Journal of hazardous materials最新文献

As the two important ambient air pollutants, particulate matter (PM_2.5) and ozone (O₃) can both originate from gas nitrogen oxides. In this study, applied by theoretical analysis and machine learning method, we examined the effects of atmospheric reactive nitrogen on PM_2.5-O₃ pollution, in which nitric oxide (NO), nitrogen dioxide (NO₂), gaseous nitric acid (HNO₃) and particle nitrate (pNO₃^-) conversion process has the co-directional and contra-directional effects on PM_2.5-O₃ pollution. Of which, HNO₃ and SO₂ are the co-directional driving factors resulting in PM_2.5 and O₃ growing or decreasing simultaneously; while NO, NO₂, and temperature represent the contra-directional factors, which can promote the growth of one pollutant and reduce another one. Our findings suggest that designing the suitable co-controlling strategies for PM_2.5-O₃ sustainable reduction should target at driving factors by considering the contra-directional and co-directional effects under suitable sensitivity regions. For co-directional driving factors, the design of suitable mitigation strategies will jointly achieve effective reduction in PM_2.5 and O₃; while for contra-directional driving factors, it should be more patient, otherwise, it is possible to reduce one item but increase another one at the same time.

Developing high-temperature-resistant adsorbents with superior porous properties is crucial for safely disposing of heavy metal-containing solid waste via pyrolysis. We synthesized aluminosilicates hydrothermally and observed that acidic conditions, especially HCl (pH=2.6), favored sponge-like mineral (NC2.6) formation with a specific surface area of 500.31 m²/g and pore volume of 0.986 cm³ /g, while alkaline conditions (pH=12.0) promoted spherical particle growth. NC2.6 exhibited higher adsorption capacity compared to kaolinite and halloysite in the PbCl₂ vapor adsorption, reaching a maximum of 137.68 mg/g at 700 ℃ (75.91 % stable). We examined the effect of CO₂ and H₂O on adsorption efficiency and explored the mechanisms using DFT and GCMC simulations. From GCMC results, CO₂ negatively impacted PbCl₂ adsorption due to competitive adsorption, while H₂O increased adsorption content (144.24 mg/g at 700 ℃) by converting PbCl₂ into oxides. DFT revealed the presence of CO₂ enhanced the adsorption stability of PbCl₂ via the formation of covalent bonds between O in CO₂ and Pb, and active O on the aluminosilicate surface. H₂O increased PbCl₂ adsorption energy, as O in H₂O occupied an active Al that originally formed a covalent bond with Cl, while the H formed a weak hydrogen bond with this Cl.

This study developed an ultrasound synergistic subcritical hydrothermal treatment method (U-SHT) to address the challenges posed by the high oil and water content, complex composition, and hazardous nature of oily sludge (OS) generated during the pretreatment of coal chemical wastewater. The study investigated the efficiency of this method for the harmless disposal and resource recovery of OS, and the migration-transformation mechanism of hazardous organic pollutants in OS. The findings revealed that U-SHT achieved a removal efficiency of chemical oxygen demand in OS of 91.16 %, an oil resource recovery efficiency of 96.60 %, and a residual oil rate of 0.28 %, meeting API emission standards. Further research indicated that the solubilizing effect of the surfactant on the oil enhanced the demulsifying effect of ultrasonic cavitation on the emulsified structure of OS, enabling ultrasound to efficiently release and disperse pollutants within OS. This promoted the decomposition and transformation of pollutants under subcritical hydrothermal conditions, with synergistic removal efficiencies for typical pollutants such as long-chain alkanes, polycyclic aromatic hydrocarbons, and phenols reaching 96.61 %, 97.63 %, and 97.76 %, respectively. Economic evaluation indicated that the cost of OS treatment was $29.66/m³, significantly lower than existing methods, demonstrating promising practical application prospects.

Air pollution exposure has been linked with coagulation function. However, evidence is limited for the relationships between air pollution, coagulation function and metabolomics in humans. We recruited a panel of 130 rural elderly from the Chayashan township in China, all of whom were free of pre-existing cardiovascular diseases and had provided residential address information. We conducted clinical examinations and collected blood samples from these rural elderly for the detection of coagulation biomarkers (e.g, activated partial thromboplastin time, fibrinogen, thrombin time, and prothrombin time) and untargeted metabolites in both December 2021 and August 2022. We used mini ambient air quality monitor to measure the mean levels of five air pollutants (e.g., PM_2.5, SO₂, NO₂, CO and O₃) during 1 to 2 weeks before blood sample collection. The Mummichog pathway analysis was used to identified potential metabolic features and pathways. In this study, we identified 5 pathways associated with both air pollution and coagulation function, and further pinpointed eight metabolic features within these pathways. The majority of these features were lipids, including arachidonic acid and linoleic acid. Overall, the findings of this study offer insights into potential mechanisms, particularly lipid metabolism, that may underlie the association between air pollution and coagulation function.

Due to adverse effects of viral outbreaks on human health, accurate detection of airborne pathogens is essential. Among many methods available for bioaerosol sampling, electrostatic precipitation (ESP) has been used to directly collect bioaerosols as hydrosols. The performance of an ESP sampler depends on its design, operational and environmental parameters such as air relative humidity (RH), air temperature, sampling liquid type and liquid temperature. Thus, it is essential to identify and maintain optimal conditions throughout sampling process to operate the sampler at its highest capacity. This study provides crucial insights into parameters that affect the collection efficiency of the aerosol-to-hydrosol ESP sampler and its virus recovery. The results indicate that air temperature does not affect collection efficiency, meanwhile, air RH, sampling liquid temperature, and salt concentration are the main parameters that significantly affect collection efficiency. Likewise, when deionized water is used as sampling liquid, hydrogen peroxide concentration increases proportionally with increasing air RH, resulting in significant decrease of virus viability. Consequently, for ESP samplers similar to our study, the following conditions are recommended: air RH of 55-65%, air and sampling liquid temperature of 37 °C, and a mixture of 10-20 mM ascorbic acid in PBS as sampling liquid.

The efficient removal of fine particles from coal-fired flue gas poses challenges for conventional electrostatic precipitators and bag filters. Recently, a novel approach incorporating deep cooling of the flue gas has been proposed to enhance the removal of gaseous pollutants and particles. However, the achievable efficiency and underlying mechanisms of particle capture within the gas cooling system remain poorly understood. This study aims to elucidate the effectiveness of gas cooling in enhancing the removal of particles through a laboratory-scale spray tower equipped with packing materials. The results demonstrate a significant increase in particle removal efficiency, from 63.4 % to over 98 %, as the temperature of the spray liquid decreases from 20℃ to -20℃. Notably, this enhancement is particularly pronounced for particles sized 0.1-1 µm, with efficiency rising from approximately 40 % to 95 %, effectively eliminating the penetration window. Moreover, we find that the spray flow rate positively influences particle removal capability, while the height of the packing section exhibits an optimal value. Beyond this optimal height, particle removal performance may decline due to an inadequate liquid-to-packing ratio. To provide insight into the capture process, we introduce a single-droplet model demonstrating that particle capture is primarily enhanced through the augmented thermophoretic force.

This study developed a continuous reactor system employing a hybrid hydrogel composite synthesized using a complex sludge microbiome and an adsorbent (HSA). This HSA-based system effectively eliminated the environmental risks associated with a mixture of the antibiotics ciprofloxacin and sulfamethoxazole, which exhibited higher toxicity in combination than individually at environmentally relevant levels. Analytical chemistry experiments revealed the in-situ generation of various byproducts (BPs) within the bioreactor system, with two of these BPs recording toxicity levels that surpassed those of their parent compound. The HSA approach successfully prevented the functional microbiome from being washed out of the reactor, while HSA efficiently removed antibiotic residues in their original and BP forms through synergistic adsorptive and biotransformation mechanisms, ultimately reducing the overall ecotoxicity. The use of HSA thus demonstrates promise not only as a mean to reduce the threat posed by toxic antibiotic residues to aquatic ecosystems but also as a practical solution to operational challenges, such as biomass loss/washout, that are frequently encountered in various environmental bioprocesses.

A hydrophobic Cu₂O cathode (Cu_xO-L) was designed to solve the challenge of low oxidation ability in electro-Fenton (EF) for treating emerging pollutants. This fabrication process involved forming Cu(OH)₂ nanorods by oxidizing copper foam (Cu-F) with (NH₄)₂S₂O₈, followed by coating them with glucose via hydrothermal treatment. Finally, a self-assembled monolayer of 1-octadecanethiol was introduced to create a low-surface-energy, functionalized Cu_xO-L cathode. Results exhibited an approximately 7.9-fold increase in hydroxyl radical (·OH) generation compared to the initial Cu-F. This enhancement was attributed to two key factors: (Ⅰ) the superior O₂-capturing ability of Cu_xO-L cathode, which led to high H₂O₂ production due to a 2 nm thick hydrophobic gas layer facilitated O₂-capturing; (Ⅱ) a relative high concentration of Cu⁺ at the Cu_xO-L cathode promoted the activation of H₂O₂ into·OH. In addition, the performance of EF with the Cu_xO-L cathode using sulfathiazole (STZ) as a model pollutant was evaluated. This study offers valuable insights into the design of O₂-capturing cathodes in EF processes, particularly for treating emerging organic pollutants.

Per- and polyfluoroalkyl substances (PFAS) have been called "forever chemicals" due to their inherent chemical stability. Their potential toxic effects on aquatic animals and health risk assessments have not been fully elucidated. In this study, we investigated the toxic effects of PFASs at environmentally relevant concentrations (200 ng/L) on crucian carp (Carassius auratus). The results showed that PFAS reduced the comfort behaviour of crucian carp and was associated with reduced levels of acetylcholinesterase and dopamine in the brain. PFAS exposure also decreased the activities of total superoxide dismutase, catalase and glutathione peroxidase, while increasing the levels of malondialdehyde. PFAS caused over-expression of the pro-inflammatory cytokines TNF-α, IFN-γ and stress-related genes Caspase-3, HSP-70 in the fish brain. Pathological staining showed that PFAS caused multifocal demyelination and perineural vacuolization in brain, intestinal tissue also showed reduced villus length and focal damage. PFASs altered the composition of the gut microbiota of crucian carp, significantly increasing the abundance of potentially pathogenic bacteria and the potential pathogenicity of the microbiota. It is suggested that PFASs may cause varying degrees of tissue damage by destabilising the gut microbiota. These results provide insights for assessing the toxicity of PFAS contaminants at aquatic environmental concentrations.

Surfactant-enhanced aquifer remediation (SEAR) has effectively removed dense nonaqueous phase liquids (DNAPLs) from the contaminated aquifers. However, restricted by structural defects, typical monomeric surfactants undergo precipitation, high adsorption loss, and poor solubilization in aquifers, resulting in low remediation efficiency. In this study, a novel sugar-based anionic and non-ionic Gemini surfactant (SANG) was designed and synthesized for SEAR. Glucose was introduced into SANG as a non-ionic group to overcome the interference of low temperature and ions in groundwater. Sodium sulfonate was introduced as an anionic group to overcome aquifer adsorption loss. Two long-straight carbon chains were introduced as hydrophobic groups to provide high surface activity and solubilizing capacity. Even with low temperature or high salt content, its solution did not precipitate in aquifer conditions. The adsorption loss was as low as 0.54 and 0.90 mg/g in medium and fine sand, respectively. Compared with typical surfactants used for SEAR, SANG had the highest solubilization and desorption abilities for perchloroethylene (PCE) without emulsification, a crucial negative that Tween80 and other non-ionic surfactants exhibit. After flushing the contaminated aquifer using SANG, > 99 % of PCE was removed. Thus, with low potential environmental risk, SANG is effectively applicable in subsurface remediation, making it a better surfactant choice for SEAR.