Distribution Pattern and Enrichment Mechanism of Selenium in Topsoil in Handan Se-Enriched Belt, North China

Round 1

Reviewer 1 Report

A professionally prepared paper deals with the concentration and distribution patterns of Se in soils in the Handan Se-enriched belt, North China. However, the English are inadequate and the attention of an English speaker would help write-up of the paper since the quality of writing is very poor.

Potentially toxic trace elements (PTEs) is more inclusive and appropriate than Heavy metals. Please, see Duffus (2002) and Hooda (2010, page 3) for a detailed discussion. 

Duffus, J.H. (2002) Heavy metals—a meaningless term? Pure Appl. Chem. 74, 793-807. Available on the IUPAC website at: http://www.iupac.org/publications/pac/2002/7405/7405x0793.htm

Hooda, Peter S. (ed.) (2010) Trace elements in soils. Chichester, U.K. John Wiley & Sons.

https://link.springer.com/article/10.1007%2Fs12665-017-6899-8

Author Response

Dear Editors and Reviewers:

Thank you for your letter and for the reviewers’ comments concerning our manuscript entitled “Distribution pattern and enrichment mechanism of selenium in topsoil in Handan Se-enriched belt, North China” (ID: sustainability-1576414). Those comments are all valuable and very helpful for revising and improving our paper, as well as the important guiding significance to our researches. We have studied comments carefully and have made correction which we hope meet with approval. Revised portion are marked in red in the paper.

 

The main corrections in the paper and the responds to the reviewer’s comments are as following:

 

Reviewer: 1
1. However, the English are inadequate and the attention of an English speaker would help write-up of the paper since the quality of writing is very poor.

A: We are very grateful to the Reviewer for this suggestion. We have modified the language description in the article.

2.Potentially toxic trace elements (PTEs) is more inclusive and appropriate than Heavy metals.

A: We are very grateful to the Reviewer for this suggestion. We have carefully studied the two recommended articles, and think that it is very necessary to change heavy metals elements into potentially toxic trace elements (PTEs), which have been revised in the article.

 

Author Response File: Author Response.pdf

Reviewer 2 Report

a flow chart with all methods and tools will be very useful, and schematic description of the results from all applied methods will help a lot for the full understanding of your approach

Author Response

Dear Editors and Reviewers:

Thank you for your letter and for the reviewers’ comments concerning our manuscript entitled “Distribution pattern and enrichment mechanism of selenium in topsoil in Handan Se-enriched belt, North China” (ID: sustainability-1576414). Those comments are all valuable and very helpful for revising and improving our paper, as well as the important guiding significance to our researches. We have studied comments carefully and have made correction which we hope meet with approval. Revised portion are marked in red in the paper.

 

The main corrections in the paper and the responds to the reviewer’s comments are as following:

 

Reviewer: 2
1. a flow chart with all methods and tools will be very useful, and schematic description of the results from all applied methods will help a lot for the full understanding of your approach

A: We are very grateful to the Reviewer for this suggestion. We have added a flow chart of research contents and methods (Figure 3) and a schematic diagram of major and trace elements measurement process (Figure 4) to the article.

Author Response File: Author Response.pdf

Reviewer 3 Report

Se is an essential trace element for humans with crucial biological functions. In this study, Se concentrations and physicochemical properties of soils in central and western Handan were determined and their spatial distribution, enrichment degree, influencing factors and geological source are investigated. Generally, the results are useful to further study the source of the Se element and its impact on the environments.

My main comments are as follows:
1.    Section 2: the Geological setting is more related to the whole China and Hebei province, but little related to the study area. The second paragraph should be rearranged, which is hard to understand in the current form.
2.    Section 3: 
Part 3.1 “The procedure of soil sample collection followed by Chinese national standard GB/T 36197-2018 (2018) and industry standard DZ/T 0258-2014 (2014).” I am confused why the number of the samples is few in the east counties.
Parts 3.2 and 3.3 are normal procedures in this field, and the description can be simplified.
Parts 3.4 only provides the demands used in this study, please give the reason to use these demands. The description in this part is too simple.
3.    Section 4:
What is the role of Part 4.1.1 in this paper?
Line 239: “there is no Se-excessive in this research, indicating that there is no potential risk of selenosis in the soils”, Why?
Part 4.1.3, the contents are subjective, and some descriptions are problematic, e.g., “Se-deficiency area mostly appears around the corners of counties”,. 
“From the perspective of stratigraphy, the high Se-enrichment area has the highest coincidence degree with Pleistocene….” How to obtain the conclusion?
The content of the Se distributions is subjective.
Part 4.2: “The mean and maximum values of Se EF in Handan and Fengfeng are ranked in the forefront among all the counties, indicating considerable impact of anthropogenic activities” how to obtain this conclusion? 
The conclusion in the second paragraph is not clear.
Part 4.3.1: please combine Table 6 to clearly present and verify your findings.
Part 4.3.2: the expression of the content is rigid. It is hard to understand the content in current form.
Part 4.4 should be rearranged. To obtain the conclusion “From the synthetically view, Se enrichment in soils in study area is principally affected by rock weathering, mining activities and coal combustion”, the related discussions are not enough.
Part 4.5 is not related to the main content of the paper.
4.    The conclusions in the paper is not clear. The authors presents abundant original data and the processed data, but the analysis about these data is not enough. Particularly, the content about the enrichment mechanism is not enough.

5.    I suggest an extensive editing of English language and style.

Author Response

Dear Editors and Reviewers:

Thank you for your letter and for the reviewers’ comments concerning our manuscript entitled “Distribution pattern and enrichment mechanism of selenium in topsoil in Handan Se-enriched belt, North China” (ID: sustainability-1576414). Those comments are all valuable and very helpful for revising and improving our paper, as well as the important guiding significance to our researches. We have studied comments carefully and have made correction which we hope meet with approval. Revised portion are marked in red in the paper.

 

The main corrections in the paper and the responds to the reviewer’s comments are as following:

 

Reviewer: 3
1. Section 2: the Geological setting is more related to the whole China and Hebei province, but little related to the study area. The second paragraph should be rearranged, which is hard to understand in the current form.

A: Thank you to the Reviewer for the comment. The original intention is to describe the complexity of strata in the west of Handan, and as a result, it expanded the scope and was wrongly written as the west of Hebei Province. We have made corrections in the article and apologize again for our mistakes.

2.Section 3: 
(1) Part 3.1 “The procedure of soil sample collection followed by Chinese national standard GB/T 36197-2018 (2018) and industry standard DZ/T 0258-2014 (2014).” I am confused why the number of the samples is few in the east counties.
(2) Parts 3.2 and 3.3 are normal procedures in this field, and the description can be simplified.
(3) Parts 3.4 only provides the demands used in this study, please give the reason to use these demands. The description in this part is too simple.

A: We are very grateful to the Reviewer for this suggestion.

(1) Part 3.1: We understand your confusion. When designing the research plan at the beginning, the research focused on the central and western regions of Handan. The reason is that previous studies have reported the selenium content in the eastern region and found that the selenium content is not high, but the central and western regions were in the data blank area. Therefore, when going out for sampling, the central and western regions of Handan were the focus of sampling, and a small number of samples were taken in the eastern region. If abnormally high selenium content points were found in the eastern region, it was planned to re-collect another batch of samples. However, the outbreak of the epidemic later made it difficult to go out for sampling. In addition, it was found that there were many points with high selenium content in the central and western regions of Handan, so the activity of replenishing samples in the eastern region was abandoned.

(2) Parts 3.2 and 3.3: We have simplified the description of the experimental procedures.

(3) Parts 3.4: We added reasons for some requirements. As for the description of PCA, we described it in Part 4.3.3.

3.Section 4:
(1) What is the role of Part 4.1.1 in this paper?
(2) Line 239: “there is no Se-excessive in this research, indicating that there is no potential risk of selenosis in the soils”, Why?
(3) Part 4.1.3, the contents are subjective, and some descriptions are problematic, e.g., “Se-deficiency area mostly appears around the corners of counties”,
(4) “From the perspective of stratigraphy, the high Se-enrichment area has the highest coincidence degree with Pleistocene….” How to obtain the conclusion?
(5) The content of the Se distributions is subjective.
(6) Part 4.2: “The mean and maximum values of Se EF in Handan and Fengfeng are ranked in the forefront among all the counties, indicating considerable impact of anthropogenic activities” how to obtain this conclusion? 
(7) The conclusion in the second paragraph is not clear.
(8) Part 4.3.1: please combine Table 6 to clearly present and verify your findings.
(9) Part 4.3.2: the expression of the content is rigid. It is hard to understand the content in current form.
(10) Part 4.4 should be rearranged. To obtain the conclusion “From the synthetically view, Se enrichment in soils in study area is principally affected by rock weathering, mining activities and coal combustion”, the related discussions are not enough.
(11) Part 4.5 is not related to the main content of the paper.

A: We are very grateful to the Reviewer for this suggestion.

(1) This part introduces the content characteristics of major and trace elements in the surface soil of the study area and compares them with the background values in the eastern plain of China, which paves the way for judging the influencing factors and causes of selenium enrichment through element content characteristics.

(2) Because the effect caused by excessive selenium is selenium poisoning, and because no sample in the study area shows excessive selenium, it is speculated that there is no potential risk of selenium poisoning in the topsoil of the study area. But now it seems that this inference is too arbitrary, and we have revised this sentence in the article. Thank the reviewers for the comment.

(3) We are sorry that the description of Se-deficiency areas is too subjective. We modified this problem in the article.

(4) Combining geological map with distribution map of Se concentration, we found that Carboniferous-Permian period was in a high Se-enrichment distribution area, so we made some changes in the sentence description in the article.

(5) For this part, some modifications have been made in the article.

(6) Thank you to the Reviewer for the comment, we found this conclusion too arbitrary and deleted it from the article.

(7) Thank you for your comments. We have revised the second paragraph of Part 4.2.

(8) Because of the format change, the contents of Table 6 are not displayed completely, resulting in the text not matching the table. The font size in the table has been adjusted to fully display the table's contents. Please accept our sincere apologies for our errors.

(9) This paragraph primarily discusses the relationship between PTEs and Se in order to demonstrate the impact of PTEs on Se enrichment.

(10) Remove any cases where the article lacks sufficient evidence, such as atmospheric precipitation, metal refining, and automobile emissions.

(11) Because selenium enrichment is associated with an increase in PTEs. Excess PTEs in soil, on the other hand, are extremely harmful to the ecology. As a result, if we wish to make the best use of Se-enriched resources, we must also assess the level of PTE enrichment in local soil. Part 4.5 is therefore utilized to investigate the amount, distribution, and source of heavy metals in soil in order to provide guidelines for the local sensible use of Se-enriched resources.

4.The conclusions in the paper is not clear. The authors present abundant original data and the processed data, but the analysis about these data is not enough. Particularly, the content about the enrichment mechanism is not enough.

A: We are very grateful to the Reviewer for this suggestion. Some modifications have been made about conclusions in the article.

5.I suggest an extensive editing of English language and style.

A: We are very grateful to the Reviewer for this suggestion. We have modified the language description in the article.

 

Author Response File: Author Response.pdf

Round 2

Reviewer 3 Report

The authors gave a good response to my comments.

One problem should be paid attention:

Line 304: I don’t agree with the finding “there is also a small area of the Se anomaly belt in the western mountainous area”. Compared with Figures 2A and 2B, it can be found that the sampling sites are abundant in Se anomaly belt. Thus, it is likely the number of sampling sites brought the low values in the surrounding places.

Correspondingly, the conclusion in section 4.1.3 should be critically treated.

Author Response

Dear Reviewer:

Thank you for your letter and for the reviewers’ comments concerning our manuscript entitled “Distribution pattern and enrichment mechanism of selenium in topsoil in Handan Se-enriched belt, North China” (ID: sustainability-1576414). Those comments are all valuable and very helpful for revising and improving our paper, as well as the important guiding significance to our researches. We have studied comments carefully and have made correction which we hope meet with approval. Revised portion are marked in red in the paper.

 

The main corrections in the paper and the responds to the reviewer’s comments are as following:

 

 

Reviewer: 3
One problem should be paid attention:

Line 304: I don’t agree with the finding “there is also a small area of the Se anomaly belt in the western mountainous area”. Compared with Figures 2A and 2B, it can be found that the sampling sites are abundant in Se anomaly belt. Thus, it is likely the number of sampling sites brought the low values in the surrounding places.

Correspondingly, the conclusion in section 4.1.3 should be critically treated.

A: We are very grateful to the Reviewer for this suggestion. We agree that there are fewer sampling points in the marginal areas of the study area, which may lead to the existence of abnormal Se values. However, the problem of sampling points can't be improved now, so we modified the contents of 4.1.3 appropriately. The last two sentences of section 4.1.3 are meant to convey the meaning: there is evidence that Se is relatively enriched in flat areas, which is compatible with our research findings, Se concentrations are higher in plain and low hilly places. However, there are small areas of Se enrichment in western mountainous areas with higher topography, which could be due to factors other than terrain. Thank you once more for your valuable advice.

Author Response File: Author Response.pdf