Science of the Total Environment最新文献

This study reports the occurrence and characterization of plastiglomerates and their micro-scale derivatives, termed microplastiglomerates, from the northeastern Bay of Bengal coast. These composite materials, formed through thermal fusion of diverse polymers with mineral and organic matter, were examined to elucidate their morphology, composition, and contaminant retention behaviour. Stereomicroscopy, confocal fluorescence microscopy, and FESEM revealed heterogeneous textures, molten polymer interfaces, and mineral inclusions, confirming their hybrid lithoplastic nature. Raman spectroscopy identified seven polymer types-polyethylene (PE), polypropylene (PP), polyethylene terephthalate (PET), polylactic acid (PLA), polyester (PES), polysulfone (PESU), and polyvinyl ether (PVE)-while XRD confirmed crystalline mineral phases such as quartz and calcite embedded within amorphous polymer matrices. TGA indicated mixed organic-inorganic composition with high thermal stability. Metal adsorption experiments demonstrated significant retention of toxic metals (Hg, Cd, Ni, Cr, and Co) on microplastiglomerate surfaces, verified through XPS, EDX, and ICP-OES analyses. Metal binding was facilitated by oxidized polymer surfaces and mineral interfaces, highlighting their capacity to act as persistent pollutant sinks. Collectively, the results reveal that microplastiglomerates represent stable, reactive, and environmentally significant composites that influence metal mobility and pollutant dynamics in coastal systems. The findings underscore the need to include plastiglomerates in coastal pollution monitoring and environmental policy frameworks, with future studies directed toward their degradation kinetics, trophic interactions, and implications for marine sediment geochemistry.

Flood-regulating ecosystem services (FRES) help reduce hydrological hazards by improving water infiltration and storage, which lowers runoff and flooding. Despite their importance, FRES are still not sufficiently integrated into Ecosystem-Based Disaster Risk Reduction (Eco-DRR) strategies. This study systematically reviewed 18 spatially explicit FRES assessments (2005-2023) and related them to social and socio-ecological vulnerability research to identify conceptual and methodological gaps. In total, 451 unique indicators were identified, with only 75 overlapping, revealing differing vulnerability perspectives across disciplines. FRES assessments were populated by environmental (40%) and land-cover (21%) indicators, while social data were more limited (8% on demographics, 2% on well-being). Among FRES studies, 55.5% included some socioeconomic indicators, 5.5% used a social vulnerability index, and 39% did not consider vulnerabilities, viewing social demand as a lack of biophysical FRES supply. Conversely, social vulnerability research rarely incorporated environmental indicators, whereas socio-ecological studies offered more integrated links between FRES, vulnerability, and disaster risk, emphasizing human reliance on ecosystem services. These findings reveal ongoing disconnects between assessments of ecological processes and human needs. A social-ecological systems framework is proposed to integrate ecosystem functions, social demands, and human dependence on ecosystems, thereby enhancing the application of FRES assessments in disaster risk management.

Climate change is driving more severe wildfires, raising urgent concerns about their impact on surface water sources. This critical review, based on 23 studies across 28 watersheds, synthesizes existing knowledge on how wildfires change the concentrations of eight contaminant categories in surface waters: suspended solids and turbidity, nutrients, organic carbon, major ions, trace metals, polycyclic aromatic hydrocarbons (PAHs), persistent organic pollutants (POPs), and wildfire-fighting chemicals (WFFCs). We observed that post-wildfire peak values reached 1142 mg/L for total suspended solids (TSS), ∼145 NTU for turbidity, 6.28 mg/L for nitrate, 31.08 mg/L for TOC, 325 μS/cm for electrical conductivity (EC), and 116 mg/L for trace metals such as zinc, with elevated levels often persisting over five years. Beyond the burned watershed, smoke plumes transport contaminants to distant basins via atmospheric deposition and subsequent runoff. These loads challenge drinking water treatment systems, potentially reducing performance while increasing health risks and operational costs. Although simulation tools exist to assess these risks, they require adaptation to account for wildfire-specific processes like atmospheric deposition and altered hydrology. As a result, further research is required on the persistence and remobilization of wildfire-derived trace metals, PAHs, POPs, and WFFCs, and on treatment performance under wildfire-affected source waters, along with long-term monitoring to supply data that improve modeling.

Farmers need information on the long-term effects of agricultural practices on crop yields and water balance. Models can be used to estimate these outcomes but parameter calibration with observed data is critical for accuracy of model outputs. Remote sensed surface soil moisture and evapotranspiration are becoming available, potentially enabling hydrological calibration when in-field data are lacking. Since the accuracy of these remote sensed data has not yet been assessed at the field scale, the objective of this study was to use combinations of locally measured soil moisture, evapotranspiration, crop yields and surface runoff to calibrate the Agricultural Policy/Environmental Extender (APEX) model for these variables and assess model performance. APEX parameters were calibrated for a 36-ha field in Missouri, United States, a spatial scale far smaller than those used in past multivariate calibration studies. Model performance was highest for outcomes included in the calibration process. However, the model struggled to simultaneously optimize crop yields and runoff performance, possibly due to limitations in the model's implementation of crop failure. Including soil moisture or evapotranspiration with runoff in the calibration process improved their respective performance but did not significantly change runoff performance. Calibration with evapotranspiration (excluding runoff) outperformed other non-runoff calibration combinations, implying that remotely sensed evapotranspiration data could help expand the spatial coverage of field-scale agricultural modeling in a region. This would allow the model to be applied more widely and to provide useful estimates of management outcomes to a larger number of US farmers.

The treatment of effluents containing pharmaceutical residues is a challenge, as these compounds require more robust and effective treatment for efficient removal. Thus, studies on the efficacy of ultrafiltration membranes using bioassays are fundamental to assess the long-term environmental impacts generated by new technologies. This study evaluated the efficiency of recycled ultrafiltration membranes modified with titanium dioxide (TiO₂) and graphene oxide (GO) in the removal of pharmaceutical compounds containing betamethasone, ketoprofen, fenofibrate, fluconazole, loratadine, and prednisone. Different sample components (feed, concentrate, and permeate) were subjected to ecotoxicity assessment bioassays using the organisms Aliivibrio fischeri and Allium cepa. The results of the tests conducted with the bacterium demonstrated that all tested membranes were effective in the treatment, as no toxicity was observed in the permeate samples for the evaluated membranes. Regarding the bioassays with A. cepa, there was no toxicity to germination and early growth for the tested samples, but biochemical and physiological alterations were observed in the seedlings. The concentrate samples from the three membranes induced higher stress in the plants, which was evidenced by increased lipid peroxidation (LP) and greater activity of the superoxide dismutase (SOD) enzyme. Higher frequencies of clastogenic and aneugenic abnormalities were also observed in the meristematic cells for the permeate samples from the third recycled membrane modified with TiO₂, graphene oxide, and photocatalysis. The effectiveness of the ultrafiltration membranes in eliminating toxic substances was confirmed by the ecotoxicological tests performed in this study.