Contamination, Ecological Risk and Source Apportionment of Heavy Metals in the Surface Sediments in the Hailar River, the Upper Source of the Erguna River between China and Russia

Round 1

Reviewer 1 Report

COMMENTS TO THE AUTHOR(S)

This study examined the “Pollution characteristics and risk assessment of sediments in Hailar River, the upper source of Erguna River, the boundary river between China and Russia”. Given that water quality is a global concern, this paper is timely and could offer new insights on surface water quality. The manuscript is generally well written and easy to understand. I suggest that the authors revise the manuscript incorporating the following comments and suggestions into an updated version.

1.       Did the authors normalize the data before statistical analysis?

2.       Add scree plot in the manuscript as it shows relationship between Eigen value and component Number.

3.       On what basis the authors concluded that Zn, Cr, Ni, Cd and Pb are mainly caused by natural sources while Cu, Hg and As by human activities.

4.       The authors should explain the most influential parameters in both principal components.

5.       Why the values of Hg is higher than the rest parameters.

6.       On what basis the authors selected Kriging technique instead of using other techniques such as IDW etc.

7.       The quality of figures is extremely low.

Author Response

Thank you very much for the pertinent comments. The manuscript has been revised and improved according to the comments.

Please see the attachment.

Author Response File: Author Response.docx

Reviewer 2 Report

Please see the attached document.

Comments for author File: Comments.pdf

Author Response

Thank you very much for the pertinent comments. The manuscript has been revised and improved according to the comments.

Please see the attachment.

Author Response File: Author Response.docx

Reviewer 3 Report

It is a very good paper.

Please explain more the concentration rate.

Please explain the detection rate as well.

Please delete the old and not much related ones.

Please add below references to manuscript and compare results:

Assessment of bed sediment metal contamination in the Shadegan and Hawr Al Azim wetlands, Iran

 

Spatial distribution and contamination of heavy metals in surface water, groundwater and topsoil surrounding Moghan’s tannery site in Ardabil, Iran

Spatial distribution, enrichment and geo-accumulation of heavy metals in surface sediments near urban and industrial areas in the Persian Gulf

Study on the heavy metal bioconcentrations of the Shadegan international wetland mosquitofish, Gambusia affinis, by inductively coupled plasma technique

Concentration of heavy metals in surface water and sediments of Chah Nimeh water reservoir in Sistan and Baluchestan province, Iran

 

 

Author Response

Thank you very much for the pertinent comments. The manuscript has been revised and improved according to the comments.

Please see the attachment.

Author Response File: Author Response.docx

Reviewer 4 Report

The manuscript choose a Trans-boundary rivers-Hailar River as the research object let the article full of interest. However, the article lacks in-depth analysis. It should be noted that principal component analysis can show the correlation between elements, but it cannot determine the specific contribution source of each element. It is suggested to add traceability analysis in this paper to deeply analyze the source of elements with high heavy metal pollution level, so as to provide scientific basis for river pollution control.

1. In lines of 73-77. There are a lot of studies like this, and the purpose of the study is too prosaic and uninnovative.

2. In lines of 80-86. Delete.

3. In lines of 97. The references of [28] was published in 1997and it doesn't fit here. The environmental protection department is not a decoration. It is impossible that nothing has changed after 25 years. Also, the researchers have nationalities, and some of the writing is not suitable for international publications.Please watch your language and quotations.

4. In lines of 309-311.The paper did not carry out traceability analysis, and the result of principal component analysis could not represent the contribution rate of natural/human factors to the corresponding elements, which is not appropriate.

 

Author Response

Thank you very much for the pertinent comments. The manuscript has been revised and improved according to the comments.

Please see the attachment.

Author Response File: Author Response.docx

Reviewer 5 Report

1. The title of the manuscript must be modified. The present title seems poorly represented with respect to the study.

2. There is no relation between the first two lines and, subsequently, the following lines of the abstract. The abstract must include the following components: a brief problem statement, your research, and findings, followed by the significance. The authors are advised to rewrite the abstract in the pattern stated above.

3. The introduction section is poorly written in a monotonous manner. The readers will find it less interesting to study the manuscript in its present form.

4. Kindly elaborate on the research novelty that is missing from the introduction.

5. State the significance of your study at the end of your introduction, for e.g., who are the primary beneficiaries of your research.

6. Line 80-86: I don't understand the paragraph. 

7. There is no mention as to how the sampling locations are identified.

8. Line 125: The acids' notation shall be modified to the proper format.

9. Pb, Cd, Cu, Ni, Zn and Cr. Why these heavy metals? Any specific reason?

10. Eqn. 1: Do you think the equation is correct? Check for the notations as well in the subsequent line.

11. Check for Eq. 2 and 3. They are incorrect.

12. Eq. 4 and 5 and their subsequent notations are in the incorrect format.

13. The results are poorly written and represented. All figures are of poor quality. Considerable modifications are required.

14. There is little information about the PCA technique employed and the results obtained. Same for the Pearson correlation.

15. Conclusion section is poorly written. Modify it accordingly.

16. References cited are not appropriate. You may take help from the following:

"Dash, S., Borah, S. S., & Kalamdhad, A. S. (2021). Heavy metal pollution and potential ecological risk assessment for surficial sediments of Deepor Beel, India. Ecological Indicators, 122, 107265."

"Dash, S., Borah, S. S., & Kalamdhad, A. S. (2020). Application of positive matrix factorization receptor model and elemental analysis for the assessment of sediment contamination and their source apportionment of Deepor Beel, Assam, India. Ecological Indicators, 114, 106291."

"El-Amier, Y. A., Elnaggar, A. A., & El-Alfy, M. A. (2017). Evaluation and mapping spatial distribution of bottom sediment heavy metal contamination in Burullus Lake, Egypt. Egyptian Journal of Basic and Applied Sciences, 4(1), 55-66."

"Vu, C. T., Lin, C., Shern, C. C., Yeh, G., & Tran, H. T. (2017). Contamination, ecological risk and source apportionment of heavy metals in sediments and water of a contaminated river in Taiwan. Ecological indicators, 82, 32-42."

Author Response

Thank you very much for the pertinent comments. The manuscript has been revised and improved according to the comments.

Please see the attachment.

Author Response File: Author Response.docx

Round 2

Reviewer 1 Report

No comments

Reviewer 2 Report

The manuscript is ready for publication.

Reviewer 4 Report

none