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Thank you for making all the requested corrections.
[# PeerJ Staff Note - this decision was reviewed and approved by Jörg Oehlmann, a PeerJ Section Editor covering this Section #]
As discussed, please address the technical issues in the manuscript. This is otherwise fine to be published.
[# PeerJ Staff Note - Please address the following:
## Author Names
The author list on your manuscript Author Cover Page, does not match the list you entered online. We only use the information in the metadata provided in the submission system. To make them match, either A) [**Upload**](https://peerj.com/manuscripts/82262/files) a manuscript with a corrected Author Cover Page or B) [**Edit your online author list**](https://peerj.com/manuscripts/82262/authors).
## Authorship
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## Figure Permissions
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## Rebuttal Letter
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## Tracked Changes Manuscript Source File
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## Acknowledgements
Please remove all financial and grant disclosure information from the Acknowledgements. This information is required to appear only in the Funding Statement for publication:
We acknowledge Petroleum Technology Fund, PTDF Nigeria for providing overseas scholarship for Bilal Ibrahim Dan-Iya.
This information should only be provided in the Funding statement [**here**](https://peerj.com/manuscripts/82262/declarations/#question_18).
## Figures
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## Remove Figure Legends from Figure Files
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## Figure Accessibility
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Please provide replacement figures measuring minimum 900 pixels and maximum 3000 pixels on all sides, saved as PNG, EPS or vector PDF file format without excess white space around the images.
## Figure/Table Citation
The submission appears to be missing a citation for Table 2, Figure 3, and Figure 7 in the text.
Please can you add a citation for Table 2, Figure 3, and Figure 7 in your manuscript at the next revision.
Note: Citations must be organized, and cited for the first time, in ascending numerical order, meaning Figure 1 must always be cited first, Figure 2 must always be cited second, and so on. The same applies to Tables.
## Figure/Table Citation
Citations must be organized, and cited for the first time, in ascending numerical order, meaning Figure 1 must always be cited first, Figure 2 must always be cited second, and so on. The same applies to Tables.
In this case:
The citation for Figure 2 (Line 116) appears before the citation for Figure 1 (Line 143).
The citation for Figure 6 (Line 310) appears before the citation for Figure 4 (Line 310).
The citation for Figure 6(Line 310) appears before the citation for Figure 5 (Line 330).
Please edit the citations in your manuscript at the next revision.#]
The reviewer is satisfied with your correction/modifications, but has some *very* minor comments remaining.
The writing is clear.
Literature can be added further.
Artilcle strure is good.
Including a few references from very recent years may increase the weight of the paper. (2021-2023)
Study design is enough
The benefits of literature are clearly stated.
Conclusions are well stated, linked to original research question
Headings and subheadings should be uniform. Differences are observed, such as when abberiavtion is used in one place and full form is used in another. e.g.;
Synthesis of ZVI nanoparticles
Characterization of nanoscale zero-valent iron
Factors affecting the performance of nZVI
Toxicity of zero-valent iron nanoparticles
Adding shapes and sizes to the synthesized nZVI using TEM would be good.
The reviewers have provided positive feedback on your work, but there are some concerns that need to be addressed before we can consider it for publication. The primary concern is the need to incorporate new and recent works into your manuscript.
Please carefully consider the suggestions made by the reviewers and address them in your revised manuscript. We encourage you to include the most up-to-date and relevant literature to strengthen your work. Once you have made the necessary revisions, please resubmit your manuscript for further consideration.
[# PeerJ Staff Note: Please ensure that all review and editorial comments are addressed in a response letter and any edits or clarifications mentioned in the letter are also inserted into the revised manuscript where appropriate. #]
[# PeerJ Staff Note: PLEASE DISREGARD THE REQUEST BY REVIEWER 3 TO REMOVE THE SURVEY METHODOLOGY SECTION. THIS IS A JOURNAL REQUIREMENT #]
[# PeerJ Staff Note: Please ensure that all review and editorial comments are addressed in a response letter and any edits or clarifications mentioned in the letter are also inserted into the revised manuscript where appropriate. #]
This review article is focused on the current methodology for the preparation of nanoscale zero-valent iron (nZVI), characterization techniques, and the reductive mechanism for heavy metal removal, with a specific emphasis on mercury. The objective of this review is to discuss the potential use of nZVI for the removal of mercury and to demonstrate its high reactivity in this application, as well as to highlight its promising prospects in environmental remediation. The investigation of relevant recent articles is presented, along with recommendations for future research and conclusions drawn from the findings.
This review is of broad and cross-disciplinary interest, within the scope of the journal, and has not been reviewed in extensive detail in the literature. The Introduction effectively introduces the subject matter and makes clear the intended audience and motivation behind the review.
No comment
The Conclusion identifies unresolved questions and gaps in knowledge and provides a clear direction for future research. Specifically, the authors note that while surface-modification of nanoscale zero-valent iron (nZVI) has shown promise for removing toxic compounds from the environment, issues with stability, agglomeration, and transportation still need to be addressed through further investigation. Additionally, the authors note that there is still a need for further research to understand the adsorption mechanisms, relocation patterns, and interactions between different heavy ionic metals in various environmental media such as groundwater, minerals, clay, and wastewater.
Overall, the argument presented in the conclusion is well-developed and supported by the evidence presented throughout the article.
The review paper entitled “Zero-valent iron nanoparticles for Hg (II) removal: A Review” seems to be worthy, although a similar type of review paper is already published. The new contribution of this paper to the related field is not clear. The paper has merit and is quite large in volume. However, the paper lacks a few points of view. A few of them are mentioned below.
The content of the article is within the scope and aim of the journal. Overall, however, the current paper needs to design further.
2. The title seems incomplete. Zero-valent iron nanoparticles for Hg (II) removal: A Review………..Hg (II) removal from where? From Soil/water/environment?
Also, ZVI (it seems not a simple nanoparticles, rather core-shell particle) or core-shell type nanoparticle? If so, the whole study needs to be alligned with core-shell nanoparticles.
General comments:
1. Overall clarity of the manuscript needs to improve.
2. The title seems incomplete. Zero-valent iron nanoparticles for Hg (II) removal: A Review………..Hg (II) removal from where? From Soil/water/environment?
Also, ZVI (it seems not a simple nanoparticles, rather core-shell particle) or core-shell type nanoparticle? If so, the whole study needs to be alligned with core-shell nanoparticles.
3. References should be cited properly according to journal style (italics). Very few recent references were cited. Please cite more recent and relevant publications related to the present review by reviewing broadly.
4. In the 2nd paragraph of the introduction, the author can start narrating with heavy metals directly instead of metal.
5. The background of the study needs to improve.
The authors have provide a comprehenive review on the use of nZVI for the removal of mercury and demonstrates that nZVI possesses high reactivities for mercury removal and have great a plication prospects in environmental remediation. The review is well written and covers a broad depth in the use of nZVI for Hg removal.
I do not recommend a section like search methodology as it seems to be irrelevant. Definitely, we use different platforms for searching the journal articles. The authors have covered different sections such as synthesis, mechanism of nZVI action, Factors affecting the performance of nZVI, Toxicity of zero-valent iron nanoparticles, Challenges and future prospects in using nZVI technology for Hg removal. Moreover, they have also provided a provide appropriate figures and tables.
I recommend to publish this work after removing search methodlogy.
As it is a review, nothing specific on this section
As it is a review, nothing specific on this section
N/A
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