Applications of Equilibrium Thermodynamics - Elements of Environmental Engineering: Thermodynamics and Kinetics - page 145

TABLE 4.9
Air-Water Partition Constants and Air-Water Mass Transfer Coefficients
for Selected Pollutants in the Natural Environment
Compound K aw ( − ) k w (m/s) k a (m/s)

Inorganic

10 − 2 10 − 3

Sulfur dioxide 0.02 9.6 × 4.4 ×

10 − 5 10 − 3

Carbon monoxide 50 5.5 × 8.8 ×

5.5 × 10 − 5 5.3 × 10 − 3 Nitrous oxide 1.6

4.9 × 10 − 4 5.1 × 10 − 3

Ozone 3

7.3 × 10 − 4 6.7 × 10 − 5 8.5 × 10 − 3

Ammonia

5.5 × 10 − 5

Oxygen 25.6 -

8.4 × 10 − 3

Water - -

Organic

5.5 × 10 − 5 8.8 × 10 − 3 Methane 42

3.1 × 10 − 5 3.0 × 10 − 3

Trichlorofluoromethane 5

4.2 × 10 − 5 3.2 × 10 − 3

Chloroform 0.183

5.2 × 10 − 5 4.1 × 10 − 3

Carbon tetrachloride 0.96

7.5 × 10 − 5 6.0 × 10 − 3

Benzene 0.23

3.5 × 10 − 5 4.5 × 10 − 3 Dichlorobenzene 0.069

2 × 10 − 5 3.8 × 10 − 5 3.1 × 10 − 3

Lindane

1.6 × 10 − 3 3.6 × 10 − 5 2.8 × 10 − 3

DDT

3.6 × 10 − 5 4.6 × 10 − 3

Naphthalene 0.021

1.6 × 10 − 3 5.0 × 10 − 5 4.0 × 10 − 3

Phenanthrene

1.1 × 10 − 5 3.3 × 10 − 5 3.2 × 10 − 3 Pentachlorophenol

4.4 × 10 − 4 1.7 × 10 − 2

PCB (Aroclor 1254) 1.9

Source: From Warneck, P. 1986. Chemistry of the Natural Atmosphere. New York: Academic Press;
Eisenreich, S.J., Looney, B.B., and Thornton, J.D. 1981. Environmental Science and Tech-
nology 5, 30-38; Mackay, D. and Leinonen, P.J. 1975. Environmental Science Technology 9,
1178-1180; Liss, P.S., and Slater, P.G. 1974. Nature , 247, 181-184.
Note: All values are at 298 K.

E XAMPLE 4.12 F LUX OF SO 2 IN THE E NVIRONMENT
The mean concentration of SO 2 in the atmosphere has been determined to be approx-
imately 3 μ g/m − 3 .SO 2 is fairly rapidly oxidized in the slightly alkaline environment
of seawater, and hence its concentration in surface ocean waters is approximately zero.
Using the data from Table 4.10 for k w , k a and the Henry's law constant K aw ,wehave
K w ={ ( 1 /k w ) + ( 1 /k a K aw ) } − 1

= 9.0 × 10 − 5 m/s. Since C iw = 0, we have for the
flux J Dry ( G ) = 9.0 × 10 5 − { 3 / 0.02 }= 0.013 μ g/m 2 /s. The flux is directed from the
atmosphere to the ocean. If the total surface area of all oceans is 3.6 × 10 14 m 2 , the
total annual flux would be 1.5

10 14 g, which is the same order of magnitude as the
estimated emissions from fossil fuel burning (Liss and Slater, 1974).

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