Experimental Study of the Usage of Combined Biopolymer and Plants in Reinforcing the Clayey Soil Exposed to Acidic and Alkaline Contaminations

Round 1

Reviewer 1 Report

Very intersting article.

I've got few suggestions:

1. The authors prove the increase in shear strength due to the use of improvement methods. Please suggest in what really situations this may be useful.

2. Please specify the type of soil (according to geotechnical classification) determined on the basis of the grain size distribution curve.

3. Please show an example of the test result from XRF.

4. How was the shear rate determined in direct shear test?

5. I think the weight of the saturated soil is little too much (line 172). More than concrete?

6. Figure 10, vertical axis - 20,40,60,80, 100%?

Author Response

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Author Response File: Author Response.pdf

Reviewer 2 Report

The manuscript entitled “Experimental study of the usage of combined biopolymer and plant in reinforcing the clayey soil exposed to acidic and alkaline contaminations” reports the results of an interesting research, having the objective to evaluate in a laboratory experiment the effects of increasing doses of a biopolymer added to soil with different pH value on oat germination and soil properties.

Although the topic is interesting there were some problems should be discussed.  

 

- The English form should be improved, in some cases the sentences are unclear (below I report some example), and I think that the text should be reviewed and closely checked. 

- The Authors defined the soil as a clayey soil: what classification they had considered? In fact, according with the USDA classification the soil under study is a silt loam soil. The tests applied (Atterberg limits, mechanical strength..) are used correctly because they are mainly utilized on clayey or silty soils since these are the soils that expand and shrink when the moisture content varies. So, the authors should pay attention in the definition of soil and modify also the title of the paper.

- In many figures presented (such as Fig. 11, Fig. 12 and so on) the authors specified on the graphs the better treatment, for example in the figure 11 they wrote “pH value of best germination rate pH=7”. In my opinion it is pointless, whereas it should be more interesting to specify if they observed some significant differences among treatments. Which experimental design was adopted and how were the data analyzed?

- In figure 10 the authors should modify the graphs presented and delete the points

- In figure 14, the authors should include in the caption the meaning of “c” and “φ”

- The figure 17 is not very clear: the heavy metal values reported on the graph are average values obtained by all XG doses (0.25%, 0.50%, 0.75…)?

 

Below I have provided some comments and remarks on the text. 

 

 Introduction: The authors provided an overview of the issue, but some inaccuracies are present, so the text should be carefully checked. 

Example: 

Page 1 line 29: replace “credence” with “opportunity” or another word that can better clarify the meaning of the sentence;

Line 40: replace “ground” with “soil” 

Lines 46-47: improve the sentence, for example delete “possibly” and add “probably” before “owing to” 

Line 52: replace “harsh environment” with “extreme environmental condition”

At the end of introduction section, I think that the author should better specify the objective of their research.

Materials and methods:  

Some paragraphs presented in Materials and Methods could be replaced in the Introduction, such as 2.3. Biopolymer and 2.4. Plant

Line 125: what means “base soil”?

Results and Discussion:

Line 266: delete “in”

Line 331: Replace “In addition” with “Moreover”

Conclusion:

Check and review carefully this paragraph. The first sentence is not very clear.

In any case, the whole manuscript should be revised.

Decision: I believe that the paper should be published after major revisions, predominantly in the  results presentation and in English form. 

Author Response

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Author Response File: Author Response.pdf

Reviewer 3 Report

Reviewer comments to the manuscript

Manuscript ID: applied sciences 1742336

Title: Experimental study of the usage of combined biopolymer and plant in reinforcing the clayey soil exposed to acidic and alkaline contaminations 

 

 

The manuscript is about the use of biopolymers and plants in the soil reinforcement. The topic of this work is interesting since it provides valuable results to manage soil contamination and minimize environmental pollution risks. 

The manuscript is well done, with appropriate methodology and detailed information about the results obtained. The results are well presented and discussed, and conclusions are also well supported by the field results. 

The main concern about the manuscript is that in the manuscript it’s missing the statistical treatment of the results.  

Also, the authors should refer if the heavy metals (HM) evaluated in this work, were the HM amounts in the soil solution or the total HM amounts in the soil. 

The Fig. 17 should refer in the YY axis if the “element content” is the “total element content” or the “soluble element content” in the soil. 

So, I agree with the publication of the manuscript after these revisions.

 

Author Response

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Author Response File: Author Response.pdf

Reviewer 4 Report

The paper investigates the role of biopolymers in soil reinforcement and promotion of vegetation growth with limited environmental impact. In particular, a soil reinforcing method with combined biopolymer (xanthan gum, XG) and plant (oat) was proposed to strengthen the clayey soil exposed to acidic and alkaline contaminations.  The methodology consists of conducting a series of laboratory tests (mainly plant cultivation tests and the direct shear  tests) that is feasible and appropriate in order to demonstrate that the biopolymer-plant soil reinforcing method is effective in improving the geotechnical performances of the acid- and alkali-contaminated clayey soil. English is also good and only minor typos need to be checked. Some requests to improve the paper. 1. In the introduction, novelties need to be explicitly listed and discussed in order to demonstrate the originality of the work. 2. Figure 6 shows several lines but only some of them have the points. Please check. 3. Figures 10, 11 and 13 need to be edited to improve the readibility of the test. 4. Conclusions. I suggest to rename this conclusion in a section called "discussion" and rewrite a more general one. Therefore, I recommend minor revisions.  

Author Response

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Author Response File: Author Response.pdf

Round 2

Reviewer 2 Report

Thanks for author’s modification. I believe that this manuscript could be accepted after minor revision.

I think that the figures could be improved. In fact, in the figures with more graphs, if the legend is the same (and so it seems to me for all figures), it could compare only one time and not on all graphs.

Moreover, in the text when the authors cite the figures with more graphs, they could cite only the figure number (for example “Figure 11 presents the variation of germination…..”). Then if they want to comment a specific graph, they cite the figure number with corresponding letter (Figure 11c)

At page 2 lines 90-96, the authors should check the sentences, it is not very clear the meaning

At page 3, line 131: replace "from" with "through"

I suggest to check the whole manuscript. 

Author Response

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Author Response File: Author Response.docx

Reviewer 3 Report

The manuscript was improved according to the reviewer suggestions. 

I agree with the publication of the manuscript in its present form.

Congratulations to authors by this interesting and valuable work 

Author Response

The authors appreciate the reviewer’s recognition of the topic’s value and potential impacts of this paper.