Importance of Particulate Matter on the Load of Hydrocarbons of Motorway Runoff and Secondary Effluents

Extractable organic matter in urban stormwater runoff. 2. Molecular characterization

“…This compound has been found in marine sediments from Tanner Basin, CA (53), and in older sediments (54); however, its formation in subaerial environments has, until this time, not been reported. These findings indicate (1) that in situ diagenetic production of 6,10,14-trimethylpentadecan-2-one from chlorophyll under mild oxidative conditions as suggested by Ikan et al (55) must include terrestrial as well as marine environments and (2) that phytol and dihydrophytol, if produced, are very rapidly transformed and/or removed.…”

“…The bound fatty acids were a significant portion of the total recoverable (i.e., extractable plus bound) acids (25-50%). These compounds released by alkali hydrolysis can be lodged in several environments: (1) esterified in plant cutin (43, 44) and microbial cellular walls ( 45), ( 2) by linkage through ester and amide bonds to the surface and/or interior of humic/fulvic substances (9), and (3) physically entrapped in or adsorbed by, clay minerals and humic/fulvic substances (37, 46). In the present study, the enhanced occurrence of 16:0, iso, and anteiso acids and odd carbon number acids is suggestive of a large bacterial component (40,47); however, it is impossible to say whether they are released from primary or secondary (38) sources.…”

“…Details of the sampling, the extraction, and the chromatographic separation of organic compounds into various classes are described in the preceding report (4). Briefly, the CHCls-extractable organics from filtered and unfiltered samples were separated into four fractions for molecular analysis: (1) total hydrocarbons (THC), (2) fatty acids (FA), (3) ketones (KET), and (4) polar compounds (PLR). The particulates were extracted exhaustively with CHCI3 to remove extractable organics and then saponified (5) to isolate the bound constituents.…”

“…The PLR fraction was silylated by using BSA (A^O-bis(trimethylsilyl)acetamide) before injection (7). Analyses of the PLR fraction were performed in two ways: (1) direct injection of the sample in excess BSA at 150 °C with temperature programming to 260¡SO °C at 4 °C/min and (2) transfer to 9:1 hexane/ethyl acetate under dry N2 followed by injection at 90 °C with temperature programming as before. The former method was used for examination of the sterols, and the latter for intermediate molecular weight species.…”

Extractable organic matter in urban stormwater runoff. 1. Transport dynamics and mass emission rates

“…Mean values for the calculated "particulate" concentration of THC and its "dissolved" (i.e., filtered) counterpart were 10.5 ± 6.4 and 0.39 ± 0.05 mg/L, respectively. MacKenzie and Hunter (12) found values in a Philadelphia storm sewer to be 2.7-5.1 mg/L (particulate) and 0.16-0.34 mg/L (dissolved); Ziircher et al (13) noted similar levels in motorway runoff in Switzerland.…”