Review Reports - Bibliometric Based Analysis of Hydrogels in the Field of Water Treatment

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

In this review, the authors provides a comprehensive overview of hydrogel research in water treatment from 2000 to 2024, using robust analytical tools. The study effectively highlights key trends, research hotspots, and the contributions of leading institutions. However, minor revisions are needed to improve clarity and flow. Specifically, the transition between topics could be smoother, and some sentences could be more concise. Additionally, the conclusions would benefit from a clearer emphasis on the practical implications of developing cost-effective and efficient hydrogel materials. With these minor adjustments, the paper is suitable for publication.

1. For Figure 1, the trend is not fully reflected because articles from 2024 have not yet been completely indexed. It is recommended to supplement the text with an estimated publication count for 2024 to better highlight the trend.

2. The highly cited articles presented in Table 3 do not fully demonstrate their relevance to water treatment. It is recommended to add more context in the main text. For instance, most of the highly cited articles were published after 2014, which aligns with your earlier analysis of publication trends.

3. For Table 4, the name "Zhuang" mentioned in the text does not appear in the table. There might be a spelling error—perhaps "Zhang Yuan" should be corrected to "Zhuang Yuan."

4. For Table 5, the data for Amirkabir University of Technology has not been included. Could this be due to the low number of publications, which might have led to its highest average citation rate? Please provide clarification in the review.

Comments on the Quality of English Language

There are some ambiguities in the text, such as using "Part citation frequency," which should be corrected to "average citation frequency." Additionally, there are spelling issues with various author names. It is recommended to thoroughly review and revise these to avoid any potential confusion.

Author Response

(1) For Figure 1, the trend is not fully reflected because articles from 2024 have not yet been completely indexed. It is recommended to supplement the text with an estimated publication count for 2024 to better highlight the trend.

Author reply: Dear experts, thank you very much for your valuable advice. According to the revised opinions, I predict the number of published papers in the whole year of 2024. From January 1, 2024 to July 1, 2024, 93 papers are published in WOS and 16 papers are published on CNKI. The predicted number of published papers in the second half of the year is not much different from that in the first half of the year. In the whole year of 2024, the number of WOS publications is about 186, and the number of CNKI publications is about 32, that is, the total number of publications in the whole year of 2024 is about 218.

(2) The highly cited articles presented in Table 3 do not fully demonstrate their relevance to water treatment. It is recommended to add more context in the main text. For instance, most of the highly cited articles were published after 2014, which aligns with your earlier analysis of publication trends.

Author Reply: Thank you for your comments, according to the revised comments. In the third part of table, I have added the analysis of relevant literature to enhance the correlation between hydrogels and water treatment mentioned in the central content of the article.

(3) For Table 4, the name "Zhuang" mentioned in the text does not appear in the table. There might be a spelling error—perhaps "Zhang Yuan" should be corrected to "Zhuang Yuan."

Author Reply: Thank you for your comments, according to the revised comments. I have corrected the spelling errors in Table 4 and further checked and corrected the spelling of the whole article.

(4)For Table 5, the data for Amirkabir University of Technology has not been included. Could this be due to the low number of publications, which might have led to its highest average citation rate? Please provide clarification in the review.

Author's reply: Thank you for your comments. I've reanalyzed the data based on your comments. Since Amirkabir University of Technology and King Saud University have the same number of publications, Amirkabir University of Technology was not added to the table in the first analysis and only its highest average citation frequency was analyzed. Thanks to your suggestions, I realized there was a certain misunderstanding, so I updated and replaced the information in the table. (5) There are some ambiguities in the article. For example, "Part citation frequency" is used, which should be changed to "average citation frequency". Additionally, there are spelling issues with various author names. It is recommended that these be thoroughly reviewed and revised to avoid any potential confusion. Author's response: Author's response: Thank you for your comment. Based on your comments, I have corrected some specific word usage and name spelling issues in this article, which have been marked in red font in the main text.

Reviewer 2 Report

Comments and Suggestions for Authors

Why did the authors use only WoS and CNKI databases for the search and not Scopus database?

It is necessary to add articles for the last two years devoted to chitosan gels and gels based on polyvinyl alcohol for the sorption of pollutants (see the works of Chistyakov E.M. et al. Scopus 51260935700).

A comparison of different methods for extracting pollutants from wastewater should be provided, and their advantages and disadvantages should be indicated. It is recommended to conduct an analysis of patents in this area (see the work https://doi.org/10.1186/s13036-024-00435-2).

It is necessary to expand the section devoted to the toxicity of hydrogels.

Author Response

（1）Why did the authors use only WoS and CNKI databases for the search and not Scopus database?

Author reply:Web of Science (WoS) is a citation index owned by ISI, and Scopus was launched by Elsevier. Scopus database and WoS database are not much different from each other in terms of quality and quantity, and both have their own advantages. However, WoS is still more popular at this stage because ISI has a longer history and is the only literature database before Scopus was founded. Besides, high-quality journals are usually included by Scopus and WOS, so I only choose CNKI and WOS.

（2）It is necessary to add articles for the last two years devoted to chitosan gels and gels based on polyvinyl alcohol for the sorption of pollutants.

Author Reply: Thank you for your comments, in response to the relevant content you raised, I will add it to section 4.1.2.

(3) A comparison of different methods for extracting pollutants from wastewater should be provided, and their advantages and disadvantages should be indicated. It is recommended to conduct an analysis of patents in this Area (see the work of https://doi.org/10.1186/s13036-024-00435-2).

Author Reply: Thank you for your comments. In response to your questions about pollutant extraction, I have supplemented them in the introduction section of this paper. In response to the supplement of part of the patent you proposed, I have added the part in Chapter 5.

Reviewer 3 Report

Comments and Suggestions for Authors

This is a well-organized review paper. After a careful evaluation, I think it can be accepted. One suggestion for this manuscript is as follows,

I think the author should add one small section to describe the basic information about "hydrogel". For example, what does it look like, and what are the main approaches used to synthesize them? In addition, it might be better if the author could also classify the hydrogels into different hydrogel-based materials (e.g., hydrogel-grafted membrane, aerogel, and adsorbent).

Comments on the Quality of English Language

Author Response

Author Reply: Thank you for your comments. According to your comments, I have added the form, synthesis method and classification of hydrogels in the Introduction part of this paper.