Characterization of particulate matter in vehicle exhaust

Habibi, Kamran.

doi:10.1021/es60075a001

Cited by 114 publications

(61 citation statements)

References 7 publications

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“…Leaded petrol also contains the additives 1,2-dibromoethane (BrCH 2 CH 2 Br) and 1,2-dichloroethane (ClCH 2 CH 2 Cl) (Hamilton, 1996). During the combustion process the lead and halogen compounds react and predominantly produce PbBrCl which is emitted into the atmosphere (Habibi, 1973). Thus a ratio n(Br)/n(Pb) = 1 mol/mol is expected for freshly emitted particles.…”

Section: Biomass Burningmentioning

confidence: 99%

Inorganic bromine in the marine boundary layer: a critical review

et al. 2003

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Abstract. The cycling of inorganic bromine in the marine boundary layer (mbl) has received increased attention in recent years. Bromide, a constituent of sea water, is injected into the atmosphere in association with sea-salt aerosol by breaking waves on the ocean surface. Measurements reveal that supermicrometer sea-salt aerosol is substantially depleted in bromine (often exceeding 50%) relative to conservative tracers, whereas marine submicrometer aerosol is often enriched in bromine. Model calculations, laboratory studies, and field observations strongly suggest that the supermicrometer depletions reflect the chemical transformation of particulate bromide to reactive inorganic gases that influence the processing of ozone and other important constituents of marine air. Mechanisms for the submicrometer enrichments are not well understood. Currently available techniques cannot reliably quantify many Br-containing compounds at ambient concentrations and, consequently, our understanding of inorganic Br cycling over the oceans and its global significance are uncertain. To provide a more coherCorrespondence to: R. Sander (sander@mpch-mainz.mpg.de) ent framework for future research, we have reviewed measurements in marine aerosol, the gas phase, and in rain. We also summarize sources and sinks, as well as model and laboratory studies of chemical transformations. The focus is on inorganic bromine over the open oceans outside the polar regions. The generation of sea-salt aerosol at the ocean surface is the major tropospheric source producing about 6.2 Tg/a of bromide. The transport of Br from continents (as mineral aerosol, and as products from biomass-burning and fossil-fuel combustion) can be of local importance. Transport of degradation products of long-lived Br-containing compounds from the stratosphere and other sources contribute lesser amounts. Available evidence suggests that, following aerosol acidification, sea-salt bromide reacts to form Br 2 and BrCl that volatilize to the gas phase and photolyze in daylight to produce atomic Br and Cl. Subsequent transformations can destroy tropospheric ozone, oxidize dimethylsulfide (DMS) and hydrocarbons in the gas phase and S(IV) in aerosol solutions, and thereby potentially influence climate. Inorganic bromine in the mbl gas phase during daytime are consistent with expectations based on photochemistry. We expect that the importance of inorganic Br cycling will vary in the future as a function of both increasing acidification of the atmosphere (through anthropogenic emissions) and climate changes. The latter affects bromine cycling via meteorological factors including global wind fields (and the associated production of sea-salt aerosol), temperature, and relative humidity.

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Section: Biomass Burningmentioning

confidence: 99%

Inorganic bromine in the marine boundary layer: a critical review

et al. 2003

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“…7 Kobringer and Geinopolos (1984) reported that tire wear produces particles with an average diameter of 20 μm. Environmental Science & Technology ARTICLE Habibi (1973) found that 57% of the Pb emitted in vehicle exhaust was associated with particles >9 μm in diameter. 28 It is well-known that the grain size distribution of RDS is an important factor in determining the mobility of particles and their associated pollutant concentrations.…”

Section: ' Discussionmentioning

confidence: 99%

Heavy Metal Contents of Road-Deposited Sediment along the Urban–Rural Gradient around Beijing and its Potential Contribution to Runoff Pollution

Zhao

Wang

2011

Environ. Sci. Technol.

102

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Understanding the contribution of road-deposited sediment (RDS) and its washoff process is essential for controlling urban runoff pollution. Ninety-seven RDS samples were collected along the urban–suburban–rural gradient from areas of five administrative units in the Beijing metropolitan region, including central urban (UCA), urban village (UVA), central suburban county (CSA), rural town (RTA), and rural village (RVA) areas. RDS washoff was evaluated with different particle sizes using a rainfall simulator. Heavy metal elements (i.e., Cr, Cu, Ni, Pb, and Zn) were estimated in both RDS and runoff samples. The RDS mass per unit area increased in the order UCA (21 ± 24 g/m2) ≈ CSA (20 ± 16 g/m2) < RTA (59 ± 63 g/m2) < RVA (147 ± 112 g/m2) ≈ UVA (147 ± 198 g/m2). Compared to RDS from the other administrative units, RDS from the UCA and CSA had higher metal concentrations and higher proportions of smaller particles, whereas that from the RVA and UVA had larger quantities of metals per unit area. UCA and CSA had lower potential runoff pollution contributions per unit area. Our findings imply that controlling the first flush in the UCA and CSA, and improving existing street cleaning methods and road surface conditions in the TRA, UVA, and RVA will be appropriate strategies for controlling runoff pollution from RDS.

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“…This hypothesis is refuted by the Allegheny 1979 size distributions, in that there is no tendency for the Pb to exist in larger particles when the traffic composition shifts toward diesels. The second explanation, related to the fact that automobiles drive through the tunnels slightly faster at night and in other periods of light traffic, is that a Pb-emission-rate increase-known (Habibi, 1970(Habibi, , 1973Ter Haar et al, 1972) to occur with increase in speed-would appear in the regression analysis as Pb from diesels since the percentage of diesels tends to be highest during these times (Figure 2). This increase is probably an order of magnitude too small to account for the effect.…”

Section: Scandium Soil Dust Accounts For All Of the Scmentioning

confidence: 99%

“…Actually, highway and urban driving give different emission rates for many species, including Pb (Habibi, 1970(Habibi, , 1973Ter Haar et al, 1972). Moreover, and as reflected in the error estimates in Table 9, there is a good deal of scatter among the reported urban-air concentrations.…”

Section: Contribution Of Vehicles To Urban Air Particulate Concentratmentioning

confidence: 99%