Particles nitrate

Li, S.-M., K. G. Anlauf, and H. A. Wiebe, Heterogeneous Nighttime Production and Deposition of Particle Nitrate at a Rural Site in North America during Summer 1988, J. Geophys. Res., 98, 5139-5157 (1993). 

Denuders have been used in several different ways. One is to extract the walls of the denuder and measure the adsorbed gas directly by ion chromatography. Denuders have also been used as difference denuders. For example, in nitric acid measurements, the combination of gas-phase HNO-, and particle nitrate has been measured using a nylon filter or Teflon-nylon filter combination in one sampling train. In a parallel sampling train, particulate nitrate alone is measured by first passing the airstream through a denuder to re-... 

Potential interferences in the measurement of nitric acid using this method include removal of gaseous HN03 on the Teflon particle filter and/or volatilization of particle nitrate collected on this Teflon filter. As discussed in Chapter 7, NH4N03 is a common particle component, but exists in equilibrium with gas-phase NH3 and HN03 ... 

FIGURE 16.37 Trends in NOx, particle nitrate (PNO,), S02, and particle sulfate (PS04) as a function of year. The 3-year means of the annual top 30 daily means are shown. NO, and S02 were measured at Long Beach (western end) and particle nitrate and sulfate at Riverside (the eastern end) (kindly provided by Leon Dolislager and B. Croes, California Air Resources Board). 

However, as expected from the chemistry discussed in Chapter 7.E, simultaneous control of NH3 has a significant effect on particle nitrate formation, since the formation of ammonium nitrate is a major mechanism for conversion of gaseous HN03 to particulate nitrate. Thus, Meng et al. (1997) predict that a 50% reduction in both NO. and NH3 would give about the same reduction in particulate nitrate. 

Paik, D. H., I.-R. Lee, D.-S. Yang, J. S. Baskin and A. H. Zewail (2004)Electrons in finitesized water cavities Hydration dynamics observed in real time. Science 306, 672-675 Pakkanen, T. A. (1996) Study of formation of coarse particle nitrate aerosol. Atmospheric Environment 30, 2475-2482... 

Tertiary sewage treatment is essentially a chemical treatment that removes the fine particles, nitrates, and phosphates in wastewater. The basic procedure is adjusted for the specific substance to be removed. Activated charcoal filtration, for example, is used to remove most of the dissolved organic compounds. And alum (Al2(S04)3) is used to precipitate phosphate ions by dissolving and freeing the aluminum cation. 

Bondietti, E.A., Papastefanou, C. (1989). Large particle nitrate artifacts in the aerodynamic size distributions of ambient aerosols. J. Aerosol Sci. 20, 667-670. 

Particles are the major cause of the ha2e and the brown color that is often associated with smog. The three most important types of particles produced in smog are composed of organics, sulfates, and nitrates. Organic particles are formed when large VOC molecules, especially aromatics and cycHc alkenes, react with each other and form condensable products. Sulfate particles are formed by a series of reactions initiated by the attack of OH on SO2 in the gas phase or by Hquid-phase reactions. Nitrate particles are formed by... 

Ma.nufa.cture. Nitroguanidine may be made by several methods. In all the processes guanidine nitrate is the iatermediate which is then dehydrated with sulfuric acid. When used ia propellants, the average particle size of nitroguanidine has to be carefully controlled. 

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