| Abstract
| - We determined the distribution of hydrophobic organiccontaminants (HOCs) to fractions of natural organic matterin a soil contaminated by chlorophenol wood preservativesmore than 30 years ago. The concentration of dissolvedorganic matter (DOM) was enhanced in soil suspensions byraising pH to 6.8−9.1. After 48 h of desorption/equilibration,the DOM fraction was separated from the particulateorganic matter (POM) of the soil by filtration. In the nextstep, DOM was flocculated by Al-nitrate, and free concentrations of HOCs were determined in the aqueous phase.The HOCs associated with DOM and POM were extractedwith toluene. No significant differences in gross carbonchemistry were detected between DOM and POM, usingX-ray photoelectron spectroscopy (XPS). Normalized toorganic C, chlorophenols (CPs) showed a similar degreeof partitioning between DOM and POM, whereas thepartitioning of polychlorinated diphenyl ethers (PCDEs),polychlorinated dibenzo-p-dioxins, and furans (PCDD/Fs)was highly shifted toward POM. The partitioning to POM,relative to DOM, increased in the order PCDE < PCDF< PCDD, reflecting the hydrophobicity of the compounds.
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