Journal of hazardous materials最新文献

Algal blooms have become a widespread concern for drinking water production, threatening ecosystems and human health. Photocatalysis, a promising advanced oxidation process (AOP) technology for wastewater treatment, is considered a potential measure for in situ remediation of algal blooms. However, conventional photocatalysts often suffer from limited visible-light response and rapid recombination of photogenerated electron-hole pairs. In this study, we prepared a Z-scheme AgBr/NH₂-MIL-125(Ti) composite with excellent visible light absorption performance using co-precipitation to efficiently inactivate Microcystis aeruginosa. The degradation efficiency of AgBr/NH₂-MIL-125(Ti) for chlorophyll a was 98.7 % after 180 min of visible light irradiation, significantly surpassing the degradation rate efficiency of AgBr and NH₂-MIL-125(Ti) by factors of 3.20 and 36.75, respectively. Moreover, the removal rate was maintained at 91.1 % even after five times of repeated use. The experimental results indicated that superoxide radicals (•O₂^-) were the dominant reactive oxygen species involved. The photocatalytic reaction altered the morphology and surface charge of algal cells, inhibited their metabolism, and disrupted their photosynthetic and antioxidant systems. In conclusion, this study presents a promising material for the application of photocatalytic technology in algal bloom remediation.

Producing a high-performance sludge biochar through a feasible method is a great challenge and is crucial for practicability. Herein, we reported a highly porous sludge biochar synthesized from agrochemical-pharmaceutical and municipal sludge blends through a novel pyrolysis-acid treatment-post pyrolysis method. The optimized biochar named ASMS91 obtained interconnected pores with a total pore volume of 0.894 cm³/g and a surface area of 691.4 m²/g through extended acid wash and subsequent post-pyrolysis, which is superior to non-activated sludge biochar. ASMS91 removed 45.3 % of wastewater COD (156 mg/L) in 24 h, which was rapid and higher performance than commercial activated carbon (1000 iodine number). This outstanding performance is due to its high adsorption ability of long-chain aliphatic compounds (e.g., 2,4-Di-tert-butylphenol, neophytadiene and eicosane) into mesopores, which accounts for 71.8 % of pore filling. ASMS91 was highly recyclable, and adsorption was reduced by only 5.3 % after the 4th cycle. It also outperformed other sludge biochar in literature in removing perfluorooctanoic acid (PFOA), 6:2 fluorotelomer sulfonate (6:2 FTS), sulfamethoxazole, methylene blue, and methylene orange. Finally, the feasibility of our proposed method was validated by a brief techno-economic analysis. This feasible approach may support future research regarding sludge valorization and low-cost chemical wastewater treatment.

Context: Chlordecone (CLD) is a carcinogenic organochlorine pesticide. CLD was shown to disturb the activity of cardiac Na⁺-K⁺-ATPase and Ca²⁺-Mg²⁺-ATPase. Conditions affecting these transmembrane pumps are often associated with cardiac arrhythmias (CA). However, little is known about the role of CLD on atrial fibrillation (AF) incidence, the most common type of CA.

Hypotheses: 1) Daily ingestion of CLD induces arrhythmogenic cardiac remodeling. 2) A phase of CLD withdrawal can reduce CLD-induced AF susceptibility.

Methods: Adult male Wistar rats (250 g-275 g) ingested daily-doses of CLD (0 μg/L, 0.1 μg/L, or 1 μg/L) diluted in their quotidian water for 4 weeks. From day (D)29 to D56, all rats received CLD-free water. Vulnerability to AF and cardiac function were evaluated at D28 and D56 by electrophysiological study, echocardiography, and optical-mapping. Levels of genes and proteins related to inflammation, fibrosis, and senescence were quantified by qPCR and immunoassays.

Results: Twenty-eight days of CLD exposure were associated with significantly increased AF vulnerability compared to CLD-free rats. Contamination with 1 μg/L CLD significantly reduced atrial conduction velocity (ERP, APD). CLD-weaning normalized food consumption and weight intake. However, after the CLD-withdrawal period of 28 days, AF inducibility, atrial inflammation (IL6, IL1β), and atrial fibrosis (Masson's trichrome staining) remained significantly higher in rats exposed to 1 μg/L CLD compared to 0 μg/L.

Conclusions: Prolonged CLD ingestion provokes atrial conduction slowing and increased risk of AF. Although CLD-weaning, some persistent damages occurred in the atrium like atrial fibrosis and atrial senescence signals, which are accompanied by atrial inflammation and arrhythmogenicity.

Hydrogel materials with hydrophilic cross-linked network exhibit remarkable super-wettability, enabling their widespread application in oily wastewater treatment. However, the single and loose structure lacks sufficient strength and porosity to resist long-term degradation. Herein, a structural synergistic molecular strategy was reported to introduce reinforcing phase structures and interfacial active sites into the polymer networks for long-term oil-water emulsion separation. The carbon skeleton was uniformly interspersed through the strongly hydrogen-bonded polymer chains via covalent bonds, resulting in a hydrogel network with high mechanical strength and exceptional flow conductivity, which maintained a separation flux of 1233 L m^-2 h^-1 after 20 separation cycles under gravitational force. Dense negative charges on the surface disrupted the internal charge stability of the oil-water emulsion, leading to remarkable demulsification with a separation efficiency exceeding 99 %. Simultaneously, the strong redox reaction of the photoheterojunction effectively removed organic dyes under visible light, enhancing the overall antifouling performance. This study provided a feasible strategy at the molecular level for optimizing the suitability of hydrogels for oil-water emulsion separation.

The behavior and fate of PFOS (perfluorooctanesulfonate) in the aquatic environment have received great attention due to its high toxicity and persistence. The nanoscale supramolecular mechanisms of interaction between PFOS and ubiquitous EPS (exopolymers) remain unclear though EPS have been widely-known to influence the bioavailability of PFOS. Typically, the exposure patterns of PFOS in aquatic animals changed with the EPS-PFOS interaction are not fully understood. This study hypothesized that PFOS exposure and accumulation pathways depended on the PFOS-EPS interactive assembly behavior and animal species. Two model animals, zebrafish and chironomid larvae, with different feeding habitats were chosen for the exposure and accumulation tests at the environmental concentrations of PFOS in the absence and presence of EPS. It was found that PFOS triggered the self-assembly of EPS to form large aggregates which significantly trapped PFOS. PFOS accumulation was significantly promoted in zebrafish but drastically reduced in chironomid larvae because of the nanoscale interactive assembly between EPS and PFOS. The decreased dermal uptake but increased oral uptake of PFOS by zebrafish with large mouthpart size could be ascribed to the increased ingestion of PFOS-enriched EPS aggregates as food. For the chironomid larvae with small mouthpart size, the PFOS-EPS assemblies reduced the dermal, oral and intestinal uptake of PFOS. The nano-visualization evidences confirmed that the PFOS-enriched EPS-PFOS assemblies blocked PFOS penetration through skin of both animals. These findings provide novel knowledge about the ecological risk of PFOS in aquatic environments.

A key challenge in oxidative potential (OP) assays is to accurately assess the cumulative impact of redox-active aerosol species rather than only their individual effects. This study investigates the OP of single and combined mixtures of 1,2-naphthoquinone (1,2-NQ), 1,4-naphthoquinone (1,4-NQ), 9,10-phenanthrenequinone (9,10-PQ), 1,4-benzoquinone (1,4-BQ), Cu, Fe, Mn, and Zn in standard ascorbic acid (OP^AA) and the synthetic respiratory tract lining fluid (OP^RTLF) assays. In both OP^AA and OP^RTLF, binary mixtures showed additive and synergistic effects in the presence of 1,2-NQ. The mixture of Cu and Zn showed substantial synergisms in both assays, while the mixtures in the absence of 1,2-NQ primarily induced antagonistic effects. For the first time, we propose linear equations to improve the prediction of OP values by considering the impacts of synergistic and antagonistic effects. Under this approach, we observed that the potential effects caused by binary mixtures in ambient particulate matter (PM) samples could account for up to 68 % of the PM-OP values in Fez, Morocco (OP_m^AA: 0.34 nmol min^-1 µg^-1 and OP_m^RTLF: 0.18 nmol min^-1 µg^-1). The present study improves the understanding of effects of chemical interaction of potentially toxic substances that are important in the understanding of PM-induced oxidative stress in the human body.

Humic substance (HS)-ferric iron (Fe(III)) coprecipitates are widespread organo-mineral associations in soils and aquifers and have the capacity to immobilize and detoxify Cr(VI). These coprecipitates undergo transformation owing to their thermodynamic instability; however, the effects of this transformation on their environmental behaviors remain unclear, particularly in aerobic environments. In this study, the aerobic transformation of humic acid (HA)-Fe(III) coprecipitates, a representative of HS-Fe(III) coprecipitates, was simulated. The environmental effect was then evaluated after conducting an adsorption-reduction batch experiment toward Cr(VI). The aerobic transformation characteristics, as well as the adsorption/reduction capacity of HA-Fe(III) coprecipitates, were found to depend strongly on their structures. In ferrihydrite (Fh)-like coprecipitates, amorphous Fh is readily transformed into crystalline hematite and goethite at aerobic environments, leading to a much lower specific surface area and adsorption capacity. However, this increasing degree of crystallization enhanced the inductive reduction ability towards Cr(VI) owing to the more significant shift of electron pairs in the FeOC bond toward the HA direction. In HS-like coprecipitates, Fe(III) always serves as a cation bridge connecting HA molecules, but can be reduced to Fe(II) by the associated HA after aerobic transformation. The produced Fe(II), therefore, drove the reduction of the adsorbed Cr(VI). These findings emphasize the pivotal role of aerobic transformation in enhancing the reduction capacity for Cr(VI), which opens a new avenue for the development of in-situ remediation agents for Cr(VI)-contaminated sites.

Micro/nano-plastics (MNPs) are emerging non-point source pollutants that have garnered increasing attention owing to their threat to ecosystems. Studies on the effects of MNPs on horticultural crops are scarce. Specifically, whether MNPs can be absorbed and transported by grapevines have not been reported. To fill this gap, we added polystyrene nanoplastics (PS-NPs, 100 nm) to a hydroponic environment and observed their distribution in grape seedlings of Thompson Seedless (TS, Vitis vinifera L.). After 15 d of exposure, plastic nanospheres were detected on the cell walls of the roots, stems, and leaves using confocal microscopy and scanning electron microscopy. This indicated that PS-NPs can also be absorbed by the root system through the epidermis-cortex interface in grapevines and transported upward along the xylem conduit. Furthermore, we analyzed the molecular response mechanisms of TS grapes to the PS-NPs. Through the measurement of relevant indicators and combined omics analysis, we found that plant hormone signal transduction, flavonoid and flavonol biosynthesis, phenylpropanoid biosynthesis, and MAPK signaling pathway biosynthesis played crucial roles in its response to PS-NPs. The results not only revealed the potential risk of MNPs being absorbed by grapevines and eventually entering the food chain but also provided valuable scientific evidence and data for the assessment of plant health and ecological risk.

Cortisone can enter aquatic ecosystems and pose a risk to organisms therein. However, few studies have explored the effects of cortisone on the gut microbiota of aquatic organisms. Here, we exposed zebrafish (Danio rerio) to cortisone at environmentally relevant concentrations (5.0, 50.0, or 500.0 ng L^-1) for 60 days to explore its toxicological effects and their association with gut microbiota changes. The terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick-end labeling assay revealed that exposure to 50 ng L^-1 cortisone significantly increased the intestinal cell apoptosis rate, 8-hydroxydeoxyguanosine contents, and caspase-3 and caspase-8 activities. Moreover, the transcriptome analysis results demonstrated a notable downregulation in the expression of most differentially expressed genes associated with apoptosis pathways, as well as changes in DNA replication, oxidative stress, and drug metabolism pathways; these results indicated the occurrence of cortisone-induced stress response in zebrafish. Molecular docking analysis revealed that cortisone can bind to caspase-3 through hydrogen bonds and hydrophobic interactions but that no such interactions occur between cortisone and caspase-8. Thus, cortisone may induce oxidative DNA damage and apoptosis by activating caspase-3. Finally, the 16S rRNA sequencing results demonstrated that cortisone significantly affected microbial community structures and functions in the intestinal ecosystem. These changes may indicate gut microbiota response to cortisone-induced intestinal damage and inflammation. In conclusion, the current results clarify the mechanisms underlying intestinal response to cortisone exposure and provide a basis for evaluating the health risks of cortisone in animals.

Under China's strict industrial control measures, the reduction of secondary pollutants (O₃ and secondary organic aerosols [SOA]) and precursors (volatile organic compounds [VOCs] and NOx) caused by industrial processes has encountered bottlenecks. In this study, the net O₃ formation rate (Net [O₃]) in summer and the self-reaction rate between peroxy radicals (Self-Rnxs) in winter are used to characterize the formation potentials of O₃ and SOA, respectively. Assuming that the precursor reduction ratio based on emission inventories is approximately equal to that based on observed concentrations, this study combines emission inventory and observation-based model (OBM) methods to indicate the potential source of secondary pollutants reduction. The findings show that strict control measures implemented by local governments, particularly those targeting industrial processes and fossil fuel combustion, are effective in reducing VOCs and NOx emissions during summer, and the two sources result in 3.8 % and 5.3 % decrease in the Net (O₃), respectively. Similarly, control measures focusing on industrial processes help to significantly reduce VOCs emissions during winter, resulting in an 8.0 % decrease in Self-Rnxs. However, current measures for industrial processes are stringent and have little potential for further reduction. Therefore, additional sources with higher reduction potentials beyond industrial processes should be subject to stringent controls in industrial cities. Given the limited emission reduction potential associated with industrial processes, this study provides perspectives for sustained reduction of secondary pollutants in industrial cities.