Environmental Science: Nano最新文献

The production of p-phenylenediamine caused abundant emission of the greenhouse gas N₂O, which has not yet received much attention. This study tackles the significant yet overlooked N₂O emissions by developing a synergistic catalytic system for simultaneous purification of N₂O and co-pollutants (NO, CH₃OH, H₂) in tail gases. Among transition metal (Fe, Cu, Co)-modified zeolites, 1%Fe-Beta demonstrated superior activity for integrated pollutant removal, achieving complete N₂O conversion at 400 °C under an NH₃ + CH₃OH + O₂ reaction system. Mechanistic investigations (TPSR, in situ FTIR, TPD, and DFT analyses) revealed that N₂O was activated as NN–O–Z over Fe-Beta under the reaction atmosphere of NH₃ + N₂O + O₂; however, the introduction of CH₃OH switches the predominant cleavage pathway from the N–O bond to the N–N bond, leading to the formation of a Z–ONN species. The nitrogen atom from the –NNO moiety then combines with CH₃OH to form a formamide intermediate (HCONH₂), which plays a vital role in enhancing the deN₂O performance. Furthermore, the presence of NH₃ opens a lower-energy route for the formation of the key formamide intermediate by facilitating N–O bond cleavage in N₂O. This synergistic mechanism enhances the low-temperature conversion efficiency of N₂O. DFT calculations further confirm that the presence of NH₃ reduces the energy barrier during the reaction process, with the Z₂[Fe–O–Fe] binuclear site serving as the primary center for N₂O adsorption and activation. This study elucidates the dual activation pathways and synergistic mechanism of N₂O under complex reaction conditions, providing new strategies and a theoretical basis for the synergistic control of multiple pollutants in industrial waste gases. The demonstrated effectiveness of 1%Fe-Beta highlights its potential for practical greenhouse gas mitigation, bridging fundamental catalytic insights with environmental engineering applications.

Elevated CO₂ and heavy metal toxicity threaten global rice production and grain quality. Zinc oxide nanoparticles (ZnO-NPs) and 24-epibrassinolide (EBR) have been shown to individually mitigate heavy metal uptake in crops; their synergistic potential effect in the context of coexisting heavy metals, particularly under elevated CO₂ conditions, remains unexplored. This study investigated the efficiency of foliar ZnO-NPs (50 mg L⁻¹) and EBR (10⁻⁸ M), both individually and in combination, in reducing cadmium (Cd) and lead (Pb) accumulation and maintaining nutritional homeostasis in rice (Oryza sativa L.) cultivated in Cd–Pb co-contaminated soil under elevated CO₂ (600 μmol mol⁻¹). Results showed that elevated CO₂ exacerbated grain Cd accumulation (11.21%) while reducing Pb (19.09%) and significantly reduced nutrient content despite a non-significant increase in rice biomass as compared to the untreated control treatment under ambient CO₂. The combined application of ZnO-NPs and EBR was most effective, significantly reducing Cd (69.60%) and Pb (87.71%) in rice grain by enhancing photosynthesis, antioxidant enzyme activity (SOD, POD, CAT, APX), and lowering oxidative stress (MDA, H₂O₂, EL). At the molecular level, the combined treatment substantially downregulated the expression levels of metal transporter genes (OsHMA2, OsHMA6, OsNRAMP5) and upregulated the expression of Fe transporter gene OsIRT1, thereby improving Fe and Zn homeostasis. Additionally, nutrient analysis further revealed that ZnO-NPs and EBR co-application reversed heavy metal and elevated CO₂ induced nutrient deficits, significantly increasing grain nutrient content: Zn (163.71%), Fe (257.08%), Mn (213.37%), Mg (189.80%), Ca (313.75%), K (304.94%), and Cu (204.25%). Overall, these findings provide novel mechanistic insights into the combined application of ZnO-NPs and EBR for mitigating Cd–Pb toxicity under elevated CO₂, offering a climate-resilient strategy for safe and high-quality rice production.

Pea (Pisum sativum) is a popular legume crop, and increasing its yield through effective cultivation techniques is a central issue. Nano-fertilizers have enormous potential to improve the yield of agricultural production. Here, we investigated the effects of molybdenum disulfide nanoparticles (MoS₂ NPs), which act as nano-fertilizers, on the growth of peas. The results revealed that application of 100 mg L⁻¹ MoS₂ NPs significantly promoted growth and rooting, and increased the chlorophyll and carotenoid contents. In addition, MoS₂ NPs increased the formation of nodules. Transcriptomic analysis revealed that genes related to plant auxin signal transduction and carbon metabolism were upregulated upon 100 mg L⁻¹ MoS₂ NPs treatment. Moreover, auxin, carbon, and nitrogen assimilation-related genes in nodules were upregulated in the MoS₂ NPs treatment groups. These results suggested that foliar application of MoS₂ NPs promoted pea growth and the accumulation of organic matter, which was able to transport abundant materials and energy to the roots. Consequently, the roots synthesize more amino acids in the nodules, supporting the growth of the aboveground parts. This study provides a comprehensive understanding of how MoS₂ NPs harmonize the carbon/nitrogen assimilation procedures in different parts of the plant. This study also offers new ideas and strategies for the application of nanotechnology to promote agricultural production, especially for yield improvement in nano-enabled agricultural fields.

A novel potentiometric sensor based on molecularly imprinted polymer (MIP) beads embedded in an asymmetric membrane configuration was developed for the trace monitoring of tetrabromobisphenol A (TBBPA), a widely used brominated flame retardant and persistent environmental pollutant. The sensor was fabricated by incorporating TBBPA-imprinted beads into a poly(vinyl chloride) (PVC) membrane plasticized with dioctyl phthalate (DOP) and drop-cast onto a reduced graphene oxide (rGO)-modified screen-printed electrode. The asymmetric design featured a surface-enriched ion-exchange layer, enabling enhanced accumulation of deprotonated TBBPA at the membrane interface. Under optimized conditions, the sensor exhibited a near-Nernstian slope of −56.6 ± 1.2 mV per decade over a linear range of 5.0 × 10⁻⁶ to 10⁻³ M and a detection limit of 5.5 × 10⁻⁷ M. The sensor demonstrated high selectivity toward TBBPA over structurally related phenols and common anions, with the enhanced discrimination attributed to the imprinting effect and nano-scale recognition features. Application to spiked environmental samples including wastewater, sediment, and plastic leachates yielded recoveries between 95.6% and 102.3%, with no significant deviation from high-performance liquid chromatography (HPLC) results (p > 0.05). The proposed MIP-based asymmetric membrane sensor offers a portable, cost-effective, and highly selective platform for on-site environmental monitoring of TBBPA.

Multi-component active ingredient delivery systems based on co-assembly have the merits of reducing drug dosage, attenuating pest resistance, enhancing ingredient utilization, broadening the control range, etc. and present excellent application prospects. Herein, a carrier-free co-assembled nanopesticide based on two first-line pesticides, abamectin B1a and imidacloprid, is successfully fabricated by a straightforward nanoprecipitation technique alone. NMR, UV-vis titration and molecular dynamics simulations reveal that intermolecular hydrogen bonding and van der Waals forces are the key driving forces for their binding. Less frequently encountered π-alkyl forces also prevail in the co-assembled systems. The co-assembled nanopesticide presents a structured spherical shape with a size of ∼200 nm. Soil permeability and UV degradation resistance are significantly higher than those of the two pure components. The surface of Ditylenchus destructor Thorne (D. destructor) treated with the nanoparticles becomes smooth, and the roughness is significantly lower than that of the control group. The activity of acetylcholinesterase (AchE) in vivo is significantly lower than that in the treatment group alone. AVM@IMI is also shown to have a better biosafety profile than commercial preparations. This strategy is expected to achieve efficient control of D. destructor and allow the green and sustainable development of agricultural controls.

Quantum dots (QDs) are increasingly used in diverse fields, and thus they inevitably spread unintentionally into the farmland ecosystem through (i) environmental release and (ii) intentional application in fertilizers, pesticides or growth promoters in agriculture. Several studies have shown that QDs can enter plants through leaf and root absorption and translocate throughout the plant, potentially affecting plant growth and development. At appropriate concentrations, QDs have been found to stimulate plant growth, enhance nutritional quality, improve resilience to abiotic stressors, and facilitate disease management. However, inappropriate concentrations of QDs, particularly those containing heavy metals or functional moieties such as hydroxyl and amino groups, may exert adverse effects including oxidative stress, cellular damage, growth retardation, and genetic toxicity. This review synthesizes the enrichment effect of QDs on plants in the farmland ecosystem from aspects such as the absorption pathway, transport mechanism, and its impact on plant growth, photosynthesis, stress resistance and yield. Accordingly, we propose that future research should be based on this “double-edged effect” to develop agricultural applications of QDs. Focus should be on elucidating the specific uptake and transport mechanisms of different types of QDs in different plant species, refining the preparation methods and application technologies of QDs, and rigorously assessing their ecological risks, to provide a sound scientific basis for the safe and effective use of QDs in agroecosystems aligned with determining their full agricultural potential.

Indoor air quality plays a critical role in human health, particularly due to prolonged exposure in enclosed environments. One major indoor air pollutant is fine particulate matter (PM 2.5), which penetrates deeply into the respiratory tract due to its small size. Previously, we reported that water microdroplets undergo spontaneous oxidation to form reactive oxygen species (ROS), and metal ions dissolved in microdroplets are reduced by electrons donated from the oxidation, forming metal nanoparticles without the need for chemical reducing agents. Because tap water used in household humidifiers typically contains metal ions such as calcium, sodium and magnesium, we hypothesize that these ions could form metal nanoparticles in microdroplets generated by ultrasonic humidifiers. To investigate this hypothesis, we operated a household humidifier with tap water and analyzed the resulting airborne particles. Measurements using both a PM monitor and dynamic light scattering (DLS) revealed the formation of metal nanoparticles in aerosolized tap water microdroplets, while no particles were detected in deionized water microdroplets. To further confirm the mechanism, we introduced electron and ROS scavengers into tap water and observed either complete inhibition or significant reduction in nanoparticle formation. Adding ROS scavengers to tap water reduced the particulate matter concentration by up to 90.4% compared to tap water alone. These results demonstrate that ROS-driven water oxidation and subsequent electron donation are central to nanoparticle production in humidifier microdroplets. This study elucidates the underlying physicochemical mechanism of nanoparticle generation in ultrasonic humidifiers and proposes a practical mitigation strategy using ROS scavengers.

Understanding the fate of cadmium (Cd) in multi-constituent systems during dynamic multi-processes is critical for its effective remediation in the environment. However, the influence of humic acids (HAs) on the transformation of iron (Fe) minerals and cadmium (Cd) dynamics remains poorly understood. This study employed microscopic characterization (X-ray diffraction, Fourier-transform infrared spectroscopy, and transmission electron microscopy) and stable Cd isotopes to investigate the effects of HA on Fe(II)-catalyzed ferrihydrite (Fh) transformation and Cd dynamics. Our results revealed that HA stabilized amorphous Fh through adsorption of its carboxyl and hydroxyl groups, inhibiting the transformation of Fh into more crystalline lepidocrocite (Lp), goethite (Gt), and magnetite (Mt). However, HA competed with Cd for the binding sites of mineral surfaces, reducing Cd retention and enhancing its mobility in solution. The Cd isotopic composition (δ^114/110Cd) of Fe minerals showed the preferential adsorption of lighter Cd isotopes onto Fh initially (−0.26‰), with δ^114/110Cd shifting as heavier isotopes incorporated into crystalline mineral structures (e.g., defects, pores, interlayers in Lp) over time. Our findings are vital for developing remediation and sustainable management strategies to balance carbon storage and heavy metal pollution control in organic-rich environments.

In advanced oxidation processes, persulfates exhibit remarkable advantages in the removal of trace and persistent organic pollutants from water. Among these oxidants, peroxymonosulfate (PMS) possesses superior activation efficiency, broader pH adaptability, and enhanced potential in regulating pollutant degradation pathways. This work systematically outlines the activation mechanisms of PMS, with emphasis on the generation of reactive species and their roles in free-radical and non-radical pathways for cleaving chemical bonds in organic pollutants. Through representative case studies, we further compare the different performances of these approaches in degrading organic pollutants. The insights provided a deeper understanding of PMS activation and its application in pollutant degradation, and provided valuable references for developing more efficient water treatment technologies.