环境科学与技术最新文献

Advanced oxidation processes (AOPs) based on peracetic acid (PAA) offer a promising strategy to address antibiotic wastewater pollution. In this study, Fe-doped graphitic carbon nitride (g-C₃N₄) nanomaterials were used to construct Fe-N_x sites, and the electronic structure was tuned by boron nitride quantum dots (BNQDs), thereby optimizing PAA activation for the degradation of antibiotics. The BNQDs-modified Fe-doped g-C₃N₄ catalyst (BNQDs-FCN) achieved an excellent reaction rate constant of 0.0843 min^-1, marking a 21.6-fold improvement over the carbon nitride (CN)-based PAA system. DFT calculations further corroborate the superior adsorption capacity of the Fe-N_x sites for PAA, facilitating its activation. Charge transfer mechanisms, with PAA serving as an electron acceptor, were identified as the source of high-valent iron-oxo species. Moreover, the BNQDs-FCN system preferentially targets oxygen-containing functional groups in antibiotic structures, elucidating the selective attack patterns of these highly electrophilic species. This research not only elucidates the pivotal role of high-valent iron-oxo species in pollutant degradation within the PAA-AOPs framework but also pioneers a wastewater treatment system characterized by excellent degradation efficiency coupled with low ecological risk, thereby laying the groundwork for applications in wastewater management and beyond.

Biomass burning organic aerosol (BBOA) is a major contributor to organic aerosol in the atmosphere. The impacts of BBOA on climate and health depend strongly upon their physicochemical properties, including viscosity and phase behavior (number and types of phases); these properties are not yet fully characterized. We collected BBOA field samples during the 2021 British Columbia wildfire season to constrain the viscosity and phase behavior at a range of relative humidities and compared them to previous studies on BBOA. Particles from all samples exhibited two-phased behavior with a polar hydrophilic phase and a nonpolar hydrophobic phase. We used the poke-flow viscosity technique to estimate the viscosity of the particles. Both phases of the BBOA had viscosities of >10⁸ Pa s at relative humidities up to 50%. Such high viscosities correspond to mixing times within 200 nm BBOA particles of >5 h. Two phases and high viscosity have implications for how BBOA should be treated in atmospheric models.

Disinfection byproducts (DBPs) in swimming pool water are a significant public health concern. The formation of aromatic halogenated DBPs in swimming pool water has not been clarified previously. In this study, the occurrence of aromatic halogenated DBPs in swimming pool water was examined, and it was found that halohydroxybenzoic acids (HBAs) and halobenzoquinones (HBQs) were the most dominant aromatic halogenated DBPs in swimming pool water that were continuously formed. Thus, the formation of HBAs and HBQs in swimming pool water from different organic precursors, including natural organic matter (NOM), pharmaceuticals and personal care products (PPCPs), during chlorination was examined. The results demonstrate that the formation of HBAs and HBQs from the PPCPs was relatively high compared with that from NOM, suggesting that the PPCPs from human inputs might be important organic precursors of aromatic halogenated DBPs in swimming pool water. The formation mechanisms of HBAs and HBQs from three typical PPCPs (benzophenone-3 (BP-3), methyl p-hydroxybenzoate (MeP) and carbamazepine) were further explored. The results show that the PPCPs containing phenolic groups with higher degradation rates (BP-3 and MeP) possessed higher formation of HBAs and HBQs. The three organic precursors underwent a series of substitution, hydrolysis, oxidation, rearrangement, and intramolecular cyclization reactions to form HBAs and HBQs, while the phenolic groups and ring structures may significantly affect the reactions. The chlorine dose, bromide/iodide concentration, and temperature significantly affected the formation of HBAs and HBQs from MeP during chlorination.

Upgrading the most difficult-to-recycle waste polyvinyl chloride remains a significant challenge due to the potential formation of highly toxic substances, such as polychlorinated biphenyls. Here, we introduce a paradigm shift with a mild photothermal dechlorination-carbonization process that converts waste polyvinyl chloride plastics into valuable carbon materials. Through detailed techno-economic assessment (TEA) process modeling, based on recycling 96,000 tons of plastics, we demonstrate that utilizing clean solar energy for photothermal conversion can save approximately 2.34 × 10¹² kJ electricity and reduce the carbon footprint by 261,912.2 tons compared to traditional thermal-driven methods, offering clear environmental benefits. Notably, this photothermal recycling method can process more than 10 types of postconsumer and mixed waste polyvinyl chloride plastics, yielding carbon materials that exhibit excellent performance as components in sodium-ion energy storage batteries. Photothermal catalytic recycling of plastics thus emerges as a green and sustainable technology with promising applications.

Previous research has widely overlooked the respiratory risks associated with cosmetic powder, a type of mixed particulate matter with intricate chemical compositions, especially in the context of wearing masks. This study investigated the inhalation risks posed by five face powders, focusing on both particulate matter (minerals and primary microplastics) and soluble components (preservatives and organic UV filters). Wearing masks significantly increased the inhalation risk of face powders, with exposure levels influenced by factors such as particle size, density, and composition. Additionally, different samples demonstrated irregular behavioral patterns when exposed to various human tissue environments. Soluble components analysis revealed that multiple additives dissolved in six body fluids, with a higher degree of release observed in the respiratory tract fluid compared to the digestive tract fluid. The alveoli may serve as a specific target for exposure to organic UV filters due to the solubilization effect of pulmonary surfactants. These findings revealed the importance of considering both particulate matter and soluble components when assessing respiratory and digestive exposure risks from cosmetic powders. Furthermore, understanding the interactions between cosmetic particles and body fluids, as well as potential synergistic toxic effects, is crucial for ensuring the safety of cosmetic products and safeguarding public health.

As graphene-based materials (GBMs) such as pristine graphene, graphene oxide, and reduced graphene oxide show great potential to be integrated in various applications, the need for environmental risk assessments grows, aiming to navigate the environmental fate and potential risk of the different forms of GBM. This study used dynamic probabilistic material flow analysis (DPMFA) to ascertain the prospective production volumes and distribution of GBMs within European freshwaters. The hazard assessment leveraged 113 data sets from peer-reviewed studies, addressing aquatic ecotoxicity across 26 species, by performing probabilistic species sensitivity distributions (SSD). Our findings reveal distinct environmental distribution patterns for GBM forms with predicted environmental concentrations in European freshwaters by 2030 of approximately 0.67 ng/L (SD = 0.24 ng/L) for pristine graphene and 0.33 ng/L (SD = 0.10 ng/L) for both graphene oxide and reduced graphene oxide, suggesting not only similar but notably minimal exposure levels. The risk characterization ratios (RCRs) for all forms of GBM were significantly below 1, indicating a negligible environmental risk within the scenarios assessed. Through detailed analysis considering the forms of the material, this research can inform regulatory decisions, support sustainable material design, and provide a solid foundation for a further investigation considering the environmental fate of GBM.

Organosulfur and organonitrogen compounds (OrgSs and OrgNs) notably influence haze formation, reflecting the intricacies of sulfur and nitrogen chemistry in the atmospheric process. Despite this, a comprehensive understanding of OrgSs and OrgNs remains elusive. Here, we conducted molecular analyses of OrgSs and OrgNs in PM_2.5 concurrently during three haze episodes in winter and summer from 2016 to 2019. OrgSs and OrgNs collectively constituted 68.8-73.8% of identified organics, with CHON (35.8%) being the most prevalent followed by CHONS (13.6%), CHN (11.5%), CHOS (5.6%), CHNS (3.2%), and CHS (0.9%). Nitrogen within CHX (CH + CHN + CHS + CHNS) compounds were predominantly present as nitriles or amines, while sulfur existed as alkaline thioethers (ESI+) or acidic mercaptans and thiophenols (ESI-). Oxygen-containing OrgSs and OrgNs exhibited greater structural complexity. Specifically, most CHON were associated with nitric esters and nitro-compounds (ESI-), or basic amino acids (ESI+). CHONS primarily comprised nitrogen heterocyclic substances containing oxygen and sulfur, with some potentially containing organic sulfates (OSs) and organic nitrates if O ≥ 4S + 3N. CHOS with (O-3S)/C ≥ 0 were identified as sulfonic acids or sulfate esters. This comprehensive spectrum of OrgSs and OrgNs enhances the understanding of the physicochemical properties of aerosols, providing insights for future laboratory and air quality model studies.