Spatial Distribution Characteristics and Potential Risk Assessment of Heavy Metals in Sludge of Shanghai Sewage Treatment Plant: A Case Study

Round 1

Reviewer 1 Report

1. The figures need to be improved, as it is almost impossible to read.

2. The conclusions are too extensive, they should be reduced and more comprehensive and present the main points. 

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

Manuscript ID: Sustainability-2188930-peer-review-v1

Title: Spatial distribution characteristics and potential risk assessment of heavy metals in sludge of Shanghai sewage Treatment Plant: A Case Study

This research is a distinguished effort by the work team. But there are some observations. In general I accept the article to publish after see my comments.

 Abstract:

44 cities sewage treatment plant in Shanghai on the spatial distribution of the eight heavy metals in sewage sludge characteristics were analyzed. The technology used for comprehensive pollution index and potential ecological risk index calculation. Hakanson sludge heavy metal pollution and potential ecological risk is evaluated, for Shanghai municipal sewage sludge heavy metal pollution characteristics study provides the basis. The results showed that the single factor pollution index of heavy metals was ranked as follows: arsenic, cadmium, mercury, nickel, copper, zinc, chromium and lead. The comprehensive pollution index of nemeluo showed that the five sewage treatment plants in Nanxiang, Eastern district, Liantang, Songxi, and Xinhe were seriously polluted. The order of the single factor potential ecological risk index of each heavy metal is Hg, Cd, Cu, Ni, Pb and Zn. To improve environmental quality and reduce ecological hazards, Shanghai's sewage treatment monitoring and control must focus on high-risk plants and reduce pollution sources.

Comments:

1.      In Abstract: the authors used long sentences. It is best for they can do short sentences. Up, I was try to do this and the authors must follow the same at all manuscript.

2.      The keywords: Not enough.

3.      The authors must update the references, there is no references in 2020, 2021 and 2022.

4.      The authors didn’t compare the obtained results with the other countries.

5.      The authors must use the abbreviation of the heavy metals at all manuscript.

6.      The simulation of the results was very excellent.

7.      The resolution of Figures must be more enhanced.

8.      The label in Figures must be translated to English, not all scientific people know Chinese language with all of my regards and respect to their language.

9.      The conclusion was very long must be focused and decreased.

Comments for author File: Comments.pdf

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 3 Report

This manuscript contains important results regarding the heavy metals in sewage from a series of water treatment plant in Shanghai/China. Although the results are important, the presentation of data should be revised before publication, since in the present form there are a few paragraphs that are nothing else than some enumeration of values.

This last recommendation and some other small ones are further presented:

Title: ok

Abstract:

- lines 9-13: please reorganize this paragraph, it is not clear;

- line 15: what is “nemeluo”?

- line 23: replace the expression “do a good job” with something more scientific;

- the whole Abstract should be revised. There are too many oversized and unclear phrases.

Keywords:

- “heavy metal sludge”? maybe “heavy metal containing sludge”.

Introduction:

- lines 37-40: please revise.

Research data background:

- table 1: I think the second column should be for “Minimum”, not “Maximum”;

Research methods:

- line 127: “heavy metal mine”?

Simulation and results analysis:

- line 177: what is meant by “radioactive”?

- figures 1-3: the legends data should be made clearer and fully translated in English;

- figure 2: I think “treatment plants” or “treatment plant system” would be better than “treatment plant”;

- lines 210-232: these two paragraphs might be rewritten in such a manner as not to be presented as an enumeration of data;

- lines 237-245: idem;

- lines 250-261: idem;

- lines 270-278: idem.

Conclusions:

- lines 284-292: idem;

- some future research perspectives might be mentioned.

Author Response

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Author Response File: Author Response.pdf

Reviewer 4 Report

Manuscipt entitled Spatial distribution characteristics and potential risk assessment of heavy metals in sludge of Shanghai sewage Treatment Plant: A Case Study concerns the problem of sewage sludge pollution with heavy metals, which is one of the biggest environmental issues nowdays. However, I have some comments to the Authors, see belo:

Research data background

In this part, the map of Shanghai should be provided in this part, because the readers can't understand the geographical location of each district after the comparative analysis of heavy metal content of sludge in different regions.

Page 5-9, Results and discussion - This part is more like a raport than scientific discssion. There are a very little references to other studies. The obtained results are not fully explained and disccused. This part needs a major revsion.

L125-126,L136-137,L151-153. The symbols in the formula should be written in the correct format.

Figure 2. elements and different areas should be written in English.

Page 11, Conclusion - This part it is just a repeating of the earlier information, only the most important observations and conclusions from the research should be included here. 

L166-205 The authors are made some comparison among the metals detected but the scientific discussion is not there

Line 166-to end of this paragraph in this paragraph authors should clearly substantiate their finding with the help of supporting references

In over all the MS need major correction/revision including results/statistics, I did not agree authenticity of the MS without statistical analysis

The MS is lack of references and insufficient discussions in all the parts I am very doubted about how the authors can tell their scientific story without proper references

Author Response

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Author Response File: Author Response.pdf

Reviewer 5 Report

The manuscript is in principle interesting but mainly for incremental knowledge. The sentences are always too long and could be broken in two. Some wording is too colloquial and not so scientific. In the discussion of the results, a bit more interpretation would have been expected. The author only list what they see but not what it means. Interpretation is forwarded to the conclusions (possible causes of) together with future perspectives. I suggest including some interpretation within the main findings of the results. Suggestions are provided in the pdf. 

Comments for author File: Comments.pdf

Author Response

Dear reviewer,

    Thank you for reviewing our manuscript and for the constructive comments, which greatly helped us to improve the manuscript. In response to your comments, we have revised the original text and marked it.

    We are deeply sorry for your inconvenience caused by us. If you have any further questions or concerns about the revised manuscript, please do not hesitate to contact us. We sincerely hope that this revised version will have a positive outcome and thank you again for your time and help. Best wishes to all of you!

Round 2

Reviewer 4 Report

Line121,144：References should be placed before punctuation symbol.