The Formation of Disinfection By-Products in Reactive Chlorine Species (RCS)-Mediated Advanced Oxidation Process

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

This study aims to investigate the formation and toxicity of disinfection by-products resulting from reactions between reactive chlorine species (RCS) and dissolved organic matter. However, the manuscript needs major revisions before it can be published. The authors should address the following concerns:

1. Abbreviations throughout the manuscript make it difficult to read. To improve readability for the readers, only essential abbreviations should be used, and full terms should be provided where appropriate.
2. A discussion should also be provided explaining why THM could not be obtained in Figure 1.
3. For determining DBP concentrations, detailed GC-MS data should be provided, including chromatograms, retention times of DBPs, and calibration curves.
4. There are some simple formatting errors; for example, the title '2.2 Laser Flash Photolysis Experiments' should not be in bold and start on a new paragraph.
5. Providing a simple figure of the experimental setup, along with the proposed reaction and any possible side products (e.g., the formation of 2SO₄⁻ from 2S₂O₈²⁻), would be helpful.
6. The conclusions section not only summarises the key findings of your study work but also explains the specific ways in which this work fundamentally advances the field relative to prior literature. For example, references 49 and 50 cited in the conclusion section should be clarified.

Comments on the Quality of English Language

The English is fine, but the extensive use of abbreviations throughout the manuscript makes it difficult to read.

Author Response

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Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

1. If the Highlights will be published, then #1 should switch places with #2.
2. Line 23: The phrase "during water treatment" sounds a bit vague. Some context could be provided to focus on the type/form of water treatment adopted in the work. 
3. Line 81: "potential health risk" is vague. Qualify what form of risk assessment was done: human, ecological, environmental risks?
4. Line 99. Check the subheading formatting.
5. Whenever the word "halogenated" or "halo-" is used, it usually implies compounds derived from any of the members of the halogen group. Is this what the authors mean, or could the authors be more specific, "chlorinated" or "chloro-"?
6. Nothing seems to be said about control samples in the M&M section.
7. Thank you for the detailed information on temperature programming for the GC-MS analysis of DBPs. However, could the authors provide a line explanation why the 22 selected DBPs required different temperature programming, beyond just saying for "effective separation"?
8. Rewrite Section 2.4 to be more descriptive of what was done in the lab.
9. Grammar needs to be checked. Many sentences are correct, but present the wrong context. For example, on line 156, the section cannot investigate!
10. Exception of the SI data, all four figures are bar charts of chloride species concentrations. Are there no other ways of presenting the results?
11. From the title, I had expected some schemes of chemical reactions showing the transformation of the reactants and products predicted from the GC-MS analysis. 
12. For the method used for analysis of the DBPs, did the authors measure possible recoveries? 

Author Response

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Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

Comment 1 : According to the guidelines for authors, bibliographic references should not be underlined and References must include the DOI.

Comment 2 : Why does the header of this article mention 'Water 2022'?"

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 made notable improvements in the revised manuscript. However, there are still concerns regarding the data presented in Figure S1. The chromatograms of the extracted samples (DBPs), analyzed using gas chromatography-mass spectrometry (GC-MS), lack clarity. The relevant peaks corresponding to the target analytes are not clearly visible. It is recommended that the authors provide chromatograms with clearly marked peaks along with the corresponding confirmation mass spectra to substantiate compound identification. Additionally, reference 50 cited in the conclusion section should be carefully checked. There appears to be an error in the citation, as it is currently displayed as "Error! Reference source not found."

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

The revision is satisfactory. 

Author Response

We have made modifications to your feedback

Round 3

Reviewer 1 Report

Comments and Suggestions for Authors

Following the recent revisions, I find the manuscript acceptable for publication in Water.