scholarly journals Effect of organic compounds on nanoparticle formation in diluted diesel exhaust

2004 ◽  
Vol 4 (3) ◽  
pp. 609-620 ◽  
Author(s):  
U. Mathis ◽  
M. Mohr ◽  
R. Zenobi

Abstract. The nucleation of nanoparticles in the exhaust of a modern light-duty diesel vehicle was investigated on a chassis dynamometer. This laboratory study is focused on the influence of volatile organic compounds (VOCs) on nucleation of volatile nanoparticles. Different organic compounds were added to the dilution air of the particle sampling under different sampling conditions. Sample temperature and relative sample humidity were varied in a wide range. The number size distribution of the particles was measured with a scanning mobility particle sizer (SMPS) and showed significant differences in response to the added organic compounds. While the nucleation mode particles showed a large variation in concentration, the accumulation mode particles remained unchanged for all compounds. Depending on the functional group, organic compounds were capable of initiating and increasing (alcohols and toluene) or decreasing (acetone, aniline, and methyl tert-butyl ether (MTBE)) nucleation mode particles. Short volatile aliphatic hydrocarbons (hexane and cyclohexane) turned out to be without effect on nucleation of nanoparticles. Possible reasons for the differences are discussed.

2004 ◽  
Vol 4 (1) ◽  
pp. 227-265 ◽  
Author(s):  
U. Mathis ◽  
M. Mohr ◽  
R. Zenobi

Abstract. The nucleation of nanoparticles in the exhaust of a modern light-duty diesel vehicle was investigated on a chassis dynamometer. This laboratory study is focused on the influence of volatile organic compounds (VOCs) on nucleation of volatile nanoparticles. Different organic compounds were added to the dilution air of the particle sampling under different sampling conditions. Sample temperature and relative sample humidity were varied in a wide range. The number size distribution of the particles was measured with a scanning mobility particle sizer (SMPS) and showed significant differences in response to the added organic compounds. While the nucleation mode particles showed a large variation in concentration, the accumulation mode particles remained unchanged for all compounds. Depending on the functional group, organic compounds were capable of initiating and increasing (alcohols and toluene) or decreasing (acetone, aniline, and methyl tert-butyl ether (MTBE)) nucleation mode particles. Short volatile aliphatic hydrocarbons (hexane and cyclohexane) turned out to be without effect on nucleation of nanoparticles. Possible reasons for the differences are discussed.


Clay Minerals ◽  
2017 ◽  
Vol 52 (1) ◽  
pp. 143-159 ◽  
Author(s):  
Mathieu Gautier ◽  
Fabrice Muller ◽  
Lydie Le Forestier

AbstractThe percolation of water through waste landfills produces leachates with high concentrations of which can generate -exchanged clays within geochemical barriers. These leachates also contain several volatile organic compounds (VOCs) which can interact with the clay barrier. The aim of the present study was to characterize the sorption of eight short-chain VOCs (acetonitrile, methyl tert-butyl ether, dichloromethane, benzene, phenol, ethanol, acetone and aniline) on -smectite, and to identify their sorption mechanisms. The samples treated were characterized by carbon and nitrogen elemental analysis, infrared spectroscopy, powder X-ray diffraction, and thermogravimetric analysis. For acetonitrile, methyl tert-butyl ether, dichloromethane and benzene, no sorption was detected. Phenol, ethanol and acetone were sorbed very weakly, through Van der Waals interactions. Aniline molecules were sorbed strongly on -smectite mainly with hydrogen bonds between aniline and interlayer water molecules. However, aniline sorption decreased the hydrophilic character of the -smectite, which may increase the permeability of the clay barrier.


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