Environmental science. Advances最新文献

Due to limited primary resources and to fulfil the demand for renewable energy in the automobile industry, defence applications, and other high-tech applications, recycling rare earth elements (REEs) and other critical elements from their secondary resources is imperative. Rigorous research and development for viable extraction and separation of REEs and other critical elements has resulted from this need. Previously, Sm–Co recycling has been done using pyrometallurgy, physical separation, and hydrometallurgy, all of which have energy, cost, time, and environmental limitations. Chemical leaching has successfully recovered and separated Sm–Co but has limitations associated with slow mass transfer and leaching kinetics, especially using viscous lixiviants, and there is a need to intensify the process for efficiency. Additionally, environmental impact is high due to extensive use of toxic, corrosive, non-selective, and expensive reagents. In this research, chemical leaching of Sm–Co was performed using Deep Eutectic Solvents (DESs), a new class of solvents under solvometallurgy. Four different DESs were studied, which are green, non-toxic, biodegradable, cheap, and selective. To enhance the mass transfer and reduce leaching time, resonant vibratory mixing (RVM) was tested. RVM intensifies mixing by establishing low energy conditions through vessel resonance, improving kinetics. Four DES combinations were prepared: choline chloride and tetrabutylammonium chloride, with oxalic acid, urea, and ethylene glycol at 80 °C. Chemical leaching of Sm–Co was performed using factors of time (hours), temperature (°C), and combination of DESs. Post-leaching, the samples were process intensified using RVM (time, intensity, and four DESs). Filtered aliquots were analysed with ICP-OES. Oxaline was the most selective DES, achieving 82% Co conversion after 2 hours of leaching and 30 minutes of RVM at 80 °C. A preliminary kinetic study determined the activation energy barrier and showed an increase in conversion (%) for both Co and Sm. 93.4% Co and 5.3% Sm conversions were achieved with only 5 hours of leaching at 90 °C, and after process intensification with RVM, conversions of 97% Co and 9.3% Sm were achieved.

As one of the most important cuisines, hotpot has been popular in China for a long time. However, volatile organic compounds (VOCs) from such activities are scarcely researched, and their threat to practitioners remains unknown. In this study, five hotpot restaurants of varying sizes in Chongqing were selected to investigate the emission characteristics of volatile organic compounds (VOCs), assess their ozone generation potential (OFP) and secondary organic aerosol generation potential (SOAp), and evaluate the associated health risks for practitioners. The results showed that the concentration range of TVOCs was 401.7–2199.7 µg m⁻³. OVOCs were the major components and accounted for about 48.0–96.5%. Ethanol was the largest contributor accounting for 24.7–91.5%. The proportion of alkanes in small and medium scale hotpot restaurants was also high and showed a contribution of 29.1–34.0%. The OFP values fell in the range of 1131.7–3805.3 µg m⁻³, and ethanol and formaldehyde were the two highest contributors. For the potential of SOA formation, aromatic hydrocarbons yielded the highest contribution and accounted for more than 78%. Meanwhile, the human health risk assessment showed both non carcinogenic and carcinogenic risk for those practitioners, in which the risk value of formaldehyde ranged from 1 × 10⁻⁵–1 × 10⁻⁴ and indicated rather high probability of carcinogenic risk.

Polychlorinated dibenzo-p-dioxins (PCDDs) are persistent organic pollutants that pose considerable threats to ecological and human health owing to their high toxicity potential. Understanding the mechanisms for underlying the base-catalyzed hydrolysis of PCDDs in aquatic environments is essential for assessing their environmental behaviour and ecological risks. Herein, we combined quantitative structure–activity relationship (QSAR) models with density functional theory calculations to analyse the base-catalyzed hydrolysis mechanisms of PCDDs. Among the four developed QSAR models, the single-parameter QSAR model based on the lowest unoccupied molecular orbital energy (E_LUMO) demonstrated the best performance, achieving a coefficient of determination of 0.89 and a root mean square error of 0.49, indicating superior overall performance. Results indicate that the second-order rate constants for base-catalyzed hydrolysis (k_OH) of PCDDs are primarily influenced by E_LUMO, molecular polarizability (α), molecular volume (V_m), degree of chlorination (N_Cl), and chlorine position. Specifically, increases in the α and V_m values of PCDDs lead to higher log k_OH values, while an increase in the E_LUMO value results in a lower log k_OH value. This study investigates the relationship between the molecular structure and the rate of base-catalyzed hydrolysis of PCDDs, providing valuable insight into their environmental fate. Furthermore, this research offers a novel theoretical perspective on the base-catalyzed hydrolysis of PCDDs, which will aid in regulatory assessments and risk management.

Removal of heavy metal ions, PFAS, and synthetic dyes from anthropogenic wastewater using versatile sustainable materials is of prime importance for a clean environment and human health. This study presents a sustainably engineered lignin-based biocomposite reinforced with chitosan, designed for multifunctionality, enhanced material performance, and produced via a ‘green’ and simple one-pot synthesis in aqueous medium. The synthesized granular material, i.e. a zwitterionic lignin-chitosan composite (ZLC), was used for the removal of a wide range of chemically diverse contaminants. ZLC showed 80–90% removal of heavy metals such as Cr(VI), Cu(II), and four different cationic and anionic dyes. It was also tested against an array of five PFAS molecules, such as perfluorinated sulfonic and carboxylic acids, showing up to 86% removal for perfluorooctane sulfonic acid (PFOS). All adsorption processes followed the pseudo-second order and Langmuir models. The material also showed antifouling behavior, demonstrating robustness for real-time application. Lastly, ZLC was tested against effluent water matrices, i.e., wastewater streams from mining areas located in Sweden. The multifunctional adsorption performance of the environment-friendly material, coupled with its ease of production, cost effectiveness, and reusability, indicates that ZLC has a high potential that can garner industrial interest for simplifying multi-step filtration processes.

This study investigates the occurrence, distribution and ecological risk of emerging contaminants (ECs) and priority pollutants (PPs) in seawater and sediments of the Saronikos Gulf and Elefsis Bay, Greece, an area continuously impacted by wastewater treatment plant (WWTP) effluents, industrial discharges and maritime traffic. Utilizing novel liquid chromatography tandem ion-mobility spectrometry and high-resolution mass spectrometry, the occurrence of more than 4000 LC-amenable organic micropollutants was investigated through wide-scope target and suspect screening. A total of 171 analytes were detected in marine samples, with pharmaceuticals identified as the most prevalent class (36% in seawater, 41% in sediments) followed by plant protection products (18% in seawater, 27% in sediments). Per- and polyfluoroalkyl substances (PFASs) were also detected in both matrices. Semi-polar ECs with higher molar mass were determined exclusively in sediments near WWTPs, possibly due to their high log P values, reflecting their affinity for particulate matter. Additionally, the seawater circulation pattern was found to play a significant role in controlling the spatial distribution of ECs. Comparison with earlier studies in the area suggests a clear shift in pharmaceutical usage by the local population. Risk assessment, based on risk quotient calculations and environmental quality standards (EQSs) set by EU legislation, revealed that PFASs exceeded annual average environmental quality standard values in 92% of seawater samples, whereas 20 ECs in seawater and 12 in sediments exceeded predicted no-effect concentrations (PNECs), indicating potential adverse effects on marine biota.

Underground hydrogen storage (UHS) is central to enabling a sustainable energy transition, providing a means to balance renewable intermittency through large-scale, long-duration storage. The success of such systems depends critically on site selection, which must integrate technical, economic, and environmental considerations. Here we apply seven multi-criteria decision-making methods to evaluate five storage options, salt caverns, lined rock caverns (LRCs), depleted oil reservoirs, depleted gas reservoirs, and saline aquifers, using 34 parameters. Across all methods, salt caverns emerge as the most suitable sites, followed by LRCs, while porous reservoirs and saline aquifers rank consistently lower. Analysis of parameter influence shows that 16 factors contribute positively to site suitability and 18 exert negative effects, underscoring the complexity of decision frameworks. This comparative assessment provides a transparent basis for risk evaluation and cost optimization, offering practical guidance for research, policy, and deployment of UHS.

The global waste crisis is a significant concern driven by urbanization and economic expansion. Untreated waste poses major environmental, economic, and societal challenges, especially affecting agriculture and industry. Addressing this crisis necessitates innovative waste management strategies and sustainable practices to mitigate the impending waste burden on ecosystems and societies worldwide. Recent advancements in biofuels and biochemicals intensified research into the conversion of biogenic waste into bio-carboxylic acid/volatile fatty acids (VFAs), driven by the dual imperatives of sustainable waste management and renewable resource development. This study presents a comparative analysis of three waste streams: cheese whey from the cheese-making industry, lignocellulosic brewery spent grains (BSG), and agricultural by-products like wheat straw (WS) assessing their efficacy in carboxylic acid production by mixed culture fermentation. Each substrate produced a diverse array of carboxylic acids, including acetic, propionic, butyric, valeric, iso-valeric, and caproic acids exhibiting unique fermentation efficiencies in carboxylic acid production. The experimental results reveal distinct fermentation efficiencies, the highest concentration of short-chain carboxylic acids (SCCA) production of 11.84 gCOD per L from CW, alongside a medium-chain carboxylic acid (MCCA) production of 3.95 gCOD per L. Notably, despite the lignocellulosic composition of the substrates, both BSG and WS demonstrated substantial and competitive yields of SCCA and MCCA. Specifically, BSG produced 10.68 gCOD per L of SCCA and 3.54 gCOD per L of MCCA, while WS yielded 11.51 gCOD per L of SCCA and 3.84 gCOD per L of MCCA. These findings highlight the viability of lignocellulosic substrates for carboxylic acid production, suggesting significant opportunities for enhancing bioprocessing strategies in biochemical and industrial applications. Taxonomic analysis of microbial communities showed a significant predominance of Firmicutes, Bacteroidota, and Actinobacteriota. The Clostridiaceae family exhibited dominance across all reactors, with respective abundances of 82.72%, 27.67%, and 61.29%. The BSG uniquely showcased an enrichment of Lactobacillaceae (23.86%), Ruminococcaceae (7.72%), and Prevotellaceae (3.24%). Key genera contributing to carboxylic acid production included Clostridium sensu stricto 1, Romboutsia, and Enterococcus. This diversity highlights the influence of substrate composition on microbial community structure, highlighting the intricate relationships between substrate nature and microbial metabolites suggesting that strategic substrate selection could optimize fermentation efficiency and enhance product yield.

Flame retardants (FRs) are widely used in indoor environments to meet fire safety requirements. One understudied environment with respect to indoor chemical exposure to FRs is the maritime environment, particularly the indoor environments of cruise ships. This study presents the first comprehensive assessment of FRs in indoor dust collected from three expedition cruise ships of varying ages and refitting histories. Ten polybrominated diphenyl ethers (PBDEs), 23 alternative halogenated flame retardants (AHFRs), and 16 organophosphate esters (OPEs) were analyzed in dust from 12–16 locations per ship. OPEs, especially tris(1-chloro-2-propyl)phosphate (TCIPP), dominated the chemical profile, with concentrations reaching up to 1786 µg g⁻¹. Concentrations of FRs in different areas on the same ships differed greatly, sometimes by an order of magnitude. Older ships exhibited significantly higher FR levels compared to the newer vessel. Estimated daily intake (EDI) modeling indicated that ship crew members—particularly those working in heavily furnished or electronic-rich areas—may experience elevated exposures through ingestion and dermal contact. Strict performance-based fire test procedures are mandatory for all products onboard ships, but no regulations exist concerning the type of FR used or the concentrations thereof. These findings underscore the need for targeted regulation and further monitoring of chemical exposures in maritime environments, especially given the extended periods that crew members spend onboard.

The efficient removal of volatile organic compounds (VOCs) remains a significant challenge in air pollution control due to their high chemical stability and adverse health impacts. Among them, toluene is a representative aromatic VOC whose degradation requires effective generation of highly oxidative hydroxyl radicals (·OH) to achieve complete mineralization. In this study, we developed alkali metal ion-doped Bi₂O₂CO₃ (BOCO) photocatalysts via a one-step hydrothermal method. Alkali metal ions (Na⁺ and Rb⁺) were successfully incorporated into BOCO via substitutional doping. The doping process disrupts uniform surface charge distribution, creating active sites that facilitate interfacial water adsorption and activation. This leads to markedly increased hydroxyl radical (·OH) generation in doped catalysts, essential for ring-opening degradation of aromatic intermediates. Hence, Rb-BOCO achieved a toluene degradation efficiency of 60.7% and retained a stable mineralization rate (50.1%) over prolonged illumination, compared with 25.3% for pristine BOCO. These findings provide a mechanistic framework for designing durable photocatalysts by tuning surface chemistry to boost ·OH radical production for efficient VOC abatement.

Ambient particulate matter (PM_2.5) exposure constitutes the leading global risk factor for non-communicable diseases. This study assesses the healthcare and economic burdens of air pollution in Kazakhstan's two major urban cities, Almaty and Astana. During 2022–2024, PM_2.5-attributable excess mortality reached 2108 ± 144 deaths in Almaty and 676 ± 41 deaths in Astana annually. The results of this research suggest that compliance with the World Health Organization (WHO) air quality guideline for annual average PM_2.5 concentrations (5 µg m⁻³) can potentially prevent 1196–1698 and 446–497 deaths in Almaty and Astana, respectively. Economic losses from PM_2.5-related mortality were estimated at USD 2.8–4.6 billion for Almaty and USD 0.9–1.5 billion for Astana per year throughout the study period. Achieving the WHO-recommended annual PM_2.5 limit of 5 µg m⁻³ by 2022 might yield annual economic benefits of USD 2941–3685 million in Almaty and USD 863–1043 million in Astana. These findings highlight the urgency of comprehensive, coordinated air quality management strategies, with a particular emphasis on fossil fuel phase-out initiatives.