William H. Zoller

Vapor-phase concentrations of arsenic, selenium, bromine, iodine, and mercury in the stack of a coal-fired power plant

A sampling and analysis procedure is described for determining vapor-phase concentrations of As, Se, Br, I, and Hg in the stack of a coal-fired power plant. The percentages of the total in-stack concentrations for these elements present in the vapor phase are as follows: Br, 98%; Hg, 98%; Se, 59%; As, 0.7-52%; and I, greater than or equal to99%. A lower limit of 99% was obtained for Cl. The vapor-phase concentration of As appears to be dependent upon the in-stack or filter mass loading. This indicates that a vaporization-condensation mechanism may control the vapor-phase concentrations of As. The result for Se indicate that the efficiency of the electrostatic precipitator affects particle vapor-phase fractionation. The results obtained in this study are compared with previous mass balance calculations.

Airborne plume study of emissions from the processing of copper ores in southeastern Arizona

The elemental composition of particulate materials in the plumes of five copper smelters in southeastern Arizona was determined. Air-filter samples were collected with a light, twin-engine aircraft. Arsenic, lead, cadmium, zinc, selenium, tungsten, indium, and other volatile and chalcophilic elements are highly enriched in the plume materials relative to the background aerosol. Marked differences in the element composition of plumes from the various smelters could be used as fingerprints to determine contributions of material from various plants at a specific impact point. (5 graphs, 27 references, 1 table)

Lead and halogens in pollution aerosols and snow from fairbanks, Alaska

Abstract The composition of lead halide pollution aerosol particles was studied in the Fairbanks area during January and February 1965. At this time of year the sun is above the horizon for less than 4 hr and prolonged cold spells (surface air temperature below −40°C) are accompanied by strong (gradients of 20–30°C/100 m) surface inversions which severely restrict the dilution volume for air pollutants. Indeed, these inversions virtually decouple the dense surface air-layer from the overlying air. Accurate quantitative information on the total output of all pollution sources is available because of the isolated location of Fairbanks and the limited, measurable sources of fuel supply. Thus, Fairbanks is a model locality for studying the production, movement, and chemical reactions of air pollutants in what amounts to a simple two-layer atmosphere. Lead was determined by inverse polarography in aerosol particles collected on Millipore filters. Measured values ranged from 6.0 μg of lead/m 3 of air in the city center, near the automobile traffic center, to 0.19 at the University of Alaska campus outside the city. These do not represent maximum values because pollutant-concentrating conditions were relatively mild during the sampling periods. Halogens were determined by neutron activation analysis of material in the aerosols and in ground-lying snows, and two components were revealed, a pollution component derived from automotive ethyl fluid combustion and a low-level natural component. In the pollution aerosol component, the weight ratio chlorine/lead averages close to the ethyl fluid value of 0.34, but bromine/lead is up to four times less than the ethyl fluid value of 0.39. Bromide-chlorine of the pollution in the snows is only 15–30 per cent of the ethyl fluid value and exhibits the lower values further from the city center. These data support the interpretation that lead halide particles, formed initially by combustion of ethyl fluid in gasoline, suffer loss of bromine by oxidation and volatilization. The smaller particles, because of greater surface area per unit mass, may suffer the most extensive bromine loss and may migrate farthest from the city center by virtue of their long atmospheric residence time.

Fractionation of elements during copper smelting

A recent study of the elemental composition of particulate material collected from the plumes of five copper smelters in southeastern Arizona indicated that arsenic, lead, selenium, cadmium, zinc, tungsten, indium, and other chalcophilic elements are highly enriched in the plume materials relative to the background aerosol. Enrichments are due to the volatilization of these elements during copper smelting. Significant differences in the elemental compositions of plumes from the various smelters appear to be due to differences in the feed material, smelting conditions, and equipment use by the smelters. (3 graphs, 13 references, 7 tables)

Atmospheric aerosol trace element chemistry at Mauna Loa Observatory: 1. 1979–1985

Aerosol samples were collected at the Mauna Loa Observatory in Hawaii from February 1979 to May 1985. The samples were analyzed via instrumental neutron activation analysis (INAA) for up to 47 elements and via ion chromatography for sulfate. The data are dominated by crustal dust that arrives via long-range transport from Asia each spring, thus creating a “dust season.” Of the 47 elements detected, 37 have a notably higher mass average during the dust season. The data record is explored using enrichment factors, principal component analysis, and chemical mass balances (receptor modeling). The crustal material accounts for 60–70% of the overall aerosol mass during dust seasons, yet only 15–20% during nondust seasons. It is by far the largest contributor to the natural variation dominating the principal component analysis by describing greater than 60% of the overall variance. Particulate sulfate is another major component accounting for 10–40% of the aerosol mass during dust seasons and 60–75% of the mass during nondust seasons. Particulate sulfate can be derived from crustal material and sea salt. Anthropogenic activity also can produce particulate sulfate or its precursors that can adhere to the surface of crustal material that travels over a polluted area. Minor components in the downslope winds are marine sea-salt aerosol contributing less than 3% of the aerosol mass during the dust season and 5–6% during the nondust season. Local basalt is considered to contribute less than 2% during the dust season and 3–4% during the nondust season. (Carbon mass is not determined and therefore no carbon-based aerosols such as soot or organic aerosols are considered in the total aerosol mass.)

Organic-rich colloidal material in estuaries and its alteration by chlorination.

Major and trace element analyses for over 30 elements indicate that chlorination increases the concentration of halogens, Mn, and certain other trace elements in the colloidal organic material in estuarine waters. The primary halogen substituent in freshwater is chlorine, whereas in brackish waters the oxidation of Brto HOBr by chlorine produces a dramatic bromine enrichment in chlorinated samples. In experiments designed to measure COS production, yields of about 113 mol of COS per mol of initial chlorine were found after storage of acidified, chlorinated samples for 1 week. This suggests that oxidation of organic matter, ultimately to COS, is quantitatively far more important than halogen substitution, or metal oxidation, in the consumption of chlorine.

Gaseous Iodine Measurements and Their Relationship to Particulate Lead in a Polluted Atmosphere

Abstract Gaseous iodine and particulate iodine and lead samples were collected simultaneously in a polluted atmosphere using activated charcoal and membrane filters. Concentrations of gaseous iodine varied from 10–18 ng m−3 and particulate iodine from 2–15 ng m−3 as determined by neutron activation analysis. The total iodine concentration found in this work is approximately twice that found in the unpolluted marine atmosphere. Lead concentrations varied from 0.4–3.7 µg m−3 as determined by atomic absorption spectrophotometry. There is an apparent relationship between the concentration of total particulate matter in the air and the ratio of particulate iodine to gaseous iodine. This relationship is consistent with laboratory investigations of gaseous I2 adsorption onto combustion aerosols reported by other investigators. Calculations indicate that the concentrations of gaseous iodine measured in this work should be sufficient to activate all lead containing particles to ice nuclei in a polluted atmosphere....

Long-term aerosol and trace acidic gas collection at Mauna Loa Observatory 1979–1991

Weekly aerosol samples have been collected and analyzed consistently at Mauna Loa Observatory from February 1979 through June of 1991. Previous studies reported data through April of 1985. This paper focuses mainly on the data from May 1985 to June 1991. However, previous data have been included when appropriate to examine the entire data record. Elemental concentrations, enrichment factors, principal component analysis and chemical mass balancing have been used to examine this 12 year data record. Yearly Asian dust episodes are the major contributor to trace metal concentrations and variance. Marine material contributes only a third of the trace metal mass compared to the crustal contribution. Anthropogenic and biogenic material usually contribute less than 5% of the trace element mass (excluding carbon and sulfate). Sulfate, which was measured by ion chromatography for part of the period, contributes a mass similar to crustal mineral; however, it does not have a strong seasonal pattern. A pollution episode in 1989 increased the budget of several elements by an order of magnitude or more. The trace acidic gas data support the conclusion that marine material in the free troposphere has been weathered, leading to a chlorine depletion in marine particles.