PAHs in road dust of Nanjing Chemical Industry Park, China: chemical composition, sources, and risk assessment.

The objectives of the present study were to research the chemical composition of PAHs in PM of road dust, explore potential sources of PAHs, and assess their carcinogenic risk. Fifty-six road dust samples were collected on the arterial and sub-arterial roads at Nanjing Chemical Industry Park during the sampling periods of autumn and winter. A resuspension system in the laboratory was used to simulate the naturally suspended road dust in the environment and collect PM.

[Molecular and Carbon Isotopic Compositions of -Alkanoic Acids in Smoke from Maize Straw Combustion].

Four cultivars of maize straw were burned under flaming and smoldering conditions. Smoke samples were colleted and analyzed by GC/MS and GC/C/IRMS to determine molecular and stable carbon isotopic compositions of -alkanoic acids in them. The results showed that -alkanoic acids in flaming smoke were composed of C to C, with a mean total content of 13895.

[Chemical Composition of Water-soluble Ions in Smoke Emitted from Tree Branch Combustion].

Water-soluble ions in particulate matter (PM) from tree branch combustion were determined. The results showed that the average content of total water-soluble ions in flaming PM from dry branches was (28.88±17.

[Chemical Composition of Alkanes and Organic Acids in Vehicle Exhaust].

The soot of 11 diesel buses and 20 gasoline cars was sampled by direct sampling, and the main organic compounds of the samples were separated and qualitatively analyzed by GC-MS. The results showed that the mass fraction of -alkanes was 1.31-149.

[Organic Carbon and Elemental Carbon in Forest Biomass Burning Smoke].

Ten kinds of trees were selected for preparing dry and wet stick samples. Concentrations of organic carbon (OC), elemental carbon (EC) in particular matter produced by sticks samples in the flaming and smoldering were analyzed through the Thermal Optical Carbon Analyzer (Model 2001A). The results showed that mean values of OC (EF(OC)), EC (EF(EC)), PM (EF(PM)) emission factors were 6.

[Emission of Particulate Matter, Organic and Elemental Carbon from Burning of Fallen Leaves].

The two kinds of burning conditions, i. e., flaming and smoldering, were selected to investigate the particulate matter (PM), organic carbon (OC), and elemental carbon ( EC) from burning of ten kinds of fallen leaves.

[Organic and element carbon in foliar smoke].

A home-made combustion and sampling apparatus was used to burn green leaves under flaming and smoldering conditions and to collect the smoke generated. The smoke was measured with Organic/Elemental Carbon (OC/EC) Analyzer using IMPROVE thermal-optical reflectance (TOR) method, to investigate the mass fractions and the distribution of OC, EC and eight carbon fractions in foliar smoke. The results showed that in smoldering condition, the mean OC, EC mass fractions of ten foliar smokes were 48.

[Composition of organic carbon/elemental carbon and water-soluble ions in rice straw burning].

Six types of rice straw were selected in China in this paper, the homemade biomass combustion devices were used to simulate the outdoor burning. The concentrations of organic carbon (OC), elemental carbon (C) and water-soluble ions in particular matter produced by the flaming and smoldering were analyzed using Thermal Optical Carbon Analyzer (Model 2001A) and Ion Chromatography(ISC 2000/ISC 3000). The results showed that the mean value of OC (EFoc) and EC (EFEC) emission factors were (6.

[Isotope compositions of elemental carbon in the smoke and ash from crop straw combustion].

Six genotypes of straws for rice, maize and wheat, respectively, were combusted under flaming and smoldering conditions, and the isotope compositions for elemental carbon ( EC) in the straw smoke and ash were investigated with an isotopic mass spectrometer. The results showed that the mean delta 13C values for EC in the flaming and smoldering smoke of rice straw were - 28. 3 per thousand and - 28.

[Chemical compositions of n-alkanols in smoke from rice and maize straw combustion].

Six genotypes of rice straw and four genotypes of maize straw were burned under different conditions, and the smoke was collected and n-alkanol in it was measured by GC-MS. Results showed that, in the smoke from rice straw flaming combustion, n-alkanol was composed of individual compounds from C14 to C34, and total contents(sigma) changed in the range of 1 604.4 to 13 889.

[Chemical compositions of n-alkanoic acids in wheat straw and its smoke].

Wheat straws of six genotypes were burned under different conditions, and n-alkanoic acids in the straw and its smoke were measured by GC/MS. The results showed that the carbon number of the fatty acids in all the smoke ranged from C8 to C32. In the flaming smoke, the total amounts of the compounds varied from 1,509.

[Chemical composition of n-alkanes in wheat straw and smoke].

Straw of six wheat species was burned under flaming and smoldering conditions. Chemical compositions of n-alkanes in the straw and its smoke were measured with GC/MS. The results showed, the main compounds in all samples were C16 to C33, and the total amounts of n-alkanes in the straw were between 19.

[Carbon isotopic compositions of n-alkanes and n-alkanoic acids in the smoke from combustion of rice straw].

In order to investigate the carbon isotopic fractionation in n-alkanes and n-alkanoic acids in smoke from rice straw combustion, six types of rice straw were burned in laboratory under flaming and smoldering conditions, and the compound specific isotopic compositions for the two classes of biomarkers in the smoke were determined. The results showed that the delta13C values of individual n-alkanes and n-alkanoic acids released from flaming burns of all the rice species ranged from -28.6 per thousand to -38.

Sorption of pyrene on two paddy soils and their particle-size fractions.

In the present study, the sorption of pyrene on two kinds of bulk paddy soils, Gleyic Stagnic Anthrosols, and Ferric accumulic Stagnic Anthrosols as well as their particle-size fractions was investigated. The sorption isotherms fitted well with Freundlich equation. For both soils, the clay fraction( < 2 microm) and coarse sand fraction(2000-250 microm) had higher sorption capacity than fine sand fraction(250-20 microm) and silt fraction(20-2 microm).

[Aging of spiked pyrene in two paddy soils and their particle-size fractions after soil incubation and changes in extractability and bio-availability to earthworm].

Effect of aging on bioavailability and extractability of persistent organic pollutants has recently been paid much attention in environmental studies. This study deals with aging of spiked pyrene, a four-ring polycyclic hydrocarbon, in two paddy soils and their particle-size fractions under laboratory incubation and change in its extractability and bioavailability. The bioavailability of aged pyrene was tested by an assay of exposure to earthworms (Eisenia foetida).