Page 330 - gas transport in porous media

Chapter 19: In Situ Measurement of Induced Flux
Flux Measurement
Sampling location "16"; 4 feet deep 329
20
18
16
Concentrations
[gas in %]
14
12
10
8
6
4
2
0
5 4 3 2 1 0 1 2 3 4
Time (in minutes)
Carbon dioxyde Methane
Flux Measurement
Sampling location "22"; 4 feet deep
25
Concentrations
[gas in %]
20
15
10
5

0
5 4 3 2 1 0 1 2 3 4 5
Time (in minutes)
Carbon dioxyde Methane
Figure 19.8. Induced in situ Flux Measurements for daughter compounds. Top: sampling in an active
methanogenesis zone. Bottom: sampling outside the active methanogenesis zone.

Conversely, we find no advective flux at sampling point “22”, just at some distance
away from sampling point “16”. We get only a weak diffusive flux after the purging
period.
A few months after this investigation, the site was dug out. During remediation
activities, it was clear that methanogenesis was occurring at the site. Characterization
of the subsurface during digging confirms that sampling point “16” was in the center
of the methanogenesis active zone, while sampling point “22” was at the edge of
this zone.

REFERENCES
Buscheck, T.E. and C.M. Alcantar, “Regression Techniques and Analytical Solutions to Demonstrate
Intrinsic Bioremediation”, in Intrinsic Bioremediation, ed. R.E. Hinchee, J.T. Wilson and D.C. Downey,
109–116, Columbus, Ohio: Battelle Press, 1995.