Road dust has been identified as one of the main sources of outdoor PM10 in Bogota (a Latin American megacity), but there are no studies that have analyzed the physicochemical characteristics and ...origins of its respirable fraction. A characterization of inorganic compounds (water soluble ions, major and trace elements, organic and elemental carbon) and an analysis of source contributions to the PM10 fraction of road dust were carried out in this study. A total of twenty road dust samples, selected from representative industrial, residential and commercial areas, were swept and resuspended to obtain the thoracic fraction. Size distribution by laser diffraction and individual particle morphology by Scanning Electron Microscopy were also evaluated. The data obtained revealed that the volume (%) of thoracic particles was higher in samples from industrial zones where heavy vehicular traffic, industrial emissions and deteriorated pavements predominated. Crustal elements were the most abundant species, accounting for 49–62% of the thoracic mass, followed by OC (13–29%), water-soluble ions (1.4–3.8%), EC (0.8–1.9%) and trace elements (0.2–0.5%). The Coefficient of Divergence was obtained to identify the spatial variability of the samples. A source apportionment analysis was carried out considering the variability of chemical profiles, enrichment factors and ratios of Fe/Al, K/Al, Ca/Al, Ti/Al, Cu/Sb, Zn/Sb, OC/TC and OC/EC. By means of a PCA analysis, five components were identified, including local soils and pavement erosion (63%), construction and demolition activities (13%), industrial emissions (6%), brake wear (5%) and tailpipe emissions (4%). These components accounted for 91% of the total variance. The results provide data to understand better one of the main sources of PM10 emissions in Bogota, such as road dust. These data will be useful to optimize environmental policies, and they may be used in future studies of human health and air quality modeling.
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•The volume (%) of the thoracic fraction of road dust was higher in industrial zones.•Road dust from the commercial sector registered enrichment by diesel vehicles.•The residential road dust revealed an enrichment by construction works emissions.•Local soils and pavement erosion were the main sources (63%) of the PM10 fraction.•SEM images provided information about the size and shape of the thoracic particles
Non-exhaust emissions from road transport include particles from brake and tyre wear, road surface abrasion and dust resuspension. Road dust loads and their chemical properties are heterogeneous and ...their knowledge is still scarce. This study aimed to characterise, for the first time in Lisbon, the thoracic fraction of road dust (PM10) by collecting samples directly from road pavements by an in situ resuspension chamber. The highest PM10 load (15.6 ± 8.75 mg m−2) was obtained on a cobblestone pavement, while for asphalt roads the mean PM10 load was 4.40 ± 0.16 mg m−2. Emission factors for asphalt pavements ranged from 83.5 to 274 mg veh−1 km−1. On average, 65.7% of the PM10 mass was reconstructed, taking into account the carbonaceous content and the sum of the elements in their oxidized form. Cu and Zn, associated with brake and tyre wear, were the most enriched elements in relation to the soil composition (EnF = 440 and 184, respectively). The highest potential ecological risk factor of individual metals (Eri) was also observed for Cu (EriCu = 393). In 90% of the sampled streets, the total carcinogenic risk was higher than 1E-4 for As, suggesting that exposure to this hazardous element may contribute to the development of cancer over a lifetime. The results showed the high contribution of certain dangerous chemical compounds associated with resuspension particles and their potential effects on human health.
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•Non-exhaust emissions have an important impact on the environment and health.•Cobbled pavement had a higher dust load than asphalt pavements.•Cu revealed the highest potential ecological harmful effect.•Cu and Zn revealed an extremely high pollution index in all road sampling sites.•Exposure to As may contribute to the development of cancer over a lifetime.
Water-soluble metals exert a significant influence on human and ecosystem health. In this study, a comprehensive investigation was undertaken to elucidate the solubilities of metals in PM2.5 and ...potential influencing factors during the dry season of 2019–2020 in urban Guangzhou, South China. The observed average solubility was <20 % for Al, Fe, Sn, and Ti; 20–40 % for V, Cr, Sb, Pb, and Ni; 40–60 % for Ba and Cu; and 60–80 % for Zn, As, Se, Cd, and Mn. Metals (Al, Ti, and Fe) originated from crustal sources (e.g., soil dust) have much lower solubilities than those (Mn, Zn, As, Se, Cd, and Ba) from fossil fuel combustion sources (e.g., traffic emission, coal combustion), suggesting the dominant role the metal sources played on solubility. Enhanced solubilities of Cu, As, Se, Cd, Sn, Sb, and Pb were associated with aerosol acidity, while those of V, Cr, Mn, Ni, Zn, and Ba were linked to organic acid complexation. For the three crustal metals, the solubilities of Al and Ti primarily depended on aerosol acidity, whereas the solubility of Fe depended on both aerosol acidity under pH < 2 conditions and organic acid complexation under pH > 2 conditions. These findings underscore the primary influence of inherent properties of the metals on their solubility and reveal the varying impacts of atmospheric physicochemical processes, with changes in their solubilities being <10 % for Cd, Sn, Sb, and Pb, 10–20 % for Cu, Cr, Mn, Ni, and Ba, and 20–30 % for As, Se, and Zn.
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•Crustal metals are less soluble than those from combustion.•Cu, As, Se, Cd, Sn, Sb, Pb, Al, and Ti solubilities increase with aerosol acidity.•V, Cr, Mn, Ni, Zn, and Ba solubilities rise due to organic acid complexation.•Fe solubility depends on aerosol acidity and organic acid complexation.
The study explores the potential of ethanol as an additive on the performance, combustion and exhaust emission characteristics of a compression ignition engine fueled with adulterated diesel ...considering the environmental protection agency tier 4 emission mandates. Results showed that the inclusion of ethanol in the adulterated diesel notably reduced engine exhaust emissions along with improvement in the performance and combustion parameters. The experiential study was followed by a Pareto-based multi-objective optimization study to achieve non-dominated solutions for the performance-emission paradigms under diesel-kerosene-ethanol blends. The functional relationships for the non-dominated sorting genetic algorithm-II were acquired with the assistance of response surface methodology technique. The optimal values of the output parameters of the engine, such as brake thermal efficiency, cumulated oxide of nitrogen & unburned hydrocarbon and carbon monoxide emissions were evaluated by utilizing a multi-attribute decision making technique using input parameters, such as brake mean effective pressure, kerosene share and ethanol share. The optimization result reveals that among the different running conditions used in this study, the engine can be operated in the most optimal manner at 2.2 bar brake mean effective pressure, 2.4% kerosene share (by volume) and 10% ethanol share (by volume).
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•Modification of kerosene adulterated Diesel was performed by Ethanol addition.•Performance, combustion and emissions of a diesel engine were investigated.•NOHC and CO emissions were within EPA Tier 4 mandate.•RSM based NSGA-II algorithms provided a set of Pareto trade-off solutions.•Optimal result was found with 2.2 BMEP, 2.4% Kerosene and 10% ethanol using TOPSIS.
In recent years, the approaches paid much attention to are adding nanoparticles in biodiesel-based fuels to overcome the disadvantages of biodiesel like high molecular mass, high viscosity, and ...pouring point, and low calorific value significantly affecting the spray, atomization, and combustion characteristics. Among the aforementioned nanoparticles, Cerium oxide (CeO2) nanoparticles show their advantages such as flexible capacity in valence transformation, large oxygen storage, and good thermal properties, CeO2 nanoparticles are thus believed to have a great potential to become an additive for the diesel engine. Indeed, in this review paper, the preparing methods and physicochemical properties of biodiesel-based fuels containing CeO2 nanoparticles were fully introduced. Furthermore, the effects of CeO2 on the atomization and micro-explosion of as-used fuels were also discussed in detail. More importantly, the combustion behavior, performance, and emission characteristics of diesel engines fuelled with biodiesel containing CeO2 nanoparticles were thoroughly analyzed. In general, the addition of CeO2 nanoparticles into biodiesel has demonstrated positive effects on reducing toxic emissions (soot, smoke opacity, NOx, CO, HC), enhancing thermal efficiency and brake power, and improving fuel consumption. However, the impacts of CeO2 nanoparticles on PM emission, human health, and the environment need to be further investigated in future researches.
•Preparing methods for CeO2-added fuels and their properties were introduced.•Effects of CeO2 nanoparticles on spray and fuel properties were mentioned.•Performance of engine fuelled with CeO2-added biodiesel was thoroughly analyzed.•Combustion and emission characteristics of diesel engine were discussed in detail.
•CuO-NiO/Al2O3 catalyst with palm oil used to synthesize green fuel.•GasTurb-13 data is validated engine performance model using green fuel.•GD10PME10 blend had the lowest TSFC, matching Jet-A1 ...efficiency at high speeds.•GD20OME30 has the lowest emissions (CO, and CO2) and temperature.•NOx rose with blends; GD10PME10 closest to Jet-A1. Optimized blends can cut NOx.
This study aims to assess the impact of using green fuel in place of biodiesel on the performance and exhaust emissions of air-breathing engines. GasTurb 13 is utilized to forecast the engine’s performance (kingTech 180 k turbojet engine). Catalytic deoxygenation of vegetable oils produces green diesel, offering an alternative to biodiesel. Physiochemical properties of GD blends (PME30GD20, PME20GD30, PME10GD10) were analyzed, and GasTurb-13 software predicted engine performance and emissions, validated with experimental data. The results show that GD10PME10 exhibited higher density (767.6 g/m3) than pure green fuel, while viscosity dropped by 53.85 % compared to PME. GD outperformed Jet-A1 by 0.74 % in heating value, with GD10PME10 having the highest at 42.63 MJ/kg. Engine performance measures included thrust, mass fuel flow, thrust-specific fuel consumption, and exhaust gas temperature. GD10PME10 showed a 12.5 % thrust increase and the lowest TSFC (95 g/kN.s) at 80,000 RPM compared to Jet-A1. GD20PME30 achieved the lowest EGT (550 °C) at the same RPM. Regarding emissions, GD20PME30 emitted the lowest CO (100,000 RPM, 150 ppm) and 0.5 % less CO2 (90,000 RPM) than Jet-A1. GD10PME10 produced the lowest NOx (12.5 ppm) at maximum speed, while Jet-A1 emitted the least NOx (7.5 ppm) at 120 k RPM. Overall, the data suggested that green fuel might increase the physiochemical properties of biodiesel blends, hence improving the fuel’s capacity to burn more effectively in aero-engines.
Tall oil is a waste energy source that can be called as the extract of trees that emerge in paper mills. Fusel oil is a sugar molasses process waste which is a waste alcohol combination of high ...molecular alcohols. In this study, tall oil acids were mixed with 20% by volume of diesel fuel and alcohol (ethanol, methanol, isopropyl, n-butanol and fusel oil) were added to the same ratio and their effects on combustion, fuel line pressure, engine performance and emissions were investigated. The mixtures were tested by using a single-cylinder engine with compression-ignition, direct injection at constant engine speed (1800 rpm) and 2 Nm, 4 Nm, 6 Nm, 8 Nm engine torques. With the use of fuel mixtures, in-cylinder pressure values decreased in all conditions compared to D100 fuel. The highest drop in in-cylinder pressure values is 7.1% with DT20M20 fuel mixture. Fuel mixtures were found to be sprayed earlier than the injector compared to diesel fuel. BSCF the highest rate of increase was seen with the DT20M20 fuel mixture at 9%. All fuel mixtures have been found to produce reduction in CO and smoke opacity emissions and an increase in HC and NOx emissions. With D100 fuel, emission values measured at (CO) 0.35 ppm and (is) 46%, respectively, decreased to (CO) 0.24 ppm and (is) 33% with the DT20I20 fuel mixture under the same conditions. The highest NOx emission was 14.8% with DT20I20. HC emission using the DT20M20 fuel mixture was determined to be 83 ppm.
Particulate matter is a component of ambient air pollution that has been linked to millions of annual premature deaths globally
. Assessments of the chronic and acute effects of particulate matter on ...human health tend to be based on mass concentration, with particle size and composition also thought to play a part
. Oxidative potential has been suggested to be one of the many possible drivers of the acute health effects of particulate matter, but the link remains uncertain
. Studies investigating the particulate-matter components that manifest an oxidative activity have yielded conflicting results
. In consequence, there is still much to be learned about the sources of particulate matter that may control the oxidative potential concentration
. Here we use field observations and air-quality modelling to quantify the major primary and secondary sources of particulate matter and of oxidative potential in Europe. We find that secondary inorganic components, crustal material and secondary biogenic organic aerosols control the mass concentration of particulate matter. By contrast, oxidative potential concentration is associated mostly with anthropogenic sources, in particular with fine-mode secondary organic aerosols largely from residential biomass burning and coarse-mode metals from vehicular non-exhaust emissions. Our results suggest that mitigation strategies aimed at reducing the mass concentrations of particulate matter alone may not reduce the oxidative potential concentration. If the oxidative potential can be linked to major health impacts, it may be more effective to control specific sources of particulate matter rather than overall particulate mass.
•Using of 3 and 7vol.% n-butanol blends in SI engine is studied for the first time.•Engine performance and emissions depend on both engine speed and blend rates.•CO and UHC for blended fuels are ...maximum at 3000–3100r/min.•The higher the rate of n-butanol, the lower the emissions and performance.•This study strongly supports using low blend rates of n-butanol (<10vol.%) in ICE.
In this paper, exhaust emissions and engine performance have been experimentally studied for neat gasoline and gasoline/n-butanol blends in a wide range of working speeds (2600–3400r/min) without any tuning or modification on the gasoline engine systems. The experiment has the ability of evaluating performance and emission characteristics, such as break power, torque, in-cylinder pressure, volumetric efficiency, exhaust gas temperature and concentrations of CO2, CO and UHC. Results of the engine test indicated that using n-butanol–gasoline blended fuels slightly decrease the output torque, power, volumetric efficiency, exhaust gas temperature and in-cylinder pressure of the engine as a result of the leaning effect caused by the n-butanol addition; CO, CO2 and UHC emissions decrease dramatically for blended fuels compared to neat gasoline because of the improved combustion since n-butanol has extra oxygen, which allows partial reduction of the CO and UHC through formation of CO2. It was also noted that the exhaust emissions depend on the engine speed rather than the n-butanol contents.
NH
-SCR (selective catalytic reduction) is important process for removal of NOx. However, water vapor included in exhaust gases critically inhibits the reaction in a low temperature range. Here, we ...report bulk W-substituted vanadium oxide catalysts for NH
-SCR at a low temperature (100-150 °C) and in the presence of water (~20 vol%). The 3.5 mol% W-substituted vanadium oxide shows >99% (dry) and ~93% (wet, 5-20 vol% water) NO conversion at 150 °C (250 ppm NO, 250 ppm NH
, 4% O
, SV = 40000 mL h
g
). Lewis acid sites of W-substituted vanadium oxide are converted to Brønsted acid sites under a wet condition while the distribution of Brønsted and Lewis acid sites does not change without tungsten. NH
species adsorbed on Brønsted acid sites react with NO accompanied by the reduction of V
sites at 150 °C. The high redox ability and reactivity of Brønsted acid sites are observed for bulk W-substituted vanadium oxide at a low temperature in the presence of water, and thus the catalytic cycle is less affected by water vapor.
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