Assessment of the Possibility of Implementing a Circular Economy by Environmental Evaluating the Life Cycle of Products Derived from Bulky Municipal Waste

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

Thanks for letting me review this work.

The study highlights the need to improve wood waste recycling to prioritize material recovery and identifies environmental hotspots in the production of secondary wooden blocks, particularly due to high electricity consumption.

The title seems too lengthy, please condense it with its main outcomes.

The keywords seem appropriate.

Abstract. Please add remarks on the methodology employed.

Introduction. This section is well-developed, but please further explain the Circular Economy paradigm for the readership not familiar with it, and add a final paragraph to introduce the following sections.

Materials and methods. A minor typo in line 200 "(". Before starting with section 2.1. right away, please add a brief introduction to explain the methods used.

Results of the life cycle assessment. Please move the research questions in line 221 to the Introduction or Methodology section. 

Results – Life Cycle Impact Assessment (LCIA). This section requires no changes.

Discussion. Please justify with the obtained data how the research questions are addressed.

Conclusions. Please re-design this section without bullet points to keep the academic style. Moreover, please add here the study's limitations and future research.

Best regards

Author Response

Dear Reviewer
Thank you very much for your comments, which have enriched our work. Attached are the responses to your comments.
Authors

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

Dear Authors,

I have reviewed the article and would like to offer the following suggestions to help the authors improve its quality and clarity:
• It would be good to mention what new elements this research brings to the field of life cycle assessment (LCA) applied to bulky waste?
• In the Materials and Methods section, analysis techniques such as Material Flow Analysis (MFA) and Life Cycle Assessment (LCA) are mentioned. However, it is not very clear how they were applied. A more detailed description of the assumptions used in the life cycle analysis and the justification for the choice of certain parameters would be beneficial.
• A discussion of production costs and economic feasibility compared to MDF, HDF and other alternatives would be useful.
• In particular, in Fig. 6, the impact of recycled blocks is lowest only if renewable energy is used – this aspect should be better emphasized in the conclusions.
Best regards

Comments on the Quality of English Language

The English could be improved to more clearly express the research.

Author Response

Dear Reviewer
Thank you very much for your comments, which have enriched our work. Attached are the responses to your comments.
Authors

Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

First, I would like to send my congratulations for this work.

The paper is well written, the text is deep and brings clear information’s about wood recovery, in terms of energy, water, transportation. Not is well clear if the recovery can save money by selling the wood blocks.

The unity Mg means what? (mega grams is metric ton?)

I could not access the www.mdpi.com/xxx/s1, Figure S1: title; Table S1: title; Video S1: title.

I the waste recovery, the greater barrier is the marketplace development.

Can you brings some considerations about this ( market size, behavior of stakeholders, durability of wood recovery,...)

Best Regard.

Author Response

Dear Reviewer
Thank you very much for your comments, which have enriched our work. Attached are the responses to your comments.
Authors

Author Response File: Author Response.pdf

Reviewer 4 Report

Comments and Suggestions for Authors

The reviewed manuscript addresses a highly significant and complex issue related to the reuse of post-consumer wood waste. So far, no technically efficient solutions have been found for wood waste other than solid wood and particleboard, primarily due to the considerable structural variability and chemical complexity of such waste, including adhesives, resins, paints, and biocides.

Although the topic of the manuscript is extremely important, the structure and presentation of its content require substantial improvements. The "Materials and Methods" section currently reads more like an additional introductory section. After significant shortening, it could be effectively incorporated into the "Introduction." Moreover, the section titled "Results of the life cycle assessment" is actually methodological and would be more appropriately placed under a genuine "Materials and Methods" section, whereas the existing Section 4 aligns correctly with what should be "Results." I strongly recommend reorganizing the manuscript according to the standard layout.

Additionally, the authors conducted an LCA assessment for the production of wood blocks using starch and tap water; however, detailed information on this production process is lacking. It is unclear whether the resulting product is fully viable, what specific functional properties it possesses (e.g., mechanical strength or thermal insulation), and whether its applications and lifecycle length could be comparable to conventional wood-based products such as particleboard.

Another critical issue pertains to the scale of the research. The authors' analyses are laboratory-scale, which makes direct comparison of their findings with industrial-scale processes from the ecoinvent database questionable. A more valid approach would involve conducting comparable laboratory-scale research—for instance, producing particleboards from post-consumer wood waste—to facilitate more credible comparisons.

A key technological aspect insufficiently emphasized in the manuscript is the challenge of decontaminating wood waste and effectively separating the lignocellulosic fraction from synthetic substances like adhesives, resins, paints, and biocides. This specific aspect, rather than the bulkiness of waste, poses the most significant technological challenge and should be highlighted more clearly in the manuscript.

The discussion of results needs expansion and supplementation with references to other studies, particularly those analyzing LCAs of various wood waste recycling methods or comparisons between laboratory-scale and industrial-scale findings.

Finally, the authors should complete the missing manuscript sections, including supplementary materials, author contributions, funding, acknowledgments, and conflicts of interest, as applicable to this type of publication.

Author Response

Dear Reviewer
Thank you very much for your comments, which have enriched our work. Attached are the responses to your comments.
Authors

Author Response File: Author Response.pdf

Round 2

Reviewer 4 Report

Comments and Suggestions for Authors

The corrected version of the manuscript can be accepted after minor revision. I only suggest to paraphrase the sentence in Conclusions finishing in line 501, as phrase "technology really environmentally friendly" does not sound scientific. Based on LCA results, it is always highly subjective to describe any technology as "environmental friendly" as there are no absolute criteria and the LCA results may differ between impact categories. I suggest to correct that ssentence.

Author Response

Dear Reviewer
Thank you very much for your comments, which have enriched our work.
We have included the response to your comments in the attachment.
Authors 

Author Response File: Author Response.docx