ACS Environmental Au最新文献

Photocatalysis has been extensively studied for its potential to harness abundant sunlight energy, yet exploration has been limited by the time and effort required for performance evaluation. To screen candidate materials, including the elements across the entire periodic table, throughput must be improved while minimizing labor. In this study, we introduce a simple, labor-saving, high-throughput assay for evaluating photocatalyst activity utilizing a 96-well microplate. The protocol provides a streamlined workflow that encompasses weighing, microplate preparation, light irradiation, spectroscopic measurement, and reaction rate analysis. Importantly, this protocol removes the bottleneck of separating photocatalyst powders from the dye solution throughout the cycles of light irradiation and spectral measurements, which significantly improves the throughput and saved labor. As a foundation for this method, we investigated the relationship between the coexistence of dye and powder against the resulting apparent absorbance and the temporal profile of absorbance during the photocatalytic reaction. From the result, we provide guidelines for determining versatile amounts of the photocatalyst and dye depending on the balance between measurement accuracy and throughput. As the method relies on the additivity of absorption and scattering within a defined optical density window, it is not restricted to a particular dye. This assay enables photocatalyst performance evaluation for ∼500/day, which holds promise for exploring the vast material space across the periodic table, significantly broadening the horizons for discovering novel photocatalysts.

Per- and polyfluoroalkyl substances (PFASs) are ubiquitous, persistent organic pollutants increasingly detected in food crops, yet their accumulation capacities and regulatory factors across various plant species remain poorly resolved. Here, we investigated the bioaccumulation patterns of PFAS in 20 vegetable species and their relations with root chemical traits in farmland irrigated with treated wastewater. Leafy vegetables (e.g., Lactuca sativa and Spinacia oleracea) accumulated substantially higher PFAS concentrations (mean: 9.24 ng/g) than the root vegetable Daucus carota, with the short-chain perfluorobutanoic acid (PFBA) identified as the dominant species for all vegetables. PFBA showed the strongest mobility and tended to accumulate in edible aerial tissues of leafy vegetables, whereas long-chain PFASs were largely retained in roots. Across vegetable species, root PFBA concentration increased with the proportion of alkyl carbon and decreased with the proportion of O-alkyl carbon in roots, whereas the long-chain perfluorononanoic acid concentration increased with dissolved organic carbon concentration in roots. PFAS exposure could be decreased by up to 90% by consuming low-concentration vegetable varieties instead of high-concentration ones. These findings highlight the critical role of plant traits and rhizosphere chemistry in governing PFAS uptake pathways and suggest that crop selection and rhizosphere management can inform risk mitigation.

Understanding stable isotopic fractionation of dissolved O₂ in aquatic environments is crucial to constrain and accurately model the processes responsible for biological O₂ consumption, which are closely linked to the overall health of an ecosystem. This study aimed to investigate whether O₂ consumption by microbial methane and ammonia oxidation may contribute to the observed discrepancy in O₂ isotopic fractionation (¹⁸ϵ) between heterotrophic O₂ respiration in laboratory incubations (-18 to -24 ‰) and in situ measurements of O₂ consumption in lakes and oceans (-10 to -18 ‰). To estimate the in vivo ¹⁸ϵ values of soluble methane monooxygenase (sMMO), particulate methane monooxygenase (pMMO), and ammonia monooxygenase (AMO), which are the first enzymes required for the oxidation of methane and ammonia, experiments were performed with three methanotrophic bacteria and one comammox (complete-ammonia-oxidizing) bacterium. The resulting ¹⁸ϵ values for pMMO and AMO ranged from -18 ± 12 to -24 ± 5 ‰, not significantly different from ¹⁸ϵ values typical for heterotrophic respiration. The ¹⁸ϵ value determined for sMMO (-22 ± 2 ‰) was in the same range, yet more negative than the previously reported ¹⁸ϵ value for the isolated enzyme. Our results provide insights into the potential reaction mechanisms of pMMO and AMO and indicate that O₂ consumption by sMMO, pMMO, or AMO cannot explain the observed discrepancy between in situ and laboratory ¹⁸ϵ values for "community" O₂ consumption in aquatic environments. Instead, the apparent difference may be attributed to aspects involving substrate diffusion limitation.

Incorporating biotransformation capabilities into in vitro assays represents one of the most critical challenges in toxicology, facilitating the transition from in vivo models to integrated in vitro strategies. Although emerging technologies show promise, their current limitations in scalability hinder their high-throughput applications. In the short to mid term, externally added biotransformation systems ("BTS": S9 and microsomal liver fractions) used together with in vitro assays offer viable alternatives. However, despite over 50 years of use, BTS are marred by reproducibility issues, raising concerns about their reliability and raising the question: Are BTS inherently unreliable, or has their reputation been flawed by methodological oversights? This review critically evaluates BTS' methodological rigor, applying a deep statistical analysis of the scientific literature. We employed Boolean operator searches across scientific literature repositories to curate a database on BTS research in conjunction with relevant in vitro assays, focusing on endocrine disruption, mutagenicity, and genotoxicity end points. Through systematic searches, screening, and eligibility criteria, we identified 229 bibliographic records. Data parametrization and extraction were conducted across 24 domains of BTS relevance and reliability. Methodological reporting rigor was assessed via scoring (reported vs nonreported data items) and revealed a lack of reproducible standards. Numerical measures associated with principal BTS reaction components were subjected to meta-regression analyses. Within the aggregated data set, no statistically significant correlations were found for BTS and related cofactor concentration-response relationships or time-related elements. Finally, descriptive statistics, multiple correspondence analysis, and Apriori algorithm-based relational networks identified qualitative patterns of methodological reporting robustness and deficiencies. In conclusion, these results emphasize shortcomings across the scientific literature in complying with appropriate methodological reporting. We offer evidence-based recommendations, in the form of a conceptual regulatory guidance framework, to enhance research practices, quality, and reproducibility of BTS applications, designed to strengthen the robustness of BTS research and its integration into regulatory-relevant hazard and risk assessment of chemicals.

Rare earth elements (REEs) are critical to modern technologies and national security, playing essential roles in electronics, electric vehicles, and defense systems. Although they are not truly rare, their widespread but low-concentration presence in the Earth's crust, combined with their chemical similarity, makes conventional mining both technically difficult and environmentally taxing. As a result, recycling REEs from electronic waste (e-waste), a practice often referred to as urban mining, has emerged as a promising alternative. However, current recycling methods face major challenges, including high energy demands, extensive use of harsh chemicals, generation of large volumes of solvent waste, and poor selectivity for REEs. These limitations significantly hinder the sustainability and scalability of REE recovery from e-waste, underscoring the urgent need for innovative, environmentally friendly strategies to extract and recover REEs. Recently, microorganism-based bioleaching and biosorption techniques have emerged as promising green alternatives to reduce the environmental burden caused by conventional recycling methods and further enhance the recovery efficiency and specificity of REEs from e-waste. Bioderived substances emerged as sustainable alternatives to upgrade the efficiency and specificity of REE exploitation and recovery from various resources. This review highlights three key areas essential for advancing REE biorecovery technologies, particularly in the context of urban biomining: (i) the use of bacteria-derived organic compounds as leaching agents for REE bioleaching from e-waste; (ii) the application of recombinant biomolecules, such as proteins, peptides, nucleic acids, and other engineered compounds, for selective biosorption and bioprecipitation of REEs; and (iii) the development and utilization of advanced microbial chassis and alternative nonchassis systems to enhance biorecovery efficiency. Key insights and future perspectives are provided to guide future design and advancement of integrated bioleaching-bioseparation systems for efficient and robust REE recovery from e-waste.

Cosmetic spray products, widely used for personal care, are popular due to their ease of application and rapid, uniform coverage. However, the particulate matter (PM) that they emit can be inhaled and deposited in the respiratory tract, potentially posing respiratory health risks. Existing studies have seldom addressed emissions from cosmetic spray products applied directly to the human body, especially the face and neck, and few have proposed practical methods to reduce exposure. This study systematically evaluates the particle size distribution and number- and mass-based concentrations of 12 products under a laboratory setting that simulated real-use conditions. It is found that PM emissions from some spray products could be significant and strongly influenced by nozzle design and product chemical composition. The maximum PM₁₀ number concentration reached 1.03 × 10⁶ #/cm³, while the maximum PM₁₀ mass concentration was 36.17 mg/m³. Using the Multiple-Path Particle Dosimetry model, we quantified the deposition doses across different respiratory regions (head, tracheobronchial, and pulmonary). To reduce exposure risks, a new development of actuator structures on a spray bottle was proposed and tested by incorporating external tubing and modifying mechanical breakup designs, without impairing the delivery efficiency of the product. Among these, tapered tubing was most effective, reducing total number- and mass-based deposition doses of submicron particles by 88.6% and 65.7%, respectively. The study highlighted significant differences in exposure risk among product types and proposed cost-effective, highly compatible engineering controls through nozzle modification, offering practical strategies for minimizing inhalation exposure from cosmetic spray products.

This research evaluates membrane distillation (MD) to treat problematic hypersaline per- and polyfluoroalkyl substances (PFAS)-laden waste streams. Results are shown for four commercially available membranes (unlaminated polytetrafluoroethylene (PTFE), polypropylene laminated PTFE, polyether ether ketone (PEEK), and polyvinylidene difluoride (PVDF)) that were tested with a model short-chain PFAS compound, perfluoropentanoic acid (PFPeA) at a concentration of 10 mg/L in the presence and absence of ion-exchange resin spent brine (10% NaCl). For each test, a new membrane with an area of 140 cm² was used, with a constant permeate temperature of 20 °C (cold) and varying feed temperatures of 50 °C, 60 °C, or 70 °C (hot). The unlaminated PTFE membrane demonstrated the best performance in treating the PFPeA-contaminated brine. The water flux through the unlaminated PTFE membrane was 50% higher than the flux through the PEEK membrane and 25% higher than that through the PVDF and laminated PTFE membranes. The laminated and unlaminated PTFE membranes achieved the highest rejection of NaCl and PFPeA (>99.7%) compared to 95 and 97% obtained by the PEEK and the PVDF membranes, respectively. During the 48-h extended experiments, the laminated PTFE membrane exhibited greater stability and mechanical strength than the other membranes, while the PEEK and PVDF membranes proved fragile. The laminated PTFE membrane was then selected for a 300-h experiment with ethanol cleaning cycles to test long-term durability. PFPeA caused reversible fouling in all tested membranes and reduced the membrane's hydrophobicity; however, ethanol cleaning was effective in removing PFPeA, indicating that with further optimization, membrane distillation may be useful for concentrating PFAS for ultimate destruction or disposal.

The paper presents the results of the synthesis and study of iron oxide-based sorbents (Fe _x O _y -NPs) obtained from iron removal station sludge by exothermic combustion in solution using glycine, urea, citric acid, and urotropine as reducing agents. X-ray phase analysis revealed that the phase composition depends on the nature of the reducing agent and temperature: at 300-500 °C, the magnetite content reached 97-99% for citric acid and urea, whereas when using glycine, the Fe₃O₄ fraction did not exceed 30%. The point of zero charge values shifted to the alkaline region with increasing synthesis temperature, reaching 8.8 at 700 °C. The specific surface area for methylene blue was up to 186 m²/g, but the calculated values exceeded the BET data by 3.5-4 times due to multilayer sorption on the functionalized surface, which is consistent with the FTIR spectra. The oil sorption capacity (OSC) of the synthesized sorbents reached 6.1 g/g (glycine, 500 °C), which is comparable to or exceeds the indicators of a number of natural and commercial sorbents. After five sorption-regeneration cycles at 800 °C, the OSC decreased by only 15.7%, confirming the stability of the material. The constructed polynomial and machine learning models (CatBoost, XGBoost) provided high accuracy of OSC prediction (R ² = 1.0), which demonstrates the promise of machine learning for optimizing synthesis conditions.

Graphene oxide (GO) coatings can improve the stable operation of membrane distillation (MD) membranes in the presence of organic contaminants by enabling the transport of water vapor through narrow interlayer spacings. However, GO's intrinsic hydrophilicity requires complex, multistep functionalization to achieve antiwetting properties, posing scale-up challenges. Here, we demonstrate a scalable fabrication of omniphobic polymer-graphene oxide (OGO) coatings on commercial PVDF membranes via sequential slot-die coating of GO followed by dip-coating in a perfluoropolyether (PFPE) solution. A highly volatile solvent and self-limited deposition enables conformal PFPE formation (∼hundreds of nanometers thick) onto GO, suppressing wetting while maintaining vapor-selective pathways with minimal transport resistance. In direct contact MD, OGO membranes achieved >99.7% NaCl rejection and >15 LMH water flux during long-term operation, even with low-surface-tension feeds containing surfactants. This GO-PFPE coating method avoids elaborate GO modification and is readily scalable, providing a generalizable strategy for antiwetting, antifouling surfaces in water remediation.

Dimethyl sulfide (CH₃SCH₃), methanethiol (CH₃SH), and dimethyl disulfide (CH₃SSCH₃) are the most predominant marine organic sulfur compounds that drive cloud formation by acting as a critical precursor of cloud condensation nuclei. However, discrepancies of natural aerosol radiative effects and climatic impacts between climate model simulations and satellite observations highlight an incomplete understanding of organic sulfur oxidation pathways. Here, we demonstrate a previously unrecognized rapid oxidation mechanism at the air-water interface of microdroplets, where volatile sulfides convert to particle precursors within milliseconds. Combining DFT calculation, QM/MM simulation, and sequential oxidation of possible intermediates, we proposed a new pathway of atmospheric particle precursor formation at the air-water interface of microdroplets, which is different from the traditional gas-phase oxidation pathway, offering a mechanistic solution to re-evaluate the model simulation gaps in natural aerosol radiative effects and climatic impacts.