Removal of Per- and Polyfluoroalkyl Substances by Electron Beam and Plasma Irradiation: A Mini-Review

Round 1

Reviewer 1 Report

This manuscript provides a concise review on the topic related to the removal efficiency and mechanisms of PFAS by electron beam and plasma irradiation, as well as the toxicity of PFASs and their transformation products, which provide state-of-the-art information to identify the knowledge gaps and propose future research directions for PFAS treatment using those two techniques. It is an interesting manuscript, well written and structured. This topic is of potential interest to the readers of Water. I only had one minor question/comment before acceptance for publication: there is a variety of methods/technologies that can be used to effectively treat PFAS contaminated waters. What matters the most is cost. The authors should add a subsection talking about the cost of practical application for those two techniques (i.e., electron beam and plasma irradiation).

Author Response

Thank you for your suggestion. We have added new content to the revised manuscript to discuss the cost of the electron beam and plasma irradiation (Line 264-283).

Reviewer 2 Report

The elimination of per- and polyfluoroalkyl compounds by electron beam irradiation and plasma treatment is discussed in this article. Some comparable work should be contrasted, and writers should demonstrate the distinctiveness of the current study in comparison to earlier published reviews. I urge that the work be published after considerable modifications, and my remarks are given below:

• There is a similar work elsewhere https://doi.org/10.1089/ees.2016.0233

The author must demonstrate uniqueness in the current review in comparison to the previous one.

• The number of references in a review is limited, and authors must add and describe other related material.
• The suggested approach should be evaluated in comparison to previous methods for eliminating per- and polyfluoroalkyl compounds.

Author Response

The elimination of per- and polyfluoroalkyl compounds by electron beam irradiation and plasma treatment is discussed in this article. Some comparable work should be contrasted, and writers should demonstrate the distinctiveness of the current study in comparison to earlier published reviews. I urge that the work be published after considerable modifications, and my remarks are given below:

1. There is a similar work elsewhere https://doi.org/10.1089/ees.2016.0233. The author must demonstrate uniqueness in the current review in comparison to the previous one.

Thanks. The review you mentioned focuses on the general introduction of all related methods available to remove PFASs, reaction mechanisms, and the problems still faced in dealing with PFAS pollution. Comparatively, our current review paper discusses the detailed information regarding the removal efficiency, specific reaction mechanisms, and secondary environmental risks of PFASs in water by the electron beam and plasma irradiation, which were not described well in the mentioned review. Especially, the product toxicity of PFASs, a very important risk parameter during the water safety assessment of the treated water, was first discussed in our study together with the comparative operating principles and reaction mechanisms of these two typical advanced oxidation/reduction processes.

2. The number of references in a review is limited, and authors must add and describe other related material.

Thank you for pointing out this issue. The applications of electron beam and plasma irradiation for PFAS removal have been receiving increasing attention worldwide. The related research is still in its infancy, and we have tried to add all available information to this review article. In the revised manuscript, we have discussed the cost of these treatments to improve the current writing (Line 264-283).

3. The suggested approach should be evaluated in comparison to previous methods for eliminating per- and polyfluoroalkyl compounds.

Thanks. This review article focuses on the abatement efficiency, detailed reaction mechanisms, operating costs, and environmental risks of PFASs by electron beam and plasma irradiation in water. This review provides a cutting-edge and systematic discussion of these issues, which have been well achieved as the key objectives. In this sense, we have refrained from comparing with other treatment methods for PFASs.

Author Response File: Author Response.docx

Reviewer 3 Report

Dear Editor,

Regarding the manuscript "Removal of per- and polyfluoroalkyl substances by ionizing irradiation and plasma treatment: A mini-review" I have read it and I judge it can be published, after minor correcttions.

I have checked in google scholar and seemingly there are no reviews about the specific topic. However, I have no checked plagiarism and self-citations.

As suggestions, I would like to point out:

L18 and throughout the text: avoid significant, using this word only regarding statistics.

Remove the first keyword, as this word is presented in the title.

Standardize the use of eletron bean and ionizing irradiation.

Please check if the good figures contains copyrights.

Table 1 and so on: [P] (not [p] is "influent" or "initial" pollutant concentration.

Please consider screening other sources to Table 1: Are there only 3 references about this theme?

The footnotes of Table 3 are confusing. They do not correspond to table, as [p] and "a" in the first column.

Please reduce the number of "e.g." and "i.e." throughout the text.

Sincerely yours.

Author Response

Regarding the manuscript "Removal of per- and polyfluoroalkyl substances by ionizing irradiation and plasma treatment: A mini-review" I have read it and I judge it can be published, after minor correcttions. I have checked in google scholar and seemingly there are no reviews about the specific topic. However, I have no checked plagiarism and self-citations. As suggestions, I would like to point out:

1. L18 and throughout the text: avoid significant, using this word only regarding statistics.

Thank you for the careful review. We checked the whole text and replaced “significant” with other words in the revised manuscript (Lines 18 and 67).

2. Remove the first keyword, as this word is presented in the title.

We removed the first keyword in the revised manuscript.

3. Standardize the use of eletron bean and ionizing irradiation.

Thank you for pointing out this problem. We use “electron beam and plasma irradiation” to unify the words in the revised manuscript.

4. Please check if the good figures contain copyrights.

All figures in this manuscript were made by us, so there is no copyright conflict. Thanks.

5. Table 1 and so on: [P] (not [p] is "influent" or "initial" pollutant concentration.

Thanks. Please note that [P] represents the initial concentration of PFAS compounds used for the electron beam irradiation and plasma treatment.

6. Please consider screening other sources to Table 1: Are there only 3 references about this theme?

Thanks. We have tried to search all related references and added all available information into the revised Table 1.

7. The footnotes of Table 3 are confusing. They do not correspond to table, as [p] and "a" in the first column.

This is a mistake, and we have corrected it in the revised manuscript.

8. Please reduce the number of "e.g." and "i.e." throughout the text.

We have reduced the number of “e.g.” and “i.e.” according to your suggestion.

Author Response File: Author Response.docx

Reviewer 4 Report

The monograph is a reliable description of the problem. A large selection of literature shows the cross-section of the problem.

The figures significantly bring the whole issue closer.

I have no substantive comments, the entire monograph is based on the latest research achievements.

I also did not detect any editing flaws.

Author Response

The monograph is a reliable description of the problem. A large selection of literature shows the cross-section of the problem. The figures significantly bring the whole issue closer. I have no substantive comments, the entire monograph is based on the latest research achievements. I also did not detect any editing flaws.

Thank you very much for your positive evaluation of our current review manuscript, which is greatly appreciated.

Author Response File: Author Response.docx

Round 2

Reviewer 2 Report

The authors addressed and responded to all of my remarks, and they updated their work accordingly. As a result, I propose that the updated work be published as is in Water.