Composting Strategy Instead of Waste-to-Energy in the Urban Context—A Case Study from Ho Chi Minh City, Vietnam

Round 1

Reviewer 1 Report

Dear Researchers,

Please find my review notes below:

1. I suggest dividing the introduction into two or three paragraphs. It’s a long and monotonous paragraph. Hard to keep the attention of the audience.
2. Please clearly explain the purpose of the study in addition to the research question.
3. Please divide section 2.1 into paragraphs (maybe for each study or country that you present). It is hard to read it and there is a lack of flow.
4. In the literature review please clearly identify the gap and need of your study. There are several studies for different countries with AHP, aren’t there any other techniques? Why the focus of your study is AHP?
5. Section 2.2 is not a part of the literature review. It might be in the methodology presenting the details about the location or another section before the methodology.
6. AHP is a tool and you use a quantitative methodology within a case study. Instead of how you used the AHP, you only explained how AHP works in general. For example: please explain how you identified the criteria? How do you validate these criteria? Why these experts? 
7. Line 255-256: Is this sentence complete or does it follow the bullet points below? Not clear.
8. Starting Line 261 the spacing changes in the paper. Please double-check the formatting.
9. Line 310: How many specialists? Or are they the experts referred to previously?
10. You need to explain how and why did you include these six experts in your study. The information you have provided is not enough.
11. Overall, the methodology section needs more details and explanations and requires major improvement.
12. There should be an additional detailed section about discussions. Section 4 only reflects the results.
13. How can the results of this study lead to future studies? What is the main contribution?

Overall, this paper needs major improvements in identifying the gap in the literature, the need for study, explaining the methodology, and discussions & conclusions with the future research and contribution in the overall literature.

Thank you.

Author Response

Dear Reviewer,
Thank you for your helpful comments. We corrected the paper according to your comments!
Sincerely, the authors!

Author Response File: Author Response.pdf

Reviewer 2 Report

The purpose of the presented study is promising, but in my opinion, only partially fulfilled. The authors explored various waste management alternatives using the AHP methodology. However, the results and conclusions are very difficult to verify. From the reader's point of view, a high dose of trust is needed for these results. The results and conclusions are austere and more or less only consider which of the alternatives would be suitable for Ho Chi Minh City, provided that certain requirements are met. The survey only reveals general views and results, which are known even without this initiative. This means that it is known at the outset which alternative is suitable for the environment as well as from an economic point of view.

The most serious shortcomings:
1. In particular, there is a lack of data that would at least partially demonstrate the suitability of the alternative that was most appropriate. It is also appropriate to support claims about the appropriateness of the alternative by economic recalculation and some relevant environmental burden reduction data.
In addition, some comparison of the costs of the waste pre-treatment and disposal process in the case of composting and energy recovery or landfilling.

2. The assessment has been carried out according to 6 researchers, whose identities could not be verified. Who specifically filled in the data in Super Decision Software? The sample of 6 people is woefully few. 
Is that so? If not, it is necessary to supplement and bring it to the right measure. 

3. It is obvious that there are many cases in different states and localities where suitable alternatives e.g. composting already work and at the same time that choosing a suitable alternative saves costs and the environment. Of course, it would help Ho Chi Minh City or Vietnam. Specifically, however, can variants be applied where the amount of money saved and the reduction of the environmental burden would be predicted if, for example, the level of separation of the population was 20, 40, 60, 80 percent? Where appropriate, comparison based on waste pre-treatment efficiency. 

Author Response

Dear Reviewer,
Thank you for your helpful comments. We corrected the paper according to your comments!
Sincerely, the Authors!

Author Response File: Author Response.pdf

Reviewer 3 Report

Dear editors, 

The submitted paper is good written, with plenty of references and exact presentation of the working technique.

So I believe that it can be accepted in the present form.

Reviewer 4 Report

• The current massive energy recovery of waste represents a problem in relation to the circular economy.
• Intensification of urban composting processes and systems can be a contribution to the issues of circular economy and raw material sustainability.
• The authors explored in the paper, whether urban composting programs can play a key role in rapidly evolving urban ecosystems in relation to material sustainability, energy recovery of waste and waste landfill minimization.
• The research uses the AHP method to analyze and hierarchize waste mixing processes before their processing, processes for the separation of organic and non-organic waste at the composting source, as well as complete sorting of waste at the source before its further processing.
• The case study confirmed that central urban composting, with the separation of organic and non-organic waste at source, is an innovative and so far the most efficient way of waste recovery. Everything is in connection with the strategy of circular material management.
• The results of the case study can be widely used, verified, and possibly modified for other cities, respectively other environmental awareness and technical equipment of waste producers.
• The paper fits into the framework of the section “Environmental Sciences - Sustainable Urban Facilities” and I recommend it for the publication in the present form.

Round 2

Reviewer 1 Report

My only recommendation is the final proofread and grammar check. Other than that, the paper addresses most of my comments with the author's comprehensive efforts.

Reviewer 2 Report

I am sorry, but even with some additions, there is still poor scientific loundness and provability for publication in a scientific journal. Curt conclusions or only certain recommendations are insufficient and not for a scientific journal. Rather, it is suitable as an opinion option for explaining the suitability of the chosen solution to officials and the general public in a popularization magazine.