Journal of hazardous materials最新文献

Aquatic ecosystems are increasingly threatened by organophosphate pesticides (OPPs) such as diazinon (DZN) and polycyclic aromatic hydrocarbons (PAHs) like benzo[a]pyrene (BaP), both of which disrupt metabolic, immune, and neural functions in fish. This study investigated the protective efficacy of Spirulina platensis (SP), a natural heat shock protein inducer (HSPi), against DZN- and BaP-induced toxicity in Acipenser stellatus fingerlings. Experimental treatments involved individual and combined exposures to DZN and BaP, with or without SP supplementation, over 1, 3, and 6 days. Gas chromatography-mass spectrometry (GC-MS) analysis identified methyl palmitate (38.43 %) and γ-linolenic acid methyl ester (GLA; 19.06 %) as the predominant bioactive constituents of SP. Exposure to DZN and BaP significantly increased hepatic cytochrome P450 (CYP450; up to 0.95 ng/mg protein), serum cortisol (to 33 ng/mL), and liver enzyme activities, while reducing acetylcholinesterase (AChE) activity by approximately 40 %. In contrast, treatments combining SP with pollutant stress markedly upregulated HSP70 expression, enhanced antioxidant enzyme activities, and elevated immune markers by 25-40 %. Furthermore, SP supplementation reduced cortisol levels by 30-35 % and restored AChE activity to near-baseline values. These findings demonstrate SP's HSP70-mediated cytoprotective effects and support its potential as a dietary strategy to mitigate multi-pollutant stress in aquatic organisms.

Constructed wetlands and other nature-based solutions (NBS) are widely used to mitigate pesticide runoff from agricultural landscapes, but their performance is often limited by short hydraulic retention times and fluctuating environmental conditions. To enhance the pollutant removal capacity of NBS, we developed a biochar-calcium peroxide (CaO₂) composite material designed to combine adsorption with oxidative degradation. The composite was fabricated by embedding biochar and CaO₂ into a cement matrix and achieved up to 76.8 % removal of tebuconazole after 30 days of static incubation, which was 2-6 times higher than CaO₂ alone (10-20 %), depending on biochar loading and solution pH. Notably, under acidic conditions (initial pH ∼5.6), the oxidative degradation contribution of the composite (35-47 %) increased by approximately 20-30 times compared with the composite without biochar (1.9 %). Moreover, incorporating CaO₂ into biochar moderated its consumption and reduced CaO₂ loss by nearly 50 % after 30 days of incubation in water, enabling a more sustained release of reactive oxygen species (ROS). The material maintained stable performance under both acidic and unbuffered conditions, demonstrating applicability under variable field environments. These findings demonstrate the potential of biochar-CaO₂ composites to improve the robustness and effectiveness of NBS for decentralized water treatment of pesticide-contaminated runoff.

As an emerging pollutant, Micro/nano plastics (M/NPs) pose a serious threat to the aquatic ecosystem and human health. Electrochemical oxidation technology has advantages such as high catalytic performance, environmental friendliness, and simple operation, and it has the potential to degrade M/NPs in water. In this work, we proposed a Ti/Sb-SnO₂ anode modified by co-doping with Sm-Mn composite intermediate layer for the electrochemical oxidation degradation of polystyrene nanoplastics (PS NPs) in water. Experimental results showed that the Ti/Sm-Mn-Sb-SnO₂ anode exhibited the best PS NPs removal efficiency (58.75 %) and the longest electrode lifespan (825 h). The doping of composite intermediate layer elements possessed a more uniform and dense crack structure on the anode surface, as well as the formation of a fuller crystal structure, effectively increasing the active sites and specific surface area for electrochemical process. Moreover, material characterization and theoretical calculations confirmed that the synergistic effect of the bimetal facilitates the electron transfer process between Sn and Sb, improves current mass transfer efficiency, and promotes the occurrence of redox reactions. Combined with DFT calculations and the identification of intermediate products, the degradation pathways of PS NPs were analyzed, which mainly included electrophilic substitution (benzene ring hydroxylation), C-C and C-H bond cleavage (chain breakage and ring opening), and hydrogen atom addition reactions. This modification strategy not only provides a new approach for NPs degradation through electrochemical oxidation but also offers theoretical basis and technical support for the future application of M/NPs pollution control in water environments.

Pollution and warming are major threats to freshwater ecosystems, yet their joint effects on predator-prey interactions structuring these ecosystems and how thermal evolution may modulate these impacts are largely unknown. Under common-garden settings, we investigated how exposure to the widespread pesticide chlorpyrifos and warming affected predator life history, metabolic rate and functional response, and prey population dynamics to predict the long-term interaction strength (intrinsic stability) of low- and high-latitude populations of Ischnura elegans damselfly larvae preying on Daphnia magna water fleas. Warming magnified the negative impact of pesticide exposure on predator performance and predation rates, but remarkably, for high-latitude predators, pesticide exposure mitigated some of the negative impacts of warming on long-term predator-prey system stability. This reversed the stressor interaction types at different biological organization levels, from negative synergistic and antagonistic to positive synergistic and antagonistic. Under warmer future conditions, thermal plasticity destabilized the predator-prey system for high-latitude predators. Interestingly, pesticide exposure helped to stabilize this system under warming, while having no effect under the current cooler thermal regime. Using a space-for-time substitution, our results suggest that joint thermal plasticity and evolution of high-latitude predators could contribute to stabilizing predator-prey systems under warming, with pesticide exposure further enhancing this effect, providing evidence that thermal evolution could alter the stressor interaction type. Our findings highlight the importance of considering thermal evolution, multiple-stressor interactions, and biotic interactions into ecotoxicology to better predict the impact of pollutants on the local persistence of species in increasingly stressed environments.

Plastic film has emerged as a nonnegligible source of microplastics (MPs) in farmland soil. However, knowledge of regarding the distribution characteristics of MPs in soil profiles and aggregates remains limited. This study focuses on the typical plastic film mulching area of Shihezi, in Xinjiang Uygur Autonomous Region, analyzing the spatial distribution of MPs in soils and soil aggregates over various durations of mulching. The results indicated that the abundance of MPs in the soil of 3-23 years of continuous mulching fields ranged from 20.90 ± 9.66-54.17 ± 21.19 items g^-1, with its abundance increased linearly with the increase of film mulching years. MPs showed obvious vertical differentiation characteristics in the soil profiles. Among them, the abundance of MPs in the surface 0-10 cm soil layer was the highest, decreasing with the increase of depth. The abundance of MPs in aggregates was positively correlated with their size. Utilizing these data, a random forest model was developed to predict MPs abundance in soil profiles and aggregates across different mulching durations. This study contributes valuable data to enhance the understanding of MPs distribution in soil layers and aggregates under long-term mulching conditions.

Surface-enhanced Raman spectroscopy (SERS) holds great promise for sensitive molecular detection across diverse fields, including environmental monitoring and food safety. However, its practical efficacy is often constrained by relatively low sensitivity and poor reproducibility over large areas. In this study, a hotspot-optimized SERS platform is developed via the interfacial co-assembly of gold nanoparticles (AuNPs) of two distinct sizes. Inspired by the clustered luminosity of stars, this Stellaris Somnia-inspired interlaced nanoarray (SSIN) features a monolayer of larger AuNPs (>90 nm) complemented by smaller AuNPs (21 nm) intercalated within interstitial gaps, significantly increasing hotspot density and SERS enhancement. This strategy enables the fabrication of highly sensitive and signal-stable nanoarrays without relying on complex anisotropic nanomaterials or laborious top-down processes. The SSIN substrate achieved exceptional detection limits of 0.392 ng/L for malachite green (MG). In real fish samples such as large yellow croaker and channel catfish, the platform successfully detected malachite green at concentrations as low as 0.5 μg/kg. The results were consistent with those obtained by HPLC-MS/MS, confirming high analytical accuracy. The substrate enabled label-free detection of trace pesticides, including difenoconazole, thiabendazole, and thiram, demonstrating broad-spectrum applicability. Moreover, the SSIN substrate maintains over 75 % of its SERS activity after 180 days of storage at room temperature, highlighting its long-term stability. This work introduces a rational, scalable, and materials-efficient co-assembly strategy to engineer robust, hotspot-dense SERS platforms. The SSIN substrate holds great promise for practical applications in environmental contaminants and food hazards monitoring and the broader field of trace analyte detection.

The widespread use of polymer-coated fertilizers raises concerns about microplastics (MPs) pollution, yet their impacts on soil-crop systems remain unclear. This study evaluated the effects of MPs derived from polyurethane (PU) and polyethylene-polycarbonate (PE-PC) coated fertilizers on tomato growth and soil enzyme activity. Results showed that PU and PE-PC MPs significantly reduced 7-day germination rates by 12.5-17.5 % and 12.5-21.7 %, respectively, and inhibited early seedling growth. Interestingly, during the 45-day stage, neither PU nor PE-PC MPs exhibited apparent phytotoxicity, and in some cases even enhanced the total fresh weight of tomato plant. Chlorophyll analysis revealed that 1 % PU MPs slightly promoted chlorophyll content, whereas high PE-PC concentrations reduce it. Soil enzyme analysis revealed increases in β-glucosidase and acid phosphatase activity but no significant change in urease activity. Furthermore, distance-based redundancy analysis (db-RDA) indicated that MPs type and concentration jointly influenced plant physiological traits and soil enzyme activities. These findings suggest that coated fertilizer-produced MPs pose potential risks at germination stages, but their adverse effects appear negligible during the vegetative growth stage. These results can provide a support for scientific application and security risk assessment of coated fertilizers.

In agricultural ecosystems, the accumulation of polyurethane microplastics (PuM) resulting from the long-term application of controlled-release fertilizer (CRF) constitutes an irreversible pollution-each kilogram of CRF introduces approximately 32,000 particles-and these particles are difficult to recover. This study proposes a synergistic approach: the combined use of CRF and humic acid (HA) not only increases crop yields by 12.3 %-22.4 % but also accelerates the degradation of polyurethane microplastics by 34.3 %-43.9 %, which is of great significance for addressing the dual challenges of ensuring food security and remediating soil microplastic contamination. This study also explores the interaction between HA and PuM: under dark conditions, HA facilitates radical formation through the cleavage and isomerization of C-H bonds in PuM macromolecules; under light conditions, the phenolic hydroxyl and carboxyl groups in HA moieties mediate the generation of reactive oxygen species via photoexcitation, thereby initiating the oxidative scission of PuM's carbon backbone. This research provides new ideas on how to solve the pollution of polyurethane microplastics in farmland and for the in-situ treatment of microplastics in farmland.

The plastisphere impact on nitrogen (N) biogeochemical processes in soil ecosystems remains poorly understood. This study investigated the N-transforming microbiota in the plastispheres of four microplastic (MP) types in paddy soils with varying physicochemical properties. We further assessed the plastisphere's potential for denitrification and nitrous oxide (N₂O) production. Our results demonstrate that polyethylene (PE) and polystyrene (PS) plastispheres exhibited a higher abundance of N-functional genes than those formed on polyvinyl chloride (PVC) and polylactic acid (PLA). In strongly acidic paddy soil, MPs acted as microbial refugia, promoting the accumulation of denitrifiers and associated functional genes. Notably, plastispheres were highly enriched in narG in soils characterized by low nitrate (NO₃⁻) levels and a high dissolved organic carbon (DOC)/NO₃⁻ ratio. Denitrifiers, such as Dechloromonas and Pseudomonas, were more prevalent in plastispheres than in soil. Compared to soil, the narG-type denitrifying community in plastispheres exhibited lower diversity but more positive interactions. Furthermore, we observed that plastispheres significantly contributed to N₂O production, with denitrification rates increasing by 5.04- to 5.76-fold in soil extracts. These findings highlight the ecological role of plastispheres in soil N cycling and identify plastispheres as a previously unrecognized source of N₂O emissions in paddy soils.

Microplastics (MPs) are increasingly recognized as vectors for microorganisms in wastewater treatment plants, although their role in shaping microbial risks under antibiotic stress remains unclear. This study investigated the colonization dynamics of bacterial communities from activated sludge on polyethylene terephthalate (PET) and low-density polyethylene (LD-PE) MPs during a 5-day sludge retention time using 16S rDNA gene high-throughput sequencing and qPCR to study the microbial communities. Microcosm experiments (n = 24) were conducted under control conditions and exposure to ciprofloxacin (CPR, 100 μg·L⁻¹), trimethoprim (TMP, 100 μg·L⁻¹), and in combination (TMPCPR, 50 μg·L⁻¹ each). All MPs were rapidly colonized within 5 days, with antibiotics accelerating early biofilm formation. LD-PE supported faster colonization, reaching 10⁹-10 ¹ ⁰ 16S rDNA gene copies g⁻¹ MP by day 5, consistently one order of magnitude higher than PET. In contrast, PET plastispheres facilitated the enrichment of potential pathogens (Chryseobacterium, Flavobacterium, Clostridium, Candidatus Microthrix), showing a 10-100 × increase in predicted pathogenic functions (1.75-9.51 %) compared to activated sludge (0.09-0.16 %). The TMPCPR mitigated pathogen enrichment relative to single-antibiotic exposures. These findings highlight polymer-specific ecological risks as PET is more prone to pathogen colonization, accumulates in sludge, whereas buoyant LD-PE disperses through effluents carrying dense but less pathogen-enriched biofilms.