Economic Evaluation of Bioremediation of Hydrocarbon-Contaminated Urban Soils in Chile
, Andrés Cumsille 1,†, Paula Piña-Gangas 4, Claudia Rojas 1, Alejandra Arancibia 2, Salvador Donghi 5,6, Cristian Stuardo 1, Patricio Cabrera 1, Gabriela Arancibia 1, Franco Cárdenas 1, Felipe Salazar 1, Myriam González 1, Patricio Santis 1, Josefina Abarca-Hurtado 2, María Mejías 2 and Michael Seeger 1,*
Round 1
Reviewer 1 Report
The manuscript entitled “Economic Evaluation of Bioremediation of Hydrocarbon-contaminated Urban Soils in Chile”, submitted by Orellana et al. reports a study analyzing the cost of various bioremediation strategies to remove hydrocarbon or heavy metal pollution in the chronically hydrocarbon-polluted urban soils of Chile so as to facilitate decision making of entrepreneurs, consultants, researchers and governmental authorities to launch initiatives to develop a local bioremediation industry capable to clean-up a high number of polluted sites in Chile.
Although the growth of the global bioremediation market has accelerated in last few years, but despite being known as one of the most efficient methods of getting rid of environmental pollutants, bioremediation has not yet been into proper application in most countries. Implementation cost has been attributed as one of the main reasons behind this. In that aspect, the current work gives a new insight into various remediation strategies and their cost. As per the comparative study, biostimulation with 10% compost (strategy BE1) showed the lowest cost treatment strategy while combination of bioaugmentation and biostimulation (strategy BAE) proved to be the most expensive technology.
As a whole, the study is good. Cost analysis of 130 different bioremediation projects is quite extensive and further strengthens the study. However, the current version of the manuscript lacks in several aspects, enlisted below as major and minor comments.
Major comments
1. The study has completely focused on cost comparison of the 5 different remediation strategies and finally concluded the most expensive and cheapest strategy. But efficacy of the methods also depends on the extent of remediation that has happened. Although as per Table S3, remediation has been found to be around 50% of initial in some cases, but the data is not exhaustive and comprises only a subset.
Hence, it would have been easier to interpret the results if the cost comparisons were drawn vis-à-vis comparison of the efficacy of each method.
2. The entire manuscript has several mistakes regarding citation of tables and figures.
E.g., Page 6, 1st paragraph: Both Figure 1, Figure 3 & Table 1 are missing from the manuscript. Also, there is no Table 2, although cited in the main text.
3. Fig S1 is very important for understanding of the setup and thus, should be included in the main text, and not as a supplementary material.
4. The current study is in line with a previous report by the same team (details given below). The previous publication should have been cited, describing how the current work is different from (or in continuation with) the previous work.
Orellana R, Cumsille A, Rojas C, Cabrera P, Seeger M, et al. (2017) Assessing Technical and Economic Feasibility of Complete Bioremediation for Soils Chronically Polluted with Petroleum Hydrocarbons. J Bioremediat Biodegrad 8:396. doi: 10.4172/2155-6199.1000396
Minor comments
1. Line numbers are missing from the whole manuscript, which makes referring to a particular sentence difficult.
2. Page 3, line 4: Although well known, but it is recommended that the authors mention the acronym of OECD where it appears.
3. Page 3, materials and Methods: "During this long period, the contamination pressure... its natural resilience"
Please cite a suitable reference, if available.
4. Page 3, last line: "The first two approaches... (named as BA)"
Rephrase the sentence as "The first two approaches were based on bioaugmentation (named as BA), with the addition of five hydrocarbonoclastic strains"
5. Page 4, line 15: "Each biopile has a total volume of 750 m3 of material and we assumed they were covered with a HDPE membrane...."
Why assumed?
Also, please define the acronym as "...high density polyethylene (HDPE) membrane..."
6. Page 4, 3rd paragraph: "On the other hand, biostimulation-based approaches did not require neither biomass reactors nor blowers"
Please rephrase as "On the other hand, biostimulation-based approaches required neither biomass reactors nor blowers"
or
"On the other hand, biostimulation-based approaches did not require either biomass reactors or blowers"
7. Page 4, end of 3rd paragraph: "The cost of installation services... were calculated according to suggested values of Peters, Timmerhaus et al. (Peters, Timmerhaus et al. 1991)"
Rephrase the sentence to make it understandable. Also, the reference should be correctly cited as "...suggested values by Peters et al. (1991)"
8. Page 5, paragraph 3: "The analysis included bioremediation with either hydrocarbons or a mixture of hydrocarbons and other contaminants, such as organic solvents, halogenated organic compounds, and heavy metals"
A list of compounds (not only classification) used in this study was expected, at least as s supplementary data.
Author Response
Please see the attachment
Author Response File: 
Author Response.docx
Reviewer 2 Report
In my opinion, this paper may be interesting for reader of Sustainability Journal. Nevertheless, there are some items that should be addressed before acceptance:
However, the manuscript is carelessly framed and contains many misprints.
No details available in Manuscript: Funding; Institutional Review Board Statement ; Consent Statement; Data Availability Statement; Conflicts of Interest
Renumber sections and subsections
The writing could be improved by strengthening the connectivity between paragraphs. There are several places where new topics are introduced and connections to the previous subject are not clear. Read whole manuscript and correct wherever required.
Consequently, the title is misleading. I suggest that the authors shorten the manuscript, the material and method is not fully explained.
Line no. is missing
PO4 is written twice in the MS but not correctly written. Correct it as PO4
The statistical analysis is not detailed. Therefore, the reference should be provided.
It is recommended to revise the letters in all the figures, Revise figure 5 for better visualization
Figure 1 should be improved.
All over the manuscript many different concepts are presented but not well linked each other. Many times, result difficult to understand the purpose of a sentence in the context of the paragraph.
The Discussion should be improved. Present the context of the study at the beginning and towards the end show in perspective the possibilities to valorize the results you have reached.
The first paragraph of the discussion looks like an introduction, which is bad. The discussion is poor, could be improved.
Update the references in the discussion. Most of your references are very old
The references are not organized in terms of Sustainability Journal format. The MDPI journal citation style is numerical in the manuscript. Many journal names are written as lowercase letters. Bibliographic data are missing in many.
Referencing need to very serious revision
Carefully read whole manuscript line by line and improve the sentence formation
Author Response
Please see the attachment
Author Response File: Author Response.docx
Reviewer 3 Report
|
1. |
Introduction page 3, 2nd line from the top |
What are the main sources of soil contamination in Chile? Are they rather spot or widespread contamination? |
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2. |
Are there any estimates of the area of hydrocarbon contaminated soil in Chile? On what basis is a soil in Chile classified as contaminated, if there are no legal regulations governing this issue? Are there any official statistics? |
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3. |
Introduction page 3, 2nd line from the top |
I suggest explaining the differences between biostimulation and bioaugmetation in 1-2 sentences. Please consider to move “In general, three main approaches have been widely used for restoring hydrocarbon-contaminated soils (Fuentes, Méndez et al. 2014; Dias, Ruberto et al. 2015). The first technology, called biostimulation, includes the enhancement of the metabolic activity of native microbial communities by providing limiting nutrients, such as phosphorous, nitrogen or oxygen, and further modification of environmental factors (Fuentes, Méndez et al. 2014). The second approach is based on the addition of hydrocarbon-degrading microorganisms, frequently applied when native microbial communities lack the metabolic capabilities or when their activity is unable to trigger significant biodegradation rates (Gentry, Rensing et al. 2004). A third approach is based on the addition of stable organic amendments, such as compost, which has been applied with success across pilot- and full-scale applications (Antizar-Ladislao, Lopez-Real et al. 2004, Kästner and Miltner 2016, Brown, Okoro et al. 2017).” from materials and method section to the Introduction section |
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4. |
Introduction page 3, 8th line from the top |
What types of soil are predominant in Chile? |
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5. |
Materials and methods, 1st paragraph of the section (page 3) |
Is this area still used for industrial purposes? |
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6. |
Have contaminated soil analyzes been performed? What parameters were tested? What were the results? |
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7. |
Materials and methods page 3, 7th line from the bottom |
One of the approaches is based on the addition of stable organic amendments, such as compost - what kind of compost, how was it prepared? |
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8. |
Materials and methods page 4, 17th line from the top |
Based on what is 20 weeks assumed? |
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9. |
Results |
Please check the font size in the last paragraph of this section |
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10. |
Discussion |
These section is just summarized data of published papers without much integrated and critical analysis. How to achieve bioremediation goals? What are the methods for evaluating the effectiveness and efficiency of bioremediation. Please add more critical discussion on the above points. |
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11. |
Conclusion |
The conclusions are very laconic. I propose to summarize: Which technique do the authors believe would be most effective in terms of costs and potential benefits? What size area can be efficiently cleaned from petroleum products and in what time? From a practical point of view, is bioremediation likely to be used more widely in Chile? |
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12. |
Table 1 |
Table 1 or Table S1 (please check the entire manuscript) |
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13. |
Table S2 |
I suggest adding a legend to the table with the explanation of BE1, BE4 etc. so that you don't have to search in the text |
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14. |
Figure 2 |
Figure 2 is cited in the text (page 7, 5th line from the top) but it is not in the supplementary materials |
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15. |
Reference |
Much of the cited literature is from 10 years ago or more. It would be necessary to update the sources, especially in the Discussion section |
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16. |
Please check the font size in the last paragraph of this section |
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17. |
DOI numbers should be added where possible |
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18. |
For internet sources, the date of access to the page should be provided |
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19. |
Please standardize the units in the manuscript and supplementary materials (e.g. USD, US$, $) |
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Author Response
Please see the attachment
Author Response File: Author Response.docx
Round 2
Reviewer 1 Report
I appreciate the efforts made by the authors to address individual query raised previously and for modifying the manuscript accordingly. However, Fig 1 & Table 1 are still missing in the manuscript (might be a technical issue) and hence, I am unable to conclude my views about the revised submission. Please check if he files were appended correctly while uploading the manuscript file.
Apart from that, I have a minor comment -
Page 5, line 150: Unplublished work need not be enlisted in the reference section. Authors can replace the citation (i.e., "55") as "(unpublished)"
Author Response
Editor-in-Chief
Sustainability Journal
Dear Reviewer,
Enclosed is a revised version of the second round of revision of the Sustainability paper no. sustainability-1845441 entitled “Economic Evaluation of Bioremediation of Hydrocarbon-contaminated Urban Soils in Chile”. We thank the editor and three reviewers’ because their comments and questions have helped to improve the paper quality considerably.
Detailed responses to the reviewers’ comments follow.
- I appreciate the efforts made by the authors to address individual query raised previously and for modifying the manuscript accordingly.
Thanks a lot for your comment. We believe all your remarks enhanced the quality of the manuscript. So, thanks a lot for that.
- However, Fig 1 & Table 1 are still missing in the manuscript (might be a technical issue) and hence, I am unable to conclude my views about the revised submission. Please check if he files were appended correctly while uploading the manuscript file.
We are sorry to read that you could not check the Figure 1 and Table 1. We have uploaded in the way that was indicated in the instructions. However, we have uploaded the same version, as well as both elements have been included in this letter (see below).
Table 1: Estimated costs per m3 of contaminated soil treated by different bioremediation approaches
|
Items |
BE1 |
BE4 |
BAE |
BA |
BAV |
|
|
Products’ costs |
Direct material costs |
US$17,5 |
US$81,9 |
US$174,0 |
US$59,9 |
US$61,4 |
|
Direct labor costs |
US$3,5 |
US$5,3 |
US$6,3 |
US$3,8 |
US$3,8 |
|
|
Manufacturing overhead costs |
US$11,6 |
US$17,4 |
US$29,2 |
US$17,5 |
US$19,0 |
|
|
Period costs |
Administrative expenses |
US$4,5 |
US$6,7 |
US$6,7 |
US$4,0 |
US$4,0 |
|
Marketing and selling expenses |
US$0,2 |
US$0,4 |
US$0,4 |
US$0,2 |
US$0,2 |
|
|
Liabilities and obligations |
Covering assets |
US$3,3 |
US$4,9 |
US$36,0 |
US$21,6 |
US$25,5 |
|
Provision |
US$8,4 |
US$12,6 |
US$39,8 |
US$23,9 |
US$27,2 |
|
|
Renewal machinery |
US$1,6 |
US$2,5 |
US$18,0 |
US$10,8 |
US$12,7 |
|
|
Total |
US$50,7 |
US$131,7 |
US$310,4 |
US$141,8 |
US$153,9 |
|
- Apart from that, I have a minor comment - Page 5, line 150: Unplublished work need not be enlisted in the reference section. Authors can replace the citation (i.e., "55") as "(unpublished)"
We thank the reviewer for the comment. We have replaced the reference for the word "(unpublished)". We made the modification with control track.
Thank you for considering our manuscript for reviewing in Sustainability Journal. We look forward to hearing from you.
Sincerely,
Roberto Orellana, PhD
Associate Professor
Biology Department
Facultad de Ciencias Naturales y Exactas
Universidad de Playa Ancha
Author Response File: 
Author Response.pdf
Reviewer 2 Report
Thanks to the authors for the work done. In this version of the manuscript, the authors took into account the comments and made the necessary changes. With the addition of new data, the article has become more interesting and disclosed, which pleases me.
A check for the English language and typing errors is necessary before publication like in line number 69, 86 words
Author Response
Editor-in-Chief
Sustainability Journal
Dear Reviewer,
Enclosed is a revised version of the second round of revision of the Sustainability paper no. sustainability-1845441 entitled “Economic Evaluation of Bioremediation of Hydrocarbon-contaminated Urban Soils in Chile”. We thank the editor and three reviewers’ because their comments and questions have helped to improve the paper quality considerably.
Detailed responses to the reviewers’ comments follow.
- Thanks to the authors for the work done. In this version of the manuscript, the authors took into account the comments and made the necessary changes. With the addition of new data, the article has become more interesting and disclosed, which pleases me.
Thanks a lot for your comment. We believe all your remarks and questions were addressing weak points of the previous version. All changes enhanced the quality of the manuscript. So, thanks a lot for that.
- A check for the English language and typing errors is necessary before publication like in line number 69, 86 words
We thank the reviewer for the comment. We have corrected the misspelling as well as other small mistakes. All modifications were made with control track.
Thank you for considering our manuscript for reviewing in Sustainability Journal. We look forward to hearing from you.
Author Response File: Author Response.pdf
Reviewer 3 Report
1. Lines 222 and 235 - Table 1 or Table S1?
2. Line 228, 234, 238 - Figure 1 or S1?
3. Lines 274 and 280 - Figure 2 or S2?
4. In the manuscript, Fig. 2 is cited twice (lines 274 and 280), but there is no Fig. 2 in the supplementary materials. Please attach Figure 2/S2.
Author Response
Dear Reviewer,
Enclosed is a revised version of the second round of revision of the Sustainability paper no. sustainability-1845441 entitled “Economic Evaluation of Bioremediation of Hydrocarbon-contaminated Urban Soils in Chile”. We thank the editor and three reviewers’ because their comments and questions have helped to improve the paper quality considerably.
Detailed responses to the reviewers’ comments follow.
- Lines 222 and 235 - Table 1 or Table S1?
We thank the reviewer the comment, however, we are clear that in both lines, 222 and 235, we are referring to Table 1, that shows the cost of bioremediation. Instead, the table S1 refers to the volume of soil treated during each bioremediation cycle
2.Line 228, 234, 238 - Figure 1 or S1?
We thank the reviewer the comment, but as above, we are clear that we are referring to Figure 1, and not Figure S1.
- Lines 274 and 280 - Figure 2 or S2? In the manuscript, Fig. 2 is cited twice (lines 274 and 280), but there is no Fig. 2 in the supplementary materials. Please attach Figure 2/S2.
We sorry we read this. However, this seems to be a problem on how Figure numbers are displaying on the reviewer version. As above, we are referring to Figure 2 in both, lines 274 and 280. Furthermore, we have not included any Figure S2, so we are not able to understand how this can shows up in the reviewer´s version of this manuscript.
We thank all these and the first-round questions, since they helped us to gain good insights to wrap up this story. Thank you for considering our manuscript for reviewing in Sustainability Journal. We look forward to hearing from you.
Author Response File: Author Response.pdf
