Journal of hazardous materials最新文献

The joint groundwater pollution prevention and control (GPPC) strategy has been extensively implemented to address the coastal region groundwater pollution challenges in China. However, regional groundwater pollution control and treatment efficiency cannot achieve the expected results due to the lack of regional priority control orders and accurate restoration levels. Thus, this study developed a new region demarcation framework method for delineating GPPC zones, in tandem with a comprehensive pollution index method, the DRASTIC model, source apportionment. To validate the new methodological framework, a case study of groundwater pollution in Qinhuangdao, the western of Bohai Bay, China, was implemented to calculate pollution prevention and control zoning. In total, 340 groundwater samples from shallow aquifers with 9 target pollutants (NO₃^-, NO₂^-, NH₄⁺, As, Cd, Cr, Cu, Pb, and Ni) were selected as the dataset for GPPC regionalization. The results showed that GPPC zoning further clarified the direction of groundwater pollution protection and management in Qinhuangdao. Compared to the traditional method, the new GPPC zoning better reflects groundwater mobility characteristics and pollution transport and enrichment patterns in terms of groundwater functional integrity and delineation. This new regional demarcation framework method contributes to providing support for the fine division of groundwater pollution zoning and precise pollution control for groundwater resource management in China.

Urban regions are suggested to be the main source of microplastic pollution in rivers. Thus, we investigated the spatiotemporal distribution of microplastics in the surface water of the Lanzhou section of the Yellow River in a semiarid region and the contributions of typical sources. The average concentration of microplastics in the surface water of the river was 0.98 particles (p) L^-1. The daily quantity flux and mass flux were 3.63 × 10⁹ p d^-1 and 95.38 kg d^-1, respectively. Most of the microplastics in the river were fibers and fragments, composed of polyethylene terephthalate, polyamide, polypropylene and polyethylene. A large quantity and mass of microplastics were found in the high-flow period of the river. The hotspots of microplastic pollution were residential and tourist reaches. The spatial distribution of microplastics was influenced by anthropogenic factors. However, the main factor influencing the temporal distribution of microplastics was precipitation seasonality. Most of the microplastics in the surface water originated from drainage ditches. The direct contribution of microplastics from atmospheric deposition was also considerable. Our results suggest that the contribution of microplastics from atmospheric deposition to urban rivers is worthy of attention.

Polyferric sulfate (PFS) coagulation has proven to be effective in addressing antimony (Sb) water pollution accidents; however, the impact of waterside plant decomposition on its effectiveness has not been adequately elucidated. This study investigated the effects of Alternanthera philoxeroides (AP) and Digitaria sanguinalis (DS) decomposition on Sb cycling after PFS treatment. Without plant decomposition, the Fe(OH)₃ hydrolysate-associated Sb remained stable, and the sediment continued to exhibit Sb sink properties. Plant residue decomposition facilitated sedimentary Sb release, and DS decomposition had a greater impact than AP decomposition. The strong decomposition phases triggered abiotic/biotic reduction processes, leading to Fe(OH)₃ dissolution and subsequent Sb(V) release. Concurrently, sulfate reduction and dissolved organic matter (DOM) release regulated Sb mobility. In addition, Sb(V) reduction occurred, and Sb(III) was elevated in the overlying water. The Sb(III) levels gradually decreased during the later aerobic stages, however, did not completely disappear within a short timeframe. Furthermore, the role of the sediment as an Sb sink was significantly hindered, maintaining relatively high levels of dissolved Sb. Sedimentary Sb speciation analysis revealed that plant decomposition induced a shift in Fe-oxyhydroxide-bound Sb to more bioavailable and stable fractions. Our results indicate that plant residue decomposition easily deteriorates PFS efficiency and increases the risk of secondary Sb pollution in water-sediment systems.

Both sulfur (S) supply and legume-rhizobium symbiosis can significantly contribute to enhancing the efficiency of phytoremediation of heavy metals (HMs). However, the regulatory mechanism determining the performance of legumes at lead (Pb) exposure have not been elucidated. Here, we cultivated black locust (Robinia pseudoacacia L.), a leguminous woody pioneer species at three S supply levels (i.e., deficient, moderate, and high S) with rhizobia inoculation and investigated the interaction of these treatments upon Pb exposure. Our results revealed that the root system of Robinia has a strong Pb accumulation and anti-oxidative capacity that protect the leaves from Pb toxicity. Compared with moderate S supply, high S supply significantly increased Pb accumulation in roots by promoting the synthesis of reduced S compounds (i.e., thiols, phytochelatin), and also strengthened the antioxidant system in leaves. Weakened defense at deficient S supply was indicated by enhanced oxidative damage. Rhizobia inoculation alleviated the oxidative damage of its Robinia host by immobilizing Pb to reduce its absorption by root cells. Together with enhanced Pb chelation in leaves, these mechanisms strengthen Pb detoxification in the Robinia-rhizobia symbiosis. Our results indicate that appropriate S supply can improve the defense of legume-rhizobia symbiosis against HM toxicity.

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.

Arsenic is recognized as a hazardous environmental toxicant strongly associated with neurological damage, but the mechanism is ambiguous. Neuronal cell death is one of the mechanisms of arsenic-induced neurological injury. Ferroptosis is involved in the pathophysiological process of many neurological diseases, however, the role and regulatory mechanism of ferroptosis in nerve injury under arsenic exposure remains uncovered. Our findings confirmed the role of ferroptosis in arsenic-induced learning and memory disorder and revealed miR-21 played a regulatory role in neuronal ferroptosis. Further study discovered that miR-21 regulated neuronal ferroptosis by targeting at FTH1, a finding which has not been documented before. We also found an extra increase of ferroptosis in neuronal cells conditionally cultured by medium collected from arsenic-exposed microglial cells when compared with neuronal cells directly exposed to the same dose of arsenic. Moreover, microglia-derived exosomes removal or miR-21 knockdown in microglia inhibited neuronal ferroptosis, suggesting the role of intercellular communication in the promotion of neuronal ferroptosis. In summary, our findings highlighted the regulatory role of miR-21 in ferroptosis and the contribution of microglia-derived miR-21 in exosomes to arsenic-induced neuronal ferroptosis.

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.