New Approach for Mining Site Reclamation Using Alternative Substrate Based on Phosphate Industry By-Product and Sludge Mixture

Round 1

Reviewer 1 Report

Reviewer Comment to manuscript sustainability-1322990

[New approach for mining site rehabilitation using alternative substrate based on phosphate industry by-product and sludge mixture]

In the title, I would replace rehabilitation with reclamation. The term rehabilitation concerns restoring the efficiency of living organisms.

Please explain the share of individual by-products in the construction of research substrates (T1-T10). And how does this relate to the implementation of the research objective (in terms of the reclamation process)?

The authors report that the experimental setup was carried out in four replications. Replications in research groups are used, i.a. in order to show the average values of the analyzed features. If we present average values, it is also worth showing, for example, standard deviations - this is important in terms of the variability of the value of the analyzed feature within research groups.

And here is my question: the results 3.1, 3.2, 3.3 presented by the authors should be understood as the means of several repetitions (then, for example, SD or value ranges should be given), or as results from one analysis?

If the presented results are not average, this is a serious methodological error that needs to be corrected.

Author Response

dear Reviewer

I hope your doing well in this predicament situation.

I would like to thank you for your time to review our article. All comments were useful for us to improve our paper.

Please, Find in enclosed file all answers of these questions and remarks.

Looking forward to hearing from you.

Pr M.HAFIDI

 

 

Author Response File: Author Response.pdf

Reviewer 2 Report

Sustainability-1322990

New approach for mining site rehabilitation using alternative substrate based on phosphate industry by-product and sludge mixture

 

Guéablé et al. have presented analysis of soil amendments used to improve mine-waste areas associated with phosphate mining in Morocco. The experiments are well designed and described and the results show some interesting patterns that may be useful for improving the practice of mine rehabilitation, especially in similar arid and semi-arid environments. However, little context or deeper analysis of the results is presented, making it difficult to translate results into recommendations, and no concrete suggestions for future research directions appear. I would like to know more about how the authors think about what their results mean and how they might proceed with further studies building on the foundation represented here.

 

Overall

 

This paper represents an important investigation for improving mine-site rehabilitation by soil amendments. However, while the experimental design is described well and the results are reported in full (if in a somewhat confusing and awkward manner), there is no real Discussion that could place these results in context and provide indicators for useful future research in this area. The Results and Discussion section contains Results, but no real Discussion beyond a few citations of other papers with more-or-less comparable results. Do the authors have any specific recommendations for future work beyond a vague description of the possibility of complications arising from the use of sewage sludge? For the conclusions regarding the possible suggestions for mine-rehabilitation managers, please provide more details. Are your proposed best-practices expensive? Do they require new arrangements with local municipal authorities (to obtain large amounts of dried sewage sludge, for example)? Are there other combinations of amendments that might be investigated?

 

Materials and Methods

 

LN 97 – how long was topsoil stored? Long-term storage of soil in the open may lead to important changes in nutrient content and other properties.

 

LN 110 – the species name for Italian ryegrass has already been defined, it does not need to be stated in full after line 101.

 

LN 145 – replace the word "Heavy" with simply "Metals"

 

LN 148 – please state version of SPSS used, and cite appropriately.

 

Table 1. It would be helpful to have a reminder of the amendments in the description of this table.

 

Results and Discussion

 

LN 157-180 – the sentences in these paragraphs appear to provide duplicate information found in Table 2. It would be easier to read if the main patterns were described without listing so many numbers in the main text, and readers can refer to Table 2 for the details.

That some substrates are refered to as having "low" or "very low" in some parameters (e.g. LN 166) raises a question about how these qualitative descriptors are applied – what standards do you use to distinguish between "low" and "very low" EC, or available phosphorous? Are these terms directly linked to plant requirements?

 

LN 190 – it is not clear why a mine study from Germany – a country not known for its aridity – is cited here. Did Machulla et al., 2005 study specifically phosphate mine spoils in a part of Germany with similar underlying geology to the studied region of Morocco?

 

Table 3, Figure 1. - the bulk density data would fit well in Table 3, instead of as a very small figure.

 

Similarly, Figure 2 could fit into Table 3, along with Figure 3. Or, Figure 2, Figure 3, and Figure 4 could be combined.

 

It is not clear why some data are presented in Tables, others in simple Figures. All of the figures are very small, and no description appears in the figure captions to highlight the important patterns. Most figures have no colour, but Figure 9 uses a mottled brown pattern instead of another variation on black and white. This lack of consistency is confusing.

 

LN 263 – how do you know that consumption of P by the plants caused the observed decreases? There are other potential routes for the removal of P, such as by leaching down out of the pots, or chemical transformation into a form that is harder to detect.

 

Figure 8. The second cut happened only 2 days after the first. Please re-scale the data to reflect growth of plants, for example by dividing the mass by the number of days since first appearance of shoots above ground (prior to Cut 1) or since the previous cut (i.e. for Cut 2). Please also re-scale the data to reflect plant growth intensity in the other figures that show data related to the three cuts.

 

LN 353-354 – this sentence appears to have been copied in from another paper or previous version of this or a related manuscript – the sudden change in citation style and the unexplained asterix * are clear signals that something strange is happening here.

 

 

Typos and other small errors

 

Excess or missing punctuation, especially comma , and period . are scattered throughout, such as the frequent appearance of an extra period at subheadings e.g. LN 156 "3.1. . Physical" – the period before Physical should be deleted.

 

LN 36-37: move the open parenthesis ( to next to 2011 – (2011). This moves the authors of the cited study outside of the parentheses, making reading easier.

 

LN 145- missing comma , in list of metals after As

 

LN 189 – same comment regarding parentheses as for LN 36-37

 

LN 292 – combine lists of citations into a single set of paretheses.

Author Response

dear reviewer,

I hope you are doing well in this predicament situation. Also, I would like to thank you to evaluate our artcile. You comments were very helpfull for us to improve the quality of our article.

Please, Find in enclosed file repsonses of all questions and remarks.

Looking forward to hearing from you.

 

Pr M.HAFIDI

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Dear Authors,

thank you for responding to the reviewer's comments.

I think the MS as it stands is publishable.

Best wishes and strength to all

Reviewer 2 Report

Sustainability-1322990 Version 2

New approach for mining site reclamation using alternative substrate based on phosphate industry by-product and sludge mixture

Review of revised submission

Guéablé et al. have substantially improved their manuscript describing mine-site reclamation in Morocco. A few minor typos, misspellings, and trivial grammatical errors are distributed throughout the manuscript, but do not seriously detract from the clear writing.

 

I like the new Table 3 and the changes I see to the text on the page before Table 3. The other tables are also well made, data are presented clearly and comparisons are easy to do.

Overall, this manuscrip t is, I think, ready to be presented to the typesetters for final tweaking. In other words, I recommend Accept.