a critical practical challenge. This paper addresses the issues of "difficult inter-generational coordination of river chiefs and limited internal government supervision" within the sustainable governance framework of urban inland rivers. Utilizing evolutionary game theory, we develop a four-player evolutionary game model that includes the previous and next generations of river chiefs, government administrative supervision departments, and the public. By examining the strategic evolution of the system under various influencing factors, we explore how local government administrative supervision departments can collaborate with the public to establish an internal and external dual-layer multi-governance supervision system, thereby encouraging river chiefs to fulfill their inter-generational responsibilities. Our findings indicate that the influence between the two generations of river chiefs is asymmetric over time and space, with the governance strategy of the previous generation having a more significant impact on the next. As comprehensive management costs increase, both generations exhibit a tendency towards negative governance intentions. Reducing the cost-sharing ratio alleviates the burden on the previous generation but hinders the continuity of governance by the next, leading to interruptions in management efforts. Enhanced administrative supervision can accelerate system stabilization, significantly affecting both generations of river chiefs. However, relying solely on increased enforcement without adjusting rewards and penalties will gradually diminish its effectiveness. Changes in performance-based rewards, penalties, and base salaries affect system stability to varying degrees, but base salary adjustments have a limited impact compared to the responsiveness of performance incentives. Although increased public reporting intensity does not significantly alter the strategy choices of the two generations of river chiefs, it does contribute to reducing system stabilization time. This study not only enriches the theoretical understanding of inter-generational responsibilities of government officials and sustainable environmental governance but also provides a theoretical foundation for the sustainable ecological management of urban inland rivers. By analyzing the impact of various factors on the strategic choices of river chiefs across generations, it offers insights into the internal mechanisms of urban inland river ecological governance. Furthermore, it supports local government administrative supervision departments in collaborating with the public to build a dual-layer multi-governance supervision system, facilitating continuous improvements in the ecological environment of urban inland rivers.