Emissions, vehicular

Control of NO emissions from nitric acid and nitration operations is usually achieved by NO2 reduction to N2 and water using natural gas in a catalytic decomposer (123—126) (see Exhaust control, industrial). NO from nitric acid/nitration operations is also controlled by absorption in water to regenerate nitric acid. Modeling of such absorbers and the complexities of the NO —HNO —H2O system have been discussed (127). Other novel control methods have also been investigated (128—129). Vehicular emission control is treated elsewhere (see Exhaust control, automotive). 

The average life of a car is 10 years. New car sales amounted to 368,000 units in the MCMA in 1989, compared to 136,000 in 1984. Vehicular transportation accounts for 22.4 million personal journeys a day 51% are taken to go to work, 24% to school, 8% for shopping, 3% for entertainment, and 14% in other activities. Although 79.4% of personal journeys are made by public transport, those 19.0% related to the use of private cars are sufficient to create traffic jams, low transit speeds and 70.4% of vehicular emissions. 

Conclusion TVOC concentration for combined indoor/outdoor air was 169.9 pg nr3 and 420.8 pg m3 at residential and roadside site respectively. At residential site, the indoor and outdoor mean concentration of TVOC was of 236.3 pg nr3 and 103.5 pg nr3 respectively. The average indoor concentration at roadside site was 453.3 pg nr3 whereas at outdoor it was 388.4 pg nr3. At both the sites, the indoor TVOC levels were higher than that at outdoors. Mean I/O ratio at residential site was 2.3 with a range of 1.7 to 2.7 while at roadside site I/O ranges from 0.9 to 1.3 with a mean value of 1.1. At residential site, contribution of VOCs at indoor and outdoor was found to be 70% and 30%, clearly indicating dominant indoor sources, whereas at roadside it was 54% and 46% for indoor and outdoor respectively giving evidence of vehicular emission effect. Seasonal trend for TVOC at outdoors was in the order of winter > summer > monsoon whereas for indoors it was winter > monsoon > summer at both the sites. 

Tanner, R. L, A. H. Miguel, J. B. de Andrade, J. S. Gaffney, and G. E. Streit, Atmospheric Chemistry of Aldehydes Enhanced Peroxyacetyl Nitrate Formation from Ethanol-Fueled Vehicular Emissions, Environ. Sci. Technol., 22, 1026-1034 (1988). 

Reformulated Gasoline (RFG) Gasoline that has its composition and/or characteristics altered to reduce vehicular emissions of pollutants, particularly pursuant to EPA regulations under the CAA. 

In order to combine the capability of these commercial producers and the capability of the certification of NMI, CENAM has launched a program called Certified Traceable Reference Materials, MRTC in Spanish. This is a similar initiative to NTRM of NIST. It is intended primarily to promote the capability of domestic industries to produce and certify CRMs in those fields where there exist enormous demand and absolute lack. This program is under development in the field of gas standards for vehicular emissions, Fig. 3, and pH measurements with domestic industries. 

While all pertinent factors that affect the distribution of vehicular emissions cannot be taken into account, emissions rates may still be represented with suflBcient accuracy to merit inclusion in an urban airshed model. For simplicity a vehicle emissions inventory can be divided into two parts ... 

Phenanthrene occurs in fossil fuels and is present in products of incomplete combustion. Some of the known sources of phenanthrene in the atmosphere are vehicular emissions, coal and oil burning, wood combustion, coke plants, aluminum plants, iron and... 

Figure 13.3 The volume distribution of the Piisadena. California aerosol measured on September 3, 1969. Photochemical processes acting on vehicular emissions lead to the increase in accumulation mode particles froin 4 A.M. to noon. Advection of cleaner air clears out the aerosol products in the afternoon. (After Whitby ct al., 1972.)...

PCBs may be released to soil from accidental leaks and spills releases from contaminated soils in landfills and hazardous waste sites deposition of vehicular emissions near roadway soil and land application of sewage sludges containing PCBs (Alcock et al. 1995 Benfenati et al. 1992 Choi et al. 1974 Gan and Berthouex 1994 Gutenmann et al. 1994 Liberti et al. 1992 McLachlan et al. 1994 Morris and Lester 1994 O Connor et al. 1990 Ohsaki and Matsueda 1994). 

Ng, K. C. and Cheng, Z. L., Environmental monitoring of benzene and alkylated benzene from vehicular emissions. Environ. Monit. Assess., 44(1-3), 437-441, 1997. 

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