Total Solid Particles Research Articles

Aerosol variability and glacial chemistry over the western Himalayas

Environmental context While it is known that aerosol deposition causes exacerbated melt of the glaciers, information about aerosol variability and deposition in the glaciated environments in the western Himalayas is still lacking. We analysed the aerosol variability, modelled the potential aerosol sources and assessed physicochemical characteristics of glacier ice in the region. This information could be foundational for initiating studies on aerosol impacts on the glacier melt besides climate change. Rationale There is increasing scientific evidence of aerosol deposition triggering glacier melting but very little understanding about the spatiotemporal variability of aerosols over the Indian Himalayas. The current study is a maiden effort to ascertain the aerosol variability in glacial environments of the Indian Himalayas. Aerosol sources were modelled and physicochemical characteristics of glacial ice were evaluated to draw firsthand insights into the light-absorbing impurities over three glaciers. Methodology Aerosol variability over four decades was analysed using MERRA-2 data (Modern-Era Retrospective analysis for Research and Applications) over five different topographically distinct mountain ranges of the western Himalayas. Information about nine physicochemical variables was analysed over the ablation zone of glaciers in the region. HYSPLIT model was used to track the air mass sources at a weekly time-step from December 2020 to November 2021 over the selected glaciers. Results and discussion MERRA-2 data analyses indicate increasing trends in surface dust, columnar dust and black carbon. The highest columnar dust concentration was found in Pir Panjal Mountain Range (PP: 125 648 µg m−2) followed by the Greater Himalayan Mountain Range of Kashmir (GH: 64 384 µg m−2), Karakoram (KA: 47 574 µg m−2), Ladakh (LA: 45 861 µg m−2) and Zanskar (ZA: 38 416 µg m−2), however, the black carbon indicated a PP > GH > LA > KA > ZA trend. HYSPLIT trajectories indicate that the contribution of global sources is highest (65%) followed by local (21%) and regional (14%) sources. Ice chemistry analysis revealed a higher concentration of total solid particles (830 mg L−1) and sulfates (14.33 mg L−1) indicative of the contribution from anthropogenic footprint and lithology. Conclusion The research underpins the need for establishing long-term aerosol observatories and a detailed hydrochemical assessment for precisely ascertaining the black carbon and allied constituents to unravel their contribution to glacier melt in the north-western Himalayas.

Problems Related to Gasification of Biomass—Properties of Solid Pollutants in Raw Gas

Nowadays, thermochemical biomass conversion appears to be a very promising way to process heat and steam generation, for use in a cogeneration unit engine, or for example in gas turbines producing electrical energy. The biggest problem regarding using the syngas in internal combustion engines, are pollutants, which have quite an inauspicious influence on their proper working. This article deals with the establishment of the distribution size of solid particles captured by the fiber filters in the syngas with a suitable cleaning design. Gas was produced in the fixed-bed “Imbert” type generator. Filter cake, which contained pollutants, was captured on a filter and then analyzed. Based on single total solid particles (TSP) components, we conclude that this includes its partial elimination.

Correlation of nanoparticle size distribution features to spatiotemporal flame luminosity in gasoline direct injection engines

Particle size distribution measured by mobility instruments is a common diagnostic used to characterize ultrafine and nanoparticle emissions in engine exhaust; however, some features of particle size distribution data are poorly correlated to in-cylinder combustion phenomena. In this work, in-cylinder spatiotemporal flame luminosity is quantitatively correlated to features in the solid particle size distribution measured in the exhaust of a gasoline direct injection engine operating in lean and stoichiometric combustion modes. A multi-channel optical sensor was used to measure diffusion flame light intensity in different areas of the combustion chamber. Total solid particle number and particle size distribution in the exhaust were measured using a scanning mobility particle sizer after a catalytic stripper that removed semi-volatile compounds. Results of the experiments showed that different flame phenomenon resulted in distinct particle size distribution characteristics. A large accumulation mode (particles with diameter of 50–100 nm) in the particle size distribution from stoichiometric engine operation with early injection resulted from anomalous diffusion flames like piston-top pool fires. In lean operation incorporating a secondary fuel injection, particle emissions were dominated by flame propagation through fuel-rich regions of the combustion chamber resulting in a comparatively broad particle size distribution. More generally, this work illustrates how particle size distribution data can be more accurately used to diagnose soot formation in gasoline direct injection engines.

Emission characterization of modern wood stoves under real-life oriented operating conditions

The quality of emission inventories substantially bases on the reliability of used emission factors (EFs). In this work EFs were studied according to recently published characterization methods, called “beReal”, reflecting real life operating conditions in Europe. EFs for four pellet stoves and nine firewood appliances (roomheaters and cookers) of carbon monoxide (CO), organic gaseous compounds (OGC), nitrogen oxides, total solid particles (TSP) of hot and of diluted flue gas, total, elemental and organic carbon (TC, EC, OC) and benzo(a)pyrene were determined.CO, OGC, TSPs, TC, EC and OC emissions from firewood appliances were significantly higher than for pellet stoves, indicating the high relevance of classifying appliances according to the operation type. TSP sampled from diluted flue gas at 40 °C (28 mg MJ−1 to 271 mg MJ−1 based on fuel input) was higher than TSP sampled from hot flue gas (21 mg MJ−1 to 70 mg MJ−1). This reveals the high relevance of sampling conditions for the determination of real life emissions. Benzo(a)pyrene emissions scattered over a wide range (0.5 μg MJ−1 to 129.8 μg MJ−1) indicating high sensitivity to unfavorable combustion conditions. Therefore a higher number of experimentally determined emissions factors could improve the reliability of EFs for inventories. CO emissions measured in beReal tests were substantially higher than official type tests, thus showing that type testing results provide limited information for the determination of real life emissions.A systematic evaluation of EFs with defined real life methods like beReal would substantially improve the reliability of emission inventories.

Distribution of persistent organic pollutants (POPs) in atmospheric particles during district heating period (DHP) and non-district heating period (N-DHP) in Shandong province, China

Persistent organic pollutants (POPs), including polycyclic aromatic hydrocarbons (PAHs), organochlorine pesticides (OCPs), phthalic acid esters (PAEs), and polychlorinated biphenyls (PCBs), were systemically investigated in total solid particles (TSPs) sampled at seven sites in Shandong province, China. The congener profile and space distribution were compared during district heating period (DHP) in winter and non-district heating period (N-DHP) in spring. The air pollution at in-land sites was worse than that at seashore sites due to the different ventilation conditions and pollutant sources. The concentrations of PAHs associated to the distribution of TSP, severer in DHP, since coal burning was the major source for both pollutants, according to the analysis of these results and diagnostic ratios. FLT, PYR, and BBF were top PAH congeners by specific mass concentrations. On the profile, OCPs, PCBs, and PAEs were more related to the ambient temperature due to the evaporation and revealed higher abundancy in N-DHP than in DHP. Based on the diagnostic ratio analysis, the source of pollution was more likely local than remote.

Correlation of Volume Ratio and Normalized Permittivity in Particle Mixture

The volume ratio in the total solid particle mixture is an important parameter indicating the characteristics of particulate mixtures. Therefore, a simple measurement method is desirable. In this paper, the normalized permittivities of two groups of particle mixtures are tested using electrical capacitance tomography (ECT) with the series and parallel models. The experimental results show that normalized permittivity changes obtained from the series ECT model have a very strong linear relationship with the volume ratio of higher permittivity materials in the mixture. The Maxwell Garnett formula can predict the normalized permittivity only after the permittivity of each type of particle is known. The comparison between two methods suggests that ECT with the series model is a better way to monitor the volume ratio in mixtures comprising two different types of solid particle.

Emissions of gases and particles from charcoal/biochar production in rural areas using medium-sized traditional and improved “retort” kilns

Charcoal is used for cooking in many parts of the developing world. Charcoal from agricultural materials can also be used as a soil amendment to enhance agricultural production, and is often termed “biochar” in this case.Charcoal may be produced in various types and scales of systems, but for rural tropical areas, traditional kiln technologies without treatment of the pyrolysis gases dominate. Traditional charcoal industry is considered to be both inefficient and polluting, emitting harmful off-gases containing methane, carbon monoxide and particles. Retort kilns, which recirculate and combust the pyrolysis gases internally have been claimed to overcome this problem. Even though retort technology has frequently been discussed, this paper is the first study determining gas emission factors for operational retort kilns in rural tropical areas. The mean emission factors for the retort kilns found in this study using identical feedstock were (in g kg−1 charcoal); carbon dioxide (CO2) = 1950 ± 209, carbon monoxide (CO) = 157 ± 64, non-methane volatile organic components (NMVOC) = 6.1 ± 3.4, methane (CH4) = 24 ± 17, total solid particles (TSP) = 12 ± 18, products of incomplete combustion (PIC) = 200 ± 97 and nitric oxides (NOx) = 1.8 ± 1.0. The corresponding value for the non-retort kilns tested was in general higher; CO2 = 2380 ± 973, CO = 480 ± 141, NMVOC = 13 ± 3.8, CH4 = 54 ± 29, TSP = 7.9 ± 2.6, PIC = 554 ± 138 and NOx = 4.3 ± 1.6. The difference between the kiln types was statistically significant (p < 0.05) for CO, NMVOC, PIC and NOx. However, the retort kilns consumed ignitable fuel such as wood in the start-up phase to reach pyrolysis temperature resulting in insignificant difference in yield between retort and non-retort kilns. In addition, retort kilns are more costly than traditional kilns, which may be challenging for implementation. It is therefore important to continue design development, especially with regard to wood consumption during the start-up phase.

Influence of traffic emissions on the composition of atmospheric particles of different sizes – Part 1: concentrations and elemental characterization

Epidemiological studies initially considered the impact of total solid particles on human health, but according to the acquired knowledge about the worse effect of smaller particles, those studies turned to consider the impact of PM10. However, for the last decade PM2.5 began to be more important, once as they are smaller they can penetrate deeper in the lungs, being possible their trapping in alveoli and worse effects on human health. Therefore, more information on PM2.5 should be provided namely concerning the levels and elemental composition. Considering the relevance of traffic on the emission of particles of small sizes, this work included the detailed characterization of PM10 and PM2.5, sampled at two sites directly influenced by traffic, as well as at two reference sites, aiming a further evaluation of the influence of PM10 and PM2.5 on public health. The specific objectives were to study the influence of traffic emission on PM10 and PM2.5 characteristics, considering concentration, size distribution and elemental composition. PM10 and PM2.5 samples were collected using low-volume samplers; the element analyses were performed by particle induced X-ray emission (PIXE). At the sites influenced by traffic emissions PM10 and PM2.5 concentrations were 7–9 and 6–7 times higher than at the background sites. The presence of 17 elements (Mg, Al, Si, P, S, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn and Pb) was determined in both PM fractions; particle metal contents were 3–44 and 3–27 times higher for PM10 and PM2.5, respectively, than at the backgrounds sites. The elements originated mostly from anthropogenic activities (S, K, V, Mn, Ni, Zn and Pb) were predominantly present in PM2.5, while the elements mostly originated from crust (Mg, Al, Si and Ca) predominantly occurred in PM2.5–10. The results also showed that in coastal areas sea salt spray is an important source of particles, influencing PM concentration and distributions (PM10 increased by 46%, PM2.5/PM10 decreased by 26%), as well as PM compositions (Cl in PM10 was 11 times higher).

Computational Design for Grain‐Oriented Microstructure of Functional Ceramics Prepared by Templated Grain Growth

We have developed a computational model using Monte Carlo simulation in order to design grain‐oriented microstructures of ceramics processed by templated grain growth for functional materials with anisotropic grain growth due to anisotropy in interfacial energies. The current model with plate‐like template particles expressed the development of grain‐oriented microstructures with the low interfacial energy planes well faceted. In addition, the proposed model gave a guiding principle for optimizing the initial parameters (i.e., ratio of templates to total solid particles, initial size and aspect ratio of template particles, and amount of liquid phase), leading to highly grain‐oriented ceramics with improved performances.

Inorganic geochemistry of roadway dust from the metropolitan area of Palermo, Italy

Inorganic matter from roadway dust collected in the urban area of Palermo, Italy, was analysed to identify the chemical elements introduced into the environment as a result of human activities. Metals of environmental concern exhibit very high enrichment factors, which in some cases exceed 100. Metal size distribution indicates that Pd, Pt, Au, Sb, Zn, S, Ni, V, Mo and Cr substantially accumulate in the finest particles, whereas Pb, Br, As, Cu, Ag and Ba are almost independent of the size fraction. SEM/EDS analyses revealed that some individual particles contain clusters of foreign particles (<10 lm) made up of Fe-Ni, Cr-Ni or Fe alone, typical of the abrasion of stainless steel. Others are aggregates of smaller Pb-Br-Cl particles. Lead isotope composition indicates that Pb pollution is mainly due to automobile exhausts and industrial sources. Pt and Pd concentrations reveal the increasing release of these elements into the environment from catalytic converters. Data indicate that monitoring Total Solid Particles, as generally done by the municipal agencies for the environment, is inadequate from a sanitary point of view, while there is a need for more attention to the presence of trace elements in air- borne particulate matter and their distribution as a function of particle size.

Energy saving and pollution control for short rotary furnace in secondary lead smelters

This work discusses a method to suppress the fugitive emissions of total solid particles (TSP) and save energy for industrial lead smelters. Pilot scale experiments simulating the industrial short rotary furnace (SRF) in lead smelters were studied. An energy study was manifested on a typical lead smelter. Factors affecting the objectives of this work have been investigated. The results obtained revealed that the rate of fuel consumption of heavy fuel (mazout) is highest in the early period of smelting. The flue gases in the existing small lead smelters are heavily loaded, with TSP outweighing the constrains given by law 4/94. About 60% of the energy input in the SRF escapes to the environment causing pollution hazards of TSP and spreading out excessive heat. Applying clean technology including pelletization of battery paste saved about 35% and 12.5% of heat and total energy consumption, whereas fugitive TSP decreases by about 67%. A theoretical model explaining the lead recovery process is given. It is based on heat and mass transfer and the thermodynamic properties of the species and reactions involved. Prediction of the findings of this model has been experimentally verified with a marginal accuracy of 4%. On an economic basis, nearly 14% of the plant turnover is saved annually.

INAA of Aerosol Samples in Mexico City

Total solid particles (TSP), respirable particles (RP) PM10 and 17 metallic pollutants were measured in dwellings in the Metropolitan Zone of Mexico Valley (MZMV) by gravimetry and instrumental neutron activation analysis (INAA). Monitoring was performed in Northeast, Center, Southeast and Southwest Zones in the winter and spring seasons. In general, the average concentration of contaminants (derived from industrial activities) that we have determined have increased with time. TSP and RP PM10 are often above the US and Mexican norms.

High spatial resolution IR observations of young stellar objects - A possible disk surrounding HL Tauri

view Abstract Citations (98) References (10) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS High spatial resolution IR observations of young stellar objects : a possible disk surrounding HL Tauri. Grasdalen, G. L. ; Strom, S. E. ; Strom, K. M. ; Capps, R. W. ; Thompson, D. ; Castelaz, M. Abstract High spatial resolution images of the T Tauri star HL Tau were obtained at 1.6 microns and 2.2 microns. The original images as well as maximum entropy image reconstructions reveal a circumstellar envelope structure, similar at both wavelenghts, and extended along P.A. = 112 deg; the 10 percent width of the structure is 1.9 sec (300 AU at 160 pc). The extended structure is interpreted as light scattered toward earth by dust in a disk surrounding this young stellar object. Polarization measurements made at 2.2 microns support this hypothesis. The total solid particle mass is, at minimum, 5 x 10 to the -7th solar mass. Publication: The Astrophysical Journal Pub Date: August 1984 DOI: 10.1086/184333 Bibcode: 1984ApJ...283L..57G Keywords: Infrared Astronomy; Pre-Main Sequence Stars; Stellar Envelopes; T Tauri Stars; Maximum Entropy Method; Spatial Resolution; Spectral Energy Distribution; Astrophysics full text sources ADS | data products SIMBAD (2)