Precipitator Design

The various design philosophies and methods used in the engineering design of precipitators for fly ash are reviewed and assessed in light of current stringent environmental standards. The basic precipitator size and electrical parameters are individually analyzed and related to particle and flue gas properties. Actual precipitator design practice is illustrated by data for a wide cross section of power plant installations.     

4th International Clean Air Congress May 16 ∼ 20, 1977 Tokyo

The ways in which anhydrous ammonia may accidentally escape to the atmosphere from refrigerated or pressurized containment are systematically reviewed. The circumstances in which the ammonia may form part of a mixture which is buoyant, neutrally buoyant, or denser than air are described and for each mode of release there is a discussion of the likely density of the resulting ammonia cloud.     

A Probability Model for Evaluating Building Contamination from an Environmental Event

ABSTRACT

Asbestos dust and bioaerosol sampling data from suspected contaminated zones in buildings allowed development of an environmental data evaluation protocol based on the differences in frequency of detection of a target contaminant between zones of comparison. Under the assumption that the two test zones of comparison are similar, application of population proportion probability calculates the significance of observed differences in contaminant levels. This was used to determine whether levels of asbestos dust contamination detected after a fire were likely the result of smoke-borne contamination, or were caused by pre-existing/background conditions.

Bioaerosol sampling from several sites was also used to develop the population proportion probability protocol. In this case, significant differences in indoor air contamination relative to the ambient conditions were identified that were consistent with the visual observations of contamination. Implicit in this type of probability analysis is a definition of “contamination” based on significant differences in contaminant levels relative to a control zone. Detection of a suspect contaminant can be assessed as to possible sources(s) as well as the contribution made by pre-existing (i.e., background) conditions, provided the test and control zones are subjected to the same sampling and analytical methods.     

Multi-elements atmospheric deposition study in Albania

For the first time, the moss biomonitoring technique and inductively coupled plasma–atomic emission spectrometric (ICP-AES) analytical technique were applied to study multi-element atmospheric deposition in Albania. Moss samples (Hypnum cupressiforme) were collected during the summer of 2011 and September–October 2010 from 62 sites, evenly distributed over the country. Sampling was performed in accordance with the LRTAP Convention–ICP Vegetation protocol and sampling strategy of the European Programme on Biomonitoring of Heavy Metal Atmospheric Deposition. ICP-AES analysis made it possible to determine concentrations of 19 elements including key toxic metals such as Pb, Cd, As, and Cu. Cluster and factor analysis with varimax rotation was applied to distinguish elements mainly of anthropogenic origin from those predominantly originating from natural sources. Geographical distribution maps of the elements over the sampled territory were constructed using GIS technology. The median values of the elements in moss samples of Albania were high for Al, Cr, Ni, Fe, and V and low for Cd, Cu, and Zn compared to other European countries, but generally were of a similar level as some of the neighboring countries such as Bulgaria, Croatia, Kosovo, Macedonia, and Romania. This study was conducted in the framework of ICP Vegetation in order to provide a reliable assessment of air quality throughout Albania and to produce information needed for better identification of contamination sources and improving the potential for assessing environmental and health risks in Albania, associated with toxic metals.     

Traditional pastoralist decision-making processes: lessons for reforms to water resources management in Kenya

The purpose of this paper is to consider the vision for public participation in water resources management embedded in Kenya's 2002 Water Act, as it relates to pastoralists. The Act envisions that responsibility for management of water resources at the local level will be devolved to community-level bodies. Our approach was qualitative and included interviews with government officials and Gabra pastoralists, observation of and participation in traditional Gabra korra meetings and focus group discussions. We conclude that the ‘institutional model’ of participation being pursued through the creation of Water Resource User Associations is particularly problematic for mobile pastoralists such as the Gabra, and we suggest an alternative strategy that would focus on the fostering of deliberation processes.     

Investigating habitat value to inform contaminant remediation options: case study

Habitat valuation methods were implemented to support remedial decisions for aquatic and terrestrial contaminated sites at the East Tennessee Technology Park (ETTP) on the US Department of Energy (DOE) Oak Ridge Reservation in Oak Ridge, TN, USA. The habitat valuation was undertaken for six contaminated sites: Contractor's Spoil Area, K-901-N Disposal Area, K-770 Scrapyard, K-1007-P1 pond, K-901 pond, and the Mitchell Branch stream. Four of these sites are within the industrial use area of ETTP and two are in the Black Oak Ridge Conservation Easement. These sites represent terrestrial and aquatic habitat for vertebrates, terrestrial habitat for plants, and aquatic habitat for benthic invertebrates. Current and potential future, no-action (no remediation) scenarios were evaluated primarily using existing information. Valuation metrics and scoring criteria were developed in a companion paper, this volume. The habitat valuation consists of extensive narratives, as well as scores for aspects of site use value, site rarity, and use value added from spatial context. Metrics for habitat value were expressed with respect to different spatial scales, depending on data availability. There was significant variation in habitat value among the six sites, among measures for different taxa at a single site, between measures of use and rarity at a single site, and among measures for particular taxa at a single site with respect to different spatial scales. Most sites had aspects of low, medium, and high habitat value. Few high scores for current use value were given. These include: wetland plant communities at all aquatic sites, Lepomid sunfish and waterbirds at 1007-P1 pond, and Lepomid sunfish and amphibians at K-901 pond. Aquatic sites create a high-value ecological corridor for waterbirds, and the Contractor's Spoil Area and possibly the K-901-N Disposal Site have areas that are part of a strong terrestrial ecological corridor. The only example of recent observations of rare species at these sites is the gray bat observed at the K-1007-P1 pond. Some aspects of habitat value are expected to improve under no-action scenarios at a few of the sites. Methods are applicable to other contaminated sites where sufficient ecological data are available for the site and region.     

Zur chemie der marsoberfläche

Analyses of 13 samples of Martian surface materials with the Viking X-ray fluorescence spectrometers show SiO₂ similar to that of terrestrial mafic rocks, whereas Fe₂O₃, Cl, and S are higher and Al₂O₃, K₂O, Rb, Sr, Y, and Zr are lower. Low totals suggest presence of CO₂, H₂O, and Na₂O. Duricrust fragments are higher in S than fines, but samples from both landing sites are surprisingly similar. We suggest that Martian surface materials are aeolian deposits of complex mixtures of weathering products of maficultramafic rocks, possibly consisting of iron-rich clays, sulfates, iron oxides, carbonates, and chlorides.