As for the field tests in the C1 compartment, the estimated DNAPL volume was
10 m
3 (contained in an average DNAPL height of 0.55 cm). Previously, DNAPL
remediation by conventional techniques and with upwelling recovered 0.9 m
3 of
DNAPL. According to the laboratory results and tests conducted in the other
compartments, a volume of 6.6 m
3 should have been recovered. The hypotheses to
explain this difference are: an aclinic substratum topography, or a recovery well not
located in the deepest part of the cell.
The injection device used with conventional DNAPL recovery and with upwelling was reused for the surfactant injection. The surfactant used was Aerosol M-80.
The injection flow rate was 2.5 m
3 /h. The injection was performed in two steps
(Maire et al. 2018).
Classical free
product recovery
Upwelling free product
recovery
12/11/2015
02/12/2015
22/12/2015
11/01/2016
31/01/2016
20/02/2016
11/03/2016
31/03/2016
20/04/2016
10/05/2016
30/05/2016
25 000
20 000
15 000
10 000
5 000
0
Cumulated volume of pumped DNAPL (l)
Upwelling free product
recovery
Classical free
product recovery
20/07/2015
09/08/2015
29/08/2015
18/09/2015
08/10/2015
28/10/2015
17/11/2015
07/12/2015
25 000
20 000
15 000
10 000
5 000
0
Cumulated volume of pumped DNAPL (l)
(a)
(b)
Fig. 2.55 Volume of free product recovered in (a) C3 compartment and (b) C4 compartment
(Joubert et al. 2016)
2 Free Product Recovery of Non-aqueous Phase Liquids in Contaminated Sites:. . .
127