Anthropogenic and natural humic materials were investigated as sorbent
s for hydrophobic solutes in aqueous solution. The first was taken fro
m a brown coal wastewater pond. The measured sorption coefficients K-O
C and K-DOM are close to literature values for both sorbents. This hol
ds for particulate (sediments) as well as for dissolved materials (hum
ic and fulvic acids). A modified solubility parameter concept is propo
sed to better understand the K-OC-K-OW correlation. It makes it possib
le to estimate sorption coefficients for nonpolar solutes based on the
ir K-OW, if the delta value of the sorbent is known. On the other hand
, measured sorption coefficients permit the calculation of this value,
which can be considered a feature of the humic fraction under study.
The mean delta value of humic organic matter estimated from sorption d
ata in this paper is 12.5 +/- 0.5 (cal cm(-3))(1/2).