Non-methane organic carbon

The concentration of vapour phase organic carbon in surface air over the oceans is 5-10 fig m-3 STP. The corresponding range over non-urban North America was found to be 10-50 fig m 3 STP. It should be noted, however, that much higher continental concentrations were measured in the Amazon jungle of Brazil. 

Duce (1978) found an acceptable residence time (2 days) for larger organic particles when he took into account only primary sources. These primary aerosol particle sources are partly natural (e.g. materials from ocean waters, wind erosion of soil3, biospheric matter, forest wildfires) and partly anthropogenic (mostly from 

4 The formation of sea salt and mineral particles is discussed in Subsection 4.2.1. 

1 More recent data suggest smaller interhemispheric gradient. For example, Rasmussen and his co-workers (see Fraser and Pearman, 1978b) observed an 11 % decrease in concentration from 30° N to 15° S. 

Tropospheric concentration of halocarbons according to Graedel and Allara (1976) 

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Duce, R. A., 1978 Speculations on the budget of particulate and vapor phase non-methane organic carbon in the global troposphere. Pure and Appl. Geophys. 116, 244-273. 

The advantages of energy recovery include cheap fuel plus decreased landfill emissions of methane, non-methane organic carbon compounds (NMOCs), and toxics (e.g., benzene, carbon tetrachloride, and chloroform). Although carbon dioxide emissions increase with the energy recovery option, the net atmospheric balance is a positive one... 

Data from the EEA (2006c) reveal that air emissions from transport follow a slightly less expressed, but well comparable trend to entire emissions between 1990 and 2004. Table 19.2 shows the share for the transport sector of certain pollutants in the EU 40% to 50% of NO, and carbon monoxide (CO), 25% of non-methane volatile organic compounds (NMVOC) and just 1% of sulphur oxides (SO,). In developing countries, and here in particular in the big megacities, the share for transport of SO, heavy metal and particulate emissions (not listed here) will -because of the old vehicle fleets - be much higher. 

NAFTA n.a. NEA NEDC NG NGC NGL NGPL NMVOC NOC NUTS North American Free Trade Agreement Not available Nuclear Energy Agency New European Driving Cycle Natural gas Natural gas from coal Natural-gas liquids Natural gas plant liquids Non-methane volatile organic carbons National Oil Company Nomenclature of Territorial Units for Statistics... 

Methanogenesis. Finally, the products of either acidogenesis or acetogenesis are transformed into methane and carbon dioxide by the methanogenic bacteria. It is well known that this step is the limiting one in case of nonparticulate substrate or non-excessively complex organic matter. 

Biogenic particles which comprise primary (fungal spores, bacteria, viruses, plant debris) and secondary organic aerosol (SOA) from biogenic non-methane VOCs are part of the commonly measured organic carbon fraction. Model results [51] indicate a... 

Phase 2 RFG was introduced in the San Francisco Bay Area and pollutant emissions were measured at the 1100 m long Caldecott tunnel during the summers of 1994 and 1997. Between the 1994 to 1997, emissions of carbon monoxide decreased by 31%, non-methane volatile organic compounds (VOC) decreased by 43%, nitrogen oxides decreased by 18%, and vehicle emission of benzene was estimated to be a 30 to 40% reduction. The use of RFG increased formaldehyde... 

The measurement of total organic carbon (TOC) is the best means of assessing the organic content of a water sample [20]. Organic carbon is oxidized to carbon dioxide (CO,) by heat and oxygen, ultraviolet irradiation, chemical oxidants, or by various combinations of these. The CO, may be measured directly by a non-dispersive infrared analyser or it may be reduced to methane and measured by a flame ionization detector in a gas chromatograph or in a TOC analyser thus equipped. The CO2 may also be titrated chemically. 

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