Open and Closed Black Soldier Fly Systems Tradeoff Analysis

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

The paper is well updated, including addressing current concerns, such as: climate change, increased demand for food, environmental deterioration and One Health (the term “One Health” could be included). These concerns, which previously, with the intention of preserving for future generations, became urgent in preservation for this generation, and cannot be postponed.

According to some authors, more than 30 million dry tons of biosolids are produced annually around the world, most of which are deposited in landfills or thrown into bodies of water, worsening eutrophication and water-borne diseases. Studies like this, using waste treatment alternatives such as the Black Soldier Fly system, could greatly reduce landfilling costs as well as greenhouse gas emissions.

The study met its objectives by comparing greenhouse gas emissions and the use of land, energy and water from both systems. Increasing understanding of what the environmental trade-offs are when choosing between these two systems: open or closed, depending on the local context, as well as the environmental and social impacts of the Black Soldier Fly system's open waste treatment systems.

Even though more research is needed to draw a broader conclusion between the two systems OS and CS, this study showed that the OS is a viable alternative to a CS, as it has a lower environmental impact.

With this, the study will be able to contribute information to decision makers and policies to guarantee a sustainable future. BSF-based bioconversion could be a promising solution.

As for the conclusion of the work, I believe it is better directed to the authors' conclusion, avoiding citations.

Small suggestions indicated in the text.

 

Comments for author File: Comments.pdf

Author Response

Thank you for the positive feedback. 

1. Thank you for the feedback. 

2. This was our intention, and we are appreciative that you agree with our assessment.

3. Thank you. We agree with your assessment.

4. You are right about this, and the citation has been removed. Thank you for your feedback. 
5. Your corrections have been included in the manuscript. Thank you once again. 

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

Overall this paper introduces the reader to a way to compare an open and closed system for BSFL rearing/ wast reduction.

The introduction is detailed, clear and easy to follow.

Methods
Lines 196-197 It states: “The drying unit consists of two mesh wire racks with wooden drawers under each drawer.” Should the second ‘drawer’ be ‘rack’?

Results

Figures 6 & 7 repeat all the information from Table 6. I am not sure if figures 6 & 7 add much to the results that the table doesn’t already. In Figure 6 the percentages start at 75% where figure 7 it starts at 0. Having these both be the same would allow for comparison between the two systems. If you keep Figure 6&7 I would remove Table 6 as it is the same information.

 
I’m not sure the journals figure formatting, but for figure 9, 10 & 11 I would remove the horizontal gridlines, and put the font and lines in black.

 

For the conclusion I would like to see summary information on what conclusions the authors have reached based on their current analyses. This is touched on a little bit int he last paragraph before the conclusions section.

The paper states the future work that should be conducted to further the work presented here. All in all, a great start/introduction to this type of comparison.

Author Response

Thank you for the positive feedback. 

1. That is correct. It should be “rack”. We appreciate your help in catching that mistake.
2. Figures 6 and 7 have been removed as they were added for visual purposes and do repeat the information in Table 6 as you noted. 
3. Figures 9, 10, and 11 have been modified according to your recommendation. 
4. Thank you for noting this. The following text has been added to incorporate your suggestion, “Increased environmental impacts from large-scale CS can be reduced by switching to OS or running a combination of both systems where possible. Although OS has minimal environmental impact, it is often overlooked due to scaling challenges. However, to achieve sustainable development and promote beneficial interactions between humans, animals, and the environment (One Health), OS should be explored as a viable and scalable biowaste solution. This study aims to pave the way for research in this area.”
5. Thank you for your analysis and feedback, which have been helpful in improving the work.

Author Response File: Author Response.pdf