Page 181 - Partition & Adsorption of Organic Contaminants in Environmental Systems

172 CONTAMINANT SORPTION TO SOILS AND NATURAL SOLIDS

TABLE 7.14. Percent Elemental Contents of Soil and Stream Organic Matter
Extracts on a Moisture-free, Ash-free Basis
Organic Matter Extract C H O N S P Ash
Sanhedrin soil humic acid 58.0 3.64 33.6 3.26 0.47 0.10 1.19
(SSHA)
Sanhedrin soil fulvic acid 48.7 4.36 43.4 2.77 0.81 0.59 2.25
(SSFA)
Suwannee River humic acid 54.2 4.14 39.0 1.21 0.82 0.01 3.18
(SRHA)
Suwannee River fulvic acid 53.8 4.24 40.3 0.65 0.60 0.01 0.68
(SRFA)
Source: Data from Chiou et al. (1986).

200
2, 4, 4'-PCB (25°C)

Apparent Solute Solubility (µg/L) 100 2, 4, 5, 2', 5'-PCB (25°C)

15

10

5 p, p'-DDT (24°C)

0
0 20 40 60 80 100
Concentration of SRHA, X (mg/L)
Figure 7.29 Apparent water solubility of p,p¢-DDT, 2,4,5,2¢5¢-PCB, and 2,4,4¢-PCB as
a function of SRHA concentration. [Data from Chiou et al. (1986).]

the lack of interference between binary solutes (for 2,4,5,2¢,5¢-PCB and 2,4,4¢-
PCB with SSHA) are in keeping with the postulated partitionlike interaction
between the solute and DOM for the solubility enhancement observed. The
different effects for a group of solutes with a given DOM are attributed to
their different K dom (or K doc) values. The calculated logK dom and logK doc values
of the solutes with SSHA, SSFA, SRHA, and SRFA are tabulated in
Table 7.15. Since, for a given DOM, the magnitude of K dom (or K doc) should be