Showing papers in "Environmental Science & Technology in 1976"
TL;DR: In this article, results of thermodynamic screening of the high-temperature desulfurization potential of 28 solids, primarily metal oxides, are reported, by use of the free energy minimization method, equilibrium sulfur removal and solid compound stability were determined at temperatures to 1500/sup 0/C.
Abstract: High-temperature processes for desulfurization of low-Btu gases are receiving increased attention. In this study, results of thermodynamic screening of the high-temperature desulfurization potential of 28 solids, primarily metal oxides, are reported. By use of the free energy minimization method, equilibrium sulfur removal and solid compound stability were determined at temperatures to 1500/sup 0/C. Eleven candidate solids based upon the metals Fe, Zn, Mo, Mn, V, Ca, Sr, Ba, Co, Cu, and W show thermodynamic feasibility for high-temperature desulfurization of low-Btu gas.
339 citations
176 citations
TL;DR: A mathematical model, based on records of national and regional fuel use, is developed that gives an excellent quantitative description of the data, indicating that the lead profiles reflect the history of lead input from the burning of coal and leaded gasoline since about 1830 and 1920.
Abstract: The distribution of stable lead has been determined in several Lake Michigan cores that have been dated using the /sup 210/Pb technique. A mathematical model, based on records of national and regional fuel use, is developed that accounts for the effect of aquatic residence time, processes of sedimentation, compaction, postdepositional redistribution of sediment solids, and the effect of finite core sectioning. The model gives an excellent quantitative description of the data, indicating that the lead profiles reflect the history of lead input from the burning of coal and leaded gasoline since about 1830 and 1920, respectively. The model is applied to obtain the sedimentation and lead deposition rates from stable lead distributions in undated sediment cores measured previously by others. The 1972 anthropogenic lead flux into the southern basin of the lake is determined to be 1.3 ..mu..g cm/sup -2/ yr/sup -1/ in comparison to the natural (precultural) flux of approximately 0.16 ..mu..g cm/sup -2/ yr/sup -1/. The anthropogenic lead deposited in the southern basin in 1972 is estimated to be approximately 240 metric tons as compared with an estimate of approximately 230 metric tons from air pollution fallout originating in the Chicago-Gary urban-industrial area. The measurement of both leadmore » and lead-210 fluxes in the same core may allow contributions of atmospheric lead to be distinguished from terrigenous pollution inputs. (auth)« less
168 citations
155 citations
152 citations
TL;DR: An analytical survey of 68 elements, dieldrin, and polychlorinated biphenyls (PCB's) was conducted in municipal sewage sludges sampled during 1972-73 from 16 American cities using several instrumental methods.
Abstract: w An analytical survey of 68 elements, dieldrin, and polychlorinated biphenyls (PCB's) was conducted in municipal sewage sludges sampled during 1972-73 from 16 American cities using several instrumental methods. Unusually elevated concentrations of certain toxic elements were found in sludges from specific cities. Relatively high levels of gold and mercury in sludge from San Francisco possibly derived from geochemical sources. Fluorine was high in several cities which fluoridate their water. PCB's were highest in sludge from Schenectady. Municipal sewage sludges result from the treatment of city sewage wastes containing human excreta, residues from food, and sometimes lumber processing, and a galaxy of industrial chemicals. These latter chemicals may derive from the manufacture of paper, textiles, rubber, plastics, leather, paints, detergents, drugs, agricultural chemicals and electrical
135 citations
TL;DR: “Bituminous Materials”, Vol IV, p 294, Van Nostrand, Princeton, \ , ~~~~ ~~-~ .
Abstract: Bituminous Materials”, Vol IV, p 294, Van Nostrand, Princeton, \\ , ~~~~ ~~-~ . ~ ---, (9) Kawahara, F. K., Enoiron. ScirTechnol.,’5,235 (1971). (10) Kawahara. F. K.. Ballineer. D. G.. Znd. Eng. Chem.. Prod. Res N.J., 1960. (14) Omang, S. R., Anal. Chim. Acta, 56,470 (1971). 1 . he”., 9,553 (1970).’ (11) Kawahara. F. K.. Santner. J. F., Ju1ian.E. C., Anal. Chem., 46, (15) Fernandez, F. J., “Perkin-Elmer Application Study”, No. 591, 1975. 266 (1974). (12) Breidenbach, A. W., Lichtenberg, J. J., Henke, C. F., Smith,D. J., Eichelberger, J. W., Stierli, H., “The Identification and Measurement of Chlorinated Pesticides in Surface Waters”, U.S. Dept. of Interior, FWPCA, WP-22, November 1966. (13) Abrahams, H., “Asphalt and Allied Substances, Industrial Raw Received for review June 25, 1974. Resubmitted October 14, 1975. Accepted February 2, 1976. Mention of products or manufacturers is for identification only and does not imply endorsement by the Environmental Protection Agency.
127 citations
TL;DR: Considerations of pollutant concentrations and rates show that realistic models of photochemical smog formation must involve all classes of hydrocarbons, as well as CO and the aldehydes, as important reactants.
Abstract: The extensive chemical and physical measurements of the Los Angeles Reactive Pollutant Program (LARPP), made during one day of the studies, November 5, 1973, are analyzed to test current theories of hydrocarbon involvement in photochemical smog formation. It is noted that the ratio of the concentration of a reactive hydrocarbon to that for acetylene decreases regularly throughout the day. Indirect estimates are made of the average ambient concentration of the HO-radical from the observed rates of removal of the hydrocarbons, C/sub 2/H/sub 4/, C/sub 3/H/sub 6/, 1-C/sub 4/H/sub 8/, iso-C/sub 4/H/sub 8/, t-2-C/sub 4/H/sub 8/, n-C/sub 5/H/sub 12/, and iso-C/sub 5/H/sub 12/, and estimated rates of O/sub 3/-alkene and O(/sup 3/P)-alkene reactions. Similar estimates are made using the change in (NO/sub x/)/(CH/sub 4/) and (NO/sub x/)/(C/sub 2/H/sub 2/) ratios with time. All of these results suggest that the average ambient level of HO-radical in the morning hours of November 5, 1973, in Los Angeles was in the range (1.0 +- 0.8) x 10/sup -7/ ppm. Considerations of pollutant concentrations and rates show that realistic models of photochemical smog formation must involve all classes of hydrocarbons, as well as CO and the aldehydes, as important reactants. (auth)
122 citations
TL;DR: In this paper, the balance between three emission modes is discussed in relation to combustion conditions and incinerator operation in a continuous feed incinerator, where polynuclear aromatic hydrocarbons are released into the environment in the ash waste from the incinerator in addition they are discharged in both the stack gases and wastewaters from the plant.
Abstract: Polynuclear aromatic hydrocarbons, formed by the incomplete combustion of municipal refuse in a continuous feed incinerator, are released into the environment in the ash waste from the incinerator. In addition they are discharged in both the stack gases and wastewaters from the plant. The balance between the three emission modes is discussed in relation to combustion conditions and incinerator operation.
101 citations
TL;DR: In this article, a technique for estimating the contributions of elemental carbon and primary organic and secondary organic materials to atmospheric particulate matter collected in California's South Coast Air Basin is described.
Abstract: A technique is described for estimating the contributions of elemental carbon and primary organic and secondary organic materials to atmospheric particulate matter collected in California's South Coast Air Basin. The technique employs a combination of solvent extractions and carbon determinations; primary organics are estimated from the carbon solubilized in cyclohexane and secondary organics by the carbon solubilized by successive extraction with benzene and methanol--chloroform minus the primary organics. At the same time an upper limit estimate of the elemental carbon is obtained from the carbon remaining insoluble after the two-step extraction. Support for this technique is provided for samples collected at four locations.
96 citations
TL;DR: In and around well-kept homes painted with low lead paints situated in a small urban community, large amounts of lead and cadmium are found, and high trace metal amounts are also found at nonresidential sites.
Abstract: In and around well-kept homes painted with low lead paints situated in a small urban community, large amounts of lead and cadmium are found. High trace metal amounts are also found at nonresidential sites. Much of the lead is probably of automotive origin. Lead levels in dusts within homes average 600 ppM and 680 ..mu..g/m/sup 2/. In nonresidential interiors, dusts average 1400 ppM Pb and 2040 ..mu..g Pb/m/sup 2/. Unexpectedly high cadmium accumulations are found, especially in carpet dusts from rubber-backed carpets. High nonresidential settled dust and soil lead contents are due to higher traffic flows. The lead content of outdoor residential dust is 600-1950 ppM and 90-6640 ..mu..g/m/sup 2/. These values increase several times around nonresidential sites. Lead and cadmium from trace urban dusts are a significant addition to the child body burden.
TL;DR: In this paper, a reactivity scale based on the rate of removal of hydrocarbons and oxygenates by reaction with the hydroxyl radical (OH) was proposed, which ranges from 10/sup 4/ for Class V containing the most reactive compounds (e.g., d-limonene).
Abstract: By use of relative and absolute rate constants for the reaction of the hydroxyl radical (OH) with a number of alkanes, alkenes, aromatics, and ketones, a reactivity scale is formulated based on the rate of removal of hydrocarbons and oxygenates by reaction with OH. In this five-class scale, each class spans an order of magnitude in reactivity relative to methane. Thus, assigned reactivities range from 10/sup 4/ for Class V containing the most reactive compounds (e.g., d-limonene). This scale differs in several significant ways from those presently utilized by air pollution control agencies and various industrial laboratories. For example, in contrast to other scales based on secondary manifestations such as yields of ozone and eye irritation, it focuses directly on initial rates of photooxidation. The proposed scale also provides a clearer understanding of the importance of alkanes in the generation of ozone during periods of prolonged irradiation. The present scale can be readily extended to include additional organic compounds (e.g., natural and anthropogenic hydrocarbons, oxygenates, chlorinated solvents), once their rate of reaction with OH is known.
TL;DR: Concentrations of chlorinated hydrocarbons in sediments are closely related to the organic contents and to particles of 8 gm or less in size, and total organic carbons of sediments as well as fulvic and humic acid fractions bear a linear relationship with respect to concentrations.
Abstract: p,p'DDE generally accounts for 60-70% of the total chlorinated hydrocarbon content in sediment, whereas PCB's (mostly Arochlor 1254) constitute almost 10-20% of the total. Other isomers of DDT and dieldrin account for the remaining fraction. Concentrations of chlorinated hydrocarbons are closely related to the organic contents and to particles of 8 gm or less in size. Total organic carbons of sediments as well as fulvic and humic acid fractions bear a linear relationship with respect to concentrations of chlorinated hydrocarbons in sediments. Total chlorinated hydrocarbon contents of sediments studied range from 0.3 to 3.5 ppm, whereas total organic carbon contents range from 0.45 to 1.70% on a dry weight basis.
TL;DR: In this paper, fly ash sampling carried out in a large combustion unit and in the chimney of a private house indicates that the composition of fly ash is significantly different from the original coal composition.
Abstract: Fly ash sampling carried out in a large combustion unit and in the chimney of a private house indicates that the composition of fly ash is significantly different from the original coal composition. Based on their mass-size distributions, the elements can be divided into three groups. A first group of elements is associated with large particles and is depleted relative to the original coal composition. A second group has a maximum concentration of small particles and is enriched in fly ash. For a third group, the mass-size functions show an intermediate behaviour. Thier concentration ratios in fly ash and coal are near unity. This division into enriched and depleted elements appears to be roughly independent of the operating conditions of the combustion process. There is some indication that the specific mass-size distribution in fly ash emitted by small domestic facilities is different from that in fly ash from larger facilities.
TL;DR: In this paper, the authors investigated the sources of atmospheric /sup 210/Po in the troposphere and found that the most important sources are soil particles and plant exudates, both of which are natural sources.
Abstract: Mean tropospheric aerosol residence times determined from cosmic ray-produced isotope activity ratios, fallout, and /sup 210/Po//sup 210/Pb ratios are concluded to be in error. Thus, complementary sources of /sup 210/Po in the atmosphere must exist. Results presented substantiate dust storms, coal-burning power plants, forest fires, and plant exudates as sources of atmospheric /sup 210/Po. Preliminary estimates of the magnitude of these and other possible complementary sources of atmospheric /sup 210/Po are made. The most important sources appear to be soil particles and plant exudates, both of which are natural sources. The largest anthropogenic source is associated with phosphate fertilizer production. Together, the complementary sources account for most of the /sup 210/Po in the troposphere. Thus, a shorter residence time of 4-6 days appears reasonable.
TL;DR: A chronology of key events: (8) Paciga, J. J., Chattopadhyay, A., Jervis, R. E., in “Nuclear Methods in Environmental .Research-11”, J R. Vogt and W. Meyer, Eds.
Abstract: 6,441-48 (1972). (9) Paciga, J. J., Chattopadhyay, A., Jervis, R. E., in “Nuclear Methods in Environmental .Research-11”, J. R. Vogt and W. Meyer, Eds., pp 286-300, University of Missouri, Columbia, Mo., 1974. (10) Hoffman, G. L., Duce, R. A,, Enuiron. Sci. Technol., 5 , 1134 (1971). (11) Gordon, G. E., Zoller, W. H., Gladney, E. S., in “Trace Substances in Environmental Health-VII”, D. D. Hemphill, Ed., pp 167-75, University of Missouri, Columbia, Mo., 1973. (12) John, W., Kaifer, R., Rahn, K., Wesolowski, J . J., Atmos. Enuiron., 7, 107-18 (1973). (13) Pattenden, N. J., presented a t the 41st Ann. Conf. of the National Society for Clean Air, 14-18 October, Cardiff, UK, 1974. (14) Bogen, J., Atmos. Enuiron., 7,1117-25 (1973). (16) Wedepohl, K. H., in “Origin and Distribution of the Elements”, L. H. Ahrens, Ed., pp 999-1016, Pergamon Press, Oxford, England, 1968. (16) Lee, R. E., Jr., Goranson, S., Emiron. Sci. Technol., 6,1019-24
TL;DR: In this article, a rapid and simple method is described for the analysis of polycyclic quinones (PQu's) derived from polynuclear aromatic hydrocarbons (PAH's), involving resolution by column and thin-layer chromatography and spectral analysis by ultraviolet, visible and fluorescence spectrophotometry, and mass spectrometry.
Abstract: A rapid and simple method is described for the analysis of polycyclic quinones (PQu's) derived from polynuclear aromatic hydrocarbons (PAH's), involving resolution by column and thin-layer chromatography and spectral analysis by ultraviolet, visible and fluorescence spectrophotometry, and mass spectrometry. Isomeric PQu's were isolated on silica gel columns and polyamide or magnesium hydroxide thin-layer plates. Applications of the above technique to photooxidation and air pollution studies are reported. 9,10-Anthraquinone, benzo(a)pyrene-6,12-quinone, benzo(a)pyrene-1,6-quinone, benzo(a)pyrene-3,6-quinone, and dibenzo(b,def)chrysene-7,14-quinone were identified in samples of suspended particulate matter collected in Toronto, Ont. Because of the very low concentrations of PQu's in the atmosphere, the collected quinones were reduced to the parent hydrocarbon prior to fluorescence analysis so that quantitative analyses could be performed. Estimations are reported of the monthly distribution in the amount of benzene soluble fraction, quinone fraction, benzo(a)pyrene, benz(a)anthracene, benzo(a)pyrene-quinone, benz(a)anthracene-quinone, and benzanthrone in suspended particulate matter, collected as part of a one-year study at York University, Toronto, Ont. The ratios of PQu content to the parent hydrocarbon content are correlated with ease of photooxidation and seasonal variations in fuel-burning practices.
TL;DR: A shrinking particle model physically described dissolution of the limestone and the rate of neutralization of sulfuric acid by limestone particles is shown to be controlled by hydrogen diffusion in the pH range of 2 to 6.
Abstract: The rate of neutralization of sulfuric acid by limestone particles is shown to be controlled by hydrogen diffusion in the pH range of 2 to 6. The first-order rate constant is 10 to 4l./(cm)2(S) at 298 K for a limestone containing 87 wt % carbonates, using as a driving force the hydrogen concentration in the bulk phase minus that at equilibrium at the end of the neutralization. A shrinking particle model physically described dissolution of the limestone. Particle sizes investigated vary from 0.037 to 0.044 mm to 0.500 to 0.595 MM. Effects of temperature (274-348 K), stoichiometry, turbulence, and carbon dioxide pressure are analyzed.
TL;DR: Of the three clays used in the study, montmorillonite had the highest attenuation capability, followed by illite and then kaolinite, and heavy metals such as Pb, Cd, Hg, and Zn were strongly attenuated by even small amounts of clay.
Abstract: To evaluate the potential of clay minerals for attenuating the various chemical constituents of landfill leachate, leachate was passed through laboratory columns that contained various mixtures of calcium-saturated clays and washed quartz sand. Leachates were run through the columns for periods of up to 10 months, during which time effluents were periodically collected and analyzed for 16 chemical constituents. Chloride, Na, and water-soluble organic compounds (COD) were poorly attenuated by passage through the clay columns; K, \"4, Mg, Si, and Fe were moderately attenuated; and heavy metals such as Pb, Cd, Hg, and Zn were strongly attenuated by even small amounts of clay. Concentrations of Ca, B, and Mn in the column effluents increased markedly over the original leachate concentrations. Of the three clays used in the study, montmorillonite had the highest attenuation capability, followed by illite and then kaolinite. Attenuation was a function of the CEC of the clay mineral, the initial exchangeable cations on the clay, the chemical composition of the leachate, and the pH of the leachate.
TL;DR: A two-stage on-line mass monitor with aerosol size separator (TWOMASS) employing the beta attenuation technique has been developed for monitoring of atmospheric aerosols with high time resolution as mentioned in this paper.
Abstract: A two-stage on-line mass monitor with aerosol size separator (TWOMASS) employing the beta attenuation technique has been developed for monitoring of atmospheric aerosols with high time resolution. This instrument independently analyzes the mass concentration of two particle size fractions. Coarse particles are inertially separated by impaction on filter paper. The fine particle fraction is collected on a high-efficiency glass-fiber filter. Carbon 14 is used as a source of beta particles which are detected by a silicon surface-barrier detector coupled to fast, low-noise nuclear electronics. A programmable calculator controls TWOMASS, calculates the mass concentration of each size fraction, plots, prints, and stores the data on tape. The instrument has been gravimetrically calibrated using laboratory and atmospheric aerosols. For 10-min sampling intervals, the precision of the instrument is 4 ..mu..g/m/sup 3/, and the accuracy is 11 percent. It has subsequently been field tested by sampling atmospheric aerosol over an extended period which indicates that it is capable of ambient air monitoring with a time response on the order of 10 min.
TL;DR: The experimental data from observations made later than the 0920 hour are in reasonable accord with the results of the two models, and within the accuracy of the data they confirm the presently accepted ozone formation mechanism.
Abstract: The extensive chemical and physical measurements of the Los Angeles Reactive Pollutant Program (LARPP), Operation 33, are analyzed to test the suitability of current mechanistic hypotheses related to ozone generation in photochemical smog. The pollutant concentrations and certain physical variables were determined from aircraft observations at various elevations and times within a well-defined air mass which moved across the Los Angeles Basin. Ground-level pollutant concentrations and ultraviolet intensities were also obtained from sites near the track of the air mass. These data, simple theory, and reaction rate constant estimates are utilized to calculate the rate constants for ozone and NO/sub x/ reactions in the atmosphere. Two theoretical models are considered. The first neglects uv light attenuation within the polluted layer and reflected light from the surface of Los Angeles, while in the second model account is taken of both of these factors. The experimental data from observations made later than the 0920 hour are in reasonable accord with the results of the two models, and within the accuracy of the data they confirm the presently accepted ozone formation mechanism.
TL;DR: Varying operating conditions, such as combustion chamber residence time and excess air, produced notable differences in particulate loading and size distribution.
Abstract: Studies determined the influence of fuel composition and combustion conditions on particulate mass loading and size distribution. The fuel composition aspect of this study was concerned with determining the effect of the change from conventional high-sulfur fuel oil (Bunker C) to desulfurized fuel oils that have lower ash and asphaltene (hexane insolubles) contents. Varying operating conditions, such as combustion chamber residence time and excess air, produced notable differences in particulate loading and size distribution.
TL;DR: A mechanism is developed to represent the chemistry of NOx/hydrocarbon/SO2 systems, and the mechanism is used to analyze available experimental data appropriate for quantitative analysis of SO2 oxidation kinetics, and detailed comparisons of observed and predicted concentration behavior are presented.
Abstract: A systematic evaluation of known homogeneous SO2 reactions which might be important in air pollution chemistry is carried out A mechanism is developed to represent the chemistry of NOx/hydrocarbon/SO2 systems, and the mechanism is used to analyze available experimental data appropriate for quantitative analysis of SO2 oxidation kinetics Detailed comparisons of observed and predicted concentration behavior are presented In all cases, observed SO2 oxidation rates cannot be explained solely on the basis of those SO2 reactions for which rate constants have been measured The role of ozone-olefin reactions in SO2 oxidation is elucidated
TL;DR: A peroxyacyl nitrate synthesis in the gas phase has been developed in this article, where molecular chlorine is photolyzed to yield chlorine atoms that abstract aldehydic hydrogen from the aldehyde.
Abstract: A new peroxyacyl nitrate synthesis in the gas phase has been developed Molecular chlorine is photolyzed to yield chlorine atoms that abstract aldehydic hydrogen from the aldehyde The acyl radical then adds oxygen and nitrogen dioxide to form the PAN Any member of the PAN family can thus be produced from its parent aldehyde cleanly and in very high yield
TL;DR: PAN and ozone or oxidant measurements were made at four different sites as discussed by the authors, three of these sites were urban locations, the other was rural, and the maximum O/sub 3/PAN/O/sub x/P PAN ratios varied at each sampling site thus preventing the prediction of PAN concentrations estimates from ambient ozone concentration alone.
Abstract: PAN and ozone or oxidant measurements were made at four different sites. Three of these sites were urban locations, the other was rural. PAN and corresponding ozone and oxidant measurements were compared. The maximum O/sub 3//PAN or O/sub x//PAN ratios varied at each sampling site thus preventing the prediction of PAN concentrations estimates from ambient ozone concentration alone. Generally high ozone concentrations were observed when corresponding high PAN concentrations were measured. However, high ozone was observed when PAN concentrations were low. These observations concur with simulated chamber irradiations and modeling predictions of ozone and PAN concentrations.