Journal of hazardous materials最新文献

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.

Distribution, sources, and controlling factors of polycyclic aromatic hydrocarbons (PAHs) in Yancheng coastal wetlands under the invasion of Spartina alterniflora (S. alterniflora) were explored, PAHs concentrations in sediment ranged from 43.02 to 154.51 ng g^-¹ dw. Source apportionment revealed that traffic emissions and combustion were the primary contributors to PAHs contamination, with a minor portion originating from petroleum. The comparison across different habitats indicated that S. alterniflora directly promoted the accumulation of PAHs, and this effect increased with time. Conversely, after S. alterniflora removal, PAHs were reduced (with a 20.57 % reduction). Moreover, S. alterniflora also changed the physicochemical properties, especially fine particles. Correlation and linear regression analysis revealed a significant relationship between physicochemical properties and PAHs, highlighting their important influence on PAHs distribution. By modifying these properties, S. alterniflora indirectly increased PAHs accumulation, with total organic carbon (TOC) as the primary controlling factor. These results indicated that the control of S. alterniflora could not only mitigate the issue of invasive species, but also modify the sediment physicochemical properties and reduce PAHs contamination. These findings provided a scientific basis for dual-effect management and remediation strategies, supporting the simultaneous remediation of S. alterniflora invasion and PAHs pollution in coastal wetlands.

The extensive use of sulfonamides (SAs) in the treatment of respiratory and bacterial infections for humans and animals have triggered their ubiquitous occurrence in environment. Anodic oxidation processes have prominent potential in degrading SAs from wastewater. Herein, carbon cotton (CC) and graphite plate (GP) are applied as anodes to degrade SAs with various R substitutions at low current density (j, 0.42-5 mA/cm2, current intensity 2.5-30 mA). At j = 1.67 mA/cm², degradation efficiency of sulfathiazole, sulfadiazine, sulfisoxazole, sulfamethoxazole, sulfapyridine, and sulfamethazine reached 100, 90.1, 81.6, 92.8, 84.2, and 90.8 % at CC, and 100, 81.5, 54.2, 79.3, 83.2 and 79.1 % at GP, respectively. Most of the degraded SAs have been mineralized in both reaction systems. Sulfaguanidine, without heterocycle in R substituent, was more refractory to degrade at CC and GP surface even at higher j. The quenching experiments and DFT calculation disclosed that direct electron transfer (DET) process took a fundamental role on SAs decomposition. The surface sorbed [•OH] was responsible for mineralization of SAs. The two anodes can efficiently degraded sulfathiazole in different high-salinity wastewater samples at low j. Low-energy consumption and excellent mineralization efficiency endowed CC and GP with promising application for electrochemical oxidation of SAs from wastewater.

Understanding how low concentrations of antibiotics influence biogeochemical cycling mediated by aquatic microbes is essential for assessing the ecological risks of antibiotic pollution. Here we examined the responses of carbon, nitrogen, and sulfur cycling genes in an aquatic microbial community to trimethoprim, lincomycin, and their combined exposure across seven sub-inhibitory concentrations spanning three orders of magnitude. We found that while the diversity of elemental cycling genes remained largely unchanged, the abundance of associated metabolic pathways declined significantly under high antibiotic levels,particularly after seven days of exposure to 10 mg/L lincomycin or ≥ 1 mg/L trimethoprim-lincomycin combinations. Some elemental cycling genes increased in abundance under elevated antibiotic exposure, accompanied by concentration-dependent enrichment of antibiotic resistance genes (ARGs). Metagenomic assembly further revealed that enriched ARGs and cycling genes co-localized on the same contigs. In addition, antibiotic exposure reshaped the topological structure of molecular ecological networks among cycling genes, indicating altered microbial interactions and ecological processes. Together, these findings show that antibiotics not only enrich resistance determinants but also modulate the abundance of carbon, nitrogen, and sulfur cycling genes, underscoring the complex impacts of anthropogenic antibiotic pollution on microbially mediated biogeochemical cycles.

Biological waste gas treatments are promising approaches for the sustainable development of the petrochemical industry, which was limited by low removal efficiency and prolonged start-up due to difficulties in biodegradation and biofilm formation. Based on the independently developed biological autocrine signaling molecule (SMH13), this study explored its performance and mechanisms on enhancing synchronously removal of n-hexane and dichloromethane. The quorum sensing (QS) of the n-hexane-degrading strain Pseudomonas sp. HY-6 was activated, and the concentration threshold to fully activate the QS was 500 µg·L^-1. The extracellular polymeric substance (EPS) secretion and cellular surface hydrophobicity were promoted by 20 % and 40 % with SMH13, which were benefit to the biofilm formation and its n-hexane utilization. The start-up period of a lab-scale biotrickling filter (BTF) treating n-hexane and dichloromethane mixed waste gas was shortened from 19 days to 13 days with 23 % improvements on elimination capacity. The enrichment of alkane-degrading genera (Mycobacterium) and halogenated hydrocarbon-degrading genera (Chujaibacter, etc.) was positively correlated. The synchronously enhanced removal of n-hexane and dichloromethane was achieved through promoting the cell proliferation, EPS secretion, biofilm formation, and functional genera enrichment by activating QS using SMH13.