Investigation of Petroleum Hydrocarbon Fingerprints of Water and Sediment Samples of the Nestos River Estuary in Northern Greece

Round 1

Reviewer 1 Report

Dear authors, the articles described the investigation of Petroleum Hydrocarbon Fingerprints in Water and Sediment Samples to characterize possible anthropic pollution, but the results on the analyzed water and sediment samples bared no evidence of environmental hazards associated with the hydrocarbon exploration and production activities of the neighboring oil and gas company. So why you talk about anthropogenic pollution? In addition, no comparison with literature data. It is a trivial work with simple results (few samples over a large area) without comparison with the literature data. Samples are few and statistical representativeness cannot be expressed. I suggest increasing the number of samples.

 

Merck, city ?

Carlo Erba, city ?

Fluka, city ?

Sigma-Aldrich, city ?

 

All the first paragraph refers to reagents and is described not very well. It would be better to put them into a Table.

 

mass spectrometer system gas chromatography-mass spectrometry – mass spectrometry repeated

Agilent, city ?

 

Study area before materials and methods

 

Figure 1 si horrible. Give much more information regarding hydrological map and topography map. You talk about probably water pollution on anthropogenic activities, so you have to explain the hydrological and geological characteristic of the sampled area.

Caption of Figure 1, add the name of the sampling

 

Line 128 “ were collected” not were taken

 

Line 130, which year?

 

2.4 add references regarding the methodology

The same for 2.5 and 2.6

 

Figure 2 is not described in the results, give more detail.

 

There are no discussion: You put results and discussion in the same way, so you must add more references related to figure 3, 4, 5, 6, 7,. 8, 9, 10 and describe the comparison with these references.

 

The articles need more comparison with literature. This work is only a presentation of results on a research without comparison with literature. As it is structured now it is not to be considered publishable, unless a whole chapter on discussions is added.

 

Author Response

Dear Esteemed Editors and Reviewers,

Thank you for your response to our research. We really appreciate your precious time to study the manuscript and comment on it. We seriously took into consideration every issue raised from your comments and we answered them below, point by point.

 

Sincerely,

The authors

 

RESPONSE TO REVIEWER 1

General issues

Dear authors, the articles described the investigation of Petroleum Hydrocarbon Fingerprints in Water and Sediment Samples to characterize possible anthropic pollution, but the results on the analyzed water and sediment samples bared no evidence of environmental hazards associated with the hydrocarbon exploration and production activities of the neighboring oil and gas company. So why you talk about anthropogenic pollution? In addition, no comparison with literature data. It is a trivial work with simple results (few samples over a large area) without comparison with the literature data. Samples are few and statistical representativeness cannot be expressed. I suggest increasing the number of samples.

Response

Thank you for comments and your willingness to review our manuscript. The current research examined the research hypothesis of anthropogenic pollution by investigating the potential environmental impact of the nearby oil and gas industry in the Prinos-Kavala basin that operates over 40 years. In respect of reviewer’s comments, authors enriched their literature with additional references, compared them with their results and further discussed them. The 21 samples repeated for 3 months and examined according to EPA 3510.

 

Specific Issues

Issue 1:

Merck, city ? Carlo Erba, city ? Fluka, city ? Sigma-Aldrich, city ?

All the first paragraph refers to reagents and is described not very well. It would be better to put them into a Table.

Response

Thank you for the comment. The whole paragraph has been rewritten and Table 1 has been added.

 

Issue 2:

mass spectrometer system gas chromatography-mass spectrometry – mass spectrometry repeated

Agilent, city ?

Response

Yes, indeed. Thank you very much for noticing that. Done. Moreover, vendor’s city has been added.

 

Issue 3:

Study area before materials and methods

Response

Thank you for the comment. The order of the sections has been changed according to the reviewer’s suggestion.

 

Issue 4:

Figure 1 si horrible. Give much more information regarding hydrological map and topography map. You talk about probably water pollution on anthropogenic activities, so you have to explain the hydrological and geological characteristic of the sampled area.

Response

According to reviewer’s request, the hydrogeological behaviour of Nestos River’s basin has been added in the manuscript (l. 88-91). Additional reference has been also added. However, the authors do not have permission to use another map.

 

Issue 5:

Caption of Figure 1, add the name of the sampling

Response

Thank you for the comment. The sampling has been defined.

 

Issue 6:

Line 128 “ were collected” not were taken

Response

Thank you for the comment. The verb has been changed according to the reviewer’s suggestion.

 

Issue 7:

Line 130, which year?

Response

Thank you for the comment. The year has been added.

 

Issue 8:

2.4 add references regarding the methodology

The same for 2.5 and 2.6

Response

Thank you for the comment. According to reviewer’s suggestion, the reference of the method has been repeated in all the required sections.

 

Issue 9:

Figure 2 is not described in the results, give more detail. There are no discussion: You put results and discussion in the same way, so you must add more references related to figure 3, 4, 5, 6, 7,. 8, 9, 10 and describe the comparison with these references. The articles need more comparison with literature. This work is only a presentation of results on a research without comparison with literature. As it is structured now it is not to be considered publishable, unless a whole chapter on discussions is added.

Response

Thank you for the comment. All the figures have been further discussed and analysed. Moreover, additional references have been used and correlated with the current study; while all the chromatograms have been replaced with new ones, that fully reveal axes, and major peaks have been marked.

Reviewer 2 Report

This manuscript focuses on the petroleum hydrocarbon fingerprint investigation of water and sediment samples in the Nestos River Springs in Bulgaria. The authors analyzed water and sediment samples from different sites of the region and analyzed the results through GCMS. The work is clearly presented, but the work would be more convincing if more supporting data are provided. Therefore, the manuscript should be revised before publication.

• The introduction of the manuscript should be improved. It might be better if the author elaborates a little bit more on the advantages of the GCMS method towards other methods. In addition, the authors may want to add the broader impact of the method to increase the integrity of this work.
• The content of the work is somewhat unbalanced. With the title of this work aiming at the investigation of the petroleum hydrocarbon fingerprints, 90% of the work is on quantifying the differences in crude oil, heating oil, bunker oil, and diesel oil. The final analysis of sediment and water samples is only presented in a single figure. The authors need to improve this.
• The quality of the figures should be improved. While some of the figures are without a proper Y-axis, some other figures are without a proper X-axis and title. Other major peaks in the spectrum should also be analyzed and marked. The improvement should be supplemented before consideration for publication.

Author Response

Dear Esteemed Editors and Reviewers,

Thank you for your response to our research. We really appreciate your precious time to study the manuscript and comment on it. We seriously took into consideration every issue raised from your comments and we answered them below, point by point.

 

Sincerely,

The authors

RESPONSE TO REVIEWER 2

Issue 1:

The introduction of the manuscript should be improved. It might be better if the author elaborates a little bit more on the advantages of the GCMS method towards other methods. In addition, the authors may want to add the broader impact of the method to increase the integrity of this work.

Response

Thank you for the comment. More references have been used regarding the dominance of GC-MS method and its main advantages have been added (l.59-63).

 

Issue 2:

The content of the work is somewhat unbalanced. With the title of this work aiming at the investigation of the petroleum hydrocarbon fingerprints, 90% of the work is on quantifying the differences in crude oil, heating oil, bunker oil, and diesel oil. The final analysis of sediment and water samples is only presented in a single figure. The authors need to improve this.

Response

Thank you for the comment. The discussion of the results has been enhanced in the results and discussion section. Moreover, an additional paragraph has been written in order to correlate the final finding with the existing literature.

 

Issue 3:

The quality of the figures should be improved. While some of the figures are without a proper Y-axis, some other figures are without a proper X-axis and title. Other major peaks in the spectrum should also be analyzed and marked. The improvement should be supplemented before consideration for publication.

Response

Thank you for the comment. All the chromatograms have been replaced with new ones that fully reveal axes. Moreover, major peaks have been marked according to the reviewer’s suggestion.

Author Response File: Author Response.pdf

Reviewer 3 Report

The aim of this work was to assess the environmental pollution by oil in the estuary of the Nestos River in northern Greece. Water and sediment samples were collected from 3 different river sites and 6 delta sites to investigate the possible impact of the adjacent oil and gas industry in the Prinos-Kavala basin. Fingerprinting techniques using gas chromatography-mass spectrometry were employed, while crude oil samples and various petroleum products were analyzed to identify biomarkers that characterize the various sources of oil spills. No petroleum hydrocarbons were detected in sediment and water samples collected from the study area.

General comments:

The article describes an important problem of environmental pollution by oil, methods of detection and quantification of individual components, and evaluation of pollution sources.

In the "Introduction" section, it would be interesting to list the health effects of crude oil and petroleum products.

In the "Conclusions" section, authors need to indicate only the conclusions drawn from the research.

The article is clearly and professionally written.

I have only a few technical details.

 

Specific comments:

Line 100         Please, insert a space ”1μL”

Line 144         Please, insert a space and use the capital letter L”10ml”

Author Response

Dear Esteemed Editors and Reviewers,

Thank you for your response to our research. We really appreciate your precious time to study the manuscript and comment on it. We seriously took into consideration every issue raised from your comments and we answered them below, point by point.

 

Sincerely,

The authors

 

RESPONSE TO REVIEWER 3

General Issues

The article describes an important problem of environmental pollution by oil, methods of detection and quantification of individual components, and evaluation of pollution sources.

In the "Introduction" section, it would be interesting to list the health effects of crude oil and petroleum products.

In the "Conclusions" section, authors need to indicate only the conclusions drawn from the research.

The article is clearly and professionally written.

I have only a few technical details.

Response

Thank you for your valuable comments and suggestions.

In the “Introduction” section, the required health effects have been added (l. 43-47) along with 4 more references [5-8].

The “Conclusions” section has been amended and restricted only into the conclusions drawn from the research.

 

Specific comments:

Issue 1:

Line 100         Please, insert a space ”1μL”

Response

Thank you for noticing that. It has been inserted.

 

Issue 2:

Line 144         Please, insert a space and use the capital letter L”10ml”

Response

Thank you for noticing that. It has been amended according to the reviewer’s suggestion.

Round 2

Reviewer 1 Report

The authors modified the paper not always following the requests. I think the work can be interesting but very simple, perhaps too much. I accept the work, even if the paper is only a presentation of the results of a work, it looks like a thesis more than a scientific work.