As(III) Removal via Combined Addition of Mg- and Ca-Based Adsorbents and Comparison to As(V) Removal via Those Mechanisms

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

1. It follows from the title of the article that the adsorption of As(III) has been investigated. However, the article also presents the results of experiments on the study of adsorbents saturated with As(V). In this regard, it is recommended to modify the title. It is also necessary to clearly describe in the section "materials and methods" which experiments in the article were performed with As(III) and which with As(V). This should also be clearly reflected in the purpose of the work and its conclusions.

2. It is necessary to compare the results obtained in this article on As(III) adsorption with the results on As(III) adsorption obtained by other authors.

Author Response

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Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

In the paper by H. Sugita et al., the combined addition of Mg- and Ca-based adsorbents was investigated to improve As(III)-removal performance and inhibit the leaching of the base material components from the adsorbents.

The paper presents interesting research from both an academic and practical point of view. In general, the paper is well-organized. However, some issues need to be carefully addressed. Therefore, it requires revision before being published in this journal.

1. Page 1, Lines 34-36: Please, add adequate references.

2. Page 1, Lines 41-42: Please, add adequate references.

3. In the „Introduction“ section, the authors should emphasize the main advantages of adsorption compared to other mentioned  As-removal methods.

4. Page 2, lines 68-70: The specific characteristics of each adsorbent described in reference [17] should be presented in the form of a table.

5. Please explain why was pH 7 chosen as the initial pH?

6. What are the advantages of these adsorbents compared to other well-known As adsorbents?

7. In the Conclusions, please add the future aspects of this study in view of the current results.

Author Response

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Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

Sugita and coauthors have presented the new As(III) rmoval method from contaminated water using the combined addition of Mg- and Ca-based adsorbents. The originality of this work is relatively high and all results are convincing. I recommend the publication of this paper after minor revision.

There are some suggestions below:

1.     The abstract part just stated the synthesis and performance, which should be a “story”. I suggest authors can further illustrate the advantage of this new method and further enhance the logic of this “story” including “Why and How” to do this work and the comparison with other mehtods.

2.     The two keywords of “arsenite removal” and “arsenic adsorption” are similar. I suggest that one of the two keywords should be deleted.

3.     Some characterizations (such as SEM images and relative EDS-mappings) should be replenished for the comparison of the As-adsorption between the original and As-uptake adsorbents.

4.     Some important new references reported in the past 3 years should be added.

Author Response

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Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

The authors have revised the manuscript, and it can be published in the present form.