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Environmental Science and Pollution... Jun 2024The sustainable utilization of waste cooking oil (WCO) as an alternative to fossil fuels has gained considerable attention due to its potential for delivering...
The sustainable utilization of waste cooking oil (WCO) as an alternative to fossil fuels has gained considerable attention due to its potential for delivering substantial environmental and economic benefits. This research attempts to explore the impact of incorporating aluminum oxide nanoparticles (AONP) into WCO on the emissions, combustion characteristics, and overall performance of a single-cylinder compression ignition (CI) engine. Comparative analyses were conducted against conventional commercial diesel fuel and pure WCO, as well as varying blends of WCO with AONP at 25 ppm, 50 ppm, and 75 ppm concentrations. The experimental results demonstrate a notable enhancement in brake thermal efficiency (BTE), with a 13.2% increase observed in the WCO + 75 AONP fuel blend compared to neat WCO. Engines fueled by WCO nanoparticle blends showed significant augmentation in-cylinder pressure and heat release rates. Furthermore, these blends exhibited a substantial reduction in carbon monoxide (CO), hydrocarbons (HC), and soot emissions by 44%, 31%, and 48%, respectively, while nitrogen oxide (NO) emissions increased by 7% compared to neat WCO. Among the assessed fuel mixtures, the WCO + 75 AONP blend demonstrated higher engine performance. This study underscores the potential of aluminum oxide nanoparticle-enhanced WCO blends as viable and environmentally responsible options for sustainable energy solutions. However, challenges such as production costs and long-term fuel stability must be addressed to establish nano-fuels as financially viable alternatives.
PubMed: 38865047
DOI: 10.1007/s11356-024-33903-9 -
Frontiers in Veterinary Science 2024Fire-related deaths are usually a consequence of carbon monoxide (CO) poisoning or shock from thermal injuries. In humans, high levels of carboxyhemoglobin (COHb)...
Fire-related deaths are usually a consequence of carbon monoxide (CO) poisoning or shock from thermal injuries. In humans, high levels of carboxyhemoglobin (COHb) concentrations in the blood can support a diagnosis of CO poisoning. In veterinary medicine, few studies investigated the pathological changes and blood COHb% in fire victims, and no data are available on post-mortem changes in blood gas composition due to fire. This study aims to investigate the pathological changes and COHb levels in both animal victims of fire and cadavers experimentally exposed to fire. For this purpose, dogs were selected and subdivided into three groups. Group A comprised 9 adult dogs, and Group B comprised 7 puppies that died under fire-related conditions. Group C was represented by 4 dog cadavers experimentally exposed to heat and smoke. A complete macroscopic, histological, and COHb evaluation were performed on each animal. Animals in Groups A and B showed cherry-red discoloration, thermal-injuries and soot deposits along the respiratory tract. Animals in Group C showed thermal injuries and soot deposits limited to the upper respiratory tract. The mean COHb% values in cadavers in Group C were lower than those observed in the other groups but higher compared to the values detected before the heat and smoke treatment. These findings suggest that both pathological changes and COHb analysis are valid tools for investigating fire-related deaths in dogs. However, the increase of COHb levels in cadavers exposed post-mortem to heat and smoke highlights how the COHb analysis should always be evaluated together with macroscopical and microscopical findings to avoid significant misjudgments in investigating fire-related fatalities in veterinary forensic practice.
PubMed: 38835893
DOI: 10.3389/fvets.2024.1396540 -
Water Research Jul 2024Urban stormwater runoff is considered a key component of future water supply portfolios for water-stressed cities. Beneficial use of runoff, such as capture for recharge...
Urban stormwater runoff is considered a key component of future water supply portfolios for water-stressed cities. Beneficial use of runoff, such as capture for recharge of drinking water aquifers, relies on improved stormwater treatment. Many dissolved constituents, including metals and trace organic contaminants (TrOCs) such as hydrophilic pesticides and poly- and perfluoroalkyl substances (PFASs), are of concern due to their toxicity, persistence, prevalence in stormwater runoff, and poor removal in conventional stormwater control measures. This study explores the operational flow rate limitations of black carbon (BC)-amended engineered media filters for removal of a wide suite of dissolved metals and TrOCs and provides validation for a previously developed predictive TrOC transport model. Column experiments were conducted with face velocities of 40 and 60 cm h to assess Douglas Fir-based biochar and regenerated activated carbon (RAC) filter performance in light of media-contaminant removal kinetic limitations. This study found that increasing the face velocity in BC-amended filters to 40 and 60 cm h, which are representative of field conditions, decreased the removal of total suspended solids, turbidity, dissolved hydrophilic TrOCs, and PFASs when expressed as volume treated relative to previous studies conducted at 20 cm h. Dissolved metals and hydrophobic TrOCs removal were not substantially affected by the increased flow rates. A predictive 1-d intraparticle pore diffusion-limited sorption model with sorption and effective tortuosity parameters determined previously from experiments conducted at 20 cm h was validated for these higher flow rates. This work provides insights to the kinetic limitations of contaminant removal within biochar and RAC filters and implications for stormwater filter design and operation.
Topics: Water Pollutants, Chemical; Filtration; Kinetics; Water Purification; Charcoal; Rain; Soot; Carbon
PubMed: 38833811
DOI: 10.1016/j.watres.2024.121811 -
Environmental Science & Technology Jun 2024Soot particles emitted from aircraft engines constitute a major anthropogenic source of pollution in the vicinity of airports and at cruising altitudes. This emission...
Soot particles emitted from aircraft engines constitute a major anthropogenic source of pollution in the vicinity of airports and at cruising altitudes. This emission poses a significant threat to human health and may alter the global climate. Understanding the characteristics of soot particles, particularly those generated from Twin Annular Premixing Swirler (TAPS) combustors, a mainstream combustor in civil aviation engines, is crucial for aviation environmental protection. In this study, a comprehensive characterization of soot particles emitted from TAPS combustors was conducted using scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), and Raman spectroscopy. The morphology and nanostructure of soot particles were examined across three distinct fuel stage ratios (FSR), at 10%, 15%, and 20%. The SEM analysis of soot particle morphology revealed that coated particles constitute over 90% of the total particle sample, with coating content increasing proportionally to the fuel stage ratio. The results obtained from HRTEM indicated that average primary particle sizes increase with the fuel stage ratio. The results of HRTEM and Raman spectroscopy suggest that the nanostructure of soot particles becomes more ordered and graphitized with an increasing fuel stage ratio, resulting in lower oxidation activity. Specifically, soot fringe length increased with the fuel stage ratio, while soot fringe tortuosity and separation distance decreased. In addition, there is a prevalent occurrence of defects in the graphitic lattice structure of soot particles, suggesting a high degree of elemental carbon disorder.
Topics: Aircraft; Soot; Nanostructures; Particle Size; Vehicle Emissions; Spectrum Analysis, Raman; Air Pollutants
PubMed: 38833713
DOI: 10.1021/acs.est.4c03478 -
Journal of Colloid and Interface Science Oct 2024This present work demonstrated the functional transformation of 3D printed metal substrates into a new family of Surface-enhanced Raman Scattering substrates, a...
This present work demonstrated the functional transformation of 3D printed metal substrates into a new family of Surface-enhanced Raman Scattering substrates, a promising approach in developing SERS-based Point-of-care (PoC) analytical platforms. l-Powder Bed Fusion (l-PBF, Additive manufacturing or 3D printing technique) printed metal substrates have rough surfaces, and exhibit high thermal stability and intrinsic chemical inertness, necessitating a suitable surface functionalization approach. This present work demonstrated a unique multi-stage approach to transform l-PBF printed metal structures as recyclable SERS substrates by colloidal carbon templating, chemical vapor deposition, and electroless plating methods sequentially. The surface of the printed metal structures was functionalized using the colloidal carbon soot particles, that were formed by the eucalyptus oil flame deposition method. These carbon particles were shown to interact with the metals present in the printed structures by forming metal carbides and function as an adlayer on the surface. Subsequent deposition of TiO onto these templates led to strong grafting of TiO and retaining the fractal structure of the soot template onto the metal surface. Electroless deposition of silver nanoparticles resulted in the formation of fractally structured TiO/Ag nanostructures and these functionalized printed metal structures were shown as excellent SERS substrates in enhancing the vibrational spectral features of Rhodamine B (RhB). The presence of TiO photocatalyst on the surface was shown to remove the RhB analyte from the surface under photochemical conditions, which enables the regeneration of SERS activity, and the substrate can be recycled. The migration of metals from the printed metal structures into the fractally ordered TiO/Ag nanostructures was found to enhance the photocatalytic activity and increase the recyclability of these substrates. This study demonstrates the potential of 3D-printed Inconel metal substrates as next-generation recyclable SERS platforms, offering a substantial advancement over traditional colloidal, thin-film, flexible, and hard SERS substrates.
PubMed: 38815369
DOI: 10.1016/j.jcis.2024.05.181 -
Environmental Science & Technology Jun 2024Residential biomass burning is an important source of black carbon (BC) exposure among rural communities in low- and middle-income countries. We collected 7165 personal...
Residential biomass burning is an important source of black carbon (BC) exposure among rural communities in low- and middle-income countries. We collected 7165 personal BC samples and individual/household level information from 3103 pregnant women enrolled in the Household Air Pollution Intervention Network trial. Women in the intervention arm received free liquefied petroleum gas stoves and fuel throughout pregnancy; women in the control arm continued the use of biomass stoves. Median (IQR) postintervention BC exposures were 9.6 μg/m (5.2-14.0) for controls and 2.8 μg/m (1.6-4.8) for the intervention group. Using mixed models, we characterized predictors of BC exposure and assessed how exposure contrasts differed between arms by select predictors. Primary stove type was the strongest predictor ( = 0.42); the models including kerosene use, kitchen location, education, occupation, or stove use hours also provided additional explanatory power from the base model adjusted only for the study site. Our full, trial-wide, model explained 48% of the variation in BC exposures. We found evidence that the BC exposure contrast between arms differed by study site, adherence to the assigned study stove, and whether the participant cooked. Our findings highlight factors that may be addressed before and during studies to implement more impactful cookstove intervention trials.
Topics: Humans; Female; Pregnancy; Adult; Cooking; Air Pollution, Indoor; Soot; Carbon; Air Pollutants; Environmental Exposure
PubMed: 38810212
DOI: 10.1021/acs.est.3c09991 -
ACS Omega May 2024In this study, simulations were carried out to study the combustion characteristics within a 600 MW W-shaped pulverized coal boiler under O/N and O/CO atmospheres. The...
In this study, simulations were carried out to study the combustion characteristics within a 600 MW W-shaped pulverized coal boiler under O/N and O/CO atmospheres. The objective of this work is to develop and validate a novel model for pulverized coal combustion under O-enriched conditions, specifically optimized for the O/CO atmosphere. The innovation in this model lies in the precise calibration of kinetic constants for soot nucleation and surface growth rates, enabling a more accurate simulation of flame characteristics (such as the flame temperature and soot volume fraction) under O-enriched combustion conditions. The study reveals that an increase in the O concentration significantly reduces the combustion flame height and flame penetration depth, thereby enhancing the local temperature inside the furnace. Moreover, at higher oxygen concentrations, the high levels of OH and O accelerate the oxidation reaction rate and shift the high-temperature zone upward. Subsequently, the maximum value of the nucleation rate increases. Therefore, compared to those of the O/N atmospheres, in the O/CO atmospheres, the peak volume fractions of soot decreased by 0.72, 25.5, and 15.9% for oxygen contents of 21, 30, and 40%, respectively. This demonstrates the impact of the oxidizing environment on soot production. Therefore, this study delves into the effects of oxygen concentration and temperature on soot formation and provides a new model for better predicting and optimizing combustion processes in industrial applications.
PubMed: 38799372
DOI: 10.1021/acsomega.4c00285 -
Journal of Hazardous Materials Jul 2024Soot nanoparticles (SNPs) are black carbon prevalent in atmospheric environment with significant impacts on public health, leading to neurodegenerative diseases...
Soot nanoparticles (SNPs) are black carbon prevalent in atmospheric environment with significant impacts on public health, leading to neurodegenerative diseases including development of Parkinson's disease (PD). This study investigated the effects of SNPs exposure on PD symptoms, employing both in vivo and in vitro PD models. In the in vivo experiments, animal behavior assessments showed that SNPs exposure exacerbated motor and cognitive impairments in PD mice. Molecular biology techniques further unveiled that SNPs aggravated degeneration of dopaminergic neurons. In vitro experiments revealed that SNPs exposure intensified ferroptosis of PD cells by increasing reactive oxygen species and iron ion levels, while reducing glutathione levels and mitochondrial membrane potential. Sequencing tests indicated elevated N6-methyladenosine (m6A) alteration of the ferroptosis-related protein, acyl-CoA synthetase long chain family member 4 (ACSL4). This study demonstrates that SNPs may exacerbate the onset and progression of PD by recruiting YTH domain-containing family protein 1 (YTHDF1) protein, enhancing m6A methylation in the ACSL4 5'UTR, amplifying ACSL4 protein expression, and accelerating the ferroptosis process in dopaminergic neurons. These molecular mechanisms underlying SNPs exacerbation of PD development may provide crucial insights for formulating environmental safety regulations and potential therapeutic strategies addressing PD in populations residing in regions with varied air quality.
Topics: Animals; Dopaminergic Neurons; Ferroptosis; Adenosine; Mice, Inbred C57BL; Parkinson Disease; Nanoparticles; Coenzyme A Ligases; Male; Methylation; Mice; Reactive Oxygen Species; Humans; RNA; RNA Methylation
PubMed: 38788584
DOI: 10.1016/j.jhazmat.2024.134691 -
Environmental Pollution (Barking, Essex... Aug 2024Through a comprehensive investigation into the historical profiles of black carbon derived from ice cores, the spatial distributions of light-absorbing impurities in...
Through a comprehensive investigation into the historical profiles of black carbon derived from ice cores, the spatial distributions of light-absorbing impurities in snowpit samples, and carbon isotopic compositions of black carbon in snowpit samples of the Third Pole, we have identified that due to barriers of the Himalayas and remove of wet deposition, local sources rather than those from seriously the polluted South Asia are main contributors of light-absorbing impurities in the inner part of the Third Pole. Therefore, reducing emissions from residents of the Third Pole themselves is a more effective way of protecting the glaciers of the inner Third Pole in terms of reducing concentrations of light-absorbing particles in the atmosphere and on glaciers.
Topics: Environmental Monitoring; Air Pollutants; Ice Cover; Asia; Soot; Atmosphere; Snow; Asia, Southern; Himalayas
PubMed: 38768677
DOI: 10.1016/j.envpol.2024.124181 -
Environmental Pollution (Barking, Essex... Aug 2024High uncertainty in optical properties of black carbon (BC) involving heterogeneous chemistry has recently attracted increasing attention in the field of atmospheric...
High uncertainty in optical properties of black carbon (BC) involving heterogeneous chemistry has recently attracted increasing attention in the field of atmospheric climatology. To fill the gap in BC optical knowledge so as to estimate more accurate climate effects and serve the response to global warming, it is beneficial to conduct site-level studies on BC light absorption enhancement (E) characteristics. Real-time surface gas and particulate pollutant observations during the summer and winter over Wuhan were utilized for the analysis of E simulated by minimum R squared (MRS), considering two distinct atmospheric conditions (2015 and 2017). In general, differences in aerosol emissions led to E differential behaviors. The summer average of E (1.92 ± 0.55) in 2015 was higher than the winter average (1.27 ± 0.42), while the average (1.11 ± 0.20) in 2017 summer was lower than that (1.67 ± 0.69) in winter. E and R (representing the mass ratio of non-refractory constituents to elemental carbon) constraints suggest that E increased with the increase in R under the ambient condition enriched by secondary inorganic aerosol (SIA), with a maximum growth rate of 70.6% in 2015 summer. However, E demonstrated a negative trend against R in 2017 winter due to the more complicated mixing state. The result arose from the opposite impact of hygroscopic SIA and absorbing OC/irregular distributed coatings on amplifying the light absorbency of BC. Furthermore, sensitivity analysis revealed a robust positive correlation (R > 0.9) between aerosol chemical compositions (including sulfate, nitrate, ammonium and secondary organic carbon), which could be significantly perturbed by only a small fraction of absorbing materials or restructuring BC through gaps filling. The above findings not only deepen the understanding of BC, but also provide useful information for the scientific decision-making in government to mitigate particulate pollution and obtain more precise BC radiative forcing.
Topics: Soot; Air Pollutants; Aerosols; Environmental Monitoring; Seasons; Particulate Matter; Light; Carbon; China; Atmosphere
PubMed: 38761879
DOI: 10.1016/j.envpol.2024.124175