Page 129 - Materials Chemistry, Second Edition

112 Practical Design Calculations for Groundwater and Soil Remediation

(b) From Example 3.19,
K = (0.015)(85) = 1.275 (for benzene)
p
K = (0.015)(22) = 0.32 (for 1,2-DCA)
p
K = (0.015)(47,800) = 717 (for pyrene)
p
(c) Use Equation (3.43) to find the air-phase retardation factor:
b ρ K p φ (1.6)(1.275) (0.15)
R a =+ + w =+ + = 39.6 (benzene)
1
1
a φ H a φ H (0.25)(0.227) (0.25)(0.227)
b ρ K p φ (1.6)(0.32) (0.15)
R a =+ + w =+ + = 67.2 (1,2-DCA)
1
1
a φ H a φ H (0.25)(0.04) (0.25)(0.04)
b ρ K p φ (1.6)(717) (0.15)
R a =+ + w =+ + = 2.3 10× 7 (pyrene)
1
1
a φ H a φ H (0.25)(0.0002) (0.25)(0.0002)
Discussion:
Pyrene is very hydrophobic and has a low Henry’s constant. Its air-
phase retardation factor is much larger than those of benzene and
1,2-DCA.

References
1. Fetter Jr., C.W. 1980. Applied hydrogeology. Columbus, OH: Charles E. Merrill.
2. USEPA. 1990. Ground water, Vol. I: Ground water and contamination.
EPA/625/6-90/016a. Washington, DC: US Environmental Protection Agency.
3. Driscoll, F.G. 1986. Groundwater and wells. 2nd. ed. St. Paul, MN: Johnson
Division.
4. Freeze, R.A., and R.A. Cherry. 1979. Groundwater. Englewood Cliffs, NJ: Prentice
Hall.
5. Todd, D.K. 1980. Groundwater hydrology. 2nd. ed. New York: John Wiley & Sons.
6. Cooper, H.H., and C.E. Jacob. 1946. A generalized graphical method for evaluat-
ing formation constants and summarizing well-field history. Am Geophys. Union
Trans. 27 (4), 526–534.
7. USEPA. 1989. Transport and face of contaminants in the subsurface. EPA/625/4-
89/019. Washington, DC: US Environmental Protection Agency.
8. Sherwood, T.K., R.L. Pigford, and C.R. Wilke. 1975. Mass transfer under reduced
gravity. New York: McGraw-Hill.
9. USEPA. 1991. Site characterization for subsurface remediation. EPA/625/4-
91/026. Washington, DC: US Environmental Protection Agency.