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Environmental Science & Technology May 2021Soot is typically the dominant component of the nonvolatile particles emitted from internal combustion engines. Although soot is primarily composed of carbon, its...
Soot is typically the dominant component of the nonvolatile particles emitted from internal combustion engines. Although soot is primarily composed of carbon, its chemistry, toxicity, and oxidation rates may be strongly influenced by internally mixed inorganic metal compounds (ash). Here, we describe the detailed microstructure of ash internally mixed with soot from four marine engines and one aviation engine. The engines were operated on different fuels and lubrication oils; the fuels included four residual fuels and five distillate fuels such as diesel, natural gas, and Jet A-1. Using annular-dark-field scanning transmission electron microscopy (ADF-STEM), we observed that ash may occur either as distinct nodules on the soot particle (decorated) or as continuous streaks (painted). Both structures may exist within a single particle. Decorated soot was observed for both distillate and residual fuels and contained elements associated with either the fuel (V, Ni, Fe, S) or with the lubrication oil (Zn, Ca, P). Painted soot was observed only for residual-fuel soot, and only contained elements associated with the fuel. Additional composition measurements by inductively coupled plasma mass spectrometry (ICP-MS) of filter samples indicated that the internal mixing trends of ash with soot were consistent with the overall ash-to-carbon ratio of the sampled combustion aerosols. Painted soot may form when molten ash coagulates with or condenses onto soot within engines.
Topics: Aerosols; Aviation; Carbon; Soot; Vehicle Emissions
PubMed: 33905233
DOI: 10.1021/acs.est.0c07130 -
Environmental Pollution (Barking, Essex... Jan 2021An improved understanding of the historical variation in the emissions and sources (biomass burning, BB vs. fossil fuel, FF combustion) of soot and char, the two...
An improved understanding of the historical variation in the emissions and sources (biomass burning, BB vs. fossil fuel, FF combustion) of soot and char, the two components of black carbon (BC), and polycyclic aromatic compounds (PACs) may help in assessing the environmental effects of the Atmospheric Brown Cloud (ABC) in SE Asia. We therefore determined historical variations of the fluxes of soot, char, and PACs (24 polycyclic aromatic hydrocarbons (PAHs), 12 oxygenated PAHs (OPAHs), and 4 azaarenes) in a dated sediment core (covering the past ∼150 years) of Phayao Lake in Thailand. The soot fluxes have been increasing in recent times, but at a far lower rate than previously estimated based on BC emission inventories. This may be associated with a decreasing BB contribution as indicated by the decreasing char fluxes from old to young sediments. The fluxes of high- and low-molecular-weight (HMW and LMW) PAHs, OPAHs, and azaarenes all sharply increased after ∼1980, while the ΣLMW-/ΣHMW-PAHs ratios decreased, further supporting the reduction in BB contribution at the expense of increasing FF combustion emissions. We also suggest that the separate record of char and soot, which has up to now not been done in aerosol studies, is useful to assess the environmental effects of ABC because of the different light-absorbing properties of these two BC components. Our results suggest that besides the establishment of improved FF combustion technology, BB must be further reduced in the SE Asian region in order to weaken the ABC haze.
Topics: Carbon; Environmental Monitoring; Geologic Sediments; Lakes; Polycyclic Aromatic Hydrocarbons; Polycyclic Compounds; Soot; Thailand
PubMed: 33310199
DOI: 10.1016/j.envpol.2020.116148 -
Analytical Chemistry Nov 2022Soot, mainly derived from incomplete combustion of fossil fuel and biomass, exists ubiquitously in different environmental matrixes. To study the detrimental effects of...
Soot, mainly derived from incomplete combustion of fossil fuel and biomass, exists ubiquitously in different environmental matrixes. To study the detrimental effects of soot on climate, air quality, and human health, accurate quantification of soot is an important prerequisite. However, until now, quantification of soot in environmental media, especially in carbonaceous media, is still very challenging. Here, we report a matrix-free laser desorption/ionization mass spectrometry (LDI-MS) method for in situ imaging of soot particles in size-segregated aerosol samples collected on filter membranes. A series of round-shaped sample spots in filter membranes were selected and subjected to MS imaging analysis, enabling direct in situ quantification of soot without solvent extraction or separation. Especially, the MS imaging with serial sample spots can overcome the problems of sweet-spot in LDI-MS and inhomogeneous distribution of soot in the filter membrane, thus greatly improving the precision of quantification. The limit of detection of soot was 4 ng/m and the recovery was 84.4-126%. By using this method, we found that a higher soot content was present in larger-sized particulate matter than smaller-sized particles, suggesting that aerosol soot was mainly derived from primary emission sources. Furthermore, this method also shows the potential to analyze nitrate and sulfate species in PM. To the best of our knowledge, it is the first method capable of simultaneous analysis of inorganic salts and soot in air samples. It represents a novel strategy for in situ quantification of aerosol soot with the advantages of high specificity, high sensitivity, separation-, solvent- and matrix-free.
Topics: Humans; Soot; Air Pollutants; Particulate Matter; Aerosols; Mass Spectrometry; Solvents; Carbon; Environmental Monitoring
PubMed: 36301736
DOI: 10.1021/acs.analchem.2c01443 -
The Science of the Total Environment Feb 2024Black carbon in sediments has been widely used as a proxy for biomass burning/fire activity to reconstruct fire history and its evolution. Wildfire studies have revealed...
Char and soot records of the Holocene fire history and its implications for climate-vegetation change and human activities within the Guanzhong Basin, southern Loess Plateau, China.
Black carbon in sediments has been widely used as a proxy for biomass burning/fire activity to reconstruct fire history and its evolution. Wildfire studies have revealed that different types of black carbon (char and soot) are formed due to changes in combustion efficiency. In this study, we obtained black carbon and its two subtypes, char and soot, from a typical Holocene aeolian loess-paleosol section in the Chilanqiao Ruins within the Guanzhong Basin, southern Loess Plateau, China. Combined with environmental proxies such as magnetic susceptibility, loss on ignition, and geochemical elements, along with AMSC and optically stimulated luminescence (OSL) dates, we reconstructed the Holocene fire history and its evolution on the southern Loess Plateau at local and regional scales. The findings indicate that the limited vegetation during the relatively dry and cold early Holocene may have inhibited the spread of fires. In the warmer and wetter middle Holocene, there was higher local smoldering fire activity, likely influenced by both wet climatic conditions and an increase in the proportion of woody plants. Additionally, the fire history in relation to human activities at Shang Dynasty (1600-1046 BCE) including land reclamation, house construction, and bronze casting has also been identified. There has been a significant increase in regional flaming fire activity in the late Holocene as a result of drier climate and increased human activity. Notably, the significant increase in regional flaming fire activity since ~1.00 ka can be primarily linked to human-set fires with the usage of gunpowder in frequent wars. This research holds great importance in enhancing our understanding of the long-term interactions among fire activities, climate change and human activities.
Topics: Humans; Soot; Fires; China; Climate Change; Human Activities; Carbon
PubMed: 37981130
DOI: 10.1016/j.scitotenv.2023.168564 -
Biosensors & Bioelectronics May 2020Advances in cutting-edge technologies including nanotechnology, microfluidics, electronic engineering, and material science have boosted a new era in the design of... (Review)
Review
Advances in cutting-edge technologies including nanotechnology, microfluidics, electronic engineering, and material science have boosted a new era in the design of robust and sensitive biosensors. In recent years, carbon black has been re-discovered in the design of electrochemical (bio)sensors thanks to its interesting electroanalytical properties, absence of treatment requirement, cost-effectiveness (c.a. 1 €/Kg), and easiness in the preparation of stable dispersions. Herein, we present an overview of the literature on carbon black-based electrochemical (bio)sensors, highlighting current trends and possible challenges to this rapidly developing area, with a special focus on the fabrication of carbon black-based electrodes in the realisation of sensors and biosensors (e.g. enzymatic, immunosensors, and DNA-based).
Topics: Animals; Biosensing Techniques; Electrochemical Techniques; Electrodes; Equipment Design; Humans; Nanostructures; Paper; Soot
PubMed: 32174547
DOI: 10.1016/j.bios.2020.112033 -
Environmental Science and Pollution... Feb 2023Physicochemical properties of nanoparticles are important in regulating nanoparticle toxicity; however, the contribution of nanoparticle charge remains unclear. The...
Physicochemical properties of nanoparticles are important in regulating nanoparticle toxicity; however, the contribution of nanoparticle charge remains unclear. The objective of this study was to investigate the pulmonary effects of inhalation of charged soot nanoparticles. We established a stably charged nanoparticle generation system for whole-body exposure in BALB/c mice, which produced positively charged, negatively charged, and neutral soot nanoparticles in a wide range of concentrations. After a 7-day exposure, pulmonary toxicity was assessed, together with proteomics analysis. The charged soot nanoparticles on average carried 1.17-1.35 electric charges, and the sizes for nanoparticles under different charging conditions were all fixed at 69 ~ 72 nm. We observed that charged soot nanoparticles induced cytotoxic LDH and increased lung permeability, with the release of 8-isoprostane and caspase-3 and systemic IL-6 in mice, especially for positively charged soot nanoparticles. Next, we observed that positive-charged soot nanoparticles upregulated Eif2, Eif4, sirtuin, mammalian target of rapamycin (mTOR), peroxisome proliferator-activated receptors (PPAR), and HIPPO-related signaling pathways in the lungs compared with negatively charged soot nanoparticles. HIF1α, sirt1, E-cadherin, and Yap were increased in mice's lungs by positively charged soot nanoparticle exposure. In conclusion, carbonaceous nanoparticles carrying electric ions, especially positive-charged, are particularly toxic when inhaled and should be of concern in terms of pulmonary health protection.
Topics: Animals; Mice; Soot; Lung; Nanoparticles; Administration, Inhalation; Mammals
PubMed: 36223019
DOI: 10.1007/s11356-022-23444-4 -
The Science of the Total Environment Sep 2022Black carbon (BC) and brown carbon (BrC) have intensive impacts on atmospheric visibility and global climate change. In this study, PM samples were collected at Pudong...
Black carbon (BC) and brown carbon (BrC) have intensive impacts on atmospheric visibility and global climate change. In this study, PM samples were collected at Pudong (PD) and Qingpu (QP) of Shanghai in 2017, and characterized typical organic molecular tracers by gas chromatography-mass spectrometer. The light absorption (Abs) of carbonaceous aerosol and water-soluble organic matter was analyzed by a multi-wavelength thermal/optical carbon analyzer and a long-range ultraviolet-visible spectrophotometer. An improved two-component model integrated with both optical and chemical fingerprints of carbonaceous aerosol was applied to analyze the Abs of BC, water-soluble organic carbon (WSOC) and water-insoluble organic carbon (WISOC), with which the potential influencing factors including emission source and atmospheric aging were investigated. Results indicated that BrC contributed 19% at PD and 16% at QP of the total light absorption of the carbonaceous aerosol at 405 nm wavelength. Meanwhile, Abs/Abs showed significant seasonal variations (27-50%) at both sites. Positive matrix factorization (PMF) analysis showed that vehicle emissions (60-61%) and biomass combustion (38-39%) were the major contributors to Abs, while biomass burning (34-40%), nitrate-relevant secondary processes (22-23%), vehicle emissions (18-19%) and biogenic SOA (13-19%) were major contributors to Abs. Hybrid combustion source (94-96%) had a predominant contribution to Abs. Statistical analysis showed that biomass burning had a great impact on the enhancement of Abs. Absorption Ångström exponent (AAE) and mass absorption efficiency (MAE) of each factor (source) using PMF analysis indicated that WSOC from combustion sources had higher AAE values (8.11 and 8.29 for coal and biomass burning, respectively) and MAE values (0.63-0.99) compared to other sources. Atmospheric aging process can lower the MAE value (0.24-0.52). Overall, our study facilitates a better understanding of the relationships among source, optical properties, and atmospheric transformation processes of the carbonaceous aerosols in Shanghai.
Topics: Aerosols; Air Pollutants; Carbon; China; Environmental Monitoring; Particulate Matter; Soot; Vehicle Emissions; Water
PubMed: 35644399
DOI: 10.1016/j.scitotenv.2022.156280 -
Chemosphere Mar 2022The toxic influence of soot microparticles on terrestrial organisms has been well studied, although there is scarce data on how microparticles could affect hydrobionts....
The toxic influence of soot microparticles on terrestrial organisms has been well studied, although there is scarce data on how microparticles could affect hydrobionts. We performed a first-ever study of the short-term (5 days) impact of furnace soot (0.005 g/L) on the structural and functional features of gill cells in the Baikal Sculpin species Paracottus knerii, Dybowski, 1874. The soot samples used in the experiment were composed of small (10-100 nm) particles and larger (up to 20 μm) aggregates. The dominant fractions of the polycyclic aromatic hydrocarbons of these microparticles were phenanthrene, fluoranthene, pyrene, benzo[a]anthracene, chrysene, benzofluoranthenes, benzopyrenes, indeno[1,2,3-c,d]pyrenes, and benzo[ghi]perylene. Trace element analysis of the soot detected the presence of C, S, Si, Al, Ca, K, Mg, P, and Fe. The gill condition was assessed with electron scanning, transmission, and laser confocal microscopy. Soot induces degenerative changes in the macrostructure and surface of secondary lamellae and increases mucus production in fish gills. A decrease in mitochondrial activity, an increase in reactive oxygen species production, and an increase in the frequency of programmed cell death in gill epithelium were observed under the influence of soot. In chloride cells, an induction of macroautophagy was detected. In general, the changes in fish gills after the short-term influence of soot microparticles indicate the stress of respiratory and osmotic regulation systems in fish. The data obtained are important for forming a coherent picture of the impact of soot on hydrobionts and for developing bioindication methods for evaluating the risks of their influence on aquatic ecosystems.
Topics: Animals; Ecosystem; Gills; Polycyclic Aromatic Hydrocarbons; Soot
PubMed: 34896428
DOI: 10.1016/j.chemosphere.2021.133241 -
Environmental Science. Processes &... Apr 2022Elemental carbon is often found in ambient particulate matter (PM), and it contributes to the PM's oxidative potential (OP) and thus poses great health concerns.... (Review)
Review
Elemental carbon is often found in ambient particulate matter (PM), and it contributes to the PM's oxidative potential (OP) and thus poses great health concerns. Previous review articles mainly focused on the methodologies in evaluating OP in PM and its relationship with selected chemical constituents, including metal ions, PAHs, and inorganic species. In recent years, growing attention has been paid to the effect of atmospheric aging processes on the OP of EC-containing airborne particles (ECCAPs). This review investigates more than 150 studies concerning the OP measurements and physico-chemical properties of both fresh and aged ECCAPs such as laboratory-generated elemental carbon (LGEC), carbon black (CB), soot (black carbon), and engineered carbon-containing nanomaterials (ECCBNs). Specifically, we summarize the characteristics of water-soluble and insoluble organic species, PAHs, quinone, and oxygen-containing functional groups (OFGs), and EC crystallinity. Both water-soluble organic carbon (WSOC) and water-insoluble organic carbon (WIOC) contribute to the OP. Low molecular weight (MW) PAHs show a higher correlation with OP than high MW PAHs. Furthermore, oxidative aging processes introduce OFGs, where quinone (CO) and epoxide (O-C-O) increase the OP of ECCAPs. In contrast, carboxyl (-COOH) and hydroxyl (-OH) slightly change the OP. The low crystallinity of EC favors the oxygen addition and forms active OFG quinone, thus increasing the OP. More detailed analyses for the EC microstructures and the organic coatings are needed to predict the OP of ECCAPs.
Topics: Air Pollutants; Carbon; Environmental Monitoring; Oxidative Stress; Oxygen; Particulate Matter; Polycyclic Aromatic Hydrocarbons; Soot; Water
PubMed: 35333266
DOI: 10.1039/d1em00497b -
Waste Management (New York, N.Y.) Jun 2024This research investigates the formation mechanism of soot and particulate matter during the pyrolysis and gasification of waste derived from Municipal Solid Waste (MSW)...
This research investigates the formation mechanism of soot and particulate matter during the pyrolysis and gasification of waste derived from Municipal Solid Waste (MSW) in a laboratory scale drop tube furnace. Compared with CO gasification atmosphere, more ultrafine particles (PM, aerodynamic diameter less than 0.2 μm) were generated in N atmosphere at 1200℃, which were mainly composed of polycyclic aromatic hydrocarbons (PAHs), graphitic carbonaceous soot and volatile alkali salts. High reaction temperatures promote the formation of hydrocarbon gaseous products and their conversion to PAHs, which ultimately leads to the formation of soot particles. The soot particles generated by waste derived from MSW pyrolysis and gasification both have high specific surface area and well-developed pore structure. Compared with pyrolysis, the soot generated by gasification of waste derived from MSW had smaller size and higher proportion of inorganic components. The higher pyrolysis temperature led to the collapse of the mesoporous structure of submicron particles, resulting in a decrease in total pore volume and an increase in specific surface area. Innovatively, this research provides an explanation for the effect of reaction temperature/ CO on the formation pathways and physicochemical properties of soot and fine particulate matter.
Topics: Particulate Matter; Solid Waste; Pyrolysis; Hot Temperature; Soot; Refuse Disposal; Incineration; Carbon Dioxide; Polycyclic Aromatic Hydrocarbons; Particle Size
PubMed: 38631177
DOI: 10.1016/j.wasman.2024.04.025