Showing papers on "Particulates published in 1978"
TL;DR: The reduction rate data suggest that the pathway of nitrate reduction to ammonia is important in coastal sediments.
Abstract: Simultaneous determinations of nitrogen gas production, ammonia, and particulate organic nitrogen formation in the coastal sediments of Mangoku-Ura, Simoda Bay, and Tokyo Bay were made by using the 15N-label tracer method. The rate of nitrogen gas production in the sediment surface layer was about 10−2 μg atom of N per g per h, irrespective of the location of the sediments examined. [15N]ammonia and -particulate organic nitrogen accounted for 20 to 70% of the three products, and after several hours of incubation, the major fraction of nondenitrified 15N in Mangoku-Ura and Simoda Bay sediments was recovered as ammonia. In Tokyo Bay sediments, particulate organic nitrogen was produced at a greater rate than was ammonia. The reduction rate data suggest that the pathway of nitrate reduction to ammonia is important in coastal sediments.
235 citations
220 citations
TL;DR: In this article, a combination of airborne particulate matter sampling and gas phase sampling was used in conjunction with computerized data elaboration to identify more than 100 compounds in the gas phase.
203 citations
TL;DR: In this paper, the chemical composition of atmospheric particulate matter collected by air filtration in the plumes from various active craters and vents at Mount Etna, Sicily, in June 1976, allowed to estimate a discharge of particulate elements to the atmosphere shown to be representative of the long-term activity of the volcano.
Abstract: Measurements of the chemical composition of atmospheric particulate matter, collected by air filtration in the plumes from various active craters and vents at Mount Etna, Sicily, in June 1976, allowed to estimate a discharge of particulate elements to the atmosphere shown to be representative of Mount Etna long-term activity. For some enriched trace elements in this volcanic aerosol (Cu, Zn, Se, Hg, Cd and Pb) the discharge from Mount Etna was compared to an estimate of the anthropogenic atmospheric release from the bordering countries of the Mediterranean basin. This comparison shows that, relative to the anthropogenic release of these elements, the discharge from Mount Etna is insignificant for Pb, comparable for Cd, Hg, Cu and Zn and is predominant for Se, in the Mediterranean atmospheric environment.
183 citations
TL;DR: Particulate matter, divided into to 53 and >53-μm size fractions, was obtained using the Large Volume in situ Filtration System (LVFS), Southlant Expedition, R.V. Chain 115, and was analysed for chemical (dry weight, Na, K, Mg, Ca, opal, Sr, C and N), organismal (species assemblage and population densities), and morphological distributions.
172 citations
TL;DR: The surface aerosol in the NE trade wind region at the island of Sal, Cape Verde Islands, was studied in a comprehensive research program as mentioned in this paper, where the authors found that the aerosol observed has a particle concentration comparable to that of clean air and a total mass like that of polluted air.
Abstract: The surface aerosol in the NE trade wind region at the island of Sal, Cape Verde Islands, was studied in a comprehensive research program. The knowledge of this aerosol is important in view of the large source represented by the Sahara for mineral particles and the worldwide transport over the Atlantic Ocean and further. Aerosol properties such as total size distribution, mass, sea salt, mineral, organic compound content, water adsorption, optical properties, and soil material were studied in a 3-week field campaign in summer 1973. The aerosol observed has a particle concentration comparable to that of ‘clean air’ and a total mass like that of ‘polluted air’ (see the definition by Study of Man's Impact on Climate (1971)). Its sea salt content is comparatively small, and its water uptake is somewhat similar to that of pure ammonium sulfate. The content of organic material is similar to that of background aerosols, but the turbidity resembles that of polluted city air. The source strength of the Sahara desert for aerosol particles was estimated from 2 years of optical measurements and found to be greater than was previously estimated.
131 citations
TL;DR: The mutagenic effect of extracts derived from airborne particulate matter was investigated with the Ames-test and the whole extract proved to be distinctly mutagenics.
98 citations
TL;DR: In this article, the global source, distribution, and fluxes of non-methane organic matter are investigated. But, the authors admit that less is known about the global sources and distribution of organic matter than any other major class of chemical substances in the atmosphere.
Abstract: Perhaps less is known about the global source, distribution, and fluxes of non-methane organic matter than any other major class of chemical substances in the atmosphere. Source strength estimates and consideration of the available concentration data suggest that the quantity of organic carbon on large particles (d>1 μm) in the global troposphere can be explained by primary emissions from anthropogenic sources and such natural sources as the ocean, crustal weathering, and forest wildfires. However, these pollution and natural sources apparently cannot account for the global tropospheric burden of small particle (d<1 μm) organic carbon. Approximately 80–160 MT/yr of small particle carbon from some additional source is required to balance this cycle. Possibilities include direct production from the leaves of vegetation and gas to particle conversion of natural and anthropogenic organic carbon compounds. The estimated production of reactive vapor phase organic compounds from natural and pollution sources is sufficient to account for the mass of this additional small particle organic carbon. However, considerably more data is required on the global distribution, source strengths, reaction pathways and rates, and removal mechanisms before an accurate description of the non-methane organic carbon cycle can be made.
88 citations
TL;DR: The concentration of 15 amino acids in hydrolyzed particulate matter from different regions and depths of the Pacific Ocean has been measured by liquid chromatography as mentioned in this paper, and the relative composition was similar for all samples in the euphotic zone, where the particulate amino acid (PAA) concentration ranged from 370 to 2260 nmoles/1 in coastal waters and from 90 to 260 nmoles /1 in open ocean.
81 citations
TL;DR: Suspended and sedimented particulate carbon, nitrogen, chlorophyll a, and phaeophytin were measured at various depths throughout the year in a small marine bay as discussed by the authors.
Abstract: Suspended and sedimented particulate carbon, nitrogen, chlorophyll a, and phaeophytin were measured at various depths throughout the year in a small marine bay. Seasonal and vertical differences in sedimentation rates were not simply related to changes in concentration of suspended particulate matter. Chlorophyll a/total pigment, carbon/nitrogen, and carbon/chlorophyll a ratios in suspended and sedimented material were usually different. Sedimentation rates generally increased with depth with greatest increases during periods of low stratification. Resuspension and horizontal transport of sedimenting material was implied by discontinuities in sedimentation at particular depths. Annual sedimentation of particulate carbon at 20 m depth (below the seasonal thermocline) was equivalent to 15% of the estimated supply from photosynthetic and chemosynthetic production, river discharge, and sewage input. Material deposited during periods of stratification, however, which coincided with high rates of primary produc...
74 citations
01 Feb 1978
TL;DR: The techniques used to characterize the chemical and physical nature of particulates in diesel exhaust emissions are reviewed in this paper, where the emphasis is on understanding the broader aspects of the fundamental nature of diesel particulates, but particulate systems in general.
Abstract: The techniques used to characterize the chemical and physical nature of particulates in diesel exhaust emissions are reviewed. The emphasis is on understanding the broader aspects of the fundamental nature of not only diesel particulates, but particulate systems in general. Consideration is given to the special nature of particulates which make them significant pollutants and to the relative place of the diesel in the formation of man-made particles. The underlying combustion processes leading to carbon and sulfur based particulates are reviewed. The important variables in steps of the combustion processes which lead to particulate formation are considered, as well as major fuel and engine factors. Collection methods are examined with examples given from current diesel dilution techniques. Probes, sampling lines, and instrumentation are considered. Methods of physical and chemical characterization are presented and examples from the current and prior diesel work at Michigan Technological University and elsewhere are given.
TL;DR: In this paper, the plume of the coal-fired Labadie power plant near St Louis was positively identified and sampled from aircraft over a range exceeding 300 km and 10 h of transport during day and night on July 9 and July 18.
TL;DR: The St. Louis ambient aerosol has been continuously monitored using a flame photometric detector (FPD) to measure particulate sulfur concentration, and in situ thermal analysis to chemically analyze the aerosol for H 2 SO 4 and its ammonium salts, NH 4 SO 4, (NH 4 ) 3 H(SO 4 ) 2, and NH 4 2 SO4, during the sixteen day monitoring period as discussed by the authors.
TL;DR: In this paper, the authors determined the contribution of automobile tire wear to air pollution and found that most of the tire debris had settled within 5 m of the pavement edge. But tire wear products are not a significant air pollution problem.
Abstract: This paper is directed to air pollution scientists interested in special mobile emission sources. The purpose was to determine the contribution which automobile tires make to air pollution. The gaseous hydrocarbon and sulfur compounds emitted in laboratory tests were identified. Although these hydrocarbons can participate in smog reactions, their mass emission rate is less than 0.1 % of the current exhaust hydrocarbon emission rate. Hydrocarbons from tires are not measurable near a freeway. The particulate emitted from tires ranges in size from 0.01 μm to more than 30 μm, with the larger particles dominating the total mass. Measurements along a California freeway showed that most of the tire debris had settled within 5 m of the pavement edge. Airborne rubber concentrations were less than 0.5 μg/m3, or less than 5% of the total tire wear. These field measurements confirm the indoor emission pattern and verify that tire wear products are not a significant air pollution problem.
TL;DR: The role of bubbles in the transfer of organic carbon in marine waters from a dissolved organic substance was investigated in this article, where an adsorptive bubble separation technique was used to determine the removal and transport of POC and nitrogen by rising bubbles from estuarine, coastal, and open ocean surface seawater samples.
Abstract: Flotation experiments with surface marine waters collected from estuarine, continental shelf, slope, and open ocean waters showed that about half of the originally present particulate organic carbon and nitrogen was adsorbed and transported by bubbles to the surface froth. Recovery values were a function of primary production and other environmental parameters. In only one instance was there evidence of selective removal of particles with C:N ratios differing from those left behind. The estimated open ocean transport of POC by bubbles was five times higher than an earlier estimate due to the unexpected efficiency of the flotation column at low concentrations of open ocean POC. Budget calculations indicated little or no conversion of dissolved to particulate organic carbon. Large macroscopic particles quickly formed in the froth produced by bubbling, an aggregation phenomenon which may be of importance in the transport of large particle POC to deep waters. Particulate matter concentrated in the surface microlayer of the sea may be living or nonliving and is not limited to organic matter (e.g. Parker and Barsom 1970; Liss 1975a,b). Microlayer concentrations of particulate organic carbon (POC) and nitrogen (PON) are substantially greater than the concentrations in the water column below the microlayer (Williams 1967; Nishizawa 197 1). Our work is an attempt to better define processes that lead to the enrichment of organic substances at the air-sea interface and the chemical and physical nature of the concentrated material. An adsorptive bubble separation technique was used to determine the removal and transport of POC and PON by rising bubbles from estuarine, coastal, and open ocean surface seawater samples. The fraction of organic particulate matter in surface waters that possessed an affinity for the air-water interface was thus empirically defined. Baylor and Sutcliffe (1963), Riley (1963), and others have investigated the role of bubbles in the transfer of organic carbon in marine waters from a dissolved
TL;DR: A total of 150 samples were collected at a 10-day anchor station in the Bornholm basin (55° 31.1'N, 15° 32.1"E) and analyzed for dissolved (< 0.4 [mu]m) and particulate trace metals as mentioned in this paper.
TL;DR: In this article, HNO3 vapor was found to be as common over marine areas, far from anthropogenic sources of NOx, as over remote continental regions, ranging from <.02 to.3 ppbv.
Abstract: Measurements of HNO3 vapor and particulate NO3− were made over continental and marine areas, at altitudes from .2 to 7 km, as a part of Project Gametag. HNO3 vapor was found to be as common over marine areas, far from anthropogenic sources of NOx, as over remote continental regions, ranging from < .02 to .3 ppbv. Urban influenced continental values ranged from .3 to .86 ppbv. Comparable HNO3 was found both above and within the boundary layer, in contrast to theoretical predictions of a negative HNO3 gradient with altitude. In many regions of the troposphere there was more HNO3 vapor than participate NO3−, although the reverse is true in the marine boundary layer, where it appears that heterogeneous chemistry converts HNO3 and Cl− to HCl and particulate NO3−. This rather limited data set suggests an HNO3 lifetime on the order of a few days.
IBM1
TL;DR: In this article, a series of experiments underscores the importance of the capillary force in the adhesion of a particulate to a surface, and the authors calculate the force required to roll a particle off a surface from the theoretical adhesion force between a particle and a surface and particulate deformation characteristics.
TL;DR: In this paper, the authors present a rationale for estimating the yield of particulate carbon for natural assemblages from data on biomass and 14C uptake, showing that the overestimation is slight (10-20%) for rapidly increasing assemblage, but ranges to severalfold for nutrient-poor, slow-growing cultures.
Abstract: Organic carbon budgets for mixed cultures of lake phytoplankton indicate that [14C]CO2 uptake overestimates net particulate carbon production. The overestimate is slight (10–20%) for rapidly increasing assemblages, but ranges to severalfold for nutrient-poor, slow-growing cultures. A rationale is presented for estimating the yield of particulate carbon for natural assemblages from data on biomass and 14C uptake.
Patent•
17 Oct 1978
TL;DR: In this paper, a method operating at relatively low pressure drop and low initial velocity for removing pollutants down to sub-micron sizes from gas streams comprising a nozzle means accelerating the gas flow and impinging the pollutants upon a plate for removal of a major portion of pollutants and then passing the gas stream through fabric filters for removing all of the remaining particulate pollutants.
Abstract: Apparatus and method operating at relatively low pressure drop and low initial velocity for removing pollutants down to sub-micron sizes from gas streams comprising a nozzle means accelerating the gas flow and impinging the pollutants upon a plate for removal of a major portion of pollutants and then passing the gas stream through fabric filters for removal of substantially all of the remaining particulate pollutants.
TL;DR: In this paper, airborne measurements of particle and gas emissions have been obtained in paroxysmal, intra-uptive, posteruptive and extraeruptive emissions from six volcanoes.
Abstract: Airborne measurements of particle and gas emissions have been obtained in paroxysmal, intraeruptive, posteruptive, and extraeruptive emissions from six volcanoes. The paroxysmal and intraeruptive emissions contained relatively few small particles (<0.1 μm in size) and little gaseous sulfur in comparison to the posteruptive and extraeruptive emissions. The majority of the SO2 injected in the atmosphere (≃0.1 Tg) by the 1976 eruption of Saint Augustine probably occurred during the intraeruptive and posteruptive stages. The paroxysmal eruptions of Saint Augustine produced about 6 Tg of particles of 0.01–66 μm in size and about 0.2 Tg of particles 0.01–5 μm in size. An additional 0.05 Tg of 0.01- to 5-μm sized particles were emitted during the posteruptive and intraeruptive periods. Estimated emission rates from the six volcanoes ranged from 3 × 102 to 5 × 10−4 kg s−1 (SO2), 4 × 10−1 to 2 × 10−4 kg s−1 (H2S), 1 × 105 to 1 × 101 kg s−1 (water vapor), 6 × 105 to 2 × 10−5 kg s−1 (particulate mass), 6 × 1019 to 3 × 1014 s−1 (condensation or Aitken nuclei), and 2 × 1018 to 1 × 1016 s−1 (cloud condensation nuclei). The impacts of these new measurements on previous estimates of worldwide particle and gas emissions from volcanoes are discussed.
TL;DR: In this article, the authors used the ecosystem method to estimate that 6.1 kg/ha/yr of sulfur is obtained from dry deposition on the ecosystem of the Hubbard Brook Experimental Forest.
Abstract: Sulfate is the predominant anion in precipitation entering the Hubbard Brook Experimental Forest, a northern hardwood forest in north-central New Hampshire. Sulfur is also the dominant element in airborne particulate matter. Losses of sulfur from the ecosystem in stream water exceed inputs in precipitation plus that released from weathering. Using the ecosystem method, it is possible to estimate (by difference) that 6.1 kg/ha/yr of sulfur is obtained from dry deposition on the ecosystem. The deposition velocity for particulate sulfur is estimated to be about 0.1 cm/s and the deposition velocity for sulfur dioxide is 0.9 cm/s. Some biogeochemical relationships of sulfur for the Hubbard Brook Forest are presented. DOI: 10.1111/j.2153-3490.1978.tb00872.x
01 Feb 1978
TL;DR: In this article, a literature review of combustion flames, theoretical calculations and dilution tunnel experiments has been performed to elucidate the chemical and physical processes involved in the formation of diesel particulate matter.
Abstract: One of the most objectionable aspects of the use of diesel engines has been the emission of particulate matter. A literature review of combustion flames, theoretical calculations and dilution tunnel experiments has been performed to elucidate the chemical and physical processes involved in the formation of diesel particulate matter. A comparative dilution tunnel study of diluted and undiluted total particulate data provided evidence supporting calculations that indicate hydrocarbon condensation should occur in the tunnel at low exhaust temperatures. The sample collection system for the measurement of total particulate matter and soluble sulfate in particulate matter on the EPA 13 mode cycle is presented. A method to correct for hydrocarbon interferences in the EPA barium chloranilate method for the determination of sulfate in particulate matter is discussed.
TL;DR: Oxygen consumption by material deposited in sediment traps suspended at different depths in a coastal marine bay was highest during summer as mentioned in this paper, and seasonal changes in respiration (Formalin sensitive oxyge...
Abstract: Oxygen consumption by material deposited in sediment traps suspended at different depths in a coastal marine bay was highest during summer. Seasonal changes in respiration (Formalin sensitive oxyge...
TL;DR: In this paper, the Saguenay Fjord was analyzed for the analysis of suspended particulate matter from near-bottom waters of the fjord during both time periods and the content of Si, Al, Ca, Mg, and K remained relatively constant in time and space.
Abstract: Analysis of major elements in suspended particulate matter from the Saguenay Fjord in May and September 1974 shows that the content of Si, Al, Ca, Mg, and K remain relatively constant in time and space, reflecting the constancy of the silicate mineralogy of the particulate matter. Large variations in time and space occur, however, in the content of Fe and Mn. High levels of Fe occur in particulate matter from near-bottom waters of the fjord during both time periods. Variations in the Fe/Al ratios indicate that Fe is enriched in the non-silicate fraction of the particulate matter (oxides, hydroxides, etc.) in the near-bottom waters, but not elsewhere. In contrast, Mn is enriched relative to both Al and Fe in particulate matter from intermediate depths, and varies in time and space. This is attributed to the in situ uptake of Mn from seawater and (or) the input of particles, already containing high levels of Mn, from the St. Lawrence Estuary.
TL;DR: In this paper, a measuring station was temporarily established at Kap Harald Moltke, a remote location in North Greenland, where daily measurements of Aitken nuclei concentrations were taken together with filter paper samples for the determination of ice nuclei and for elemental analysis of the particulate.
TL;DR: The emphasis is on the mixture of sulphur oxides, particulate matter, and related pollutants produced by the burning of fossil fuels that relates primarily to the effects on health in the United Kingdom but draws on relevant experience elsewhere as well.
TL;DR: Measurements of particulate copper in the atmosphere near the island of Tasmania indicate that the ocean is a source of atmospheric copper.
Abstract: Measurements of particulate copper in the atmosphere near the island of Tasmania indicate that the ocean is a source of atmospheric copper. A biogenic agent may be responsible for the approximately 20,000-fold enrichment of copper during aerosol production from the ocean.
TL;DR: It is demonstrated that exercising athletes are incurring physiologically dangerous levels of carboxyhemoglobin when performing in legal ambient air concentrations of CO—25 ppm, and concentrations of the poisonous gas in many indoor skating rinks regularly exceed the national ambient standards by as much as 300%.
Abstract: Carbon monoxide (CO) levels were measured in enclosed skating rinks in the Boston area. The 1 hr National Ambient Air Quality Standard of 35 ppm was exceeded in 82% of the sampled hours. In a separate study, alveolar breath samples were taken of 12 Harvard hockey players, indicating a fivefold increase in carboxyhemoglobin levels after 93 min of exercise in air with a relatively low 25 ppm CO concentration. This paper demonstrates that exercising athletes are incurring physiologically dangerous levels of carboxyhemoglobin when performing in legal ambient air concentrations of CO—25 ppm, and concentrations of the poisonous gas in many indoor skating rinks regularly exceed the national ambient standards by as much as 300%. It is suggested that the Clean Air Act should be amended to include indoor public exposure to at least the criteria pollutants of carbon monoxide, sulfur dioxide, nitrogen dioxide, and suspended particulates. The U. S. Environmental Protection Agency should require revisions in State Impl...