Environmental Research最新文献

This study quantifies structure-property relationships in surfactant-foamed porous metakaolin-based geopolymers, linking pore architecture to methylene blue (MB) adsorption, thermal insulation, compressive strength, and filtration. MB is used here as a representative cationic organic probe to elucidate the coupling between pore connectivity and mass-transfer/adsorption kinetics. Sixteen formulations were prepared using H₂O₂ (2 wt%) as the foaming agent and either sodium dodecyl sulfate (SDS, 1.6-3.0 wt%) or vegetable oil (3.0-6.0 wt%) as stabilizers under ambient and 60 °C curing. Surfactant-containing systems exhibited total porosity >70%; in SDS systems, open porosity typically exceeded 85% of the total. Thermal conductivity spanned 0.125-0.54 W/(m·K); unfoamed matrices were 0.5311 W/(m·K) (ambient) and 0.45 W/(m·K) (60 °C), whereas foamed samples predominantly fell within 0.10-0.30 W/(m·K). Bulk density and conductivity followed a strong linear relation. The unfoamed matrix exceeded 50 MPa at 3 d and 60 MPa at 28 d; H₂O₂ foaming reduced strength substantially, consistent with increased porosity. Enhanced pore connectivity accelerated adsorption kinetics: the matrix required >200 min to equilibrate, H₂O₂-only specimens equilibrated within 60 min, and SDS-modified specimens (1.6-2.3 wt%) within 20 min. Under 2 wt% H₂O₂ + 2.3 wt% SDS at 60 °C, maximum MB uptakes reached 0.212/0.455/0.906 mg/g at initial concentrations of 10/20/40 mg/L, respectively. While MB served as the model adsorbate, intended engineering deployments focus on contaminants prevalent in urban stormwater-specifically selected hydrophobic organics-and thus prioritize use as pre-treatment media in inlet vaults, filter layers within permeable pavement bases, and rooftop runoff modules. In such installations, low thermal conductivity can help buffer seasonal temperature swings, while the quantified links between pore connectivity and flux and between density and conductivity provide design guidance for multifunctional geopolymers that integrate adsorption, filtration, and insulation.

The precise detection of nitrite as a stable, end product and downstream metabolite of NO is critical for understanding exercise-induced physiological adaptation in athletes. However, typical electrochemical techniques usually have restricted sensitivity, photointerference, and matrix-dependent inaccuracy when detecting biological samples. In this work, we fabricated a PEC platform exploiting an ultrahigh-photocurrent CdS/polyaniline (CdS/PANI) heterostructured film to facilitate accurate and selective nitrite detection as a biologically important health parameter of exercise-induced NO metabolism. When the CdS quantum structure is combined with the conductive PANI, strongly increased visible light absorption efficiency and more rapid charge separation were achieved, and electron-hole recombination was inhibited. Such synergistic effects result in strong photocurrent responses, with nitrite being an efficient electron acceptor and contribute to a substantial concentration-dependent reduction of the photocurrent. It provides an acceptable limit of detection, a wide linear range, good selectivity toward the traditional biological interferents, and stability during use. The proposed CdS/PANI PEC system offers a rapid, cost-effective, and analytically powerful strategy for evaluating exercise-induced metabolic changes and highlights its strong potential for future applications in sports physiology, biomarker detection, and personalized performance monitoring.

Mining production has driven human development but has also led to sustained ecological damage. Vegetation serves as a critical carrier and indicator of ecosystem conditions in resource-extraction zones. Therefore, monitoring vegetation sustainability in such regions is crucial for both environmental conservation and regional growth. Leveraging the Google Earth Engine (GEE), this study employed trend analysis and an improved LandTrendr algorithm to quantitatively assess the spatiotemporal characteristics of vegetation changes (greening and browning) and abrupt changes (disturbance and recovery) in the Shizhuyuan mining zone and surrounding areas in southern China from 1997 to 2020. The enhanced LandTrendr algorithm resolved the common issue of vegetation recovery being erroneously detected before disturbance, making it particularly suitable for vegetation monitoring in mined landscapes. Additionally, machine learning algorithms were applied to classify vegetation change patterns. The results indicate a general greening trend across the region, with localized browning driven by human activities. Disturbances were primarily concentrated in 1999, 2003, and 2012, with disturbance and recovery processes following a distinct temporal sequence. Over 60% of the disturbed vegetation within the typical mining zone has been restored. Spoil heaps nearest to urban centers showed the most notable recovery, with over 64% of the area achieving high-quality restoration, exhibiting clear spatiotemporal characteristics of damage and recovery, reflecting targeted artificial reclamation efforts. This research provides a practical monitoring approach for tracking vegetation dynamics in mining-affected regions, offering valuable support for ecological studies and the development of environmental management strategies.

Per- and polyfluoroalkyl substances (PFASs) are highly persistent pollutants that disrupt plant-microbe interactions and compromise the performance of constructed wetlands (CWs). Here, we demonstrate a synergistic strategy combining carbon dots (CDs) and arbuscular mycorrhizal fungi (AMF) to alleviate PFAS-induced stress and enhance CW remediation efficiency. CD amendment markedly improved plant physiological performance under PFAS exposure, increasing photosynthetic efficiency and antioxidant enzyme activities, while simultaneously facilitating AMF colonization. Under high PFAS concentrations, the AMF-CDs treatment increased AMF colonization density by 33.3-100% relative to AMF alone, indicating substantial protection of symbiotic functionality. Metagenomic and community analyses revealed that the AMF- CDs combination reshaped the rhizosphere microbiome, enriching taxa such as Chloroflexi, Planctomycetes, and Campylobacterota that are functionally linked to nitrogen cycling, PFAS transformation, and metabolic resilience. These microbial shifts enhanced nutrient turnover and strengthened redox coupling processes critical for pollutant degradation. Consequently, the AMF-CDs system achieved pronounced improvements in water quality, with total phosphorus (TP), chemical oxygen demand (COD), total nitrogen (TN), and NH₄⁺-N removal efficiencies elevated by 34.3-158.3% compared with untreated controls. This study provides the first evidence that CDs function as nano-bridging agents that stabilize the root-microbe interface, reinforce AMF-plant symbiosis, and drive microbial community specialization toward pollutant degradation. The AMF-CDs synergistic mechanism offers a sustainable and scalable nano-bio strategy for restoring PFAS-contaminated ecosystems and advancing next generation constructed wetland technologies.

The ecological and health risks of 6PPDQ (N-(1,3-Dimethylbutyl)-N'-phenyl-p-phenylenediamine-quinone) have raised significant concerns. We recently demonstrated that the Aryl Hydrocarbon Receptor (AhR) mediates 6PPDQ-caused extrinsic apoptosis and heart defects; however, the underlying molecular pathways remain elucidated. In this study, we observed that inhibition of Protein Kinase A (PKA) effectively mitigated 6PPDQ-caused apoptosis and cardiac dysfunction in zebrafish larvae. Subsequent experiments revealed significant increases in both PKA levels and cyclic adenosine monophosphate (cAMP) concentrations within the hearts of zebrafish embryos exposed to 6PPDQ. Notably, pharmacological inhibition or genetic knockdown of AhR abolished 6PPDQ-induced PKA overexpression. Dual-luciferase reporter assays indicated that AhR activation by 6PPDQ directly enhance the transcription of adcy6a, which encodes an adenylate cyclase (AC) isoform predominately expressed in the heart of zebrafish. Inhibition of β-adrenergic receptors did not significantly influence the AC/cAMP/PKA cascade. Furthermore, exposure to 6PPDQ induced phosphorylation of cAMP response element-binding protein (CREB), an effect that was mitigated by PKA inhibition. Activated CREB subsequently promoted the expression of Fos, a component of the activator protein-1 (AP-1) transcription factor family. Inhibition of Fos (AP-1) counteracted the 6PPDQ-induced overexpression of fas and faslg, as well as the subsequent extrinsic apoptosis. In conclusion, our findings indicate that AhR activation by 6PPDQ triggers AC/cAMP/PKA cascade through direct transcriptional upregulation of adcy6a. PKA-mediated phosphorylation of CREB then facilitates the overexpression of fas and faslg via AP-1, resulting in extrinsic apoptosis and cardiac defects.

In this study, seven alkali-activated mortar mixtures were produced using waste andesite dust (WAD), fly ash (FA), and calcium aluminate cement (CAC). All mortar specimens were stored under ambient conditions of 20 ± 2°C and 50 ± 10% relative humidity until testing. Flexural and compressive strengths were evaluated at curing ages of 7, 28, and 56 days. A comprehensive microstructural characterization of selected mortars was performed through phase analysis (XRD), morphological and chemical investigations (SEM/EDX/mapping), and examination of the three-dimensional pore structure (micro-CT). Additionally, a Life Cycle Assessment (LCA) was conducted for all mortar scenarios using 1 m³ of mortar as the functional unit. The mixture containing 66.6% WAD and 33.3% CAC exhibited the highest compressive strength among all formulations, reaching 35.5 MPa after 56 days of ambient curing. Micro-CT analyses revealed that this mixture also possessed the lowest porosity. The incorporation of CAC led to the formation of additional crystalline phases, such as sodium anorthite. Due to its low Ca content, WAD primarily produced an N-A-S-H gel-dominated matrix, whereas hybrid mixtures also developed C-A-S-H gel. Furthermore, FESEM and EDX mapping confirmed that the addition of CAC resulted in a denser and more compact microstructure, attributable to the increased concentration of Ca ions, which directly contributed to enhanced mechanical performance. Although CAC-containing mixtures showed improved strength and microstructural density under ambient curing, their environmental impacts were higher; in contrast, the WAD-based mixture exhibited the lowest environmental footprint.

Purpose: This study aimed to evaluate the associations of prenatal exposure to organophosphate pesticides (OPP) with eczema and allergic rhinoconjunctivitis (AR) in 4-year-old Japanese children.

Methods: The participants in this study were Sub-Cohorts of the Japan Environment and Children's Study (JECS). The maternal urinary OPP metabolite concentrations of six dialkylphosphates (DAPs) were measured by lipid chromatography coupled with tandem mass spectrometry, corrected by specific gravity. Eczema and AR cases were defined according to the International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire for children at 4 years old. Multiple logistic regression analysis was used to examine the associations of DAPs with eczema and AR. Sub-group analyses were performed to explore the association between DAP metabolites and AR and eczema in children with elevated (≥170 IU/mL) and lower (<170 IU/mL) serum IgE levels.

Results: Data from 4218 participants were analyzed. The highest DAP concentration was observed in the dimethylthiophosphate (DMTP) (Median: 3.33 ng/ml). Out of the six measured OPP metabolites, only 3 could be used for the analyses. There were positive associations of dimethylphosphate (DMP) (adjusted OR=1.30; 95%CI=1.06-1.59; FDR-adjusted p=0.048) with eczema. No associations were found with AR or IgE alone. Sub-group analysis revealed a positive association between DMTP and eczema in children with lower IgE levels (<170 IU/mL) (adjusted OR=1.28; 95%CI=1.04-1.57; p=0.02).

Conclusion: Prenatal DMP and DMTP were associated with an increased risk of eczema in children aged 4, with this association confined to children with DMTP and lower IgE levels, while no associations were found with AR or IgE levels.

Pollution of agricultural soils by microplastics (MPs) is an escalating global concern, yet high-altitude agroecosystems remain largely understudied despite their ecological sensitivity and dependence on mountain farming systems. This review synthesizes current evidence on microplastic sources, behavior, and environmental impacts in low-temperature soils, emphasizing how unique physicochemical conditions and cold-adapted microbiomes shape MPs deposition, mobility, degradation, and biotic interactions. MPs consistently alter soil microbial diversity, enzymatic activity, and nutrient cycling processes, with well-documented plant uptake studies, raising concerns. MPs also act as carriers of chemical pollutants and microbial agents, potentially elevating ecological risks. Although microbial and insect-associated biodegradation pathways have been documented, their efficiency and environmental relevance in cold-hilly agricultural soils remain poorly understood. By identifying key knowledge gaps, including limited field data, poor understanding of MPs-climate interactions, and the absence of MPs monitoring frameworks, this review highlights the need for biologically led remediation strategies, sustainable alternatives to agroplastics, and adaptive policies to strengthen the resilience of high-altitude agricultural systems.

As contemporary high-tech advancements progress, the strategic significance of rare earth elements is increasingly highlighted. Beyond mitigating supply risks, their recovery from wastewater offers direct benefits for environmental protection and human health, making it an indispensable practice. In this work, dual-template ion-imprinted mesoporous membranes (IMMs) were prepared by direct copolymerization and evaporation-induced self-assembly with chitin nanocrystals as the structural template, Nd³⁺ as the ion-imprinting template, and iminodiacetic acid-modified silane coupling agent as the functional monomer for the selective adsorption of Nd³⁺. The influence of structural porosity, pH, initial ion concentration, adsorption time, and temperature on the adsorption performance was systematically characterized. It was found that IMMs had an average pore size and a specific surface area of 11.20 nm and 221.30 m² g^-1, respectively. At pH = 5 and 25 °C, IMMs had the maximum adsorption capacity for Nd³⁺ at 117 mg g^-1 at a solid-to-liquid ratio (mg:mL) of 1:1, and the selective factors (SF) for Nd³⁺ in the presence of Al³⁺, Fe³⁺, and La³⁺ were 74.14, 23.86, and 15.93, respectively, which is advantageous compared to the other reported ion-imprinted adsorbents. The selective adsorption of Nd³⁺ was also confirmed with the industrial ore leaching wastewater. The adsorption isotherm followed the Langmuir model with pseudo-second-order kinetics, and the adsorption process was exothermic. The proposed IMMs are easy to prepare and collect, which is of practical importance for large-scale applications.

Excessive sludge production and unstable suppression of nitrite-oxidizing bacteria (NOB) are key obstacles to sustainable mainstream partial nitrification (PN) in conventional activated sludge systems. This study demonstrates how a mainstream PN reactor equipped with encapsulated biofillers, operated under carbon-nitrogen decoupling, can achieve stable nitritation with minimal sludge production for low C/N domestic wastewater. Hydrolysis-acidification and denitrification (HA-DN) was used as a front-end carbon management module, redirecting readily biodegradable organics to denitrification, removing 72.9% of influent SCOD and producing an extremely carbon-limited influent (C/N ≈ 0.8-1.2) for the PN stage. Within the PN reactor, the encapsulated biofiller created a high-density, long-SRT autotrophic niche whose internal oxygen gradient selectively enriched ammonia-oxidizing bacteria (AOB), completely washed out NOB, and maintained a nitrite accumulation rate >98% even under increased ammonium loading. Under this combined high-DO and carbon-starved regime, residual heterotrophic bacteria (HB) were confined to a low-abundance, maintenance-oriented guild and shifted toward endogenous respiration rather than net growth. Consequently, the observed sludge yield in the PN stage was as low as 0.013 kgMLSS/kgCOD, representing a >93% reduction compared with typical CAS operation. Thus, carbon-nitrogen decoupling, realized through an encapsulated, carbon-starved PN niche, provides a generalizable strategy to achieve stable mainstream partial nitrification with minimal sludge production in low C/N domestic wastewater treatment.