A chemical extraction method for mimicking bioavailability of polycyclic aromatic hydrocarbons to wheat grown in soils containing various amounts of organic matter

Journal Article · Sat Apr 01 00:00:00 EST 2006 · Environmental Science and Technology

OSTI ID:20752115

Tao, Shu; Xu, Fuliu; Liu, Wenxin; Cui, Yanhong; Coveney, Jr, Raymond M ^[1]

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1. Peking University, Beijing (China). Laboratory for Earth Surface Processes, College of Environmental Sciences

Severe contamination of agricultural soils by polycyclic aromatic hydrocarbons (PAHs) occurs in many places in China mainly as a result of coal and biomass combustion. Because ingestion is the main source of human exposure to PAHs and vegetables are basic ingredients for the Chinese diet, it is important to know how and to what extent PAHs are accumulated in vegetables produced in contaminated soils. This study, evaluated the extent to which organic matter contents in soils influence the accumulation of PAHs by the roots of wheat plants and have developed a rapid chemical method for determining the bioavailability of PAH. Four PAHs, naphthalene, acenaphthylene, fluorene, and phenanthrene, were added to natural soil samples with different amounts of organic matter for pot experiments to evaluate apparent bioavailability of PAHs to wheat roots (Triticum aestivum L.). The extractabilities of PAHs in the soil were tested by a sequential extraction scheme using accelerated solvent extraction with water, n-hexane, and a mixture of dichloromethane and acetone as solvents. The water or n-hexane-extractable PAHs were positively correlated to dissolved organic matter (DOM) and negatively correlated to total organic matter (TOM), indicating mobilization and immobilization effects of DOM and TOM on soil PAHs, respectively. The apparent accumulation of PAHs by wheat roots was also positively and negatively correlated to DOM and TOM, respectively. As a result, there are positive correlations between the amounts of PAHs extracted by water or n-hexane and the quantities accumulated in plant roots, suggesting the feasibility of using water- or n-hexanes-extractable fractions as indicators of PAH availability to plants. 19 refs., 8 figs., 1 tab.

• OSTI ID: 20752115
• Journal Information: Environmental Science and Technology, Vol. 40, Issue 7; Other Information: [e-mail]; ISSN 0013-936X
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
01 COAL, LIGNITE, AND PEAT
POLYCYCLIC AROMATIC HYDROCARBONS
BIOLOGICAL AVAILABILITY
WHEAT
NAPHTHALENE
SOILS
SOIL CHEMISTRY
ORGANIC MATTER
ROOT ABSORPTION
BIOLOGICAL ACCUMULATION
SOLVENT EXTRACTION
BIOLOGICAL INDICATORS
HEXANE
WATER
PHENANTHRENE
CONDENSED AROMATICS
ORGANIC SOLVENTS
ACETONE
METHYLENE CHLORIDE
COAL
BIOMASS
COMBUSTION PRODUCTS
CHINA