Environmental Assessment of Wastewater Treatment and Reuse for Irrigation: A Mini-Review of LCA Studies
Round 1
Reviewer 1 Report
This is an interesting review. However, the following issues need clarification:
1. Page 1, lines 17 to 20, “About half of the studies focused on a limited number of life cycle impact category indica-17 tors, despite some of them employing multi-indicator assessment methods.” and “Nearly half of the studies focused on a small number of life cycle impact category indicators, despite some of them employing multi-indicator assessment methods” are repeated.
2. Page 2, line 47, this manuscript stated that “15 million m3/day of untreated wastewater is used globally for crop irrigation in China, Pakistan, Colombia, Chile, Syria, South Africa, Morocco, and Peru.” How did the data of “15 million m3/day” calculate? Would this value be different in summer and winter?
3. Page 9, lines 110 to 111, “An increasing number of publications is observed after 2015.” Based on the trend shown in Figure 1b, it should be “2017” rather than “2015”.
4. Abbreviations should be defined the first time they are used, BOTH in the abstract and in the main text. Then the abbreviation is used instead of the full name. Please define “WWTP” on Page 9, line 128, since it is mentioned the first time here. Please use the abbreviation “LCIA” for “Life cycle impact assessment” on Page 11, line 186, since it is already mentioned previously.
5. Page 13, line 237, the manuscript stated that “This sensitivity analysis which is applied in 14 studies [7,12,63,13,15,19,20,26,27,39,55]”. However, there are only 11 papers/studies mentioned here. Please double check it.
6. Page 9, lines 104 to 106, “The European-LCA 104 analysis is mainly applied in water-stressed regions of Italy [12,22,31,42,52,54,62] and 105 Spain [14,21,23,28,46,55,60] with 8 studies, respectively.” However, the value for studies is 7 not 8.
7. Page 10, please keep the names of LCIA methods in the main text consistent with those in Figure 2.
8. Page 13, it should be “LCA Software” rather than “LCIA software” in Figure 5.
Author Response
Dear Reviewer,
We appreciate your precious time in reviewing our paper and providing valuable comments. We have carefully considered the comments and tried our best to address every one of them. We update the literature and now instead of 47 papers we include 59 papers. This was thanks also to gray literature. We argue that section main findigs/highlights does not make sense and this section we merged into a new section named discussion and concluding remarks. The manuscript was edited for proper English language, grammar, punctuation, spelling, and overall style by highly qualified native and professional software.
Below we provide the point-by-point responses.
Page 1, lines 17 to 20, “About half of the studies focused on a limited number of life cycle impact category indica-17 tors, despite some of them employing multi-indicator assessment methods.” and “Nearly half of the studies focused on a small number of life cycle impact category indicators, despite some of them employing multi-indicator assessment methods” are repeated.
Reply: Thank you for your observation. It was a mistake. We deleted the wrong sentence and left the correct one.
Page 2, line 47, this manuscript stated that “15 million m3/day of untreated wastewater is used globally for crop irrigation in China, Pakistan, Colombia, Chile, Syria, South Africa, Morocco, and Peru.” How did the data of “15 million m3/day” calculate? Would this value be different in summer and winter?
Reply: Thank you for your comment. The volume of water present is not calculated by us but just is taken as a reference. We check the reference and no explanations are given on how this number is calculated. We believe that this value represents the average as it represents the global value. And, yes, the value could change in winter and summer according to the water flows from urban wastewater treatment plants.
Page 9, lines 110 to 111, “An increasing number of publications is observed after 2015.” Based on the trend shown in Figure 1b, it should be “2017” rather than “2015”.
Reply: Thank you for your observation. We revised it and believe that the correct value is 2016.
Page 13, line 237, the manuscript stated that “This sensitivity analysis which is applied in 14 studies [7,12,63,13,15,19,20,26,27,39,55]”. However, there are only 11 papers/studies mentioned here. Please double-check it.
Reply: Thank you for your observation. We revised it and now all 15 references are correctly cited. If the paper will be accepted, We would carefully revise the proper citation during proof stage.
Page 9, lines 104 to 106, “The European-LCA 104 analysis is mainly applied in water-stressed regions of Italy [12,22,31,42,52,54,62] and 105 Spain [14,21,23,28,46,55,60] with 8 studies, respectively.” However, the value for studies is 7 not 8.
Reply: Thank you for your observation. We revised it and now all references are correctly cited. We apologize for the eventual mistakes as this is due to the software we used for placing the references.
Page 10, please keep the names of LCIA methods in the main text consistent with those in Figure 2.
Reply: Thank you for your observation. We revised it and now all methods are correctly cited among figures and text.
Page 13, it should be “LCA Software” rather than “LCIA software” in Figure 5.
Reply: Thank you for your observation. We revised it. LCA software is a more correct, life cycle impact assessment (LCIA) software tool also make sense.
Reviewer 2 Report
Dear authors,
thanks for giving me the opportunity to read your interesting paper.
In my opinion it provides a sound contribution to science.
However, the contribution could/should be enhanced by
- improving the structure: mistake by too much content between 2 and 2.1; dominance of 2 --> should be divided
- better describing the procedure of identifying relevant literature
- explaining how and why you selected the criteria for your analysis
- improving the alignment the order and content of table 1 and the text
- improving the format of the figures
- better structuring the findings presented in chapter 2.5
- better aligning the conclusions to the content of chapter 2
- conducting a careful proofreading (there is a moderate number of mistakes)
Best regards
Author Response
Dear Reviewer,
We appreciate your precious time in reviewing our paper and providing valuable comments. We have carefully considered the comments and tried our best to address every one of them. Please note as follows:
1 ) We conducted a careful proofreading to eleminate eventual mistakes. The manuscript was edited for proper English language, grammar, punctuation, spelling, and overall style by highly qualified native and professional software.
2) We update the literature and now instead of 47 papers we include 59 papers. This was thanks also to gray literature idenfitied through Google scholar. As explained publications were identified using Web of Science and Google Scholar and the keywords “wastewater”, “irrigation”, “agricultural reuse”, “LCA”, “life cycle assessment” and “environmental impact”.
3) We improved the structure by dividing section 2 into more sections.
4) We argue that section main findigs/highlights does not make sense and this section we merged into a new section named discussion and concluding remarks. We believe that now conclusions are better aligned with the content of paper.
5) We improved the format of the figures and correct for any eventual errors.
Reviewer 3 Report
Dear Authors,
the paper aim is very interesting and it is a very current topic, environmental impact and water scarcity is a very interesting topic.
A review of the scientific literature on environmental assessment in the irrigation sector was presented. In general, the article is well structured, but some changes are needed to be published.
- In review articles it is necessary to motivate the different choices made. Why were only 47 of the total 61 papers considered?
- Did you search for the articles by single keyword or by using the and, or functions?
- Interpretation of the results is not sufficient. Further investigation is needed
Author Response
Dear reviewer,
We appreciate your precious time in reviewing our paper and providing valuable comments. We have carefully considered the comments and tried our best to address every one of them. Please note as follows:
A review of the scientific literature on environmental assessment in the irrigation sector was presented. In general, the article is well structured, but some changes are needed to be published.
- In review articles it is necessary to motivate the different choices made. Why were only 47 of the total 61 papers considered?
Reply: We update the literature and now instead of 47 papers we include 59 papers. This was thanks also to gray literature idenfitied through Google scholar. As explained publications were identified using Web of Science and Google Scholar and the keywords “wastewater”, “irrigation”, “agricultural reuse”, “LCA”, “life cycle assessment” and “environmental impact”.
The studies Only studies including an impact assessment phase were selected.
- Did you search for the articles by single keyword or by using the and, or functions?
Reply: In WOS We perform search using and/or function. Some of examples strings are listed below:
- https://www.webofscience.com/wos/woscc/summary/998c6f49-7ccb-44dc-868c-eaf0dcd17c89-52010c60/relevance/1
- https://www.webofscience.com/wos/woscc/summary/998c6f49-7ccb-44dc-868c-eaf0dcd17c89-52010c60/relevance/1
In Sciencedirect and Google scholar we perform search using a combination of keywords presented above.
- Interpretation of the results is not sufficient. Further investigation is needed
Reply: We argue that section main findigs/highlights does not make sense and this section we merged into a new section named discussion and concluding remarks. We believe that now conclusions are better aligned with the content of paper and fit with the objective which is to present a mini review instead of a full review.
Round 2
Reviewer 3 Report
Dear Authors,
it has been improved in accordance with the recommendations of the reviewers. The article is now well written and well structured with evident innovation proposed.
The method, the approach and the results obtained can be used to increase the sustainability of the sector in question.
I propose to the authors to continue their research in this area
