Particulate carbon

Anhydride manufactured by acetic acid pyrolysis sometimes contains ketene polymers, eg, acetylacetone, diketene, dehydroacetic acid, and particulate carbon, or soot, is occasionally encountered. Polymers of aHene, or its equilibrium mixture, methylacetylene—aHene, are reactive and refractory impurities, which if exposed to air, slowly autoxidize to dangerous peroxidic compounds. 

National Ambient Air Quality Standards. Under the Clean Air Act, six criterion pollutants, ie, pollutants of special concern, have been estabhshed by the EPA sulfur oxides (SO ), particulates, carbon monoxide (CO), nitrogen oxides (NO ), o2one (photochemical oxidants), and lead. National Ambient Air QuaUty Standards (NAAQS) were developed by EPA based on threshold levels of air pollution below which no adverse effects could be experienced on human health or the environment. 

Hagell GT, Pocklington R (1973) A seagoing system for the measurement of particulate carbon, hydrogen and nitrogen. Report Ser./BI-R-73-14,1-18... 

Eolys A process for removing 80 to 90 percent of the particulate carbon from diesel exhaust gases. It uses a catalytic fuel additive containing cerium. Developed by Rhone-Poulenc in 1995 and licensed to Sumitomo Metal Mining Company in Japan in 1996. 

It is seen by examination of Table 1.11(b) that a wide variety of techniques have been employed including spectrophotometry (four determinants), combustion and wet digestion methods and inductively coupled plasma atomic emission spectrometry (three determinants each), atomic absorption spectrometry, potentiometric methods, molecular absorption spectrometry and gas chromatography (two determinants each), and flow-injection analysis and neutron activation analysis (one determinant each). Between them these techniques are capable of determining boron, halogens, total and particulate carbon, nitrogen, phosphorus, sulphur, silicon, selenium, arsenic antimony and bismuth in soils. 

Krambeck et al. [40] measured small quantities of particulate carbon in lake waters by an automated furnace combustion infrared procedure. The whole sequence of operations was controlled with the aid of an AIM65 desktop computer. The system was successfully operated for routine analysis of samples of lake water with particulate organic carbon values of 100-300ug L 1 carbon a single analysis takes 8min. The relative standard deviation was about 1%. 

Whitfield and McKinley [24] studied some of the factors affecting the determination of particulate carbon and nitrogen in river water sediments. 

The effect of storage of water samples before determination of nitrogen and carbon associated with particulate matter was investigated. Freezing of the samples, and storage at 5°C, both affected the results obtained, but changes were minimized if the samples were filtered immediately after collection and the particulate matter stored on the filter paper. It is recommended that samples for determination of particulate carbon and nitrogen should be filtered immediately, and analysed as soon as possible. 

Depth Profiles where 1 dbar is approximately equal to 1 m water depth (a) Percent Saturation of O2, (b) Particulate Carbon, (c) DOC,... 

Gachier H, Buat-Menard P, Fontagne M, Ghesselet R, Long-range transport of continentally derived particulate carbon in the marine atmosphere Evidence from stable isotope studies, K/Zms 38B 161—177, 1986. 

Commercial carbon black is a spherical colloidal form of nearly pure carbon particles and aggregates with trace amounts of organic impurities adsorbed on the surface. Potential health effects usually are attributed to these impurities rather than to the carbon itself. Soots, by contrast, contain mixmres of particulate carbon, resins, tars, and so on, in a nonadsorbed state. ... 

Particulate carbon in the atmosphere exists predominantly in three forms elemental carbon (soot) with attached hydrocarbons organic compounds and carbonates. Carbonaceous urban fine particles are composed mainly of elemental and organic carbon. These particles can be emitted into the air directly in the particulate state or condense rapidly after Introduction into the atmosphere from an emission source (primary aerosol). Alternatively, they can be formed in the atmosphere by chemical reactions involving gaseous pollutant precursors (secondary aerosol). The rates of formation of secondary carbonaceous aerosol and the details of the formation mechanisms are not well understood. However, an even more fundamental controversy exists regarding... 

Rosen, Hansen, Dod and Novakov found a high correlation between optical absorptivity and the particulate carbon loading in 24-h samples from several California cities ( 5). Elemental carbon, a primary pollutant which is directly related to the absorptivity, was found to be a large fraction of the carbonaceous aerosol. They were able to place a low limit on the amount of secondary organic aerosol produced in correlation with ozone. 

We have calculated the emission inventory of particulate carbon and lead in the Los Angeles Metropolitan area for 1973. 

Proceedings of the Symposium on Particulate Carbon Atmospheric Life Cycle. Wolff, G.T. Klimisch, R.L., Eds.,... 

Chang, S. G., R. Brodzinsky, L. A. Gundel, and T. Novakov, Chemical and Catalytic Properties of Elemental Carbon, in Particulate Carbon Atmospheric Life Cycle (G. T. Wolff and R. L. Klimsch, Eds.), pp. 159-181, Plenum, New York, 1982. 

Turpin, B. J., J. J. Huntzicker, S. M. Larson, and G. R. Cass, Los Angeles Summer Midday Particulate Carbon Primary and Secondary Aerosol, Environ. Sci. Technoi, 25, 1788-1793 (1991). 

Four major methods have been used to separate the organic elemental carbon thermal methods, digestion, extraction, and optical techniques. These are discussed in detail in the volume on particulate carbon edited by Wolff and Klimisch (1982) and in the article by Cadle et al. (1983). 

Fung, K., Particulate Carbon Speciation by Mn02 Oxidation, Aerosol Sci. Technol., 12, 122-127 (1990). 

Wolff, G. T and R. L. Klimisch, Eds., Particulate Carbon Atmospheric Life Cycle, Plenum, New York, 1982. 

The carbon content of MSW cannot be converted into C02 entirely, and due to incomplete combustion, minor amounts of CO and soot particles are found in the flue gases. The particulate carbon is known to be involved in the formation of volatile and toxic compounds especially poly-chlorodibenzo-dioxins and -furanes. Tests in the fully working incinerator plants revealed the presence of particulate carbon, chlorides, and Cu compounds as catalysts in the fly ash (see also Table 3). 

Measurements of radionuclides are also used to determine removal mechanisms and controls for carbon and metal cycling in the ocean. For example, the removal of Th from the euphotic zone is closely coupled to the vertical flux of particulate organic carbon. The deficiency of Th with respect to its parent—near-surface waters is used to estimate the export flux of particulate organic carbon (Buesseler, 1991). Measurements of Th and in the upper water column provided the primary data relahng to particulate carbon fluxes during JGOFS. 

Although Table I is generally self-explanatory, the carbonaceous material measurements require comment. Because of its chemical complexity, carbonaceous material is frequently characterized only on the basis of carbon measurements. These measurements attempt to divide the carbonaceous material into organic C and elemental C . Carbon present in carbonate salts, frequently a minor contributor to the total particulate carbon, can be determined independently. Elemental carbon is among the most important pollutants in visibility reduction. Polycyclic aromatic hydrocarbons (PAHs) are relatively minor constituents of the particulate carbon but are of great interest in health effects studies. PAHs can also serve as model compounds in developing improved sampling techniques for semivolatile carbonaceous materials. 

Even within the subset of boreal lakes there is probably a direct relationship between external inputs of organic matter and their importance to zooplankton (Meili, M. Fry, B. Kling, G. W. unpublished data). In the case of Lake N2 and other upland arctic lakes, thermokarst processes and active erosion of shoreline peat banks are much less important than they are in coastal plain lakes (62, 75, 103). In addition, DOC made up less of the total organic carbon in Lake N2 than it did in the humic lake studied by Hessen (72) the ratio of DIC DOC.POC in Lake N2 was 25 8 1 (Table II), whereas in the humic lake the ratio was 1.6 21 1. The lower loading rates of particulate carbon and the smaller relative amounts of DOM in Lake N2 may explain the observation that pelagic productivity depended mainly on new algal production. 

Particulates, carbon C Incomplete combustion of fossil fuels (p. 95) Covers surfaces with carbon particles... 

Figure 3 presents data on the distribution of volume of water above different depth intervals, and the inputs of organic carbon to surface waters above the same depths. High inputs of organic matter to a small volume of water over the shelves are registered. This is due to inputs from rivers, not only of particulate carbon, but also of mineral nutrients which increase the primary productivity and organic input in these regions. 

Tin may be transported in the atmosphere by the release of particulate matter derived from the combustion of fossil fuels and solid wastes. The vapor pressure of elemental tin is negligible (Cooper and Stranks 1966). Tin in aerosol samples that existed in particulate-carbon masses was removed from the atmosphere predominantly by gravitational settling (Byrd and Andreae 1986). The half- life of airborne particles is usually on the order of days, depending on the size of the particle and atmospheric conditions (Nriagu 1979). Removal by washout mechanisms (such as rain) is thought to be unimportant. 

Shibata, H., H. Mitsuhashi, Y. Miyake, and S. Nakano. 2001. Dissolved and particulate carbon dynamics in a cool-temperate forested basin in northern Japan. Hydrological Processes 15 1817-1828. 

Menzel, D. W., and Vaccaro, R. F. (1964) The measurement of dissolved organic and particulate carbon in seawater. Limnol. Oceanogr. 9,138-142. 

Carbon in Intermediate and Deep Ocean Carbon in Ocean Sediments Marine Particulate Carbon Flux... 

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