X-ray photoelectron spectroscopic studies of iron oxides

Particulate matter (PM) emissions from stationary combustion sources burning coal, fuel oil, biomass, and waste, and PM from internal combustion (IC) engines burning gasoline and diesel, are a significant source of primary particles smaller than 2.5 μm (PM2.5) in urban areas. Combustion-generated particles are generally smaller than geologically produced dust and have unique chemical composition and morphology. The fundamental processes affecting formation of combustion PM and the emission characteristics of important applications are reviewed. Particles containing transition metals, ultrafine particles, and soot are emphasized because these types of particles have been studied extensively, and their emissions are controlled by the fuel composition and the oxidant-tem-perature-mixing history from the flame to the stack. There is a need for better integration of the combustion, air pollution control, atmospheric chemistry, and inhalation health research communities. Epidemiology has demonstrated t...

https://www.tandfonline.com/doi/pdf/10.1080/10473289.2000.10464197

Combustion aerosols: factors governing their size and composition and implications to human health.

A quantitative assessment of source contributions to inhalable particulate matter pollution in metropolitan boston

This paper examines the linkages between the carbon cycle and sedimentary processes on land. Available data suggest that sedimentation on land can bury vast quantities of organic carbon, roughly 1015 g C yr−1. To evaluate the relative roles of various classes of processes in the burial of carbon on land, terrestrial sedimentation was modeled as a series of 864 scenarios. Each scenario represents a unique choice of intensities for seven classes of processes and two different global wetland distributions. Comparison was made with presumed preagricultural conditions. The classes of processes were divided into two major component parts: clastic sedimentation of soil-derived carbon and organic sedimentation of autochthonous carbon. For clastic sedimentation, masses of sediment were considered for burial as reservoir sediment, lake sediment, and combined colluvium, alluvium, and aeolian deposits. When the ensemble of models is examined, the human-induced burial of 0.6-1.5·1015 g yr−1 of carbon on land is entirely plausible. This sink reaches its maximum strength between 30° and 50° N. Paddy lands stand out as a type of land use that warrants future study, but the many faces of rice agriculture limit generalization. In an extreme scenario, paddy lands alone could be made to bury about 1·1015 g C yr−1. Arguing that terrestrial sedimentation processes could be much of the sink for the so called “missing carbon” is reasonable. Such a hypothesis, however, requires major redesign of how the carbon cycle is modeled. Unlike ecosystem processes that are amenable to satellite monitoring and parallel modeling, many aspects of terrestrial sedimentation are hidden from space.

https://agupubs.onlinelibrary.wiley.com/doi/pdf/10.1029/98GB00741

Terrestrial sedimentation and the carbon cycle: Coupling weathering and erosion to carbon burial

In natural ground water systems, both chlorine and bromine occur primarily as monovalent anions, chloride and bromide Although dissolution or precipitation of halite, biological activity in the root zone, anion sorption, and exchange can affect chloride/bromide ratios in some settings, movement of the ions in potable ground water is most often conservative Atmospheric precipitation will generally have mass ratios between 50 and 150; shallow ground water, between 100 and 200; domestic sewage, between 300 and 600; water affected by dissolution of halite, between 1,000 and 10,000; and summer runoff from urban streets, between 10 and 100 These, and other distinctive elemental ratios, are useful in the reconstruction of the origin and movement of ground water, as illustrated by case studies investigating sources of salinity in ground water from Alberta, Kansas, and Arizona, and infiltration rates and pathways at Yucca Mountain, Nevada

Uses of Chloride/Bromide Ratios in Studies of Potable Water

Coal, fly ash, slag, and combustion gases from a large cyclone-fed power plant 870 MW(e) were analyzed for a suite of elements. Mass balance calculations show that the sampling and analyses were generally adequate to describe the flows of these elements through the plant. Most Hg, some Se, and probably most Cl and Br were discharged to the atmosphere as gases. As, Cd, Cu, Ga, Mo, Pb, Sb, Se, and Zn were quite concentrated in fly ash compared to the slag, and were more concentrated in the ash discharged through the stack than in that collected by the precipitator. Al, Ba, Ca, Ce, Co, Eu, Fe, Hf, K, La, Mg, Mn, Rb, Sc, Si, Sm, Sr, Ta, Th, and Ti show little preferential partitioning between the slag and the collected or discharged fly ash. Cr, Sc, Na, Ni, U, and V exhibit behavior intermediate between the latter two groups. (auth)

Jeul F. Emery

Papers

Pathways of thirty-seven trace elements through coal-fired power plant