Sorption of organic pollutants to soils is an environmentally
important process that affects properties such as bioavailability,
ecotoxicity, rate of degradation and their mobility. The affinity of
a soil for a given molecule is usually expressed as a partition constant
(Kd), which is simply the sorbed concentration divided by the
solution concentration. In general, Kd increases with the organic C
content of the soil, and hence Kd values are often normalized to the