Solid waste disposal generates substantial carbon and nitrogen leakage, adversely affecting air quality, aquatic ecosystems, and the climate. However, the coupled cycles of carbon and nitrogen within this sector remain insufficiently understood. This study develops an integrated carbon and nitrogen budget for China's solid waste sector from 1980 to 2023. Over this period, atmospheric carbon emissions increased 3.6-fold, reaching 34.0 million tons (Tg) C yr-1 in 2023, while nitrogen losses peaked at 1.4 Tg N yr-1 in 2005 before declining. By 2060, an optimized co-control strategy could reduce carbon leakage by 87 % (30.2 Tg C yr-1) and nitrogen leakage by 96 % (0.9 Tg N yr-1), yielding net social benefits of US$34.6 billion. Source reduction strategies, particularly waste recovery programs and Pay-As-You-Throw tariffs, are the most cost-effective mitigation options. These findings underscore the critical role of solid waste management in promoting a circular economy and achieving sustainable development.

Abstract The carbon and nitrogen cycles are central to climate regulation, ecosystem health, and food security, yet their integration into the Sustainable Development Goals (SDGs) framework remains limited. By using a Coupled Human and Natural Systems model, we quantify carbon and nitrogen emission thresholds to achieve related SDGs in China. We find that meeting carbon‐ and nitrogen‐related SDGs requires reductions of 59% in greenhouse gas emissions and 50% and 56% in nitrogen emissions to air and water, respectively, relative to 2020 levels. Achieving these targets could deliver US$988 billion in societal benefits, six times the implementation cost, through yield promotion, improved public health, restored ecosystems, and climate change mitigation. Under current best practices, greenhouse gas reductions reach only 19% of the target values, with nitrogen reductions reach 18%. While industrial and energy transitions could yield substantial carbon dioxide and nitrogen oxides reductions in eastern China, agricultural nitrogen losses remain high in major crop‐ and livestock‐producing regions. Closing these gaps will require integrated policies, deep socioeconomic transformation, and advanced carbon‐nitrogen management technologies, providing a transferable pathway for aligning environmental and economic objectives within the SDG framework.

The release process of endogenous phosphorus (P) in the sediments of large ecological wetlands and their connected rivers in the plain river network area shows temporal and spatial differences. This study investigated P dynamics of the sediments in a large ecological wetland and its connected rivers in a plain river network area. Sample collection occurred across three periods (October 2024, March 2025, and July 2025). P source-sink characteristics and microbial regulatory mechanisms were analyzed to clarify differences in the P release processes between wetland (SS) and river (SH) sediments. The results showed that the total phosphorus (TP) concentration in overlying water was highest in July (0.16 mg/L), while the TP content in SS was relatively low, with a mean value of 514.1 mg/kg. SS generally acted as a P sink, with its zero equilibrium P concentrations (EPC0) significantly lower than those of river sediments (SH), reaching a minimum of 0.01 mg/L, and its maximum P sorption capacity (Q(max)) higher, with a maximum value of 1.413 mg/g. In contrast, SH mainly served as a P source, with a particularly high release risk in spring and summer. Seasonal changes significantly influenced P behavior, and sorption capacity was highest in spring (March), while the high EPC0 of SH still facilitated P release under actual water conditions. In autumn, elevated microbial diversity enhanced organic matter mineralization to increase EPC0 and P release risk (p < 0.05), while in summer, specific functional phyla (Proteobacteria and Bacteroidota) simultaneously regulated both adsorption capacity (Q(max)) and release threshold (EPC0) through organic matter mineralization, iron reduction, and competitive sorption (p < 0.05). This study provides scientific support for internal pollution control in ecological wetlands and watershed phosphorus management in plain river network areas.

Grasslands play a crucial role in providing essential ecosystem services through biogeochemical processes. Improving grassland productivity and nitrogen use efficiency, reducing reactive nitrogen losses, and ensuring environmental sustainability represent major challenges, especially under the influence of global climate change. While previous studies have shown substantial effects of individual climate change factors on grassland nitrogen cycling, a comprehensive understanding of how grassland nitrogen cycling responds to multiple climate change remains limited. In this study, using data from 150 countries, we identified climate warming as the primary driver of increased nitrogen harvest, biological nitrogen fixation, and nitrogen surplus in global managed and undisturbed grasslands. These increases, with respective increments of 19.8, 8.8, and 28.2%, were determined by comparing scenarios with and without climate change from 1980 to 2020. Precipitation variability further amplifies these nitrogen increases, displaying notable spatial heterogeneity. Conversely, elevated atmospheric CO2 levels mitigate nitrogen surplus by enhancing plant nitrogen uptake. Under the SSP2-RCP4.5 scenario for the year 2050, nitrogen input, harvest, and surplus in global grasslands are projected to increase annually by 22.3, 7.2, and 15.1 million tonnes, respectively, compared to baseline scenarios. These climate-induced alterations in nitrogen budgets could incur additional costs up to USD $69 billion because of associated impacts on human health and ecosystem integrity. Our findings emphasize the urgent need for robust management strategies aimed at mitigating the negative effects of climate change on grassland nitrogen cycling, thereby supporting global sustainable development objectives.

Climate change and environmental degradation caused by greenhouse gases (GHGs) and reactive nitrogen (Nr) emissions are getting exacerbated globally. As a major emitter of both GHGs and Nr, China faces double pressure of GHGs and Nr mitigation to achieve carbon neutrality and environmental sustainability. This study performed the first integrated analysis of the potential and the synergies of GHG (CO2, CH4, and N2O) and atmospheric Nr pollutant (NOx and NH3) mitigation based on multiple models. Here we show that with an integrated policy implementation, China can achieve a 66% reduction of GHG and 68% of air N pollutants by 2050, which would bring society benefits of 2,500 billion USD, 5 times exceeding the implementation costs. Synergistic emission reductions led by industry would be in advantage until around 2030 with carbon peak achieved, while agriculture-led reductions show improved synergies in abatement potential and cost-effectiveness after peak carbon. This demonstrates that the control priority on GHG and atmospheric Nr pollution needs to be switched in the post-peak period to achieve future zero carbon and clean air in China.

Achieving the 2030 Sustainable Development Goals (SDGs) requires balancing well-being with environmental protection, yet the role of nitrogen across these goals remains poorly understood. Here, we show how dietary nitrogen intake and nitrogen release to air and water are associated with SDG progress across 166 countries from 2000 to 2022. Higher per-capita nitrogen intake is positively associated with social and economic SDGs, whereas nitrogen release is negatively associated with environmental goals. Economic development is linked to improved SDG performance but also to greater dietary nitrogen demand and nitrogen losses, while warming is associated with pressure on food systems and nitrogen management. Nitrogen-related factors account for 38% of the variation in SDG scores, compared with 34% for climatic conditions and 28% for socio-economic factors. These findings identify nitrogen management as a cross-cutting component of sustainable development and support strategies that align food security, pollution control and climate adaptation across development contexts. Balanced nitrogen intake and lower nitrogen releases are linked to progress across the Sustainable Development Goals, helping align human well-being with environmental protection and highlighting the need for context-specific nitrogen management.

Achieving the Sustainable Development Goals (SDGs) by 2030 is becoming difficult as global progress lags. Nitrogen is key to food security and environmental sustainability, making its management crucial for advancing multiple goals within the timeline. Here, we introduce an SDG-driven framework to evaluate nitrogen management under sustainable shared socioeconomic pathways. We show that meeting balanced and achievable targets, defined as an average nitrogen-related SDG index score above 75 with individual target scores exceeding 60, requires reducing global nitrogen emissions by 50 million tonnes (Tg) by 2030, 32% of 2020 levels, entailing decreases of 30 Tg in the atmosphere and 20 Tg in aquatic ecosystems. Existing technological strategies can deliver only half of the required mitigation, even with investments of $176 billion that yield economic benefits of $291 billion. This highlights that technologies alone are insufficient, and meaningful progress toward the SDGs depends on integrating mitigation techniques with broader socioeconomic transitions.

This study investigated the characteristics and interrelationships of polycyclic aromatic hydrocarbons (PAHs), phthalate esters (PAEs), and microbial communities in coastal river sediments and benthic mollusks collected from an e-waste recycling area in Taizhou, Zhejiang Province. In sediments, 16 PAHs and six PAEs were detected, with concentrations ranging from 2.66 to 379.99 mu g/kg and 76.5 to 3426.57 mu g/kg, respectively. Four-ring PAHs (particularly fluoranthene and pyrene) and Bis(2-ethylhexyl) phthalate (DEHP) were dominant, with DEHP posing a potential risk, especially at site 10, warranting further attention. In contrast, only eight PAHs and four PAEs were detected in mollusks, with concentrations of 60.14-523.10 mu g/kg and 144.55-3005.71 mu g/kg, respectively. Two-ring PAHs (particularly naphthalene) and Dibutyl phthalate (DBP) were dominant, likely derived directly from the overlying water. The PAHs in sediments primarily originated from fossil fuel combustion, biomass burning, and coal combustion, while PAEs were likely derived from the release of plastic waste from solid waste recycling. Lower concentrations and fewer PAH and PAE species were observed in the sediments near the ocean and at greater distances from the e-waste recycling sites. Significant differences were observed in microbial communities between sediment and mollusk samples. Dominant phyla shared by both sample types include proteobacteria, bacteroidetes, firmicutes, and acidobacteria. The concentration of low-ring PAHs was correlated with the microbial communities, particularly in mollusk samples. Relationships were also identified between microbial communities and DEHP concentrations in sediments or DBP concentrations in mollusks.

Human activities have significantly disrupted the global nitrogen cycle, positioning it as one of the most severely surpassed planetary boundaries. As the country with the largest nitrogen flux, China faces numerous environmental challenges due to excessive losses of reactive nitrogen (Nr) to both air and water from various sources. By quantifying the regional nitrogen boundaries for air and water at the county level, we found that the aggregated regional safe boundaries in China for the atmospheric release of Nr, nitrogen runoff to surface water and leaching to groundwater are 14.6, 5.2 and 4.8 million tonnes per year, respectively. In 2020, the cumulative Nr losses exceeded these boundaries by 54%, 262% and 258%, respectively. Implementing cross-system technical mitigation measures could potentially halve the total Nr losses to both air and water, yielding benefits that are ∼2.5 times greater than the net implementation costs. Despite most counties being capable of meeting the emission boundary for the atmospheric release of Nr after abatement, the boundaries for surface water and groundwater remain exceeded in over half of the counties. This highlights a significant asymmetry in nitrogen-pollution control between air and water, further necessitating socioeconomic transformations to effectively address the persistent issue of water pollution in China.

Nitrogen plays a critical role in Earth's biogeochemical cycles, acting as both an essential nutrient for life and an environmental pollutant. Managing nitrogen use within safe boundaries is crucial for achieving the Sustainable Development Goals, particularly under the pressures of a growing global population. Here, we quantified the temporal dynamics in the safe boundary for nitrogen input to the human-nature system in view of surface water quality in China, driven by changes in management practices and runoff over the period of 1980 to 2020. Insufficient nitrogen management in the human-nature system led to a reduction in the safe nitrogen boundary from 27 Tg N year-1 in 1980 to 17 Tg N year-1 in 2006. Subsequently, improvements in agricultural nitrogen use efficiency and urban waste management contributed to an expansion of this boundary, which reached 34 Tg N year-1 by 2020. Further integration of nitrogen management strategies spanning agriculture, urban waste, and human dietary patterns is needed to maintain nitrogen use within the established safe boundary by 2050, generating societal benefits of US$335 billion for ecosystems, human health, climate, and food supply, with associated implementation costs of US$106 billion. These findings demonstrate that improved nitrogen management practices can dynamically expand the safe operating space for higher nitrogen utilization to support human well-being while keeping nitrogen pollution within safe environmental limits.

Carbon and nitrogen are central elements in global biogeochemical cycles. To effectively manage carbon and nitrogen in China, we developed a comprehensive model for quantifying their fluxes, investigating their interplay across 16 human and natural subsystems. Between 1980 and 2020, nitrogen losses in China increased 2.3-fold and carbon emissions surged 6.5-fold. Integrated carbon and nitrogen management holds the potential for a 74% reduction in nitrogen losses to air and water and a 91% decrease in carbon emissions to the atmosphere by 2060. Compared with separate control of carbon or nitrogen, integrated management delivers an additional reduction of 1.8 million tons of nitrogen and 26.5 million tons of carbon by 2060, bringing out a 37% decrease in unit abatement cost and a net societal benefit of 1384 billion USD.

As global climate change accelerates, it is imperative to obtain a more accurate understanding of the impacts of climate change on biodiversity and identify climate refugia to guide effective protection. This study utilized the endangered Tragopan caboti as a model organism. A species distribution model was constructed via a holistic approach that incorporated various biological mechanisms, including local adaptation, dispersal, responses to environmental variation, and species interactions. We considered future (2041-2060 and 2081-2100) conditions (SSP126, SSP245, and SSP585) and identified three types of refugia (stable refugia, transitional refugia, and potential refugia). Our research shows that: (1) Models that factored in biological mechanisms demonstrated enhanced predictive accuracy. (2) Future scenario predictions indicate a substantial reduction (8.82 %-62.42 %) in Tragopan caboti habitat, with even less (3.76 %-22.23 %) habitat available due to dispersal. (3) The two subspecies of Tragopan caboti exhibit divergent responses to climate change: Tragopan caboti caboti is particularly sensitive to climate change and is undergoing a significant habitat loss, while Tragopan caboti guangxiensis is anticipated to acquire new suitable habitats. (4) Protective actions, tailored to the characteristics of each type of refugia, include habitat preservation for stable refugia, facilitation of species dispersal for transitional refugia, and reduction of dispersal barriers for potential refugia. The research underscores the pressing need to adopt species distribution models grounded in biological mechanisms and to identify and protect climate refugia, thereby establishing a scientific basis for informed and efficacious conservation efforts to adapt climate change.

Groundwater, essential for irrigation, industry, and drinking, plays a crucial role in environmental health and human well-being. A major threat to groundwater quality is nitrate pollution, primarily stemming from human activities. Safeguarding nitrogen levels in groundwater within regional thresholds remains a global challenge. By integrating 3,134 groundwater samples and nitrogen budget modeling, we found that China's national average nitrate concentration has risen by 29% since the 2000s, reaching 14 mg N L-1. The main sources of nitrate contamination are cropland, landfills, and wastewater disposal, with average annual nitrogen leaching of 1.91 ± 0.16, 0.86 ± 0.18, and 0.63 ± 0.17 million tonnes, respectively; these sources collectively account for 73% of the total nitrate leakage during 2000-2020. Current robust mitigation practices could reduce nitrogen leaching into groundwater by 45% (1.93 million tonnes N), delivering a net societal benefit of US$83 billion in China. Nevertheless, this reduction remains insufficient to meet the safe nitrogen boundary for all provinces, underscoring a compelling necessity for additional measures and policy guidance tailored to protect groundwater resources on a site-specific basis.

Amplifying small subunit (SSU) rRNA genes with universal primers in assessing microbial populations diversity, but target microorganisms are sometimes omitted due to inadequate primer coverage. Adding degenerate bases to primers can help, but existing methods are complex and time-consuming. This study introduces a user-friendly tool called "Degenerate primer 111" for adding degenerate bases to existing universal primers. By aligning one universal primer with one uncovered target microorganism's SSU rRNA gene, this tool iteratively generates a new primer, maximizing coverage for the target microorganisms. The tool was used to modify eight pairs of universal primers (515F Parada-806R Apprill, S-D-Bact-0341-b-S-17/S-D-Bact-0785-a-A-21, OP_F114-KP_R013, 27F-1492R, 341F-806R, OP_F066-KP_R013, 515F Parada-926R Quince, 616*F-1132R), and generated 29 new universal primers with increased coverage of specific target microorganisms without increasing coverage of non-target microorganisms. To verify the effectiveness of the improved primers, one set of original and improved primers (BA-515F-806R and BA-515F-806R-M1) was used to amplify DNA from the same sample, and high-throughput sequencing of the amplicons confirmed that the improved primers detected more microbial species compared to the original primers. Future researchers can use this tool to develop more personalized primers to meet their diverse microorganism detection needs.

Outbreaks of Escherichia coli (E. coli) O157:H7 in farms are often triggered by heavy rains and flooding. Most cells die with the decreasing of soil moisture, while few cells enter a dormant state and then resuscitate after rewetting. The resistance of dormant cells to stress has been extensively studied, whereas the molecular mechanisms of the cross-resistance development of the resuscitated cells are poorly known. We performed a comparative proteomic analysis on O157:H7 before and after undergoing soil dry-wet alternation. A differential expression of 820 proteins was identified in resuscitated cells compared to exponential-phase cells, as determined by proteomics analysis. The GO and KEGG pathway enrichment analyses revealed that up-regulated proteins were associated with oxidative phosphorylation, glycolysis/gluconeogenesis, the citrate cycle (TCA cycle), aminoacyl-tRNA biosynthesis, ribosome activity, and transmembrane transporters, indicating increased energy production and protein synthesis in resuscitated O157:H7. Moreover, proteins related to acid, osmotic, heat, oxidative, antibiotic stress and horizontal gene transfer efficiency were up-regulated, suggesting a potential improvement in stress resistance. Subsequent validation experiments demonstrated that the survival rates of the resuscitated cells were 476.54 and 7786.34 times higher than the exponential-phase cells, with pH levels of 1.5 and 2.5, respectively. Similarly, resuscitated cells showed higher survival rates under osmotic stress, with 7.5%, 15%, and 30% NaCl resulting in survival rates that were 460.58, 1974.55, and 3475.31 times higher. Resuscitated cells also exhibited increased resistance to heat stress, with survival rates 69.64 and 139.72 times higher at 55°C and 90°C, respectively. Furthermore, the horizontal gene transfer (HGT) efficiency of resuscitated cells was significantly higher (153.12-fold) compared to exponential phase cells. This study provides new insights into bacteria behavior under changing soil moisture and this may explain O157:H7 outbreaks following rainfall and flooding, as the dry-wet cycle promotes stress cross-resistance development.

Microplastics (MPs) are ingested by humans through the daily consumption of drinking water. Pipe scales are recognized as important sites of MPs occurrence in the drinking water distribution system (DWDS). Despite extensive research on drinking water, no study has been conducted to investigate the distribution of MPs in pipe scales within an operational DWDS. The underground placement of DWDSs brings challenges for sampling pipe scales. In this study, 5 tap water and 16 pipe scales samples were collected from a typical DWDS. The analysis of MPs abundance in these 21 samples filled the data gap in the distribution of MPs in both pipe scales and tap water along the DWDSs. MPs were detected in all water samples (1.74-20.88 MPs/L) and pipe scales samples (0.03-3.48 MPs/cm2). In tap water, MPs abundance increased abruptly in the stagnant-slow flow region and reached the maximum value (20.88 MPs/L), even surpassing the abundance in raw water (6.42 MPs/L). In the pipe scales, MPs abundance decreased from the upstream to downstream of DWDS and was associated with the heavy metal concentration. MPs smaller than 150 & mu;m accounted for 91.6% of the tap water (21-971 & mu;m) and pipe scales (20-2055 & mu;m). The abundance of MPs showed a logarithmic increase as the size decreased. The proportion of MPs fibers in tap water was lower than that in pipe scales. A total of 35 MPs polymers were detected, with 34 polymers in pipe scales and 26 polymers in tap water. In terms of abundance, polyethylene terephthalate (50.0%) was the dominant polymer in pipe scales, while polyamide (70.3%) was the dominant polymer in tap water. Regarding detection rate, polyamide was detected in all 21 samples, followed by polyurethane in 19 samples. The distribution of MPs along the longitudinal direction of the DWDS was correlated with heavy metal. While the distribution of MPs in the vertical direction of large diameter pipe scales was dependent on their sizes, and densities. The greatest abundance, size and density of MPs were detected at the bottom 120-degree.

Tidal freshwater zones (TFZs) can significantly affect nutrient transport from watersheds to estuaries through biogeochemical cycling. Phytoplankton, pivotal in nutrient cycling, have been relatively understudied within TFZs. Employing accessory pigment analysis, this study assessed the contribution of diverse phytoplankton groups to chlorophyll a (chl a ) biomass over an annual cycle under baseflow conditions. Spatial and temporal patterns in chl a concentrations and community structure as inferred from accessory pigment analysis were evaluated in relation to temperature, dissolved inorganic nitrogen (DIN), soluble reactive phosphorus (SRP), and DIN/SRP ratios. Downstream phytoplankton transport and seasonal succession within the TFZ, driven by nutrient levels and temperature, lead to variations in chl a concentration and community composition. Overall chl a levels were higher in the TFZ than in the upstream river and downstream estuary, with cyanobacteria prominently contributing to chl a biomass, especially in the lower TFZ sections. This study underscores the role of prolonged residence times and nutrient enrichment in TFZs, resulting in elevated chl a concentrations and shaping phytoplankton community composition, with implications for downstream estuaries.

In this paper, we obtain families of two-fold doubly-connected uniformly rotating vortex patches of the 2-D incompressible Euler equations emanating from some specific annuli. The main difficulty comes from strong degeneracy of the problem, neither the kernel of linearization is one-dimensional nor the transeversallity condition holds. To this end, we make a detailed analysis on the nonlinear functional and the bifurcation curves are obtained by perturbing real algebraic varieties defined by truncated polynomials. In addition, our result partially answers an problem proposed by Hmidi and Mateu in (Adv.Math.302 (2016), 799-850).