Science of the Total Environment最新文献

The recycling of spent lithium-ion batteries has become a common concern of the whole society, with a large number of studies on recycling management and recycling technology, but there is relatively little study on the pollution release during the recycling process. Pollution will restrict the healthy development of the recycling industry, which makes relevant research very significant. This paper monitored and analyzed the battery recycling pretreatment process in a formal factory, and studied the pollution characteristics of particulate matter, heavy metals, and microplastics under different treatment stages. In addition, the release characteristics of VOCs during pyrolysis were also studied. When the green pretreatment process was used, PM₁₀ concentration in most processing units was below 100 μg/m³, indicating that the overall pollution prevention and control effect in the workshop is well-done. Particulate matter in workshop contained a large amount of metal components, mainly Fe, Cu, Co, Mn, Ni, etc. Microplastics were widely distributed in ground dust, and small-size microplastics are suspended in the air for a long time because of Brownian motion. Collecting ground dust and particulate matters is beneficial for controlling the emission of microplastics. During thermal treatment, Ethylene carbonate and dimethyl carbonate in the electrolyte would enter the atmosphere, and a large amount of short chain hydrocarbons released together, forming VOCs pollution. This study summarized distribution characteristics of different pollutants in a battery recycling factory. The basic pollution data provided are beneficial for improving the recycling technology of spent lithium-ion battery.

Pacific oysters face recurring outbreaks of Pacific Oyster Mortality Syndrome (POMS), a polymicrobial multifactorial disease. Although this interaction is increasingly understood, the role of epigenetics (e.g., DNA methylation) appears to be of fundamental importance because of its ability to shape oyster resistance/susceptibility and respond to environmental triggers, including infections. In this context, we comprehensively characterized basal (no infection) and POMS-induced changes in the methylome of resistant and susceptible oysters, focusing on the gills and mantle. Our analysis identified differentially methylated regions (DMRs) that revealed distinct methylation patterns uniquely associated with the susceptible or resistant phenotypes in each tissue. Enrichment analysis of genes bearing DMRs highlighted that these epigenetic changes were specifically linked to immunity, signaling, metabolism, and transport. Notably, 31 genes with well-known immune functions were differentially methylated after POMS, with contrasting methylation patterns between the phenotypes. Based on the methylome differences between phenotypes, we identified a set of candidate epibiomarkers that could characterize whether an oyster is resistant or susceptible (1998 candidates) and whether a site has been exposed to POMS (164 candidates). Overall, the findings provide a deeper understanding of the molecular interactions between oysters and POMS infection, opening new questions about the broader implications of epigenetic mechanisms in host-pathogen dynamics and offering promising strategies for mitigating the impacts of this devastating disease. Beyond its biological aspects, this study provides insights into potential epigenetic biomarkers for POMS disease management and targets for enhancing oyster health and productivity.

Mercury (Hg) and persistent organic pollutant (POP) accumulation among species and biomagnification through food webs is typically assessed using stable isotopes of nitrogen (δ¹⁵N) and carbon (δ¹³C) in bulk (whole) tissues. Yet, bulk isotopic approaches have limitations, notably from the potential overlap of isotope values from different dietary sources and from spatial variation in source (baseline) signals. Here, we explore the potential of fatty acid carbon isotopes (FA δ¹³C) to (1) evaluate the trophic structure of a marine food web, (2) distinguish feeding patterns among four marine mammal consumers, (3) trace contaminant biomagnification through a food web, and (4) explain interspecific variation in contaminants among high-trophic position predators. In the Cumberland Sound (CS) food web of Nunavut, Canada, ranging from zooplankton to Greenland shark (Somniosus microcephalus), FA δ¹³C values for the monounsaturated FAs, 20:1 and 22:1 isomers, did not vary across the food web, while the long-chain polyunsaturated FA, 22:6n3 showed δ¹³C values that were enriched by ~1.5 ‰ with each trophic position. Values of δ¹³C for shorter-chain and saturated FAs varied widely across this food web. In East Greenland (EG) marine mammals, FA δ¹³C values were significantly higher in migratory sub-Arctic species relative to Arctic residents. Linear models using FA δ¹³C as explanatory variables for contaminant concentrations demonstrated that baseline-corrected δ¹³C values of certain dietary FAs explained more variation in POP concentrations than did bulk stable isotopes in EG marine mammals. However, bulk δ¹⁵N better explained Hg variation in the CS food web. This study details the FA δ¹³C instrumental methods, such that other researchers can test this novel approach on other species, locations, and food webs to further evaluate whether the δ¹³C values of certain diet-derived FAs consistently show limited or predictable trophic fractionation and may therefore be useful for assessing the accumulation and biomagnification of lipophilic contaminants.

Mangrove ecosystem has attracted global attention as a hotspot for mercury (Hg) methylation. Although numerous biotic and abiotic parameters have been reported to influence methylmercury (MeHg) production in sediments, the key factors determining the elevated MeHg levels in mangrove wetlands have not been well addressed. In this study, Hg levels in the sediments from different habitats (mudflats, mangrove fringe, and mangrove interior) in the Futian mangrove wetland were investigated, aiming to characterize the predominant factors affecting the MeHg production and distinguish the key microbial taxa responsible for Hg methylation. MeHg concentrations in the sediments from the mangrove interior (1.03 ± 0.34 ng g^-1 dw) were significantly higher than those in mudflats (0.26 ± 0.08 ng g^-1 dw) and mangrove fringe (0.45 ± 0.10 ng g^-1 dw). Mangrove vegetation also promoted the accumulation of organic matters in sediments, which stimulated the growth of methylators, ultimately leading to an elevated MeHg level in the sediment. The data from 16S sequencing and random forest analysis further indicated that the increased abundances of Desulfococcus and Desulfosarcina, which belong to complete-oxidizing microbes with acetyl-CoA pathway and are favored by mangrove vegetation, were the primary contributors to MeHg production. Besides, syntrophic partners of methylators (e.g. Syntrophus) also play a considerable role in MeHg production. The present findings provide a deep understanding of Hg-methylation in mangrove wetlands, and offers valuable insights into of the interactions between mangrove plants and soil microbiome in the presence of Hg contamination.

Agricultural activities are essential for sustaining the global population, yet they exert considerable pressure on the environment. A major challenge we face today is agricultural pollution, much of which is diffuse in nature, lacking a clear point of origin for chemical discharge. Modern agricultural practices, which often depend on substantial applications of fertilizers, pesticides, and irrigation water, are key contributors to this form of pollution. These activities lead to downstream contamination through mechanisms such as surface runoff, leaching, soil erosion, wind dispersal, and sedimentation. The environmental and human health consequences of diffuse pollution are profound and cannot be ignored. Accurate assessment of the risks posed by agricultural pollutants is crucial for ensuring the production of safe, high-quality food while safeguarding the environment. This requires systematic monitoring and evaluation of agricultural practices, including soil testing and nutrient management. Furthermore, the development and implementation of best management practices (BMPs) are critical in reducing the levels of agricultural pollution. Such measures are essential for mitigating the negative impacts on ecosystems and public health. Therefore, the adoption of preventive strategies aimed at minimizing pollution and its associated risks is highly recommended to ensure long-term environmental sustainability and human well-being.

Glaciers of Jammu and Kashmir are retreating faster than those in the broader northwestern Himalayas, yet some glaciers in the Chenab River basin display signs of periodic advancement and mass gain (2005-2007). These features, such as coalescing lobate structures and blocked meltwater streams, raise intriguing questions about localized glacier dynamics. While global concerns over climate change and glacier retreat persist, the lack of detailed evidence regarding glacier advance in this region warrants further investigation. Consequently, a comprehensive investigation of the Bhut and Warwan sub-basin glaciers of the Chenab River basin, was conducted to understand their spatio-temporal evolution between 1993 and 2021. Our analysis revealed an area loss (6.7 %), surface thinning (-0.3 ± 0.4 ma^-1), increased debris cover (11 %), and reduced glacial velocity (54 % in Bhut and 20 % in Warwan) between 1993 and 2021. In contrast, we also observed periodic insignificant glacier advancement on nine glaciers, a balanced state on twelve, and the complete disappearance of 113 glaciers in these three decades. Among Bhut and Warwan sub-basins, the former revealed higher average velocity, slowdown, and thinning compared to the latter. The higher average velocity in the Bhut sub-basin is controlled by relatively higher precipitation, and the increase in overall debris coverage possibly governs the enhanced slowdown and thinning. We conclude that while the climate controls the long-term and periodic glacier response, the spatial variability is governed largely by the debris thickness, which is variable among glaciers and might also be changing. Furthermore, the aforementioned geomorphological evidence of some glacier advances, while happening locally, does not well represent the state and recent dynamics of the glaciers in these regions overall.

In recent decades, microplastics (MPs) have emerged as one of the biggest environmental challenges in aquatic environments. Ingestion and toxicity of MPs in seawater (SW) and freshwater (FW) fish have been studied extensively both in field and laboratory settings. However, the basic mechanism of how fish deal with MPs in SW and FW remains unclear, although physiological conditions of fish differ significantly in the two environments. In this study, using Javanese medaka (Oryzias javanicus), a euryhaline fish that adapts readily to both SW and FW, we investigated elimination of MPs in fish in SW and FW environments. We exposed O. javanicus larvae (21 days post-hatching) to 0.25 mg/L of fluorescent polystyrene microspheres (1 μm) for 24 hours and then conducted an elimination test for up to 5 days. Results showed that the gut retention time of MPs is longer in FW than in SW, indicating that MP elimination occurs more quickly in SW than in FW. However, higher numbers of MPs tended to be retained longer in SW larvae than FW larvae. Subsequently, using a fluorescent marker, gastrointestinal fluid was found to move more rapidly in the SW group. This finding indicates that water drinking accelerates gastrointestinal fluid movement, which moves MPs through the gut in SW larvae. Beside the difference in physiological conditions, MP elimination was faster when food was available, suggesting that feeding also affects MP elimination in fish. Internal factors such as body size and intestine length were also examined, but indicated no significant difference. Therefore, osmoregulation and feeding both influence MP elimination in fish.

Substantial amounts of mercury (Hg) are projected to be released into Arctic watersheds as permafrost thaws amid warmer and wetter conditions. This may have far-reaching consequences because the highly toxic methylated form of Hg biomagnifies rapidly in ecosystems. However, understanding how climate change affects Hg dynamics in permafrost regions is limited due to the lack of long-term Arctic Hg records. Using a 27-ka Hg sediment record from Burial Lake, northwestern Alaska, we examine how well-characterized temperature, precipitation, and vegetation shifts affected Hg mobilization in a catchment underlain by permafrost. During the Last Glacial Maximum (29.6-19.6 ka), Hg concentrations (63 ± 5 μg/kg) and Hg flux (8.6 ± 2.2 μg m^-2 yr^-1) remain relatively stable. Abrupt warming trends, starting at 17.6 ka, do not coincide with Hg levels. After 15 ka, the ecosystem transitions to shrub tundra, Hg concentrations (101.2 μg/kg) peak at 14.2 ka, while flux (5.3 ± 1.3 μg m^-2 yr^-1) declines and stabilizes. At ~11 ka, increased precipitation coincides with a 72 % rise in Hg concentrations and a 32 % increase in Hg flux compared to average Hg levels since 15 ka. These results suggest that summer rainfall was the primary driver of Hg mobilization from the catchment, while the vegetation shift influenced lake sediment Hg concentrations. At 1990 CE, peak Hg levels represent an 88 % increase in Hg concentrations (196.3 μg/kg) and a sixfold rise in Hg flux (38.1 μg m^-2 yr^-1) above background levels, underscoring the need for further research to understand Hg dynamics driven by anthropogenic Hg emissions and climate change.

Understanding the kinematics of aerosol horizontal transport and vertical mixing near the surface, within the atmospheric boundary layer (ABL), and in the overlying free troposphere (FT) is critical for various applications, including air quality and weather forecasting, aviation, road safety, and dispersion modeling. Empirical evidence of aerosol mixing processes within the ABL during synoptic-scale events over arid and semiarid regions (i.e., drylands) remains sparse. We explored how synoptic-scale weather systems impact aerosol mixing processes within the daytime ABL over a site located in a dryland. We used ground-based Doppler lidar measurements collected during three events: a cold-front passage, a fair-weather day, and a dryline passage over Lubbock, Texas. The measurements of backscatter and vertical velocity fields were obtained with temporal and vertical resolutions of 1 s and 60 m, respectively. Here, we documented observations of aerosol transport and mixing within the ABL and found that frontal passages are crucial for understanding ABL features and aerosol mixing processes. For example, our findings suggest that during a dryline passage yielding a water vapor mixing ratio drop of 10 g kg^-1, the boundary layer characteristics transition from being shallow and stratified throughout a stable, pre-dryline ABL aerosol regime (300 m deep) to a deep and well-mixed structure within the post-dryline ABL (2200 m deep) confirming a higher ABL depth growth rate (∼300 mh^-1) than under quiescent conditions (∼125 m h^-1). The results for the frontal case reported aerosol mixing via frontal lifting to an altitude of 1250 m from the ground due to strong updrafts (>7 m s^-1). Additionally, Doppler lidar measurements helped to characterize the aerosol mixing and transport processes in dry regions under different weather conditions which yielded close correspondence with the observed variability in near-surface particulate matter (i.e., PM_2.5) concentrations (e.g., increase in PM_2.5 from 9 μg m^-3 to 27 μg m^-3 due to a cold front passage). The aerosol transport, along with the derived properties of the mean up- and downdraft observations and variance-based (both vertical velocity and aerosol backscatter) turbulence profiling helped explain how frontal airmass exchanges impact aerosol loading near the surface. The results obtained emphasize the need to consider the impact of synoptic-scale events over drylands in both observational and atmospheric modeling studies.

Wetland macrophytes play a critical role in the performance of treatment wetlands (TWs), primarily through nutrient uptake. However, this retention is temporary, as nutrients are released back into the water upon the decomposition of plant litter. The removal of stored nutrients from TWs can be efficiently achieved by harvesting plants during the peak of the growing season, albeit with significant ecological disturbance. Therefore, winter harvesting is recommended, although the specific amounts of nitrogen (N) and phosphorus (P) removed during this period remain uncertain. This study aimed to evaluate the effectiveness of winter harvesting in removing substantial nutrient amounts compared to belowground storage. Experimental harvesting was conducted over five winters (2018, 2019, 2021, 2022, and 2023) at the Vända free-water surface TW system in Estonia, focusing on above-ice biomass (stems, leaves, flowers) and below-ice biomass (roots and rhizomes). The dry weight and nutrient content of these biomasses were analysed. Findings indicated a gradual increase in nutrient pools within Typha latifolia plants, without significant differences between the two subsequent wetlands or a clear correlation with vegetation cover. Winter harvesting of above-ice biomass removed approximately 50 % of plant biomass, and about 30 % of N and P accumulated in the macrophytes, as most nutrients were already stored in the rhizomes by the end of the growing season.