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Keywords = specific emission of toxic components

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21 pages, 1157 KB  
Review
Light-Converting Polymer Coatings for Spectral Engineering in Sustainable Agriculture: Materials, Fabrication Routes and Photophysical Challenges
by Alibek Mutushev, Aida Sanat, Dauren Mukhanov, Assiya Nuraly, Meruyert Shaukharova, Akzhunis Akimbayeva and Juan María Gonzalez-Leal
Coatings 2026, 16(7), 757; https://doi.org/10.3390/coatings16070757 (registering DOI) - 26 Jun 2026
Viewed by 159
Abstract
Light-converting polymer coatings and films are emerging passive photonic materials for spectral engineering in sustainable and protected agriculture. By absorbing ultraviolet or weakly used spectral components and re-emitting in visible bands that overlap with photosynthetic pigments and plant photoreceptor action regions, these materials [...] Read more.
Light-converting polymer coatings and films are emerging passive photonic materials for spectral engineering in sustainable and protected agriculture. By absorbing ultraviolet or weakly used spectral components and re-emitting in visible bands that overlap with photosynthetic pigments and plant photoreceptor action regions, these materials can modify the radiation environment without additional electrical energy input. This critical narrative review analyses light-converting polymer films and coatings from a materials and coatings perspective, with emphasis on photophysical mechanisms, polymer matrices, luminophore families, coating fabrication routes, optical transparency, photoluminescence, aggregation phenomena, photostability and scalability. The photobiological background is included as a concise framework that justifies the spectral targets of the conversion process. Rare-earth complexes, inorganic phosphors, quantum dots, aggregation-induced-emission systems and organic dyes are compared as candidate luminophores. Particular attention is devoted to the general challenges associated with organic luminescent coatings, including dispersion, aggregation, optical transparency, photostability, and scalability. A PMMA/PDI coating system is discussed only as an illustrative case study demonstrating these broader materials-design considerations. Extrusion, solution casting, spin-coating, dip-coating and sol–gel processing are evaluated as fabrication strategies for laboratory and large-area greenhouse applications. The work concludes by identifying the main gaps that must be addressed before practical deployment: quantitative UV–Vis and photoluminescence characterization, absolute quantum yield, haze and scattering, thickness and morphology mapping, accelerated UV aging, weathering resistance, toxicity assessment and crop-specific validation. Full article
(This article belongs to the Section Thin Films)
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30 pages, 2181 KB  
Review
Urban Parks as Beneficial and POP-Contaminated Landscapes
by João P. V. Ferreira, Luís Pinto da Silva and Joaquim C. G. Esteves da Silva
Environments 2026, 13(2), 92; https://doi.org/10.3390/environments13020092 - 7 Feb 2026
Viewed by 1000
Abstract
Urban parks are essential to sustainable cities, providing climate regulation, supporting biodiversity, and offering vital spaces for recreation and overall well-being. At the same time, their soils can act as long-term reservoirs for persistent organic pollutants (POPs), reflecting decades of atmospheric deposition, diffuse [...] Read more.
Urban parks are essential to sustainable cities, providing climate regulation, supporting biodiversity, and offering vital spaces for recreation and overall well-being. At the same time, their soils can act as long-term reservoirs for persistent organic pollutants (POPs), reflecting decades of atmospheric deposition, diffuse urban emissions, and historical land-use practices. This review synthesises current knowledge on the occurrence, sources, and environmental behaviour of priority POPs, including OCPs, PCBs, PCDD/Fs, PBDEs, PFAS, and PAHs, in the soils of urban parks and gardens worldwide. Evidence from multiple regions reveals consistent patterns: urban parks accumulate complex mixtures of legacy and emerging contaminants, reflecting both historical inputs and ongoing urban activities. These contaminants primarily contribute to scenarios of chronic, low-level exposure through the ingestion of soil and dust, inhalation of resuspended particles, dermal contact, and, in some cases, dietary intake when food is cultivated in contaminated park soils. While such exposure pathways have been associated with a range of adverse health outcomes in toxicological and epidemiological studies, the presence of POPs in park soils does not imply that urban parks represent hazardous environments. Instead, it emphasises the importance of proportionate, evidence-based assessments within spaces that yield substantial net benefits to public health. Despite growing research interest, significant gaps remain, including limited understanding of mixture toxicity, insufficient data on temporal trends, a lack of harmonised monitoring strategies, and the absence of exposure scenarios specifically tailored to recreational soils. This review also examines major international and European regulatory frameworks and soil-quality guideline approaches relevant to urban and recreational soils, identifying mismatches between scientific evidence and regulatory practice. By integrating perspectives from environmental chemistry, toxicology, urban ecology, and policy, this review highlights the importance of targeted monitoring and context-specific management strategies to ensure that urban parks remain safe, healthy, and equitable components of increasingly complex urban landscapes. Full article
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26 pages, 2825 KB  
Review
Ecotoxicological Aspects of Hair Dyes: A Review
by Letícia Cristina Gonçalves, Matheus Mantuanelli Roberto and Maria Aparecida Marin-Morales
Colorants 2026, 5(1), 4; https://doi.org/10.3390/colorants5010004 - 26 Jan 2026
Viewed by 2122
Abstract
Hair dyes are widely used across all socioeconomic groups and regions worldwide. However, some studies indicate that these products contain substances known to be toxic to a wide variety of organisms. Moreover, dyeing practices generate effluents that may carry the toxicity of hair [...] Read more.
Hair dyes are widely used across all socioeconomic groups and regions worldwide. However, some studies indicate that these products contain substances known to be toxic to a wide variety of organisms. Moreover, dyeing practices generate effluents that may carry the toxicity of hair dyes into the environment. Due to these facts, there is great concern about the impacts these products may have on the environment, as well as on the health of their users and professionals in the field of cosmetology. This scoping review analyzed 184 publications from major databases (PubMed, SciELO, Scopus, Google Scholar, and MEDLINE). Ultimately, 126 scientific studies published between 1981 and 2024 were included based on methodological rigor and their relevance to the One Health framework. According to the literature, the components of hair dyes can induce adverse responses in biological systems, ranging from reversible topical irritations to severe systemic effects. Among the studies evaluated, more than half reported significant toxicological or genotoxic associations related to oxidative dye components such as p-phenylenediamine and its derivatives. These compounds are frequently associated with various types of human cancers, including breast, prostate, bladder, skin, ocular cancers, and brain tumors. In addition to their effects on humans, hair dyes exhibit ecotoxicity, which may threaten the maintenance of ecosystems exposed to their residues. The reported environmental impacts result from effluent emissions after successive hair washes that release unreacted dye residues. Due to the low biodegradability of these compounds, conventional wastewater treatment methods are often ineffective, leading to environmental accumulation and changes in aquatic ecosystems, soil fertility, and trophic balance. Data on the toxicity of hair dye effluents remain scarce and sometimes contradictory, particularly regarding the effects of their transformation products and metabolites. Overall, the evidence underscores the need for continuous monitoring, updated risk assessments, and the adoption of advanced treatment technologies specific to beauty salon effluents. The information presented in this work may support further studies and guide public management agencies in developing policies for mitigating the impacts of hair dye pollutants within the One Health perspective. Full article
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19 pages, 3780 KB  
Article
Carbon Nanotube-Based Filters for the Adsorption of Toxic Compounds in Cigarette Smoke
by Luigi Madeo, Pietro Figliuzzi, Assunta Perri, Anastasia Macario, Carlo Siciliano and Pierantonio De Luca
C 2026, 12(1), 8; https://doi.org/10.3390/c12010008 - 20 Jan 2026
Cited by 2 | Viewed by 1417
Abstract
This study investigates the use of carbon nanotubes (CNTs) in the development of a filter capable of capturing toxic and carcinogenic compounds found in cigarette smoke dispersed in the environment. The aim is to contribute to the reduction in passive exposure to these [...] Read more.
This study investigates the use of carbon nanotubes (CNTs) in the development of a filter capable of capturing toxic and carcinogenic compounds found in cigarette smoke dispersed in the environment. The aim is to contribute to the reduction in passive exposure to these substances, with potential benefits for public health and air quality. Carbon nanotubes were selected for their exceptional adsorption properties, attributed to their high specific surface area and porous structure. The material’s adsorptive performance was evaluated based on the quantity used, to determine the optimal mass that ensures the best filtering capacity. To test the system, an experimental setup was assembled to simulate real-world smoke emission conditions. Filters containing CNTs were subjected to gravimetric analysis to measure the amount of retained substances, and to gas chromatography to identify the adsorbed chemical compounds. The results confirm the potential of carbon nanotubes as an advanced filtering material, paving the way for robust solutions to mitigate the environmental impact of secondhand smoke. The results indicate that CNT-based filters, particularly those containing 0.06 g of material, are highly effective in retaining several toxic components of cigarette smoke, including nicotine. This configuration achieves a strong reduction in harmful organic species while using a moderate amount of adsorbent, suggesting a promising selectivity of CNTs toward the most hazardous molecules. Full article
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19 pages, 2244 KB  
Article
Enhancement of Rheological Performance and Smoke Suppression in Sepiolite-Modified Asphalt
by Yongle Xu, Hongling Fan, Jing Yang and Peng Yin
Materials 2025, 18(24), 5627; https://doi.org/10.3390/ma18245627 - 15 Dec 2025
Cited by 1 | Viewed by 538
Abstract
To address the technical bottleneck of the coordinated improvement of high-temperature rutting resistance, low-temperature cracking resistance and environmental protection performance of road asphalt, and to address the existing problems in the research of sepiolite modified asphalt, such as the ambiguous microscopic mechanism of [...] Read more.
To address the technical bottleneck of the coordinated improvement of high-temperature rutting resistance, low-temperature cracking resistance and environmental protection performance of road asphalt, and to address the existing problems in the research of sepiolite modified asphalt, such as the ambiguous microscopic mechanism of action, the lack of quantitative relationship between dosage and performance, and the unclear adaptability of modification processes, this study employed high-purity sepiolite as a modifier. After optimizing its microstructure through organic and surface modification, the sepiolite with the best compatibility with asphalt was selected. Four dosage gradients of 2%, 4%, 6%, and 8% were designed. Rheological tests were conducted to investigate the effects of sepiolite on the rutting resistance at high temperature, the cracking resistance at low temperature, and the fatigue durability of asphalt. Gas chromatography–mass spectrometry (GC–MS) was used to analyze changes in the organic components of asphalt fumes, while Fourier-transform infrared spectroscopy (FTIR) and gel permeation chromatography (GPC) were applied to reveal the microscopic interaction mechanisms and smoke-suppression principles. Results show that pristine sepiolite exhibits the best compatibility with asphalt. Although modified sepiolite shows a 43–45% increase in specific surface area, the overall high–low temperature coordination of the modified asphalt decreases by 10–15%. The sepiolite dosage has a significant influence on asphalt performance: when the dosage is 4–6%, the rutting factor of asphalt increases by 25–30%, indicating the best high-temperature deformation resistance; at 4%, the asphalt creep stiffness decreases by over 15%, minimizing the low-temperature cracking risk; and at 2–4%, the fatigue life extends by 9–13%, with the most notable improvement at 2%. In terms of smoke suppression, the porous structure of sepiolite adsorbs 3–5% of the light volatile components in asphalt, while its metal oxides inhibit the release of aliphatic and aromatic hydrocarbons, reducing toxic fume emissions by 12–18%. Microscopically, the interaction between sepiolite and asphalt is dominated by physical adsorption without chemical functional group recombination. The fibrous network of sepiolite enhances the structural stability of asphalt, while the adsorption of small and medium molecular components optimizes the molecular weight distribution, achieving a dual effect of performance enhancement and smoke suppression. Full article
(This article belongs to the Section Construction and Building Materials)
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17 pages, 615 KB  
Article
The Causal Relationship Between Long-Term Exposure to Major PM2.5 Constituents and the Rate of Emergency Department Visits: A Difference-in-Differences Study
by Peizhen Zhao, Chenxi Xie, Shenghao Wang, Shao Lin, Guanghui Dong, Jiashun Li, Sen Yu, Ting Zhang, Xiaozhou Yu, Xian Lin, Sizhe Li, Xiaoru Wu, Jiyuan Zhou and Wangjian Zhang
Toxics 2025, 13(11), 973; https://doi.org/10.3390/toxics13110973 - 12 Nov 2025
Cited by 1 | Viewed by 1324
Abstract
Fine particulate matter (PM2.5) is a well-established health hazard, yet population-level causal evidence on the long-term effects of its chemical constituents and their interactions with environmental and socioeconomic factors remains scarce. This study leveraged quasi-experimental variation in PM2.5 exposure across [...] Read more.
Fine particulate matter (PM2.5) is a well-established health hazard, yet population-level causal evidence on the long-term effects of its chemical constituents and their interactions with environmental and socioeconomic factors remains scarce. This study leveraged quasi-experimental variation in PM2.5 exposure across Guangdong province, China, during 2007–2018 to evaluate its causal impact on emergency department (ED) visits. We applied a Difference-in-Differences (DID) causal inference framework to obtain counterfactual estimates of long-term exposure effects and complemented this with generalized Weighted Quantile Sum (gWQS) regression to treat PM2.5 as a complex mixture, quantify joint effects, and identify toxic components. The results showed that each interquartile increase in long-term PM2.5 exposure was associated with a 10.2% rise in ED visits, with nitrate (weight = 0.299) and sulfate (0.294) contributing the most strongly, while organic matter exerted greater effects in less-developed regions. Temperature variation further modified these effects, with a 1 °C increase in average summer temperature associated with a 3.3% increase and a decrease in winter temperature linked to a 0.54% increase in constituent-related ED visits. Socioeconomic stratification revealed heterogeneous toxicity profiles across regions. These findings provide robust causal evidence on constituent-specific risks of PM2.5, highlight the utility of integrating causal and mixture methods for complex exposures, and support targeted emission control and climate-adaptive strategies to protect vulnerable populations. Full article
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18 pages, 4356 KB  
Article
Development of Low-Smoke Epoxy Resin Carbon Fiber Prepreg
by Yu Zhao, Lili Wu, Yujiao Xu, Dongfeng Cao and Yundong Ji
Polymers 2025, 17(19), 2710; https://doi.org/10.3390/polym17192710 - 9 Oct 2025
Viewed by 1214
Abstract
The smoke toxicity of epoxy resin limits the application of its carbon fiber composites in marine interior structures. To address this issue, a novel epoxy resin (EZ) was synthesized by grafting phenyl propyl polysiloxane (PPPS) onto ortho-cresol novolac epoxy resin (EOCN), building upon [...] Read more.
The smoke toxicity of epoxy resin limits the application of its carbon fiber composites in marine interior structures. To address this issue, a novel epoxy resin (EZ) was synthesized by grafting phenyl propyl polysiloxane (PPPS) onto ortho-cresol novolac epoxy resin (EOCN), building upon the group’s earlier work on polysiloxane-modified epoxy resin (EB). The results confirmed successful grafting of PPPS onto EOCN, which significantly enhanced the thermal stability and char residue of EZ. Specifically, the peak heat release rate (PHRR), total heat release (THR), peak smoke production rate (PSPR), and total smoke production (TSP) of EZ were reduced by 68.5%, 35%, 73.1%, and 48.3%, respectively, attributable to the formation of a stable and compact char layer that suppressed smoke generation. By blending EZ with EB resin, a low-smoke epoxy system (LJF-2) was developed for prepreg applications. Carbon fiber composites (LJF-CF) prepared from LJF-2 exhibited minimal smoke emission and a unique bilayer char structure: a dense inner layer that hindered smoke transport and a thick outer layer that provided thermal insulation, delaying further resin decomposition. Silicon was uniformly distributed in the char residue as silicon oxides, improving its stability and compactness. Without adding any flame retardants or smoke suppressants, LJF-CF achieved a maximum smoke density (Ds,max) of 276.9, meeting the requirements of the FTP Code for ship deck materials (Ds,max < 400). These findings indicate that LJF-CF holds great promise for use in marine interior components where low smoke toxicity is critical. Full article
(This article belongs to the Section Polymer Applications)
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18 pages, 1887 KB  
Article
Chemical Dissection of PM2.5 in Cigarette Smoke: Main and Sidestream Emission Factors and Compositions
by Yujian Zhou, Hong Huang, Changwei Zou, Mengmeng Deng, Xiang Tu, Wei Deng, Chenglong Yu and Jianlong Li
Toxics 2025, 13(9), 711; https://doi.org/10.3390/toxics13090711 - 23 Aug 2025
Cited by 1 | Viewed by 5033
Abstract
Despite increasing evidence that cigarette smoke is a significant source of indoor fine particulate matter (PM2.5), quantitative emission factors (EFs) for PM2.5 and its toxic chemical composition in mainstream (MS) and sidestream (SS) smoke are still not well defined. In [...] Read more.
Despite increasing evidence that cigarette smoke is a significant source of indoor fine particulate matter (PM2.5), quantitative emission factors (EFs) for PM2.5 and its toxic chemical composition in mainstream (MS) and sidestream (SS) smoke are still not well defined. In this study, we employed a custom-designed chamber to separately collect MS (intermittent puff) and SS (continuous sampling) smoke from eleven cigarette models, representing six brands and two product types, under controlled conditions. PM2.5 was collected on quartz-fiber filters and analyzed for carbon fractions (using the thermal–optical IMPROVE-A protocol), nine water-soluble inorganic ions (by ion chromatography), and twelve trace elements (via ICP-MS). SS smoke exhibited significantly higher mass fractions of total analyzed species (84.7% vs. 65.9%), carbon components (50.6% vs. 44.2%), water-soluble ions (17.1% vs. 13.7%), and elements (17.0% vs. 7.0%) compared to MS smoke. MS smoke is characterized by a high proportion of pyrolytic organic carbon fractions (OC1–OC3) and specific elements such as vanadium (V) and arsenic (As), while SS smoke shows elevated levels of elemental carbon (EC1), water-soluble ions (NH4+, NO3), and certain elements like zinc (Zn) and cadmium (Cd). The toxicity-weighted distribution indicates that MS smoke primarily induces membrane disruption and pulmonary inflammation through semi-volatile organics and elements, whereas SS smoke enhances oxidative stress and cardiopulmonary impairment via EC-mediated reactions and secondary aerosol formation. The mean OC/EC ratio of 132.4 in SS smoke is an order of magnitude higher than values reported for biomass or fossil-fuel combustion, indicative of extensive incomplete combustion unique to cigarettes and suggesting a high potential for oxidative stress generation. Emission factors (µg/g cigarette) revealed marked differences: MS delivered higher absolute EFs for PM2.5 (422.1), OC (8.8), EC (5.0), Na+ (32.6), and V (29.2), while SS emitted greater proportions of NH4+, NO3, Cl, and carcinogenic metals (As, Cd, Zn). These findings provide quantitative source profiles suitable for receptor-oriented indoor source-apportionment models and offer toxicological evidence to support the prioritization of comprehensive smoke-free regulations. Full article
(This article belongs to the Section Air Pollution and Health)
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14 pages, 2209 KB  
Article
Effect of Different Deodorants on SBS-Modified Asphalt Fume Emissions, Asphalt Road Performance, and Mixture Performance
by Zhaoyan Sheng, Ning Yan and Xianpeng Zhao
Processes 2025, 13(8), 2485; https://doi.org/10.3390/pr13082485 - 6 Aug 2025
Viewed by 967
Abstract
During large-scale pavement construction, the preparation of SBS-modified asphalt typically produces large amounts of harmful fumes. The emergence of deodorants can effectively alleviate the problem of smoke emissions during the asphalt manufacturing process. On the basis of ensuring the original road performance, exploring [...] Read more.
During large-scale pavement construction, the preparation of SBS-modified asphalt typically produces large amounts of harmful fumes. The emergence of deodorants can effectively alleviate the problem of smoke emissions during the asphalt manufacturing process. On the basis of ensuring the original road performance, exploring more suitable dosages and types of deodorant is urgently needed. Five commercial deodorants were evaluated using an asphalt smoke collection system, and UV-visible spectrophotometry (UV) was employed to screen the deodorants based on smoke concentration. Gas chromatography–mass spectrometry (GC-MS) was used to quantitatively analyze changes in harmful smoke components before and after adding two deodorants. Subsequently, the mechanisms of action of the two different types of deodorants were analyzed microscopically using fluorescence microscopy. Finally, the performance of bitumen and asphalt mixtures after adding deodorants was evaluated. The results showed that deodorant A (reactive type) and D (adsorption type) exhibited the best smoke suppression effects, with optimal addition rates of 0.6% and 0.5%, respectively. Deodorant A reduced benzene homologues by nearly 50% and esters by approximately 40%, while deodorant D reduced benzene homologues by approximately 70% and esters by approximately 60%, without producing new toxic gases. Both deodorants had a minimal impact on the basic properties of bitumen and the road performance of asphalt mixtures, with all indicators meeting technical specifications. This research provides a theoretical basis for the effective application of deodorants in the future, truly enabling a transition from laboratory research to large-scale engineering applications in the construction of environmentally friendly roads. Full article
(This article belongs to the Section Materials Processes)
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9 pages, 2222 KB  
Proceeding Paper
Research and Analysis of the Real-Time Interaction Between Performance and Smoke Emission of a Diesel Vehicle
by Iliyan Damyanov, Rosen Miletiev and Tsvetan Ivanov Valkovski
Eng. Proc. 2025, 100(1), 34; https://doi.org/10.3390/engproc2025100034 - 14 Jul 2025
Cited by 2 | Viewed by 1365
Abstract
In recent decades, environmental requirements for reducing the toxic components emitted from vehicle exhausts have decreased drastically. Technologies for after-treatment of diesel vehicle emissions are being improved continuously in order to meet increasingly stringent regulations. Passenger cars are a significant source of air [...] Read more.
In recent decades, environmental requirements for reducing the toxic components emitted from vehicle exhausts have decreased drastically. Technologies for after-treatment of diesel vehicle emissions are being improved continuously in order to meet increasingly stringent regulations. Passenger cars are a significant source of air pollution, especially in urban areas. The EU has decided to phase out internal combustion engines. Stricter Real Driving Emissions (RDE) testing procedures have also been introduced, aiming to assess the emissions of nitrogen oxides (NOx) and particle number (PN). The present work investigates the interaction between performance and smoke emissions of a diesel vehicle on a pre-established route in an urban environment with an everyday (normal) driving style. The results showed that when the vehicle is technically sound and meets its technical specifications, smoke emissions are within normal limits. Full article
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15 pages, 4479 KB  
Article
Impact of Ethanol–Diesel Blend on CI Engine Performance and Emissions
by Mieczysław Sikora, Piotr Orliński and Mateusz Bednarski
Energies 2025, 18(9), 2277; https://doi.org/10.3390/en18092277 - 29 Apr 2025
Cited by 3 | Viewed by 2047
Abstract
The aim of this study was to assess the impact of adding ethanol to diesel fuel on particulate matter (PM) and nitrogen oxides (NOx) emissions in the Perkins 854E compression-ignition engine. Tests were carried out under European Stationary Cycle (ESC) conditions using the [...] Read more.
The aim of this study was to assess the impact of adding ethanol to diesel fuel on particulate matter (PM) and nitrogen oxides (NOx) emissions in the Perkins 854E compression-ignition engine. Tests were carried out under European Stationary Cycle (ESC) conditions using the Horiba Mexa 1230 PM analyzer (HORIBA, Ltd., Kyoto, Japan) for particulate measurement and the AVL CEB II analyzer (AVL, Graz, Austria) for NOx concentration. The engine under investigation featured direct injection, turbocharging, a common-rail fuel supply system, and complied with the Stage IIIB/Tier 4 emission standard. Two types of fuel were used: conventional diesel fuel (DF) and diesel with a 10% ethanol additive by volume (DFE10). In addition to emissions measurements, key engine performance parameters, such as torque, effective power, and fuel consumption, were analyzed. The ESC test was specifically chosen to isolate the influence of the fuel’s properties by avoiding the effects of changes in combustion control strategies. Due to the lower calorific value of DFE10 compared to DF, a slight increase in fuel consumption was observed under certain operating conditions. Nevertheless, overall engine performance remained largely unchanged. The test results showed that the use of DFE10 led to a significant 44% reduction in particulate matter emissions and a moderate 2.2% decrease in NOx emissions compared to conventional diesel fuel. These findings highlight the potential of ethanol as a diesel fuel additive to reduce harmful exhaust emissions without negatively affecting the performance of modern diesel engines. Full article
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18 pages, 7147 KB  
Article
The Influence of Powering a Compression Ignition Engine with HVO Fuel on the Specific Emissions of Selected Toxic Exhaust Components
by Piotr Orliński, Mieczysław Sikora, Mateusz Bednarski and Maciej Gis
Appl. Sci. 2024, 14(13), 5893; https://doi.org/10.3390/app14135893 - 5 Jul 2024
Cited by 8 | Viewed by 2778
Abstract
The aim of the research was to determine the potential of hydrotreated vegetable oil (HVO) in reducing nitrogen oxides and particulate matter emissions from the Perkins 854E-E34TA compression ignition engine. The concentrations of these toxic exhaust gas components were measured using the following [...] Read more.
The aim of the research was to determine the potential of hydrotreated vegetable oil (HVO) in reducing nitrogen oxides and particulate matter emissions from the Perkins 854E-E34TA compression ignition engine. The concentrations of these toxic exhaust gas components were measured using the following analyzers: AVL CEB II (for NOx concentration measurement) and Horiba Mexa 1230 PM (for PM measurement). The measurements were carried out in the ESC test on a compression ignition engine with direct fuel injection and a turbocharger. The engine had a common rail fuel supply system and met the Stage IIIB/Tier 4 exhaust emission standard. Two fuels were used in the tests: diesel fuel (DF) and hydrotreated vegetable oil (HVO). As part of the experiment, the basic indicators of engine operation were also determined (torque, effective power, and fuel consumption) and selected parameters of the combustion process, such as the instantaneous pressure of the working medium in the combustion chamber, maximum pressures and temperatures in the combustion chamber, and the heat release rate (HRR), were calculated. The tests were carried out in accordance with the ESC test because the authors wanted to determine how the new generation HVO fuel, powering a modern combustion engine with a common rail fuel system, would perform in a stationary emission test. Based on the obtained research results, the authors concluded that HVO fuel can replace diesel fuel in diesel engines even without major modifications or changes in engine settings. Full article
(This article belongs to the Special Issue Alternative Fuels in Future Energy System)
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24 pages, 16615 KB  
Article
Adsorption of Lead (II) Ions onto Goethite Chitosan Beads: Isotherms, Kinetics, and Mechanism Studies
by Tanawit Sirijaree and Pornsawai Praipipat
ChemEngineering 2023, 7(3), 52; https://doi.org/10.3390/chemengineering7030052 - 1 Jun 2023
Cited by 27 | Viewed by 6254
Abstract
Lead is a highly toxic heavy metal that creates a water pollutant. It can be released from industrial processes, agricultural chemistry, and community wastes, affecting creatures and human health even at a low concentration. As a result, it is advised that lead be [...] Read more.
Lead is a highly toxic heavy metal that creates a water pollutant. It can be released from industrial processes, agricultural chemistry, and community wastes, affecting creatures and human health even at a low concentration. As a result, it is advised that lead be removed before releasing wastewater into the environment. This study synthesized three chitosan bead materials from shrimp shell wastes which were chitosan powder beads (CB), chitosan powder mixed with goethite beads (CFB), and chitosan powder beads coated with goethite (CBF) for removing lead in an aqueous solution. Their surface area, pore volumes, and pore sizes were explored according to Brunauer– Emmett–Teller, and their crystalline formations were investigated using an X-ray diffractometer. Their surface structures were studied using field emission scanning electron microscopy and a focus ion beam, and their chemical compositions were determined using an energy dispersive X-ray spectrometer. Their chemical functional groups were identified via Fourier-transform infrared spectroscopy. In addition, batch experiments were conducted to investigate the effects of several factors on removing lead, and the adsorption isotherm and kinetics were also investigated for determining their adsorption pattern and mechanism. In addition, the desorption experiments were studied to confirm their possible material reusability. The CBF demonstrated the highest surface area and smallest pore size compared with the other materials. In addition, the pore sizes of the CFB and CBF were micropores, whereas those of the CB were mesopores. All materials were semicrystalline structures, and the specific goethite peaks were observed in the CFB and CBF. All materials had spherical shapes with heterogeneous surfaces. Six chemical components of O, C, Ca, N, Cl, and Na were discovered in all materials, and Fe was only found in the CFB and CBF because of the addition of goethite. Five main chemical functional groups of N–H, O–H, C–H, C–O, and –COOH were found in all materials. The optimum conditions of the CB, CFB, and CBF for removing lead were 0.5 g, 16 h, pH 5, 0.5 g, 16 h, pH 5, and 0.4 g, 14 h, pH 5, respectively. The results of the batch experiments demonstrated that the CB, CFB, and CBF were high-efficiency adsorbents for removing lead in solution by more than 95%, whereby the CBF showed the highest lead removal of 99%. The Freundlich isotherm model and pseudo-second-order kinetic model helped to well explain their adsorption pattern and mechanism. The maximum lead adsorption capacities of the CB, CFB, and CBF were 322.58, 333.33, and 344.83 mg/g, respectively. Furthermore, all chitosan materials can be reused for more than three cycles with high lead removal by more than 94%; so, they are potential materials for application in industrial applications. Full article
(This article belongs to the Special Issue Feature Papers in Chemical Engineering)
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17 pages, 831 KB  
Article
PM10 Resuspension of Road Dust in Different Types of Parking Lots: Emissions, Chemical Characterisation and Ecotoxicity
by Ismael Casotti Rienda, Célia A. Alves, Teresa Nunes, Marlene Soares, Fulvio Amato, Ana Sánchez de la Campa, Nóra Kováts, Katalin Hubai and Gábor Teke
Atmosphere 2023, 14(2), 305; https://doi.org/10.3390/atmos14020305 - 3 Feb 2023
Cited by 24 | Viewed by 5791
Abstract
The thoracic fraction of road dust (PM10) was measured for the first time in Portugal in parking areas, both outdoors and indoors, with the aim of completing existing studies carried out in active lanes of various roads. An in situ resuspension [...] Read more.
The thoracic fraction of road dust (PM10) was measured for the first time in Portugal in parking areas, both outdoors and indoors, with the aim of completing existing studies carried out in active lanes of various roads. An in situ resuspension chamber was used to collect a total of 23 samples in three parking areas of Aveiro, whilst the laboratory procedures included determination of carbonaceous content (OC and EC) by a thermo-optical technique, elemental composition by ICP-MS and ICP-OES after acid digestion, and the Aliivribrio fisherii bioluminescent bacteria ecotoxicity bioassay. Dust loadings (DL10) obtained were 18.5 ± 9.8 mg PM10 m−2, in outdoor parking, and 1.8–23.7 mg PM10 m−2 for indoor parking, corresponding to emission factors of 476 and 75–589 mg veh−1 km−1, respectively. OC represented 9–30 % of PM10 for the indoor parking areas. However, for the outdoor samples, the high iron oxide content jeopardised the OC-EC separation. In those samples, carbonates accounted for 10.0 ± 3.3% of the PM10 mass. The analysis of elemental components focused on major elements (Al, Ca, Fe, K, and Mg) as well as minor elements. The total mass fraction of element oxides accounted for 27.1% (outdoor) and 23.6–34.3% (indoor). ΣPAH calculated for all parking areas accounted for 8.38–36.9 μg g−1 PM10. The ecotoxicological bioassay showed that all aqueous solutions were toxic to bioluminescent bacteria, whereas no clear correlations could be made with specific component groups, with the exception of ΣPAH and EC50. Full article
(This article belongs to the Special Issue Feature Papers in Air Quality)
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13 pages, 4101 KB  
Article
The Impact of Metal-Based Nanoparticles Produced by Different Types of Underwater Welding on Marine Microalgae
by Konstantin Pikula, Konstantin Kirichenko, Vladimir Chernousov, Sergey Parshin, Alexander Masyutin, Yulia Parshina, Anton Pogodaev, Alexander Gridasov, Aristidis Tsatsakis and Kirill Golokhvast
Toxics 2023, 11(2), 105; https://doi.org/10.3390/toxics11020105 - 22 Jan 2023
Cited by 5 | Viewed by 3166
Abstract
Underwater wet welding is commonly used in joining pipelines and in underwater construction. Harmful and hazardous compounds are added to many flux-cored wires for underwater welding and cutting, and can have a negative impact on marine life. The specific objective of this study [...] Read more.
Underwater wet welding is commonly used in joining pipelines and in underwater construction. Harmful and hazardous compounds are added to many flux-cored wires for underwater welding and cutting, and can have a negative impact on marine life. The specific objective of this study was to evaluate the aquatic toxicity of two suspension samples obtained using welding electrode and flux-cored wire in marine microalgae Attheya ussuriensis and Porphyridium purpureum. Growth rate inhibition, cell size, and biochemical changes in microalgae were evaluated by flow cytometry. The results of the bioassay demonstrated that the suspension obtained after welding with electrode had an acute toxic impact on diatomic microalgae A. ussuriensis, and both tested suspensions revealed chronic toxicity in this microalga with a 40% growth rate inhibition after exposure to 40–50% of prepared suspensions for 7 days. Red algae P. purpureum revealed tolerance to both suspensions caused by exopolysaccharide covering, which prevents the toxic impact of metal cations such as Al, Ti, Mn, Fe, and Zn, which are considered the main toxic components of underwater welding emissions. Full article
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