Geoscience Reference
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molecular weight and structure information.
131
More detailed information about
estimating these coefficients is available in SPARC.
145
Values for partition coefficients can be obtained from laboratory experiments.
As stated earlier, laboratory studies have shown that the partition coefficient is related
to the hydrophobicity of the chemical and organic matter content of the sediment
for organic chemicals. Many organic pollutants of current interest are nonpolar,
hydrophobic compounds whose partition coefficients correlate quite well with the
organic fraction of the sediment. Karickoff et al.
146
and Schwarzenbach and Westall
147
have developed empirical expressions relating equilibrium partition coefficients to
laboratory measurements, leading to fairly reliable means of estimating appropriate
values for
K
oc
as given below:
Karickhoff et al.
146
log
K
oc
: 1.00log
K
ow
- 0.21
(4.39)
Schwarzenbach and Westall
147
log
K
oc
: 0.72log
K
ow
+
0.49
(4.40)
These relationships have proven very useful for predicting equilibrium partition
coefficients of a great number of neutral hydrophobic organic compounds between
water and natural sorbents of very different origins. Other chemical property esti-
mation methods are reported by Lyman et al.
148
Table 4.39 provides a list of measured
log
K
ow
values for a number of organic chemicals of environmental interest. Deter-
mination of
K
ow
values for organic chemicals needs experimental analysis. Recent
data on such values may be found in BCPC,
116
EXTOXNET,
118
and the Merck
Index.
149
TABLE 4.39
Octanol/Water Partition Coefficients of Some Selected Organics
Chemical
log
K
ow
As Cited in
Bromoform
2.3
Schnoor et al.
150
Carbofuran
1.60
Schnoor
131
Carbofuran
17-26
DPR
117
Chloroform
1.90-1.97
Schnoor
131
Chloroform
1.97
Schnoor et al.
150
Chloroform
6.22
Merck Index
149
2-Choloroethyl vinyl ether
1.28
Schnoor
131
2-Choloroethyl vinyl ether
4.08-4.28
Kidd and James
151
DDT
6.4
Schnoor
131
DDT
3.98-6.36
Pontolillo and Eganhouse
152
Ethylbenzene
3.34
Schnoor et al.
150
Hexachlorobenzene
6.41
Schnoor et al.
150
Pentachlorophenol
5.01
Schnoor
131
2-Nitrophenol
1.75
Schnoor et al.
150
Tetrachloroethylene
2.88
Schnoor et al.
150
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