Science of the Total Environment最新文献

The coupling between organic matter (OM) and minerals considerably influences the phosphorus (P) cycle within the hyporheic zone, but the role of different geological mineral-organic complexes (MOCs) on P burial during hyporheic exchange remains under-explored. This study investigates the effects of OM and iron (Fe)/calcium (Ca) coupling on P migration within the hyporheic zone of an agricultural tributary to the Danjiangkou Reservoir. These relationships were explored by measuring hyporheic flow (q), organic and inorganic P forms, and sediment PO₄-P adsorption capacity [following treatment with fulvic acid (FA), Fe-OM, or Ca-OM]. Multivariate statistical analysis, X-Ray Diffraction, Fourier-transform Infrared Spectroscopy, and X-ray Photoelectron Spectroscopy were employed to elucidate the underlying mechanisms. Results indicate that upward hyporheic flow transports dissolved porewater P into surface water, contributing 11.27-12.13 % of the total P flux. MOCs associated with Fe(III)/Ca silicate minerals, along with FA and labile OM, were identified as key OM fractions influencing P migration, contributing 5-24 %, 10-11.7 %, and 6-14.9 % to the overall flux, respectively. FA and labile OM facilitate P release, whereas MOCs enhance P retention. Ca-OM is the most efficient PO₄-P adsorption [adsorption capacity (AC): 0.8980-0.9524 mg/g], followed by Fe-OM (AC: 0.5120-0.7020 mg/g), original sediment (AC: 0.4368-0.5596 mg/g), and FA (AC: 0.2657-0.2769 mg/g). Cation bridges, primarily formed by -OH and -NH₂ groups within Ca-OM (outer-sphere complexes), promote greater P adsorption than Fe-OM (inner-sphere complexes, mainly associated with -COOH). However, Fe-OM-P exhibits a more stable structure. In high P environments, P adsorption onto Ca-OM may induce the release of labile OM, temporarily retaining P through resorption onto labile OM. Hyporheic flow with higher pH and Eh values promotes MOC formation, underscoring their significant P retention capacity. Therefore, strategic MOC use within the hyporheic zone is crucial for mitigating surface water eutrophication.

Climate variability impacts the structure and functioning of marine ecosystems and can trigger behavioural responses in organisms. We investigated whether such variability modulates diet and migration in the North Atlantic fin whale (Balaenoptera physalus). To reconstruct the dietary and migratory behaviours over time, we conducted stable isotope analysis of nitrogen (δ¹⁵N) and carbon (δ¹³C) along baleen plates from 29 fin whales sampled off southwestern (SW) Iceland in summer. We estimated a baleen growth rate of 16.1 ± 2.5 cm per year from the stable isotope oscillations observed along the baleens. We also assigned a deposition date for each baleen segment, thus obtaining isotopic sequential time series. We then assessed the potential association of these time series with the main climate patterns of the North Atlantic basin. Baleen δ¹⁵N and δ¹³C values are associated with the North Atlantic Oscillation (NAO) and the Atlantic Multidecadal Oscillation (AMO). During high AMO and low NAO periods, which tend to decrease krill abundance, there is an increase in both the mean and standard deviation of baleen δ¹⁵N values, suggesting that fin whales shift to higher trophic resources and expand their dietary niche. Additionally, high AMO periods, which relate to positive temperature anomalies, lead to a decrease in baleen δ¹³C values, suggesting that fin whales adjust their migratory routes and destinations towards higher latitudes. Significant variation in isotopic niche width between years also reflected these dietary and migratory behavioural shifts. This highlights the plasticity of the North Atlantic fin whale behaviour, a trait likely to strengthen the resilience of the species within the current context of rapid and intense climate variability.

The effects of fertilization on soil denitrifying microorganisms are well-documented. However, the impact of global warming on these microorganisms, particularly regarding the interaction with fertilization, remains poorly understood. Here, a 4-year field warming experiment that included experimental warming (ET) and ambient temperature control (AC), with nitrogen (N) fertilizer applied (CF) or without N fertilizer (CK), was employed to assess the response of the abundance and community of nirK-, nirS- and nosZ- type denitrifiers to warming and fertilization in paddies, and to understand their relationship with potential denitrification rate (PDR). The results showed that warming amplified the positive effect of fertilization on abundance of nirK and nirS genes, while the abundance of nosZ remained unaffected. The copies of nirK and nirS under the ET-CF treatment were notably higher than in the other treatments. In the terms of biodiversity, warming diminished the effect of fertilization on the α-diversity of nirK and nirS, but it did not influence the α-diversity of nosZ. Besides, warming intensified the effect of fertilization on the β-diversity of nirK, while the β-diversity of nirS and nosZ remained unchanged in response to fertilization. Additionally, the community structure of denitrifiers varied with warming and/or fertilization. Specifically, Mesorhizobium (nirK), Proteobacteria (nirS) and Rhizobiales (nosZ) were dominant in AC-CK treatment. In the AC-CF treatment, Proteobacteria (nirK/S), Rhizobiales (nosZ) were the main taxa. For the ET treatments (ET-CF, ET-CK), Bradyrhizobiaceae (nirK), Proteobacteria (nirS) and Alphaproteobacteria (nosZ) were predominant. Correlation analysis revealed that soil pH, carbon and N content were the primary factors influencing nirK-, nirS-and nosZ- type denitrifiers. Moreover, PDR showed a positive relationship with nirK abundance, α-diversity of nosZ, and SOC. Overall, the results demonstrate that warming can modify the response of denitrifiers to fertilization, subsequently affecting denitrification rates, a phenomenon that merits attention.

Layered double hydroxides (LDHs) and their calcined products layered double oxides (LDOs) are widely used as adsorbents for pollutant removal. Their adsorption performance are significantly influenced by intercalated ions, while previous studies primarily focusing on the impact of individual ions. For the first time, this paper reports the mechanism of the synergistic enhancement of phosphate adsorption properties of LDO by bicomponent interlayer ions. The ZnAl-LDO by fluorine‑chlorine co-doping (F, Cl-ZnAl-LDO) exhibits excellent adsorption capacity of 158.9 mg_P/g, surpassing that of single-component intercalation Cl-ZnAl-LDO and F-ZnAl-LDO, as well as most LDH-based adsorbents. Further research and density functional theory calculations indicate the differential adsorption enhancement mechanism of the interlayer ions. Chlorine functions as the exchanged anion, whereas fluorine facilitates the complete replacement of chloride ions and hydroxyl groups by phosphate. This finding highlights the potential of utilizing the synergistic effects between different interlayer ions to design and synthesize advanced phosphate adsorbent materials.

Bensulfuron-methyl (BSM) enters the environment through agricultural practices, posing a threat to the health of aquatic organisms. Currently, the toxic mechanisms of BSM on crayfish (Procambarus clarkii) have not been thoroughly investigated. In this study, crayfish were exposed to BSM solutions at concentrations of 0, 5, and 10 mg/L for 48 h. The study integrated physiological, gut microbiota, and transcriptomic analyses to investigate the mechanisms of action. BSM exposure induced oxidative stress responses in crayfish, resulting in changes in superoxide dismutase (SOD), catalase (CAT), glutathione reductase (GSH) activity, and malondialdehyde (MDA) levels. Exposure to BSM caused damage to the intestinal tissues, reduced gut microbiota diversity, increased the abundance of harmful bacteria, and led to intestinal dysfunction. Analysis of the hepatopancreas revealed significant tissue damage. Transcriptomic data indicated that BSM affects the growth of crayfish through genes related to immune response (SLC17A5, CTSD, CTSB, NFKBIA, Mincle). The lysosomal pathway and NF-κB pathway were notably affected. This study analyzed the negative impacts of BSM on crayfish from various levels and provided detailed data to enhance our understanding of the toxic mechanisms of BSM in aquatic organisms.

The global warming and environmental pollution are two crucial contemporary concerns. As both are strongly connected with urbanisation and anthropogenic impact on the environment, they often affect the ecosystem simultaneously. Aquatic habitats are particularly susceptible to thermal and chemical pollution. Temperature influences nearly all physical and chemical features of water bodies and trace metals are known for their toxicity to aquatic organisms. However, effects of multiple stressors, cumulative effects as well as response and possible adaptations of organisms are still open questions. Thus, the aim of this study was to characterize the combined effect of temperature and two trace metals (Co and Ni) on the metal bioaccumulation and viability of a model aquatic macrophyte Elodea canadensis Michx. We exposed shoots of E. canadensis to three temperatures and four metal concentrations (together and separately) applied at environmentally relevant levels. Shoot growth and metal concentration in plants were measured after 120 h. Moreover, after 24, 72 and 120 h the changes in leaf cell morphology and viability were analysed. The results showed that metal accumulation was dose-dependent and was not affected by temperature. The growth of plants was not affected by temperature nor metals. On the other hand, the exposure to Co and Ni and the elevated temperature negatively affected cell viability of E. canadensis leaves which manifested by increased permeability of plasma membranes and visible necroses. The greatest damaged leaf areas were determined after 120 h in the highest concentration of both metals and the highest temperature which indicates synergistic impact of trace metals and temperature on performance of macrohydrophytes. The observed phenomena suggest that global warming and/or thermal pollution may have implications for the performance of aquatic macrophytes in chemically polluted waters, their ability to spread and colonize polluted habitats and their suitability in phytoremediation.

Adsorption is of great significance in the water pollution control. Carbonaceous adsorbents, such as carbon quantum dots, carbon nanotubes, graphene, and activated carbons, have long been deployed in sustainable wastewater treatment due to their excellent physical structure and strong interaction with various pollutants; these features allow them to spark greater interest in environmental remediation. Although numerous eye-catch researches on carbon materials in wastewater treatment, there is a lack of comprehensive comparison and summary of the vivid structure-activity-application relationships of different types of carbonaceous adsorbents at the molecular and atomic level. Herein, this review aims to scrutinize and contrast the adsorption mechanisms of carbonaceous adsorbents with different dimensions, analyzing the qualitative differences in adsorption capacity from microscopic perspectives, structural diversity caused by preparation methods, and environmental external factors affecting adsorption occurrence. Then, a quantitatively in-depth critical appraisal of traditional and emerging contaminants in wastewater treatment using carbonaceous adsorbents, and innovative strategies for enhancing their adsorption capacity are discussed. Finally, in the context of growing imposed circularity and zero waste wishes, this review offers some promising insights for carbonaceous adsorbents in achieving sustainable wastewater treatment.

In an earlier study published in Science of the Total Environment (Taylor et al., 2019), we used an established hydrological model (based on what is known as the Kuzcera curve), to analyse the impacts of logging on water yields in a major watershed - the Thomson water supply catchment - in the Central Highlands of Victoria, south-eastern Australia. We demonstrated that under some plausible climate change projections, the impacts of logging on catchment water yields may exceed those resulting from climate change (Taylor et al., 2019). In a Letter to the Editor (2024), it was argued there were problems with our analysis and, as a result, if the Thomson water supply catchment was subject to logging and thinning such actions may be "water positive". While we acknowledge a lack of availability in forest and hydrological field inventory data across the Thomson catchment, as well as variability in differing modelled results, we outline some important reasons our original conclusions that logging may lead to reduced water yields remain vali.

The European Union, as delineated in Regulation (EU) 2020/741, sets forth minimum criteria for the reuse of wastewater. Directive 86/278/CEE sets the regulations for the reuse of sewage sludge in agriculture. This study aimed to investigate the treated water derived from a pilot plant situated in Granada, Spain, that utilizes membrane bioreactor technology to process real urban wastewater with the quality standards necessary for agricultural reuse. Additionally, the study evaluated the utilization potential of other resources generated during wastewater treatment, including biogas and biostabilized sludge. The pilot plant incorporated a membrane bioreactor featuring four ultrafiltration membranes operating continuously alongside a sludge treatment line operating in batch mode. The pilot plant operated during four cycles, each with distinct hydraulic retention times (6 h and 12 h) and variable mixed liquor-suspended solids concentrations (ranging from 2688 mg L^-1 to 7542 mg L^-1). During these cycles, the plant was doped with increasing concentrations of emerging contamination compounds (diclofenac, ibuprofen, and erythromycin) to test their effect on the resources derived from the treatment. Subsequently, a tertiary treatment involving an advanced oxidation process was applied to the different water lines, which left the wastewater treatment plant for a period of 30 min and utilized varying concentrations of oxidant. The results indicate that the effluent obtained meets the required quality standards for agricultural use. Therefore, there is potential to use this waste as a resource, which is in line with the principles of the circular economy. Furthermore, the other resources generated during the treatment process, such as the biogas produced during the digestion process and the biostabilized sludge, have the potential to be used as resources according to the circular economy indicators.

Desert areas offer rich solar resources and low land use costs, ideal for large-scale new energy development. However, desert ecosystems are fragile, and large-scale photovoltaic (PV) power facilities pose ecological risks. Current assessments of PV plant sites in deserts lack consideration of wind-sand hazards and ecological impacts. In this study, we have developed a new large-scale photovoltaic (PV) site selection model that integrates the analytic hierarchy process with geographic information system technology, and applies it to the desert regions of China. The results show that the potential for large-scale PV power plants in China's deserts is significant, with 69.4 % of the region assessed as medium or higher. The most suitable area is 12.7 × 10⁴ km² (7.6 % of the overall study area), mainly centered in the Tibetan Plateau's Qaidam Basin Desert and the deserts of northern China, characterized by favorable solar resources, climate, and terrain. Across all regions, gravel deserts are recognized as more suitable for the construction of large-scale PV power projects than sandy deserts. Considering varying PV installation density scenarios with an installed capacity potential of 36.4-84.9 TW and system costs ranging from 10.0 to 33.5 trillion USD, the study estimates an annual solar power generation potential of 47-110 PWh which is 1.7-3.9 times the global electricity demand. Carbon emissions could be reduced by 26.8-62.6 gigatons annually, offsetting 73-170 % of global emissions. Covering just 4.8-11.5 % of China's desert area (8 × 10⁴-19.4 × 10⁴ km²) would meet the projected 2025 electricity needs of the country. This study lays the groundwork for spatial planning and benefit assessment of large-scale PV projects in desert regions, and reduces conflicts between PV plant construction and local ecosystem.