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61.
Walter A. Baxter 《Journal of the Air & Waste Management Association (1995)》2013,63(12):817-820
Motivated by heightened recent interest, Koppers Co. has been experimenting with ammonia conditioning of power boiler flue gases for the purpose of improving the precipitability of the emitted fly ash. Chemical reactions resulting from ammonia injection are postulated. Measurements on three pulverized coal and two cyclone fired boilers, all of which emit acidic ash, are described. In all five cases, considerable but varying, increase in precipitator power input and collection efficiency resulted when gaseous ammonia in the amount of 1 5 ppm was injected between the economizer and air preheater. The conditioned fly ash showed decreased acidity and inconsistent change in electrical resistivity. Unless air heater temperatures were unusually high (>400°F), tendency of the air heater to plug was an additional, but unwanted, result. At one station with high air heater outlet temperature ammonia injection has been adopted as a permanent solution to community pressure for reduction of stack discharge. Ammonia injection downstream of the air heater produced no effect. Future plans are presented to continue the program beyond results described here. 相似文献
62.
Walter F. Dabberdt Hanwant B. Singh 《Journal of the Air & Waste Management Association (1995)》2013,63(9):876-881
Emergency plans for oxidant controls provide the basis for taking preventive action to protect public health. Historic oxidant data (1970 to Sept. 1974) from the South Coast Air Basin (SCAB), were evaluated to assess episode characteristics in an area where emergency strategies are most likely to be enforced. These findings, together with an objective study of a test case episode (June 1974) using a photochemical air quality simulation model, suggest that the currently conceived emergency plans for oxidant control are unlikely to be effective. It is concluded that, because of the chemical and mefeorofogfcal complexities of the episodes, they are extremely difficult both to predict and concurrently to control over their short-lived duration. 相似文献
63.
Walter John Georg Reischl 《Journal of the Air & Waste Management Association (1995)》2013,63(8):872-876
A cyclone with a 47 mm after-filter has been developed for ambient air size-selective monitoring. It has been extensively evaluated with laboratory-generated aerosol. Variation of the pressure drop and 50% cut point with flow rate show that the cyclone operates in a single flow regime with a vortex in the outlet flow. The particle size cutoff curve is comparable in sharpness to a cascade impactor and is the same for solid or liquid particles. At 21.7 L/min, D 50 is 2.5μm and at 15.4 L/min, D 50 is 3.5 μm. Collection efficiency data for flow rates from 8 to 27 L/min fit a universal curve when plotted vs. the normalized particle diameter, (D-D 50)/D 50 Reentrainment of previously deposited particles is less than 1 % of the loading per day. In field tests the cyclone has proved to be a very satisfactory size-selective sampler. 相似文献
64.
Walter Piulle Robert Carr John Lagomarsino 《Journal of the Air & Waste Management Association (1995)》2013,63(1):100-104
Stringent particulate emissions limits and increasing awareness of stack opacity is leading the utility industry to use high efficiency particulate control systems. In response to this trend, the Electric Power Research Institute (EPRI) is conducting several research programs aimed at improving the operation, maintenance and performance of particulate control systems. One of these programs, RP-1401, “Reliability Assessment of Particulate Control Systems,” is developing operation, maintenance and design data bases for both electrostatic precipitators and fabric filters. This paper discusses some of the intermediate findings of the work done on fabric filters. 相似文献
65.
Mesay Mulugeta Christian J. EngelsenGrethe Wibetoe Walter Lund 《Waste management (New York, N.Y.)》2011,31(2):253-258
The release and charge-based fractionation of As, Cr, Mo, Sb, Se and V were evaluated in leachates generated from recycled concrete aggregates (RCA) in a laboratory and at a field site. The leachates, covering the pH range 8.4-12.6, were generated from non-carbonated, and artificially and naturally carbonated crushed concrete samples. Comparison between the release of the elements from the non-carbonated and carbonated samples indicated higher solubility of the elements from the latter. The laboratory leaching tests also revealed that the solubility of the elements is low at the “natural pH” of the non-carbonated materials and show enhancement when the pH is decreased. The charge-based fractionation of the elements was determined by ion-exchange solid phase extraction (SPE); it was found that all the target elements predominantly existed as anions in both the laboratory and field leachates. The high fraction of the anionic species of the elements in the leachates from the carbonated RCA materials verified the enhanced solubility of the oxyanionic species of the elements as a result of carbonation. The concentrations of the elements in the leachates and SPE effluents were determined by inductively coupled plasma mass spectrometry (ICP-MS). 相似文献
66.
De Maria S Rivelli AR Kuffner M Sessitsch A Wenzel WW Gorfer M Strauss J Puschenreiter M 《Chemosphere》2011,84(9):1256-1261
Although the beneficial effects on growth and trace element accumulation in Salix spp. inoculated with microbes are well known, little information is available on the interactions among trace elements and macronutrients. The main purpose of this study was to assess the effect of phytoaugmentation with the rhizobacteria Agromyces sp., Streptomyces sp., and the combination of each of them with the fungus Cadophora finlandica on biomass production and the accumulation of selected trace elements (Zn, Cd, Fe) and macronutrients (Ca, K, P and Mg) in Salix caprea grown on a moderately polluted soil. Dry matter production was significantly enhanced only upon inoculation with Agromyces sp. Regarding the phytoextraction of Cd and Zn, shoot concentrations were mostly increased after inoculation with Streptomyces sp. and Agromyces sp. + C. finlandica. These two treatments also showed higher translocation factors from roots to the leaves for both Cd and Zn. The accumulation of Cd and Zn in shoots was related to increased concentrations of K. This suggests that microorganisms that contribute to enhanced phytoextraction of Cd and Zn affect also the solubility and thus phytoavailability of K. This study suggests that the phytoextraction of Zn and Cd can be improved by inoculation with selected microbial strains. 相似文献
67.
68.
Lionel Baldwin Joseph Palomba Jr. Captain Walter Schirra 《Journal of the Air & Waste Management Association (1995)》2013,63(8)
A panel discussion looking forward to the environment in the year 2000, was arranged by Lionel V. Baldwin, Program Chairman for APCA’s 67th Annual Meeting. To provide a lofty introduction of the subject he reached into outer space for a moderator—Captain Walter M. Schirra, one of the original astronaut team. 相似文献
69.
Walter A. Lyons Lars E. Olsson 《Journal of the Air & Waste Management Association (1995)》2013,63(11):876-881
A two-day field program in Chicago studied mesoscale pollution transport during typical lake breezes. Streamlines calculated from serial pibal data suggest that a nearly closed circulation cell traps pollutants emitted near a shore line. Optically tracked tetroons confirm the helical trajectory of air within the lake breeze regime. Pollutants released within the inflow layer move inland, rise in a narrow zone of updrafts (100 cm/sec) at the lake breeze front, advect lakeward in the return flow layer aloft, and then subside back down into the inflow layer. Pollution then fumigates back to the surface as the air returns inland a second time causing concentrations higher than would otherwise be expected. Spectral aerosol measurements (0.5-3.0 and 7.0-9.0 micrometer size ranges) made by an instrumented aircraft reveal a marked particle size sorting. 相似文献
70.
This study investigates whether departments performing the same functions in different firms incur similar changes in structural configuration in response to industry-wide stimuli. Based on the proposition that the context of functional departments is similar across firms, changes in differentiation, integration, and perspective are hypothesized. Managers' perceptions of the validity of a series of statements to conditions five to 10 years ago and to present conditions are contrasted and show statistically significant shifts in these structural configurations. This change is confirmed by the analysis of responses of other managers in different departments within the same firms. Correlation analysis shows significant agreement among alternative measures of the same aspects of structure, and significant comovement among different structural dimensions. The later result supports the quantum theory of organizations. 相似文献