Structural Changes in French VF Treatment Wetland Porous Media during the Rest Period: An Ex Situ Study Using X-ray Tomography

Round 1

Reviewer 1 Report

The paper analyzes, through the x-ray computed tomography, the structural changes in samples from French vertical flow treatment wetlands during an ex situ drying experiment. Overall it is a well written paper that contributes to additional knowledge. The figures and tables show meaningful content and are presented appropriately. Therefore, I suggest publishing the manuscript in Water after a minor revision is performed considering the following comments:

• Line 338: Replace Figure 5 with Figure 4 and cite the Figure 5 at the end of the phrase;
• Figure 7 should be inserted into the main text after their first citation (line 410);
• Results and discussion: The authors need to place their findings relevant to the existing literature. Thus, I propose, to integrate the paper with a valid discussion, which integrates the study with a comprehensive review of research findings in the context of the peer-reviewed literature.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

We appreciate the authors have dedicated much time and resources to prepare and submit their manuscript to the journal of Water. We would like to thank them for that. Having gone through the paper it makes an interesting reading. In its current form, however, the paper merits much attention to align it with the papers which appear in Water. Worth mentioning that the paper is well written. We, therefore, recommend the following major and minor changes be considered:

Major:

• Reading your paper, you describe the size of the samples to be cylinders measuring 5cm by 16cm. Simply, one could wonder how the finding of these small specimens scale with the actual wetlands;
• It is logical to ask if when obtaining the PSD one considers deviations from perfect pore circular geometries; It will also help to mention the size of the papers as well as their variability
• How is the connectivity of the void space differing from permeability if that’s the case? It will help to distinguish the two of these are discrete parameters in the manuscript;
• Perhaps it would be meaningful to consider in the paper the effects of external influences such as the impact on wind or temperature on some of the parameters/variables scrutinized in the paper;
• Oxygen transport appears to be an interesting variable for a host of reasons; can the authors elaborate more on this parameter by perhaps actively considering how O₂ levels change in their study;
• It would also be meaningful to explain how other elements can affect the effectiveness of wetland resting from the biological standpoint, for example, the presence of roots or aerobic bacteria;
• Concluding, the study is interesting as is but does not make the case about its how value could/can be; it will be vital to better articulate the merits of the method and why it is exciting enough to arouse interest from other reseachers.

Minor:

• Plz check the paper for spelling errors. It can’t be that the first sentence of the paper contains a spelling mistake: “operatiional” plz amend;
• Same as above; plz rectify: “ofdifferent;”
• Again page 2, correct word “” Never seen such a word before;
• Line 85: word “representativeness” does not appear appealin.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Round 2

Reviewer 2 Report

Dear authors,

thanks for the prompt response about the matters raised for your manuscript. We understand you are in a hurry to publish the document. Prior to that it will help to re-consider more carefully the comments of:

- How is the connectivity of the void space differing from permeability if that’s the case? It will help to distinguish the two of these are discrete parameters in the manuscript;

Plz add some references and a few lines in the manuscript for the sake of completeness (of the manuscript).

- It would also be meaningful to explain how other elements can affect the effectiveness of wetland resting from the biological standpoint, for example, the presence of roots or aerobic bacteria;

Presumably this point was not addressed in the text other than mentioning it in the intro. It will help to consider these elements as part of the study. If not it will be meaningful to explain why they have been omitted as points of interest.

More attention is needed.

Author Response

Please see the attachment

Author Response File: Author Response.pdf