Geophysically based analysis of breakthrough curves and  ion exchange processes in soil

Ben Moshe, Shany; Kessouri, Pauline; Erlich, Dana; Furman, Alex

doi:https://doi.org/10.5194/hess-25-3041-2021

Articles | Volume 25, issue 6

https://doi.org/10.5194/hess-25-3041-2021

© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.

https://doi.org/10.5194/hess-25-3041-2021

© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.

Articles | Volume 25, issue 6

Research article

|

08 Jun 2021

Research article |

| 08 Jun 2021

Geophysically based analysis of breakthrough curves and ion exchange processes in soil

Shany Ben Moshe, Pauline Kessouri, Dana Erlich, and Alex Furman

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Final revised paper (published on 08 Jun 2021)
Supplement to the final revised paper
Preprint (discussion started on 17 Sep 2020)
Supplement to the preprint

Interactive discussion

Status: closed

AC: Author comment | RC: Referee comment | SC: Short comment | EC: Editor comment

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- Supplement

RC1: 'Review on the manuscript: Geophysically-based analysis of BTCs and ion exchange processes in soil', Anonymous Referee #1, 01 Oct 2020
- AC1: 'Response to referee #1', Shany Ben Moshe, 10 Dec 2020
- AC2: 'Response to referee #1 (attached: PDF with figures)', Shany Ben Moshe, 10 Dec 2020
RC2: 'Referee-Report on: "Geophysically-based analysis of BTCs and ion exchange processes in soil" by Shany Ben Moshe et al.', Anonymous Referee #2, 12 Oct 2020
- AC3: 'Response to referee #2 (attached: PDF with figures)', Shany Ben Moshe, 10 Dec 2020
RC3: 'RC3', Anonymous Referee #3, 06 Nov 2020
- AC4: 'Response to referee #3 (attached: PDF with figures)', Shany Ben Moshe, 10 Dec 2020

Peer-review completion

AR: Author's response | RR: Referee report | ED: Editor decision

ED: Reconsider after major revisions (further review by editor and referees) (30 Dec 2020) by Christine Stumpp

AR by Shany Ben Moshe on behalf of the Authors (07 Feb 2021) Author's response Author's tracked changes Manuscript

ED: Referee Nomination & Report Request started (12 Feb 2021) by Christine Stumpp

RR by Anonymous Referee #2 (15 Mar 2021)

RR by Anonymous Referee #3 (15 Mar 2021)

Suggestions for revision or reasons for rejection

Ben Moshe et al, review round 2:
In their revised manuscript, titled “Geophysically-based analysis of BTCs and ion exchange processes in soil” Ben Moshe et al. successfully addressed several of my initial comments in the first round of review. My concerns in this second round of review, however, remain largely in the approach that the authors took to calibrate their model. Mainly, the poorly described consideration of only the partial real conductivity dataset when fitting the “reactive” solute scenarios. In its current form, I think the manuscript clearly demonstrates SIP’s ability to depict breakthrough patterns, and the assessment of the non-reactive solute transport is compelling. However, the authors’ current approach to model calibration is purely based on the real conductivity data, which makes sense for the non-reactive Na+ case, but it requires an ambiguous data cut-off for Zn and Ca. Which raises the question: Why not use the imaginary conductivity data to calibrate the models for reactive species that undergo ion-exchange?
Would using imaginary conductivity for reactive solutes versus real conductivity for conservative solutes allow for the full timeseries of each signal to be considered in the calibration procedure and thus provide an approach that allows untrained SIP users to apply the method to specific cases? Such a comparison would greatly improve the strength of the manuscripts’ argumentation.

Specific comments:
The description of fitting the “non-reactive” vs “reactive” cases is confusing. Figure 4 presents the full time series SIP dataset based on the cumulative experimental time, but figures 4b and c seem to redefine the starting time. It would be clearer if everything was plotted in relation to a single start time, but the injection of the different solutions was clearly highlighted.
Equations 6 and 7 imply that the authors assumed linear retardation for the Ca2+ and Zn2+ ions. Is this justified for this particular loamy soil? Is there evidence to suggest that Ca and Zn sorption could exhibit a saturation-type (Langmuir/Freundlich) behavior?
Are the estimated parameters from the SIP-based calibration able to capture the Na+ and Ca2+ breakthrough behavior when considering that both ions are present at the same time? (Figure 3b)
What subset of the Ca2+ breakthrough concentrations is plotted in Figure 4c, and how does that differ from what is shown in Figure 3b?
Lines 224 – 225: I find the distinction between a reactive Ca2+ fraction and a non-reactive fraction misleading. An alternative, process-based approach, would be to compare the imaginary conductivity profiles to the adsorbed reactive species concentrations and attempt to calibrate the model that way, in turn validating it with the concentration breakthrough curve. For the latter case perhaps using the imaginary conductivity data presented in 6b would be best.
What non-reactive species concentration is being presented in Figure 4b: Cl-, Na+?
Lines 269-280: Yes, but the SIP channels are at “earlier” locations within the columns. To better address this interpretation perhaps a comparison between imaginary conductivity and Cl-concentrations at those locations in the columns would be warranted. I find the use of “stability” vague here. Perhaps the authors could elaborate. An alternative explanation could be the interplay between the contributions of Stern- and Diffuse-layer polarization during the exchange process. The Na-Ca exchange may have released higher-mobility Na ions that temporarily remained in the diffuse layer (contributing to diffuse layer polarization) before moving into the bulk solution.
Lines 297 – 300: Why not fit the “reactive” model form Zn and Ca using the imaginary conductivity (as the imaginary resistivity)? Figure S2 again shows that only a subset of the real conductivity dataset was used for the calibration of Ca and Zn transport, this is poorly described and also not justified.

Minor comments:
Presenting things either in PV or time makes interpreting the results confusing. Please choose one standard.
Figure 2: I find the y-axis location at 1 Hz an odd way to present the data, it also partly covers the numerical values on the y-axis. I recommend moving the axis to 0.1 Hz (the left hand side limit).
In general, I find the manuscript has too many acronyms, and the use of BT vs BTC is also confusing. In addition, I recommend not to abbreviate geo-electrical with GE.
“Stern layer” should be capitalized
Line 4: “soil profiles” to “soil profile”
Line 5: “The SIP signature was recorded…”
Line 9 and 11: A conductivity does not “react”. Recommend to change to “changed in response to”
Line 139: “denoted”
Line 145: “Stokes” law
Line 152: inductively coupled plasma - optical emission spectrometer
Line 224: “constructed”
Line 235: 4b and 4b?

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ED: Publish subject to revisions (further review by editor and referees) (07 Apr 2021) by Christine Stumpp

AR by Shany Ben Moshe on behalf of the Authors (20 Apr 2021) Author's response Author's tracked changes Manuscript

ED: Publish as is (09 May 2021) by Christine Stumpp

Short summary

A non-invasive geophysical method (spectral induced polarization, SIP) was used to characterize and predict solute transport patterns in soil columns. Our results show that SIP-based breakthrough curve (BTC) analysis is superior over conventional outflow-based analysis as it can characterize system heterogeneity and is superior over electrical-conductivity-based analysis as it is capable of distinguishing between the adsorption end-members without the need for sampling.