Accumulation of Vanadium by Nanoscale Zero-Valent Iron Supported by Activated Carbon under Simulation Water Conditions: A Batch Study

Round 1

Reviewer 1 Report

The present work describes a study about the removal of vanadium (V) from simulated water (SW) using nanoscale zero-valent iron immobilized on activated carbon. The authors investigated also the effects of various parameters on the removal of vanadium, including pH, dissolved oxygen, co-presence of common ions such as Fe, Al, Zn, etc.. A section is also dedicated to a study of kinetic models of adsorption. The manuscript is quite fluent, and the topic of the research is interesting and captivating. The removal of toxic substances from water is indeed vital for global development. Thus, I recommend accepting the manuscript after these (minor) revisions:

-          Some more details related to the health effected caused by vanadium should be added in the introduction section: this will emphasize and give more importance to the manuscript.

-          The introduction section must be enriched with a few sentences related to the importance of using abundant metals for the development of new materials, as the author effectively did (not only related to water purification, but also to other fields, such as catalysis or hydrogen storage). I recommend citing some recent examples regarding the use of abundant metals in different research area, such as 10.1016/j.matdes.2021.109953, 10.1002/adsu.202100394 and 10.1002/anie.202100270

-          Line 93-94: adsorption kinetics is not a parameter affecting the removal of V. The fact that the manuscript discusses the adsorption kinetics should be placed in another sentence.

-          Line 100 the sentence is not clear. Furthermore, the authors should put the formula of sodium metavanadate, not the abbreviation of vanadium after naming the salt.

-          Line 106, Zhu should have capital letter.

-          Figure 3 and 4: is it possible to color the bars?

-          In general, in all figures, standard deviation values should be included

-          Lines 265-270. What are the “great number of models” (isn’t this sentence quite exaggerated, is it?) used to fit the data? Can the author specify these models and list them? What are the fitting data obtained with the cited other models? In addition, reporting only the R² is not enough to prove a good fit to a specific model. Please add at least another parameter (e.g., sum of squared errors?), comparing the results with other kinetic models (or at least justify the absence of these data)

-          Fig. 6 is interesting, but some of the texts are too small. Enlarge them. This should be generally done for all figures.

-          Table 2: what happen after the 5^th cycles? When does the removal efficiency start to sensibly decrease?

-          The conclusion section is poor and should be enriched.

Author Response

Dear Editors and Reviewers:

Thank you for your letter and for the reviewers’ comments concerning our manuscript entitled “Accumulation of Vanadium by Nanoscale Zero-Valent Iron Supported by Activated Carbon under Simulation Water Conditions: A Batch Study”. Those comments are all valuable and very helpful for revising and improving our paper, as well as the important guiding significance to our researches. We have studied comments carefully and have made correction which we hope meet with approval. Revised portion are marked in green in the paper. The main corrections in the paper and the responds to the reviewer’s comments are as flowing:
Responds to the reviewer’s comments:

Author Response File: Author Response.pdf

Reviewer 2 Report

The manuscript is devoted to the vanadium removal by nanoscale zero-valent iron supported material. The discussion is well presented. However, I suggested to present the applied kinetics models in the discussion part even the fitting was not that good. Especially Boyd model.

Author Response

Dear Reviewers:

Thank you for your letter and for the reviewers’ comments concerning our manuscript entitled “Accumulation of Vanadium by Nanoscale Zero-Valent Iron Supported by Activated Carbon under Simulation Water Conditions: A Batch Study”. Those comments are all valuable and very helpful for revising and improving our paper, as well as the important guiding significance to our researches. We have studied comments carefully and have made correction which we hope meet with approval. Revised portion are marked in green in the paper. The main corrections in the paper and the responds to the reviewer’s comments are as flowing:
Responds to the reviewer’s comments:

Author Response File: Author Response.pdf

Reviewer 3 Report

-Need some SEMs for better understanding of iron decoration on biochar

- How iron particles being decorated? how can be proved?

-Any raman spectra to see the differences of the ID/IG before and after ?

-the mechanism of the effect need to be supported with some scientific literatures.

- There is a need to compare the similar works of iron decorating on biochar for removal application and make a table for comparison wit this work:

https://www.sciencedirect.com/science/article/pii/S2090123221001478

https://www.sciencedirect.com/science/article/pii/S1383586621010066

https://www.sciencedirect.com/science/article/pii/S221334372100097X

https://www.mdpi.com/1504900

https://www.mdpi.com/2071-1050/14/14/8690

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https://www.sciencedirect.com/science/article/pii/S0927775720310426

 

 

 

Author Response

DearReviewers:

Thank you for your letter and for the reviewers’ comments concerning our manuscript entitled “Accumulation of Vanadium by Nanoscale Zero-Valent Iron Supported by Activated Carbon under Simulation Water Conditions: A Batch Study”. Those comments are all valuable and very helpful for revising and improving our paper, as well as the important guiding significance to our researches. We have studied comments carefully and have made correction which we hope meet with approval. Revised portion are marked in green in the paper. The main corrections in the paper and the responds to the reviewer’s comments are as flowing:
Responds to the reviewer’s comments:

Author Response File: Author Response.pdf

Round 2

Reviewer 3 Report

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