Development of a Model for the Implementation of the Circular Economy in Desert Coastal Regions

Round 1

Reviewer 1 Report

I enjoyed reading this article and topic of this work is very relevant in todays changing world. Still, I believe there are a few places that would need additional attention of the author(s).

First, in the Conclusion section, there is this part “….biochemical and biofuels. The crop and algae residues are processed through anaerobic digestion to obtain biogas and digestate. The biogas is upgraded, and the carbon dioxide stream is fed to the microalgae. Nutrients are recovered from the digestate and used for food production. Alternatively, the biogas can be burnt in a combined heat and power unit to produce electrical and thermal energy, from which the resultant CO2 is fed to the microalgae.” that appears in this detail and form first time in the article. I think all these details should be placed somewhere earlier in the manuscript. There is no mention of biofuels production anywhere in the manuscript before this (except in the Figure 1), and I think this might be an important component in some parts of the world. I would like to see more on this earlier in the manuscript, as well as more discussion on this part of the system. Also, “biogas” part of the system is not discussed or explained before in the manuscript and it should be done. Do example systems (locations) have any practices they implemented to address biogas portion of the system? How about biofuels? What do they do with the side products (brine) and how do they address possible environmental issues? I would like to see more discussion how to tackle possible downsides of this proposed model. Is there any work done on this issue? In my opinion, Conclusion section should be a place to summarize all presented concepts, not to mention/introduce a new one. That should be done in some earlier part of the manuscript.

Second, I would like to see more discussion on how to tackle possible downsides of this proposed model. Is there any work done on this issue? How to address issue of side products and how to protect (not to degrade) environment in these sensitive systems anymore. This is very important issue and part of any system (not just costal systems). Authors should address this in their work.

I agree that more research is needed (like this: “Studies are needed to ensure environmental, social, and economic sustainability before deploying pilot testing. Within these studies, life cycle assessment, techno-economic analysis, and a biodiversity study are recommended to ensure the deployment of this model without harming the environment or protected species.”), but it would be useful for a reader to see if any work has been done so far on this topic in any similar system that authors think can be replicated/used.

Author Response

Dear Reviewer, 

Please see the attachment.

Kind regards, 

Author Response File: Author Response.docx

Reviewer 2 Report

Manuscript entitled “Development of a Model for the Implementation of the Circular Economy in Desert Coastal Regions” Cabrera-González and othes

Abstract – heading missing

Authors highlighted the challenges of food production in arid regions due to water. The study covered two coastal desert regions on the American continent with similar geographical characteristics.

They also highlighted that growth of both deserts as cities ranging from 400,000 to 900,000 inhabitants.

Abstract: Need to add more data, overall ok

Keywords: Ok

Introduction: written well,

Environmental characteristics of the Atacama & Sonoran- add more details and add it in graphical or tabular form, also add some high-resolution photographs of different intervals.

Circular economy mode; very informative, add latest relevant studies

Figure – 1 : Need to improve resolution

Water desalination – add flow diagram of full concept

Solar Energy – add quantify data and photographs or flow diagram of solar energy utilization or production  

Hydroponic systems for food production – concept is well define, need to add photographs and importance of hydroponics system

Water dosing with hydrogels for agriculture – add quantify data and importance and utility in tabular form for more clarification,

Microalgae culture as a biomass and Seaweed farming and processing for food supply and biochemicals – not clear pl rewritten whole paragraphs (L205-220).

. Recovery of nutrients from wastewater treatment streams and anaerobic digestion – add methodology (flow diagram, photographs, recovery % in tabular form.

Figure 2 : GOOD

. Conclusions – the whole conclusion is combination of very generalize statement, pl add some relevant or study data in relation to production, development and future importance.

 Overall MS in informative, lack of presentation, incomplete and generalize sentences, need major modification.

Author Response

Dear Reviewer 2,

Please see the attachment.

Kind regards. 

Author Response File: Author Response.docx

Reviewer 3 Report

This is a very 'thin' paper. There needs to be a critique of the circular economy principle. What about the governance and financial sustainability of the propsed model? A fundamental element of CE is cooperation. One of the most critial challenges is the paradigm shift that would be needed to shake off the idea of infinite economic growth. In addition there are some errors which need to be addressed: 

Peace 7 Turner is missing from the references

reference 30 - the first author should be Martinez-Cordova, L.R. There are two authors missing from the reference. The name of the journal is incomplete

Author Response

Dear Reviewer 3,

Please see the attachment.

Kind regards,

P

Author Response File: Author Response.docx

Round 2

Reviewer 1 Report

I find topic of this work relevant and important, especially in the light of climate change and possibility of more regions needing implementation of similar systems.

I see improvements from the first version but would suggest a few additional steps to improve paper quality:

Lines 100-1006 have a repeated sentence(s). In addition to this, a lot of parts in the manuscript sound repetitive, so overall it would need reorganization.

New sections (such as one on biofuel production) sound disorganized and need better framing/organization. There is a lot on new information (compared to previous version of the manuscript), but still, things look just piled on top of each other. It is very hard to follow the author’s message in those new parts of the paper. Also, there is a few typos and I believe those new section would benefit of a few rounds of additional reading and rewriting. To clearly communicate the message with a reader, this manuscript needs a bit more work on organization and writing/communication.

Author Response

Dear Reviewer, 

Please see the attachment. 

Author Response File: Author Response.docx

Reviewer 2 Report

Authors incorporated all suggestion, now it may be accepted

Author Response

Dear Reviewer, 

Thank you very much for your positive comment. 

Kind regards, 

Reviewer 3 Report

The authors have addressed my comments, but not necessarily in a satisfactory way. For example, on page 2, Neves and Marques (2022) studied the drivers and barriers to transition from a linear to a circular economy, evaluating the role of social, environmental, and economic factors. What were the conclusions and recommendations of this paper? The authors' proposal for a circular economy model needs to be framed within the context of precedent studies, such as Neves and Marques, so more detail needs to be given about these precedent studies - how have they informed the model? One sentence is not sufficient. The same comment applies to these two sentences: Smol, Adam, and Preisner (2020) proposed a circular economy model for the water and wastewater sector focusing on the circular economy principles of reduction, reclamation, reuse, recycling, recovery and rethink. According to Ferronato et al. (2019), circular economy models vary in every context due to social, environmental, financial, and political differences. For this reason, this study focuses on a macroscale model for DCRs. Please elaborate on the findings of these papers and how they informed your model. There is a vast literature on the circular economy - the three papers cited simply scratch the surface, so I would like to see more evidence of background reading which would then provide a more solid foundation for the model. In its current form the research conducted seems very lazy.

There are some sloppy errors too. For example, on page 3 - However, the new Chilean constitution proposal mentioned that the state would promote a circular economy but did not explain how (Propuesta Constitución política de la república de Chile 2022). This is a repeat of a sentence four lines previously.

The English language needs to be revised by a native English speaker, as there are numerous gramatical errors (e.g. incorrect use of the definite article) and various sentences that do not make sense. For example, on page 3 - to recover affected sites by illegal disposal. What does that mean? If I, as a native English speaker, do not understand (though I can guess what you are trying to say) then an international audience will also not understand.

Reference 27 - this is a book, so why do you write American Journal of Agricultural Economics?

Author Response

Dear Reviewer, 

Please see the attachment. 

Kind regards, 

Author Response File: Author Response.docx

Round 3

Reviewer 3 Report

I have done my best to improve the quality of the manuscript