Chemical Inventory Research Articles

Exploitation of Catalytic Dyads by Short Peptide‐Based Nanotubes for Enantioselective Covalent Catalysis

AbstractExtant enzymes with precisely arranged multiple residues in their three‐dimensional binding pockets are capable of exhibiting remarkable stereoselectivity towards a racemic mixture of substrates. However, how early protein folds that possibly featured short peptide fragments facilitated enantioselective catalytic transformations important for the emergence of homochirality still remains an intriguing open question. Herein, enantioselective hydrolysis was shown by short peptide‐based nanotubes that could exploit multiple solvent‐exposed residues to create chiral binding grooves to covalently interact and subsequently hydrolyse one enantiomer preferentially from a racemic pool. Single or double‐site chiral mutations led to opposite but diminished and even complete loss of enantioselectivities, suggesting the critical roles of the binding enthalpies from the precise localization of the active site residues, despite the short sequence lengths. This work underpins the enantioselective catalytic prowess of short peptide‐based folds and argues their possible role in the emergence of homochiral chemical inventory.

Exploitation of Catalytic Dyads by Short Peptide-Based Nanotubes for Enantioselective Covalent Catalysis.

Extant enzymes with precisely arranged multiple residues in their three-dimensional binding pockets are capable of exhibiting remarkable stereoselectivity towards a racemic mixture of substrates. However, how early protein folds that possibly featured short peptide fragments facilitated enantioselective catalytic transformations important for the emergence of homochirality still remains an intriguing open question. Herein, enantioselective hydrolysis was shown by short peptide-based nanotubes that could exploit multiple solvent-exposed residues to create chiral binding grooves to covalently interact and subsequently hydrolyse one enantiomer preferentially from a racemic pool. Single or double-site chiral mutations led to opposite but diminished and even complete loss of enantioselectivities, suggesting the critical roles of the binding enthalpies from the precise localization of the active site residues, despite the short sequence lengths. This work underpins the enantioselective catalytic prowess of short peptide-based folds and argues their possible role in the emergence of homochiral chemical inventory.

Plastic protective nets: A significant but neglected “reservoir” for priority chemicals as revealed by composition analysis

As chemical-intensive products, plastics are potential sources of emerging contaminants and pose risks to the ecosystem. However, knowledge on the inventory and emissions of chemicals in plastics remains scarce, prohibiting the lifecycle assessment of their environmental exposure. Herein, full compositions of plastic protective nets (PPNs, one globally used plastics) were analyzed via nontarget screening with mass spectrometry, optical emission spectrometry, infrared spectroscopy and thermogravimetric analysis. Nontarget screening identified 861 non-polymeric organic chemicals, which were classified by network-like similarity analysis into 9 communities, dominated by phthalates (PAEs), aliphatic/oxalic esters and branched alkanes. Notably, around 80.8% (696) of the chemicals were first observed in plastics, suggesting aplenty plastic additives have previously been overlooked. Quantification results indicated PPNs contained higher levels of priority chemicals, including detrimental lead (1.17 × 104 ng/g), benzotriazoles ultraviolet stabilizers (6.66 × 103 ng/g) and PAEs (1.87 × 104 ng/g) than other plastics commonly reported. Emission projections revealed that dibutyl phthalate in PPNs had an annual release (1.83 × 103 kg) comparable to that from greenhouse films in China. These findings suggest PPNs are a significant but neglected “reservoir” for priority chemicals, which could inform future research on resolving plastic compositions, so as to promote sound chemical management.

Variable Salinity and Hydrogen Production in Europa's Ocean

AbstractEuropa's long‐term habitability depends on thermodynamics—modulated by tidal evolution—and geochemical pathways that define chemical and energy inventories for use by putative biology. Hydrogen produced from the reaction of water and rock during serpentinization is one potential source of metabolic energy. Here, we demonstrate how thermally modulated volumetric changes to Europa's ice shell, ocean, and fluid‐accessible rocky mantle influence oceanic salinity and serpentinization rates in Europa's interior. During periods of steady cooling, hydrogen flux into the ocean remains relatively constant because of the continuous propagation of thermal cracking into the rocky mantle regardless of ocean composition. However, during periods of fluctuating heat production driven by changes in orbital eccentricity, modulation of the ice shell volume, and consequently the salinity and water activity of the ocean, alters the serpentinization rate. In parallel, the extent of fracturing within the seafloor varies, changing the volume of reactable rock available. Our results show that the stability of serpentinization reactions on Europa over time highly depends on the thermal‐orbital evolution and oceanic salt content. The variability in the hydrogen production rate is significant across potential orbital histories, varying by up to 15 orders of magnitude for the lowest salinity and most kosmotropic ocean conditions, such as dilute MgSO4 compositions. We also show that this variability decreases with increasing ocean salinity and more chaotropic compositions, such as a concentrated NaCl ocean. These results suggest new ways that ocean composition and water activity are essential to stable habitable conditions in ocean worlds.

X-Rays Trace the Volatile Content of Interstellar Objects

The nondetection of a coma surrounding 1I/‘Oumuamua, the first discovered interstellar object (ISO), has prompted a variety of hypotheses to explain its nongravitational acceleration. Given that forthcoming surveys are poised to identify analogs of this enigmatic object, it is prudent to devise alternative approaches to characterization. In this study, we posit X-ray spectroscopy as a surprisingly effective probe of volatile ISO compositions. Heavily ionized metals in the solar wind interact with outgassed neutrals and emit high-energy photons in a process known as charge exchange, and charge-exchange-induced X-rays from comets and planetary bodies have been observed extensively in our solar system. We develop a model to predict the X-ray flux of an ISO based on its chemical inventory and ephemeris. We find that while standard cometary constituents, such as H2O, CO2, CO, and dust, are best probed via optical or infrared observations, we predict strong X-ray emission generated by charge exchange with extended comae of H2 and N2—species that lack strong infrared fluorescence transitions. We find that XMM-Newton would have been sensitive to charge exchange emission from 1I/‘Oumuamua during the object’s close approach to Earth, and that constraints on composition may have been feasible. We argue for follow-up X-ray observations of newly discovered ISOs with close-in perihelia. Compositional constraints on the general ISO population could reconcile the apparently self-conflicting nature of 1I/‘Oumuamua and provide insight into the earliest stages of planet formation in extrasolar systems.

Interstellar Carbonaceous Dust Erosion Induced by X-Ray Irradiation of Water Ice in Star-forming Regions

The chemical inventory of protoplanetary midplanes is the basis for forming planetesimals. Among them, solid-state reactions based on CO/CO2 toward molecular complexity on interstellar dust grains have been studied in theoretical and laboratory work. The physicochemical interactions between ice, constituted mainly of H2O, and dust surfaces are limited to a few experimental studies focusing on vacuum ultraviolet and cosmic-ray processing. In this work, the erosion of C dust grains induced by X-ray irradiation of H2O ice was systematically investigated for the first time. The work aims to provide a better understanding of the reaction mechanism using selectively isotope-labeled oxygen/carbon species in kinetic analysis. Ultrahigh vacuum experiments were performed to study the interstellar ice analog on submicron, thick C dust at ∼13 K. H2O or O2 ice was deposited on the presynthesized amorphous C dust and exposed to soft X-ray photons (250–1250 eV). Fourier-transform infrared spectroscopy was used to monitor in situ the newly formed species as a function of the incident photon fluence. Field emission scanning electron microscopy was used to monitor the morphological changes of (non-)eroded carbon samples. The X-ray processing of the ice/dust interface leads to the formation of CO2, which further dissociates and forms CO. Carbonyl groups are formed by oxygen addition to grain surfaces and are confirmed as intermediate species in the formation process. The yields of CO and CO2 were found to be dependent on the thickness of the carbon layer. The astronomical relevance of the experimental findings is discussed.

Parsec scales of carbon chain and complex organic molecules in AFGL 2591 and IRAS 20126

Context. There is a diverse chemical inventory in protostellar regions leading to the classification of extreme types of systems. Warm carbon chain chemistry sources, for one, are the warm and dense regions near a protostar containing unsaturated carbon chain molecules. Since the presentation of this definition in 2008, there is a growing field to detect and characterise these sources. The details are lesser known in relation to hot cores and in high-mass star-forming regions - regions of great importance in galactic evolution. Aims. To investigate the prevalence of carbon chain species and their environment in high-mass star-forming regions, we have conducted targeted spectral surveys of two sources in the direction of Cygnus X - AFGL 2591 and IRAS 20126+4104. Methods. We observed these sources in frequency ranges around 85, 96, and 290 GHz with the Green Bank Telescope and the IRAM 30m Telescope. We have constructed a local thermodynamic equilibrium (LTE) model using the observed molecular spectra to determine the physical environment in which these molecules originate. We map both the observed spatial distribution and the physical parameters found from the LTE model. We also determine the formation routes of these molecules in each source using the three-phase NAUTILUS chemical evolution code. Results. We detect several lines of propyne, CH3CCH, and cyclopropenylidene, c-C3H2 as tracers of carbon chain chemistry, as well as several lines of formaldehyde, H2CO, and methanol, CH3OH, as a precursor and a tracer of complex organic molecule chemistry, respectively. We find excitation temperatures of 20−30 K for the carbon chains and 8−85 K for the complex organics. The observed abundances, used as input for the chemical evolution code, are 10−9 to 10−10 for both CH3CCH and CH3OH. The CH3CCH abundances are reproduced by a warm-up model, consistent with warm carbon chain chemistry, while the observed CH3OH abundances require a shock mechanism sputtering the molecules into the gas phase. Conclusions. Single-dish observations are useful for studying the envelope-scale chemistry of star-forming regions, including mechanisms such as warm carbon chain chemistry. As well, LTE models lend well to the wide-band maps obtained from these telescopes. The physical and chemical environment determined for complex hydrocarbons and complex organics lends understanding to high-mass star formation.

Volatile organic compounds emitted by conventional and “green” cleaning products in the U.S. market

Exposure to cleaning products has been associated with harm to the respiratory system, neurotoxicity, harm to the reproductive system, and elevated risk of cancer, with greatest adverse impacts for workers exposed in an occupational setting. Social and consumer interest in cleaning products that are safer for health created a market category of “green” products defined here as products advertised as healthier, non-toxic, or free from harmful chemicals as well as products with a third-party certification for safety or environmental features. In the present study we examined the air quality impacts of cleaning products and air fresheners, measuring the number, concentrations, and emission factors of volatile organic compounds (VOCs) in an air chamber following product application. Across seven common product categories, 30 products were tested overall including 14 conventional, 9 identified as “green” with fragrance, and 7 identified as “green” and fragrance-free. A total of 530 unique VOCs were quantified with 205 additional VOCs detected below the limits of quantification. Of the quantifiable VOCs, 193 were considered hazardous according to either the California's Department of Toxic Substances Control Candidate Chemicals List or the European Chemical Agency's Classification and Labeling Inventory. The total concentration of VOCs and total emission factors across all products with detections ranged from below limits of detection to 18,708 μg/m3, 38,035 μg/g product and 3803 μg/application. Greater total concentration, total emission factors, and numbers of VOCs were generally observed in conventional cleaning products compared to products identified as “green”, particularly compared to fragrance-free products. A hazard index approach was utilized to assess relative risk from measured VOC emissions. The five products with the highest hazard indices were conventional products with emissions of 2-butoxyethanol, isopropanol, toluene and chloroform. Overall, this analysis suggests that the use of “green” cleaning products, especially fragrance-free products, may reduce exposure to VOC emissions.

Requirements for inventory models of radioactive waste

Abstract. The aim of the final disposal of radioactive waste is to ensure the best possible safety for the long-term protection (i.e. 1 million years) of humans and the environment from ionizing radiation and other harmful effects of this waste. In Germany, the Site Selection Act (StandAG) regulates the procedure for determining the site with the best possible safety for a repository with high-level radioactive waste. One of the mandatory aspects of the StandAG is to perform various preliminary safety assessments in order to assess the expected extent of the safe confinement of the radioactive waste. For this purpose, all information (in particular on the quantity, type, composition and activity) of the waste (i.e. the inventory) is required to conduct the respective safety assessment. On behalf of the Federal Office for the Safety of Nuclear Waste Management (BASE) and within the framework of the research project “Significance of the radioactive waste inventory in the site selection for a repository (InvEnd)”, Brenk Systemplanung GmbH identified the characteristics of the inventory required for the preliminary safety assessments. To determine these inventory characteristics, two main data sources were analysed, namely the generic but host-rock-specific concepts for a German high-level radioactive waste repository and the inventory data and approaches of other countries with technologically developed repository programmes. The identified characteristics can be divided into different groups (e.g. geometric, chemical, radiological and physical) and categories such as primary inventory data that are essential for carrying out the preliminary safety assessments or secondary inventory data which validate the primary inventory data. The evaluation of the impact of the identified characteristics shows that especially data on component-specific chemical composition and component-specific radionuclide inventory have a high impact on the results of safety assessments. These characteristics are, in turn, dependent on other characteristics, such as the irradiation history and the original chemical composition of the fuel in addition to the structural parts of the fuel assemblies. Furthermore, the study assesses uncertainties of the inventory characteristics, such as data uncertainty and conceptual uncertainty. The extent of data uncertainty depends on the inventory characteristic. However, in most cases, only qualitative assessments are possible. Conceptual uncertainties depend on the degree of simplification used to define reference wastes but cannot be quantified yet, as no reference wastes have been defined. The results of this study enable authorities and waste management organizations to identify the key data of high-level radioactive waste inventories that are essential for conducting safety assessments of repositories, even during early stages of site selection and planning.

Simulating Properties of Canadian Research Reactor Fuels Important to Disposal

Canada has operated 17 research reactors at 11 different locations. The spent fuel from these research reactors differs significantly from CANDU fuel, which makes up the vast majority of spent fuel in Canada, and will eventually require disposal. The focus of this paper is to identify properties specific to Canadian research reactor fuel designs that would impact their suitability for disposal. The radionuclide inventory, hazardous chemical inventory, decay heat, residual enrichment, radiation decay rates, and gas generation of several Canadian research reactor fuel designs were simulated using the SCALE 6.2.4 software suite. The National Research Universal U3Si/Al dispersion rod, the National Research Experimental uranium metal X-rod, the Royal Military College UO2 SLOWPOKE-2 core, and the Whiteshell Reactor 1 uranium carbide bundle were investigated. Fuel burnup is the primary driver for the concentration of most radionuclides, hazardous chemicals, decay heat, and radiation decay rates. Carbon-14, chlorine-36, and mercury are driven by initial impurities in the fuel, which vary by fuel design. Low burnup, enriched fuels constitute a reasonable bounding case for the evaluation of criticality safety and proliferation risks. Canadian research reactor fuels are unlikely to present a greater risk of over pressurization from helium generation than CANDU fuel. Overall, the small volume of Canadian research reactor fuels requiring disposal is an important factor in the evaluation of disposal requirements.

Descriptors for binding energies at clusters: The case of nanosilicates as models of interstellar dust grains.

Binding energies of radicals and molecules at dust grain surfaces are important parameters for understanding and modeling the chemical inventory of interstellar gas clouds. While first-principles methods can reliably be used to compute such binding energies, the complex structure and varying sizes and stoichiometries of realistic dust grains make a complete characterization of all adsorption sites exposed by their surfaces challenging. Here, we focus on nanoclusters composed of Mg-rich silicates as models of interstellar dust grains and two adsorbates of particular astrochemical relevance; H and CO. We employ a compressed sensing method to identify descriptors for the binding energies, which are expressed as analytical functions of intrinsic properties of the clusters, obtainable through a single first-principles calculation of the cluster. The descriptors are identified based on a diverse training dataset of binding energies at low-energy structures of nanosilicate clusters, where the latter structures were obtained using a first-principles-based global optimization method. The composition of the descriptors reveals how electronic, electrostatic, and geometric properties of the nanosilicates control the binding energies and demonstrates distinct physical origins of the bond formation for H and CO. The predictive performance of the descriptors is found to be limited by cluster reconstruction, e.g., breaking of internal metal-oxygen bonds, upon the adsorption event, and strategies to account for this phenomenon are discussed. The identified descriptors and the computed datasets of stable nanosilicate clusters along with their binding energies are expected to find use in astrochemical models of reaction networks occurring at silicate grain surfaces.

Rapid planning and analysis of high-throughput experiment arrays for reaction discovery

High-throughput experimentation (HTE) is an increasingly important tool in reaction discovery. While the hardware for running HTE in the chemical laboratory has evolved significantly in recent years, there remains a need for software solutions to navigate data-rich experiments. Here we have developed phactor™, a software that facilitates the performance and analysis of HTE in a chemical laboratory. phactor™ allows experimentalists to rapidly design arrays of chemical reactions or direct-to-biology experiments in 24, 96, 384, or 1,536 wellplates. Users can access online reagent data, such as a chemical inventory, to virtually populate wells with experiments and produce instructions to perform the reaction array manually, or with the assistance of a liquid handling robot. After completion of the reaction array, analytical results can be uploaded for facile evaluation, and to guide the next series of experiments. All chemical data, metadata, and results are stored in machine-readable formats that are readily translatable to various software. We also demonstrate the use of phactor™ in the discovery of several chemistries, including the identification of a low micromolar inhibitor of the SARS-CoV-2 main protease. Furthermore, phactor™ has been made available for free academic use in 24- and 96-well formats via an online interface.

HD 222925: A New Opportunity to Explore the Astrophysical and Nuclear Conditions of r-process Sites

With the most trans-iron elements detected of any star outside the solar system, HD 222925 represents the most complete chemical inventory among metal-poor stars enhanced with elements made by the rapid neutron capture (“r”) process. As such, HD 222925 may be a new “template” for the observational r-process, where before the (much higher-metallicity) solar r-process residuals were used. In this work, we test under which conditions a single site accounts for the entire elemental r-process abundance pattern of HD 222925. We found that several of our tests—with the single exception of the black hole–neutron star merger case—challenge the single-site assumption by producing an ejecta distribution that is highly constrained, in disagreement with simulation predictions. However, we found that ejecta distributions that are more in line with simulations can be obtained under the condition that the nuclear data near the second r-process peak are changed. Therefore, for HD 222925 to be a canonical r-process template likely as a product of a single astrophysical source, the nuclear data need to be reevaluated. The new elemental abundance pattern of HD 222925—including the abundances obtained from space-based, ultraviolet (UV) data—call for a deeper understanding of both astrophysical r-process sites and nuclear data. Similar UV observations of additional r-process–enhanced stars will be required to determine whether the elemental abundance pattern of HD 222925 is indeed a canonical template (or an outlier) for the r-process at low metallicity.

A Comprehensive Exploration of Chemical Inventory: Multifaceted Challenges and Profound Insights

This paper provides a comprehensive exploration of the multifaceted challenges and profound insights associated with chemical inventory. It highlights the critical findings and contributions in the areas of safety, efficiency, and compliance within chemical inventory facilities. By emphasizing the importance of robust risk assessments, implementation of safety measures, adherence to regulatory frameworks, and development of comprehensive emergency response plans, this paper aims to foster safer, more efficient, and compliant chemical inventory environments. Drawing attention to the tragic Beirut port explosion in 2020, this paper underscores the urgent need to address the challenges inherent in chemical inventory and presents valuable insights to mitigate potential hazards.

How Many Chemicals in Commerce Have Been Analyzed in Environmental Media? A 50 Year Bibliometric Analysis.

Over the past 50 years, there has been a tremendous expansion in the measurement of chemical contaminants in environmental media. But how many chemicals have actually been determined, and do they represent a significant fraction of substances in commerce or of chemicals of concern? To address these questions, we conducted a bibliometric survey to identify what individual chemicals have been determined in environmental media and their trends over the past 50 years. The CAplus database of CAS, a Division of the American Chemical Society, was searched for indexing roles "analytical study" and "pollutant" yielding a final list of 19,776 CAS Registry Numbers (CASRNs). That list was then used to link the CASRNs to biological studies, yielding a data set of 9.251 × 106 total counts of the CASRNs over a 55 year period. About 14,150 CASRNs were substances on various priority lists or their close analogs and transformation products. The top 100 most reported CASRNs accounted for 34% of the data set, confirming previous studies showing a significant bias toward repeated measurements of the same substances due to regulatory needs and the challenges of determining new, previously unmeasured, compounds. Substances listed in the industrial chemical inventories of Europe, China, and the United States accounted for only about 5% of measured substances. However, pharmaceuticals and current use pesticides were widely measured accounting for 50-60% of total CASRN counts for the period 2000-2015.

Dynamically coupled kinetic chemistry in brown dwarf atmospheres – I. Performing global scale kinetic modelling

ABSTRACT The atmospheres of brown dwarfs have been long observed to exhibit a multitude of non-equilibrium chemical signatures and spectral variability across the L, T, and Y spectral types. We aim to investigate the link between the large-scale 3D atmospheric dynamics and time-dependent chemistry in the brown dwarf regime, and to assess its impact on spectral variability. We couple the miniature kinetic chemistry module ‘mini-chem’ to the Exo-FMS general circulation model (GCM). We then perform a series of idealized brown dwarf regime atmospheric models to investigate the dynamical 3D chemical structures produced by our simulations. The GCM output is post-processed using a 3D radiative transfer model to investigate hemisphere-dependent spectral signatures and rotational variability. Our results show the expected strong non-equilibrium chemical behaviour brought on by vertical mixing and global spatial variations due to zonal flows. Chemical species are generally globally homogenized, showing variations of ±10 per cent or less, dependent on pressure level, and follow the dynamical structures present in the atmosphere. However, we find localized storm regions and eddies can show higher contrasts, up to ±100 per cent, in mixing ratio compared to the background global mean. This initial study represents another step in understanding the connection between 3D atmospheric flows in brown dwarfs and their rich chemical inventories.

Lessons Learned: Benzene Distillation Vapor Explosion and Fire

We present here a narrative of an incident that occurred in a chemistry laboratory while purifying benzene using a distillation apparatus. The incident resulted in an injury to a graduate student and a fire that caused approximately $3.5 million in damage including repair/refurbishment costs. Unfortunately, due to the extent of the fire, a direct cause of the incident could not be determined. The lessons learned from this incident that could have potentially prevented the incident altogether, or at least reduced damage, include performing a risk assessment of both the experiment and the situation at the time, maintaining proper housekeeping of the lab, maintaining an updated and accurate chemical inventory, checking in on long duration experiments, always calling for back-up, ensuring the lab and buildings are up to code, wearing proper personal protective equipment, and always calling 911 in an emergency.

A mini-chemical scheme with net reactions for 3D general circulation models

Context. The chemical inventory of hot Jupiter (HJ) exoplanet atmospheres continues to be observed by various ground- and space-based instruments in increasing detail and precision. It is expected for some HJs to exhibit strong non-equilibrium chemistry characteristics in their atmospheres, which might be inferred from spectral observations. Aims. We aim to model the 3D thermochemical non-equilibrium chemistry in the atmospheres of the HJs WASP-39b and HD 189733b. Methods. We coupled a lightweight, reduced chemical network ‘mini-chem’ that utilises net reaction rate tables to the Exo-FMS general circulation model (GCM). We performed GCM models of the exoplanets WASP-39b and HD 189733b as case studies of the coupled mini-chem scheme. The GCM results were then post-processed using the 3D radiative-transfer model gCMCRT to produce transmission and emission spectra to assess the impact of non-equilibrium chemistry on their observable properties. Results. Both simulations show significant departures from chemical equilibrium (CE) due to the dynamical motions of the atmosphere. The spacial distribution of species generally closely follows the dynamical features of the atmosphere rather than the temperature field. Each molecular species exhibits a different quench level in the simulations, which is also dependent on the latitude of the planet. Major differences are seen in the transmission and emission spectral features between the CE and kinetic models. Conclusions. Our simulations indicate that considering the 3D kinetic chemical structures of HJ atmospheres has an important impact on the physical interpretation of observational data. Drawing bulk atmospheric parameters from fitting feature strengths may lead to an inaccurate interpretation of chemical conditions in the atmosphere of HJs. Our open source mini-chem module is simple to couple with contemporary HJ GCM models without substantially increasing required computational resources.

Occurrence, fate and ecological risks of 90 typical emerging contaminants in full-scale textile wastewater treatment plants from a large industrial park in Guangxi, Southwest China

Recent industrial relocation in China causes lots of environment concerns including risks of emerging contaminants (ECs). Herein, the occurrence, fate, removal and ecological risks of 34 per- and polyfluoroalkyl substances (PFAS), 17 endocrine disrupting chemicals (EDCs), 16 phthalate esters (PAEs), and 23 polycyclic aromatic hydrocarbons (PAHs) were investigated in two textile WWTPs (conventional and Fenton-modified) from a large textile industrial park in Southwest China. Totally 50 ECs were identified and the levels followed the order of PAEs > EDCs > PFAS ≈ PAHs. The EDCs predominated in textile washing and rinsing wastewater whereas the PAEs did in desizing wastewater. Biphasic correlations of log Kd and log P, molecular weight, and numbers of rings (r2 = 0.63–0.66, p < 0.01) were observed for PAHs, suggesting that hydrophobicity might not facilitate adsorption of super-hydrophobic PAHs onto activated sludge. 63–69% of detected ECs were effectively removed by two textile WWTPs with removal efficiencies ≥ 80%, which were much higher than previous reports. Fenton processing enhanced the removal efficiencies for long-chain PFAS rather than short-chain PFAS. The PAEs and EDCs posed a medium-to-high risk to aquatic organisms and were screened as the priority ECs. To date, such a comprehensive investigation for ECs has not been previously conducted in textile WWTPs and this study provides basic information about regional chemical emission inventory of ECs.

Early Release Science of the exoplanet WASP-39b with JWST NIRSpec G395H

Measuring the abundances of carbon and oxygen in exoplanet atmospheres is considered a crucial avenue for unlocking the formation and evolution of exoplanetary systems1,2. Access to the chemical inventory of an exoplanet requires high-precision observations, often inferred from individual molecular detections with low-resolution space-based3–5 and high-resolution ground-based6–8 facilities. Here we report the medium-resolution (R ≈ 600) transmission spectrum of an exoplanet atmosphere between 3 and 5 μm covering several absorption features for the Saturn-mass exoplanet WASP-39b (ref. 9), obtained with the Near Infrared Spectrograph (NIRSpec) G395H grating of JWST. Our observations achieve 1.46 times photon precision, providing an average transit depth uncertainty of 221 ppm per spectroscopic bin, and present minimal impacts from systematic effects. We detect significant absorption from CO2 (28.5σ) and H2O (21.5σ), and identify SO2 as the source of absorption at 4.1 μm (4.8σ). Best-fit atmospheric models range between 3 and 10 times solar metallicity, with sub-solar to solar C/O ratios. These results, including the detection of SO2, underscore the importance of characterizing the chemistry in exoplanet atmospheres and showcase NIRSpec G395H as an excellent mode for time-series observations over this critical wavelength range10.