ionic contribution to the self-potential signals associated with
TRANSCRIPT
-
8/2/2019 Ionic Contribution to the Self-potential Signals Associated With
1/18
Ionic contribution to the self-
potential signals associatedwith a redox front
A. Revil , F. Trolard , G. Bourri , J. Castermant
, A. Jardani , C.A. Mendona
Presented by:
Fathiya Al-Hadhrami
-
8/2/2019 Ionic Contribution to the Self-potential Signals Associated With
2/18
Agenda
Why they did the research ?(objective)
What did they do?(method)
What did they find?(observations)
What dose it mean?(discussion of results)
Who cares?(significant)
Final message to take home(conclusion)
-
8/2/2019 Ionic Contribution to the Self-potential Signals Associated With
3/18
we consider the case of a sharp redox potential distribution
generated in a water-saturated porous medium with no
electron conductor present to bridge electron donors and
acceptors in the system.
These experiments demonstrate that despite the absence of
electron conductors, self-potential anomalies can be
observed.
However, their magnitudes are much weaker than in the
case of the geobattery associated with an abiotic electronic
conductor.
Objective
-
8/2/2019 Ionic Contribution to the Self-potential Signals Associated With
4/18
Experimental setup
Sketch of the experimental setups, Experiment 1. In Phase 1,2(A. Revil et al., 2009)
-
8/2/2019 Ionic Contribution to the Self-potential Signals Associated With
5/18
Experimental setup
Sketch of the experimental setups, Experiment 2. In Phase 1,2(A. Revil et al., 2009)
-
8/2/2019 Ionic Contribution to the Self-potential Signals Associated With
6/18
Distribution of the self-potential at the top surface of the tank for Experiment 1 (Phase 2). (A. Revilet al., 2009)
Observations
-
8/2/2019 Ionic Contribution to the Self-potential Signals Associated With
7/18
Distribution of the corrected redox potential inside the tank, at a depth of 3 cm, 3 h after theDC power supply was shut down (left) Distribution of the corrected redox potential across a
profile in the tank (along y at x=25 cm)(right)(A. Revil et al., 2009)
Observations
-
8/2/2019 Ionic Contribution to the Self-potential Signals Associated With
8/18
Variation of the self-potential signals with depth and time with respect to the reference
electrode. a. Self-potential signals versus depth 3 h after the DC power supply was shut
down. These profiles are shown at 5 distinct locations in the tank. b. Self-potential signals
versus time at 1 cm from the working and auxiliary electrodes(A. Revil et al., 2009)
Observations
-
8/2/2019 Ionic Contribution to the Self-potential Signals Associated With
9/18
Distribution of the
redox potential,
self-potential,
and pH along two
profiles
in Experiment 2.
(A. Revil et al.,
2009)
Observations
-
8/2/2019 Ionic Contribution to the Self-potential Signals Associated With
10/18
Map of the self-potential (SP) at different time intervals during Phase 1,2 experiment 2
(A. Revil et al., 2009)
Observations
-
8/2/2019 Ionic Contribution to the Self-potential Signals Associated With
11/18
Map of the self-potential (SP) at different time intervals during Phase 1(A. Revil et al.,
2009)
Observations
-
8/2/2019 Ionic Contribution to the Self-potential Signals Associated With
12/18
Map of the self-potential (SP) at different time intervals during Phase 1(A. Revil et al.,
2009)
Observations
-
8/2/2019 Ionic Contribution to the Self-potential Signals Associated With
13/18
Discussion of the observations
Description of phase 1:
-
8/2/2019 Ionic Contribution to the Self-potential Signals Associated With
14/18
Description of phase 1:
There were 3 transport processes:
Discussion of the observations
Operation Equations Comments
Electro-migration (OH)=20.6108 m2 s1 V1, e1.6 h.
-
8/2/2019 Ionic Contribution to the Self-potential Signals Associated With
15/18
Evolution of the pH and the
redox potential at the cathode
and at the
anode as a function of
time(Experiment 2, Phase 1,
total duration of Phase 1:6
days). 1(A. Revil et al., 2009)
Observations
-
8/2/2019 Ionic Contribution to the Self-potential Signals Associated With
16/18
Discussion of the observations
Description of phase 2:
-
8/2/2019 Ionic Contribution to the Self-potential Signals Associated With
17/18
Tomography of the self-potential signals 3 h after the DC power supply was shut down.
Created by Jardani et al. (2007, 2008) (A. Revil et al., 2009)
Discussion of the observations
-
8/2/2019 Ionic Contribution to the Self-potential Signals Associated With
18/18
in the presence of a sharp redox potential gradient only
modest self-potential signals are generated in a porous
material in the absence of an electronic conductor.
despite their small magnitudes, the diffusion potentials
observed in the experiments were measurable and can be
easily observed .
An assumption that a possibly biotic electronic
conductor should be presented to explain the high values
of SP anomalies in contaminated landfill was presented.
Conclusion