Effluents, stationary sources

In the area of pollution control, file removal of NOx from stationary sources effluents, such as power plant stack gases, has been accomplished by use of titania-vanadia catal)rsts, which promote the reduction of NOx with NH3 to produce nitrogen and water. 

The control of NO from stationary sources includes techniques of modification of the combustion stage (primary measures) and treatment of the effluent gases (secondary measures). The use oflow-temperature NO,.burners, over fire air (OFA), fiue gas recirculation, fuel reburning, staged combustion and water or steam injection are examples of primary measures they are preliminarily attempted, extensively applied and guarantee NO reduction levels of the order of 50% and more. However, they typically do not fit the most stringent emission standards so that secondary measures or flue gas treatment methods must also be applied. 

ASTM D 7295 Standard Practice for Sampling and Determination of Hydrogen Cyanide (HCN) in Combustion Effluents and Other Stationary Sources. Annual Book of Standards, Vol. 11.07, ASTM International, West Conshohocken, PA. 

A serious govemment/industry program to abate air pollution from stationary sources has been underway for about five years. Until recently this program has concentrated on the development of effluent treatment technology directed to the electric utility industry. This prioriy was based primarily on mass emission, i.e., that 70% of total U.S. SOj. emissions as indicated in Table IV come from electric utilities. 

Pollutants are emitted daily with the effluents produced by stationary and non-stationary sources. The first type includes industrial processes, energy production, waste incineration, and domestic burning, whereas the second type includes automotive emissions and emissions from aeroplanes. Road and air traffic make a substantial contribution to NO and particulate emissions. 

Further, for most stationary source air emissions, the pollutant is present in very low concentrations. Large volumes of air must be treated to remove the contaminant, often requiring costly and energy-intensive treatment steps. It is intuitively attractive simply to convert the contaminant chemically with a catalyst into harmless compounds that need not be removed from the effluent stream. 

Standard sampling trains are specified for some tests. One of these standards is the system specified for large, stationary combustion sources (4). This train was designed for sampling combustion sources and should not be selected over a simpler sampling train when sampling noncombustion sources such as low-temperature effluents from cyclones, baghouses, filters, etc. (5). 

The Portable Unit has successfully demonstrated its capability for thermal treatment of hazardous wastes at the source of the material. This type of on-site treatment would eliminate the need of transportation of hazardous materials to a distant site of stationary treatment equipment. The Portable Unit also has demonstrated that it can be moved to a site and be ready to treat material very quickly, a capability which will be very important in operation of full scale equipment. The on-site treatment of the Times Beach dioxin contaminated soil resulted in no dioxin detected in any of the incinerator effluent streams. The product of the testing activity was soil with no detectable level of dioxin. Dioxin contaminated soil thermally treated in this manner will yield soil which can be disposed as non-hazardous material. The decontamination was performed without exceeding RCRA requirements for particulate emissions and with dioxin destruction efficiencies surpassing the required percentage. The overall conclusion was that the infrared incinerator can very effectively remove dioxin from contaminated... 

Vandegrift, A.E., Shannon, L.J. et al., Handbook of Emissions, Effluents, and Control Practices for Stationary Particulate Pollutant Sources, Report of NAPCA... 

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