Journal of hazardous materials最新文献

Enterococci are common indicators of fecal contamination and are used to assess the quality of fresh and marine water, sand, soil, and sediment. However, samples collected from these environments contain various cells and other factors that can interfere with the assays used to detect enterococci. We developed a novel assay for the sensitive and specific detection of enterococci that is resistant to interference from other cells and environmental factors. Our interference-resistant assay used 30-nm gold nanoparticles (AuNPs), streptavidin, and a biotinylated Enterococcus antibody. Enterococci inhibited the interaction between streptavidin and biotin and led to the disaggregation of AuNPs. The absence of enterococci led to the aggregation of AuNPs, and this difference was easily detected by spectrophotometry. This interference-resistant AuNP assay was able to detect whole cells of Enterococcus in the range of 10 to 10⁷ CFU/mL within 3 h, had high specificity for enterococci, and was unaffected by the presence of other intestinal bacteria, such as Escherichia coli. Our examination of fresh and marine water samples demonstrated no interference from other cells or environmental factors. The interference-resistant AuNP assay described here has the potential to be used as a rapid, simple, and effective method for monitoring enterococci in diverse environmental samples.

Direct ingestion of micro/nanoplastics (MNPs) results in significant accumulation in gastrointestinal (GI) tract of fish. The breathing process of fish makes MNPs easily retained in their gills. However, the uptake of MNPs in other fish organs remains largely unknown, let alone their kinetic processes. Herein, microplastics (MPs) and nanoplastics (NPs) in vivo imaging and precise quantification in various tissues (GI tract, gill, liver, brain, eye, and skin) of seawater (SW)- and freshwater (FW)- acclimated medaka Oryzias melastigma were achieved at an environmentally relevant concentration. Subsequently, the distribution kinetics of MNPs was investigated over a 96-h uptake and 48-h depuration period. MNPs were quickly and mostly captured in GI tract and gill of O. melastigma, and then transferred to liver and brain likely via blood circulation. Such transport was more efficient for NPs as compared to MPs, as evidenced by the consistently higher bioconcentration factors in both SW and FW conditions. The detection of MNPs in eye and skin of O. melastigma was more of an adsorption process, although the specific mechanisms of adsorption and absorption process can hardly be clearly differentiated. This study presented distribution kinetics of MNPs in O. melastigma and highlighted their possible transportation among tissues.

The intensive use of various antibiotics for clinical and agricultural purposes has resulted in their widespread use in wastewater treatment plants. However, little research has been conducted on the effects of antibiotics on nitrite accumulation, antibiotic degradation pathways, or the microbial community structure in nitrification systems. In this study, a laboratory-scale sequencing batch reactor was used to treat wastewater containing cefalexin (CFX) at different doses (5, 10, 15, and 20 mg/L). The results showed that the nitrification performance was gradually inhibited with increasing CFX concentration. Ammonia-oxidizing bacteria (AOB) are more tolerant to CFX than nitrite-oxidizing bacteria (NOB). Under 15 mg/L of CFX, NOB were completely suppressed, whereas AOB were partially inhibited, as evidenced by an ammonium removal efficiency of 60 % and a 90 % of nitrite accumulation ratio. The partial nitritation was achieved. CFX can be degraded into 2-hydroxy-3phenylpyrazine and cyclohexane through bacterial co-metabolism, and CFX degradation gradually diminishes with decreasing nitrification performance. The abundance of Nitrospira gradually decreased with increasing CFX concentration. Ferruginibacter, Hydrogenophaga, Thauera, and Pseudoxanthomonas were detected at relative abundances of 13.2 %, 0.4 %, 0.9 %, and 1.3 %, respectively, indicating their potential roles in antibiotic degradation. These findings provide insight into the interactions between antibiotics and microbial communities, which are beneficial for a better understanding of antibiotic degradation in nitrification systems.

Evidence on the link of long-term exposure to ozone (O₃) with childhood asthma, rhinitis, conjunctivitis and eczema is inconclusive. We did a population-based cross-sectional survey, including 177,888 children from 173 primary and middle schools in 14 Chinese cities. A satellite-based spatiotemporal model was employed to assess four-year average O₃ exposure at both residential and school locations. Information on asthma, allergic rhinitis, eczema and conjunctivitis was collected by a standard questionnaire developed by the American Thoracic Society. We used generalized non-linear and linear mixed models to test the associations. We observed linear exposure-response associations between O₃ and all outcomes. The odds ratios of doctor-diagnosed asthma, rhinitis, eczema, and conjunctivitis associated with per interquartile increment in home-school O₃ concentration were 1.31 (95 % confidence interval [CI]: 1.28, 1.34), 1.25 (95 %CI: 1.23, 1.28), 1.19 (95 %CI: 1.16, 1.21), and 1.28 (95 %CI: 1.21, 1.34), respectively. Similar associations were observed for asthma-related outcomes including current asthma, wheeze, current wheeze, persistent phlegm, and persistent cough. Moreover, stronger associations were observed among children who were aged > 12 years, physically inactive, and exposed to higher temperature. In conclusion, long-term O₃ exposure was associated with higher risks of asthma, allergic rhinitis, conjunctivitis and eczema in children.

This investigation explored the potential of utilizing alkali-treated corn cob (CC) as a solid carbon source to improve NO_X and SO₂ removal from flue gas. Leaching experiments unveiled a hierarchy of chemical oxygen demand release capacity: 0.03 mol/L alkali-treated CC > 0.02 mol/L > 0.01 mol/L > 0.005 mol/L > control. In NO_X and SO₂ removal experiments, as the inlet NO_X concentration rose from 300 to 1000 mg/m³, the average NO_X removal efficiency increased from 58.56 % to 80.00 %. Conversely, SO₂ removal efficiency decreased from 99.96 % to 91.05 %, but swiftly rebounded to 98.56 % by day 18. The accumulation of N intermediates (NH₄⁺, NO₃^-, NO₂^-) increased with escalating inlet NO_X concentration, while the accumulation of S intermediates (SO₄^2-, SO₃^2-, S⁰) varied based on shifts in the population of functional bacteria. The elevation in inlet NO_X concentration stimulated the growth of denitrifying bacteria, enhancing NO_X removal efficiency. Concurrently, the population of nitrate-reducing sulfur-oxidizing bacteria and sulfate-reducing bacteria expanded, aiding in the accumulation of S⁰ and the removal of SO₂. The comparison experiments on carbon sources confirmed the comparable NO_X and SO₂ removal efficiencies of alkali-treated CC and glucose, yet underscored differences in intermediates accumulation due to distinct genus structures.

Perfluorooctanoate (PFOA) and perfluorooctane sulfonate (PFOS), two prominent per- and polyfluoroalkyl substances (PFASs), are potentially harmful to many human organs. However, there only exist limited methods to mitigate their health hazards. The aim of this study is to combine a bioinformatics analysis with in vitro experiments to discover small molecules that can alleviate liver damage caused by PFOA/PFOS. We identified 192 and 82 key genes related to hepatocytes exposed to PFOA and PFOS, respectively. The functional enrichment analysis of key genes suggested cellular senescence may be important in PFOA/PFOS-induced hepatotoxicity. The in vitro models revealed that PFOA/PFOS led to hepatocyte senescence by increasing the activity of SA-β-gal, inducing mitochondrial dysfunction, impacting cell cycle arrest, and elevating the expressions of p21, p53, IL-1β, and SASP-related cytokines. The drug-target gene set enrichment analysis method was employed to compare the transcriptome data from the Gene Expression Omnibus database (GEO), Comparative Toxicogenomics Database (CTD), and the high-throughput experiment- and reference-guided database (HERB), and 21 traditional Chinese medicines (TCMs) were identified that may alleviate PFOA/PFOS-induced liver aging. The experimental results of co-exposure to PFOA/PFOS and TCMs showed that sanguinarine has particular promise in alleviating cellular senescence caused by PFOA/PFOS. Further investigations revealed that the mTOR-p53 signaling pathway was involved in PFOA/PFOS-mediated hepatic senescence and can be blocked using sanguinarine.

The misuse of chloramphenicol (CAP) has jeopardized environmental safety. It is critical to create an effective and sensitive CAP detection technique. In this paper, a composite of chitosan (CS)-derived carbon material modified hollow spherical hydroxylated poly(3,4-propylenedioxythiophene) (PProDOT-2CH₂OH) was designed, which innovatively used o-phenylenediamine and p-aminobenzoic acid as bi-functional monomers to prepare molecular imprinting polymer (MIP) sensors for highly sensitive analysis and determination of CAP. It was found that the hollow spherical structure of PProDOT-2CH₂OH significantly enhanced the rapid electron migration. When combined with the CS-derived carbon material, which has multi-functional sites, it improved the electrical activity and stability of the sensor. It also provided more active centers for the MIP layer to specifically recognize CAP. Therefore, this MIP sensor had a wide linear response (0.0001 ∼ 125 μM), a low limit of detection (LOD, 6.6 pM), excellent selectivity and stability. In addition, studies showed that the sensor has potential practical value. ENVIRONMENTAL IMPLICATION: Chloramphenicol (CAP) is one of the most widely used antibiotics with the highest dosage due to its low price and broad-spectrum antimicrobial properties. Due to its incomplete metabolism in living organisms and its difficulty in degrading in the environment, contamination caused by it can pose a threat to public health. In this study, a novel molecularly imprinted sensor (MIP/PC2C1/GCE) was designed to provide a new idea for rapid and precise removal of CAP by adsorption. The detection of CAP in pharmaceutical, water quality, and food fields was realized.

As a commonly used food additive, excessive nitrite intake seriously affects people's health in daily life. As the stomach is the main organ involved in nitrite intake, achieving fast and in situ detection of nitrite in the stomach is of great significance for avoiding the hazards caused by nitrite. However, owing to the poor stability or low sensitivity of existing fluorescent probes under acidic conditions, their application for nitrite detection within the stomach remains challenging. To solve this problem, we developed novel probes specifically designed to maintain stability and demonstrate high sensitivity to nitrite under acidic conditions. Utilizing the optimized probe (DHUROS-11), nitrite levels in environmental and real samples were successfully quantified. Notably, tracing of nitrite within the stomach of mice in real time was realized by using DHUROS-11 as the probe.

The presence of polyethylene terephthalate (PET) microplastics (MPs) in waters has posed considerable threats to the environment and humans. In this work, a heterogeneous electro-Fenton-activated persulfate oxidation system with the FeS₂-modified carbon felt as the cathode (abbreviated as EF-SR) was proposed for the efficient degradation of PET MPs. The results showed that i) the EF-SR system removed 91.3 ± 0.9 % of 100 mg/L PET after 12 h at the expense of trace loss (< 0.07 %) of [Fe] and that ii) dissolved organics and nanoplastics were first formed and accumulated and then quickly consumed in the EF-SR system. In addition to the destruction of the surface morphology, considerable changes in the surface structure of PET were noted after EF-SR treatment. On top of the emergence of the O-H bond, the ratio of C-O/C=O to C-C increased from 0.25 to 0.35, proving the rupture of the backbone of PET and the formation of oxygen-containing groups on the PET surface. With the verified involvement and contributions of SO₄^•- and ^•OH^, three possible paths were proposed to describe the degradation of PET towards complete mineralization through chain cleavage and oxidation in the EF-SR system.