Intensification of Lead, Copper and Antimony Removal Using Brown Algae Adsorption Coupled to Hydrodynamic Cavitation

Round 1

Reviewer 1 Report

In this Paper, the authors studied the adsorption capacity by varying the experimental conditions, such as adsorbent dosage, solution concentration, contact time, recirculation flow and hydrodynamic cavitation. Also, adsorption kinetic and isotherm models were investigated. Overall, I think the significance of this work fully meets the requirement of Sustainability. Therefore, I recommend this manuscript for publication in Sustainability. My comments are as follows:

1.      In results and discussion, the comparison of present results with the results of other similar investigations in literature should be comparatively discussed in detail. This is needed to place this work in perspective with other works in the field and provide more credibility for the present results. You must define clearly the novelty and the critical improvements in your paper compared to the experimental results of other similar works.

2.      Hydrodynamic cavitation has been widely accepted as a promising strategy for intensification of metal ions revomal. The authors should illustrate the novelty of this work when compared with others.

3.      Some references are not marked with page numbers, and some refer to chemical formulas with wrong subscripts. The authors should check them carefully.

4.      Although the English is acceptable, some words and sentences should also be further polished.

Author Response

Good morning, the manuscript is sent with the observations 

best regards

Juan Medina

Author Response File: Author Response.docx

Reviewer 2 Report

Dear Authors,

Congratulations to your research results. The topic you choosed is a very important one in environmental science and technology. Nevertheless I have some advises to improve your manuscript.

1. First on Line11 and later on, the proper writing of your algae is: Macrosystis pyrifera (italic).

2. Chapter 2.6. Line 158. Correct: 50 micrometer, not "um". The detailed description of Venturi tube is missing, its sizes, cavitation features, as well as it would be nice to deeperly elaborate the effect of hydrodynamic cavitation on biosorption.

3. Concerning isotherms, I would advise you to try the three parameter Tóth-isotherm since it is quite phenomenological to describe such a complex process as biosorption.

4. Chapter 3.2 is written NOT in English, should be translated.

5. Conclusions should be extanded with more obtained results using ones from P. 13. with the posible explanations.

I  wish you good luck for your further research!

Author Response

Good morning, the manuscript is sent with the observations 

best regards

Juan Medina

Author Response File: Author Response.docx

Reviewer 3 Report

1. At line 236, authors state that "Fig. 2a presents micrographs of calcium alginate. the prepared calcium alginate were 2–3 mm in diameter and compact (Fig. 2b)." Please indicate the "2-3 mm in diameter" in the figure.

2.At line 240, authors state that " As seen in Fig. 2, the images before and after lead ions adsorption were different in surface topography and roughness" However,  the figure captions didn't show this statement. Is the figure 2(b) is a SEM image?

3.At line 242, authors state that "As it can be seen, the structure of the hy drogel is highly porous before adsorption (Fig. 3a and c)," Please check the figure 3a and c.

4.At line 398, authors state that "From the figures 11,12 y 13 the factor (X4) shows a very significant influence on the percentage of removal for Pb, Cu and Sb ions, especially when  factor is at the high level. " Please give some discussion about this results.

Author Response

Good morning, the manuscript is sent with the observations 

best regards

Juan Medina

Author Response File: Author Response.docx

Round 2

Reviewer 1 Report

The authors have addressed all the issues, and the manuscript can be accepted.

Author Response

good day, thanks for your attention

 

Juan 

Author Response File: Author Response.pdf

Reviewer 3 Report

I have no further comments on this manuscript.

 

Author Response

good day, thanks for your attention

Author Response File: Author Response.pdf