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Partitioning of CPs, PCDEs, and PCDD/Fs between Particulate and Experimentally Enhanced Dissolved Natural Organic Matter in a Contaminated Soil
journal contribution
posted on 2006-11-01, 00:00 authored by Sofia Frankki, Ylva Persson, Mats Tysklind, Ulf SkyllbergWe determined the distribution of hydrophobic organic
contaminants (HOCs) to fractions of natural organic matter
in a soil contaminated by chlorophenol wood preservatives
more than 30 years ago. The concentration of dissolved
organic matter (DOM) was enhanced in soil suspensions by
raising pH to 6.8−9.1. After 48 h of desorption/equilibration,
the DOM fraction was separated from the particulate
organic matter (POM) of the soil by filtration. In the next
step, 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 extracted
with toluene. No significant differences in gross carbon
chemistry were detected between DOM and POM, using
X-ray photoelectron spectroscopy (XPS). Normalized to
organic C, chlorophenols (CPs) showed a similar degree
of partitioning between DOM and POM, whereas the
partitioning 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.