Journal of hazardous materials最新文献

Microalgae-based remediation of emerging contaminants (dimethyl phthalate, DMP) represents a promising strategy for green, low-carbon development within a circular economy. However, the limited knowledge of the toxicity mechanisms underlying DMP-induced algal apoptosis has constrained its broader application under high pollutant loads. To address this challenge, microalgae were cultured in DMP-containing media under blue-light illumination, and proteomic analysis was employed to elucidate the molecular mechanisms governing toxicity response and photoregulation. The results showed that exposure to 100 mg/L DMP under blue-light antagonism exerted no significant effect on microalgal growth, whereas 500 mg/L DMP induced significant growth inhibition (58.76 %). The redox imbalance led to increases in antioxidant levels by 2.37-fold (carotenoids), 61.67 % (SOD), and 25.91 % (CAT). Concurrently, high-dose DMP significantly compromised cell membrane integrity (31.80 %) and decreased mitochondrial membrane potential (22.40 %), which was associated with Cytochrome C-mediated activation of downstream caspase cascades, leading to programmed cell death. In contrast, low DMP concentrations promoted carotenoid biosynthesis under blue light to mitigate reactive oxygen species accumulation and circumvent redox disorder-induced cell death. These findings reveal the key regulatory mechanisms of DMP-coupled blue light on the apoptosis and metabolic reprogramming in microalgae and provide a theoretical and practical basis for developing efficient and tunable algal-based bioremediation strategies.

Fine particulate matter is prone to serving as a carrier for toxic air pollutants and can harm health through exposure processes such as inhalation. We analyzed the PM_2.5 concentration at different operation points in the welding workshop, as well as the exposure levels of metal elements and polycyclic aromatic hydrocarbons (PAHs) carried by PM_2.5 to explore the health risks of PAHs and harmful metal elements from the perspective of occupational populations. The results showed that the average PM_2.5 concentrations at the two points exceeded the national secondary air quality standard (75 μg/m³). The contents of Fe and Zn were the highest, both exceeding 10 %. The total PAHs concentration at the manual repair point (MRP)was 14.17 ng/m³, and that at the welding point (WP)was 14.44 ng/m³. The correlation analysis results showed that Ni exposure was associated with elevated blood pressure, Li affected lipid metabolism. BbF and Chr were negatively correlated with red blood cell count. Phe, and BaA were positively correlated with hemoglobin. The incremental lifetime cancer risk (ILCR) of Cr at the WP (2.14 ×10^-4) exceeded the safety threshold, while the carcinogenic risks of other elements such as As and Ni were within the acceptable range (10⁻⁶-10⁻⁴). The hazard quotient (HQ) of all elements was less than 1, and the ILCR (10⁻⁶-10⁻⁴) and HQ (<1) of PAHs exposure at the two points were at a relatively low level. The results provide a scientific basis for the monitoring of welding fumes and reduce occupational hazards caused by welding fume exposure.

This study developed a long-wave ultraviolet (UVA)/nitrite (NO₂^-) system to degrade antibiotics in aquaculture wastewater, using NO₂^- as a treatment agent in line with the "waste-to-treat-waste" approach. It further advanced the understanding of reactive nitrogen species (RNSs)-mediated oxidation by quantifying radical dynamics, assessing transformation product ecotoxicity, and evaluating system performance under varying environmental conditions. The degradation of sulfamethoxazole (SMX), a model antibiotic, was primarily driven by RNSs, with nitric oxide radicals (NO•) emerging as the most impactful species. Steady-state analysis revealed that the RNSs concentration ([RNSs]_SS = 1.79 × 10^-13 M) was significantly higher than that of hydroxyl radical (•OH) ([•OH]_SS = 2.25 × 10^-14 M). Among RNSs, NO• was dominant ([NO•]_SS = 1.51 × 10^-13 M), followed by nitrogen dioxide radicals (NO₂•, [NO₂•]_SS = 2.76 × 10^-14 M) and peroxynitrite (ONOO⁻, [ONOO⁻]_SS = 4.19 × 10^-18 M). RNSs contributed 55.97 % to SMX degradation, surpassing UVA (3.23 %) and •OH (40.80 %). Furthermore, ten transformation products were identified, showing relatively low toxicity and minimal ecological impact. Additionally, the UVA/NO₂⁻ system remained stable across varying temperatures and anion concentrations, making it promising for real-world wastewater treatment. This study establishes a quantified methodology for RNSs, providing critical insights into their kinetic behavior and role in antibiotic degradation.

Organochlorine pesticides (OCPs), notably dichlorodiphenyltrichloroethane (DDT) and hexachlorocyclohexane (HCH) isomers, persist in agricultural soils. This study compared the dissipation dynamics of DDT metabolites and HCH isomers in legacy contaminated and freshly spiked soils. To assess the phytoremediation potential of C4 perennial grass Miscanthus × giganteus (Mxg), dormant rhizomes were planted into contaminated and uncontaminated soils in glasshouse pot experiments. Initial and final DDT and HCH concentrations were measured via headspace solid-phase microextraction gas chromatography-mass spectrometry. In freshly spiked soils, α-HCH showed the highest dissipation (from 98 to 8 µg/kg, 92 %) and β-HCH the lowest (from 9 to 4 µg/kg, 50 %). In legacy soil, δ-HCH had the highest dissipation (from 103.2 to 2.1 µg/kg, 98 %), but β-HCH concentrations increased from 0.7 to 28.5 µg/kg, indicating possible isomerization. DDT transformation products (DDE and DDD) were prominent in legacy soil, but not in the freshly spiked soil. In the contaminated non-plant treatment, ∑HCH and ∑DDT decreased 71 % and 45 %, respectively. The root-to-soil ratio indicated OCP uptake, but these compounds proved highly toxic to this Miscanthus clone. Future research should explore other genotypes in polluted areas with localised amendments like biochar to reduce toxicity, enhance uptake, and stimulate transformations.

Diesel exhaust (DE) entering the environment poses a significant risk to public health, but the molecular mechanisms of DE-induced metabolic disorders remain largely unknown. Here we elucidated the impacts of DE exposure on hepatic lipid metabolism using a range of cohort, in vivo, and in vitro approaches. The cohort study revealed altered liver function indices of diesel engine testers (DETs) compared to those of non-DETs and with increasing exposure duration. Mice exposed to DE via whole-body exposure system developed hepatic steatosis, which coincided with an upregulation of the fatty acid transporter CD36, and a marked increase in long-chain fatty acids. Mechanistically, enhanced CD36 expression was predominantly related to the activation of aryl hydrocarbon receptor (AHR). Notably, treatment with organic extract of diesel exhaust particulate (DEP-OE) up-regulated the AHR/CD36 signaling pathway, and led to lipid accumulation in primary mouse hepatocytes. Both effects were markedly diminished by AHR and CD36 knockdown. Finally, we show that targeted inhibition of AHR alleviated DE-induced steatosis in mouse liver. Together, we demonstrate that the organic components of DE cause hepatic steatosis by activating the AHR/CD36 signaling pathway. Our research elucidates DE exposure risks and sheds new insights into the early prevention of diseases in DE-exposed populations.

Humic acid (HA), a redox-active soil and groundwater compound rich in functional groups (e.g., carboxyl, phenolic hydroxyl, and quinyl group), can complex with Fe(II) to form HA-Fe(II). While HA significantly influences contaminant behavior, the mechanisms it regulates Fe(II) structure-reactivity relationships remain unclear. This study demonstrates that HA content critically controls the Fe(II)-mediated reductive dechlorination of carbon tetrachloride (CT), exhibiting a dual regulatory effect: dechlorination is initially suppressed at lower HA concentrations but enhanced at higher concentrations. Macroscopically, HA mediates the exposure of Fe(OH)₂ (100) facets via a concentration-dependent threshold mechanism, directly modulating the electron-donating capacity of surface Fe(II) sites. HA content tunes Fe(II)'s electron-donating capacity at the electronic-structure level by synergistically altering Fe-O bond lengths, octahedral distortion, and the internal electric field. This regulation stems from HA's role as a weak-field ligand, which modifies the electronic occupancy of Fe(II) complexes' antibonding e_g* orbitals, thereby impacting electron transfer efficiency. HA content modulates the Schikorr reaction, providing insights into complex iron-based reduction processes. Through multi-scale analysis, this work elucidates the structure-activity relationship between natural organic matter and iron minerals in pollutant degradation, offering a theoretical foundation for designing environmental remediation materials.

Though unconfirmed, several studies consistently suggest that microplastics (MPs) may expand the spatial distribution of harmful algae and trigger harmful algal blooms (HABs). However, current understanding of the species composition and spatiotemporal variations of epimicroplastic harmful algae (EHA) remains insufficient, limiting in-depth exploration of MP-EHA interactions and their environmental implications. Therefore, we conducted field investigations and cultivation experiments across four Chinese bays. Results revealed 41 EHA species were identified, predominantly dinoflagellates and diatoms (e.g., Karlodinium veneficum, Prorocentrum obtusidens, Pseudo-nitzschia pungens). 33 %-60 % of EHA species overlapped with planktonic counterparts, implying partial EHA may derive from external sources. Field investigations showed dinoflagellates had significant positive correlations with nutrients, while cultivation experiments revealed temperature and nutrients as significant drivers of EHA communities-with some dinoflagellates correlating positively with temperature, indicating EHA may pose higher environmental risks in warm, nutrient-rich seasons. Notably, the EHA included toxic species rarely reported in China but frequently associated with global HABs (e.g., Amphidinium carterae, Margalefidinium polykrikoides, Fibrocapsa japonica), highlighting the need for continuous monitoring of their dynamics in Chinese waters. This study improves understanding of EHA composition and dynamics, offers critical insights into forecasting HABs, and provides practical value for mitigating aquaculture and human health risks.

Antibiotics are emerging pollutants that adversely affect microbial activity, disrupt nitrogen cycling, and reduce overall system performance in aquaponic systems. This study assessed the performance of media-based aquaponic systems amended with biochar mixed with zero-valent iron (BC/ZVI) under treatments with oxytetracycline (BZ-OTC), sulfadiazine (BZ-SDZ), and amoxicillin (BZ-AMX). Results demonstrated that the BZ-SDZ consistently outperformed the others by mitigating the harmful effects of sulfadiazine, achieving > 99 % antibiotic removal, producing the highest spinach biomass (25.40 ± 3.68 g), promoting the greatest fish growth (24.11 ± 0.44 g) and minimizing nitrous oxide (N₂O) emissions. These benefits are attributed to ZVI-driven redox reactions degrading residual SDZ and biochar's adsorption capacity reducing antibiotic bioavailability to plants and microbes. In contrast, the BZ-OTC showed moderate improvements, while BZ-AMX exhibited the least efficacy. Overall, BC/ZVI media enhanced nutrient use efficiency, system stability, and microbial diversity under antibiotic stress, providing a reliable strategy for sustainable aquaponic production in contaminated environment.

The use of multiple pesticides in agriculture has caused mixed residues, complicating food safety testing. Surface-enhanced Raman scattering (SERS) offers high sensitivity and fingerprinting capabilities for pesticide detection; however,its application is limited by spot size, uneven sample distribution, spectral analysis challenges in mixed samples, and the lack of integrated automated systems for sample preparation, detection, and analysis. Hence, we developed a SERS microfluidic chip integrated with plasmonic microsphere lens arrays, which integrates optical field-modulated microspheres and plasmonic nanostructures to realise the transition of SERS detection from point-hotspots to uniform area-hotspots, achieving high-sensitivity, high-stability Raman detection under wide-field laser excitation. Moreover, a comprehensive a sample-to-answer total analysis system was established with this chip as the core, incorporating the micro-QuEChERS pretreatment module for efficient extraction of pesticides in complex matrices and the random forest-dual annealing spectral parsing algorithm for mixed spectral analysis. The results indicate that the limits of detection for 2,4-dichlorophenoxyacetic acid, acetamiprid, and thiabendazole were 1.15 nM, 0.63 nM, and 0.69 nM, respectively. The linear ranges were 10⁻⁴-10⁻⁹ M, with R² values of 0.9982, 0.9989, and 0.9996, respectively. Average recoveries ranged from 90.8 % -104.66 %, 89.1 %-107.89 %, and 89.73 %-108.4 %, respectively, with relative standard deviations below 8 %. The algorithm quantified mixed pesticides with mean absolute percentage errors of 4.96 %, 5.35 %, and 7.72 %, respectively. The system showed 3 s detection response and 15-minute analysis time. Thus, the method provides a rapid, on-site solution for detecting mixed pesticides in complex matrices by exceptional optical performance and automated processing functionality.