Waste to Wealth: Value Recovery from Bakery Wastes

Round 1

Reviewer 1 Report

This is a composting trial for treating bakery waste, cow manure, and leaves using EM culture. The reviewer has comments below.  Please revise the manuscript following the comments.

 

• The title of “Bakery waste materials (BW) into compost” is not appropriate because BM was not only the material but cow dung (CD) and dry leaves were also mixed for treatment.The weight of CD (1.5 kg) was larger than one of BW (1.0 kg).  So, the title mis-leads the readers and must be changed.
• Lines 53–56 and Lines 75–77 are redundant.
• Erase “Fairy Food” on Line 74. The name is on Line 118 and it is enough. 
• Why did the authors use 18 L bins for composting (Line 117).
• Data on Lines 137–142 should be in a table.
• The sentence “The dry leaves pro” was cut here on Line 209 and jumped to Line 213.Arrange it neat.
• Table 2 says Temperature 43–66 oC are acceptable range. The temperature of 43 oC is pretty low and is not good for disinfecting pathogenic organisms.  How do the authors think on this matter?
• Standard errors are enough for Table 1, aren’t they? Re-arrange Table 1. It is very difficult to see the table.  How about the standard errors are written in parentheses after the mean values?
• Why C1 to C5 were not used in Table 1?
• The scales of X and Y axes of Figure 1 are missing, which is critically important for evaluating a compost operation.
• What are a, b, and c in Figs. 5, 6, 7, 8, and 10? Need explanations.
• Figure 9 needs more explanations. Why are there 3 samples for each C1–6?
•  

Author Response

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Author Response File: Author Response.pdf

Reviewer 2 Report

This is the second revision of the paper, which is resubmitted. The authors have revised figures 1 and 2 based on my previous comments. Here, I wish to provide just one more comment. 

About the temperature of the compost, the authors have provided a good discussion in lines 235-263. I think that the authors have achieved the valid compost temperatures. I invite them to consider citing the papers listed below as confirming documents.

https://doi.org/10.1016/j.ecoenv.2019.109667

https://doi.org/10.1016/j.ijheh.2020.113670

https://doi.org/10.1016/j.biortech.2020.124388  

Although discussing about the scale size of the composting system is valid, the overall composting conditions including aeration, regular mixture, etc. are also important to be discussed within a few phrases.

Author Response

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Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

• English should be brushed up.
• Temperature curve stopped at 90 days. Why? Other data continued up to 119 days.
• In Section 3.1.8, C:N or C/N?  Which one?

Author Response

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Author Response File: Author Response.pdf

This manuscript is a resubmission of an earlier submission. The following is a list of the peer review reports and author responses from that submission.

Round 1

Reviewer 1 Report

Sustainability-1062000 review

 

Conversion of Bakery Waste Materials into Compost and Characterization of its Physicochemical Properties and Phytotoxicity

1. Introduction

• First paragraph: What’s the destiny of the wastages? What serous environmental issues do they cause?
• Have other studies done something like this study? What are their results? Give some examples How you come up with your idea in this study?
• What’s the purpose of this study?

 

2. M & M

• Line 103-105; add reference to each method.
• What’s the ratio of each components in each compost? 1:1? (C1-C6)
• Incorporate 2.7 to the rest of M&M instead of separating it as a single section.
• With only two replicates in the phytotoxicity trial, how can you conduct statistical analysis, normally, we’ll need at least three replicates in trial to make the data analyzable and the result convincing.
• Is the 2.10 repeated 2.2?
• How do you compare the treatment? Did you use multiple comparison? Which method did you use in conducting data analysis?

3. Results and discussion

• Add significant difference in all the table or figures if applicable, add SE in tables.
• Check reference formatting in texts.
• How the properties of compost feedstock related to the compost parameter or process?
• You already have figures showing Ph, moisture, and EC, why add Table 3-5? Table 3-5 are all repeat data.
• The order of 3.1 should be rearranged. Table 4 or figure 2b should be in the place where you describe the results.
• Table 7 and figure 3a repeated. Why do you think it’s in the order of C3>C2…? Do you have any thoughts on the results?
• Table 8 and figure 5 repeated.

4. Conclusion

       Not super convincing based on the results.

Comments for author File: Comments.pdf

Author Response

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Author Response File: Author Response.pdf

Reviewer 2 Report

This paper demonstrates the quality and applicability of compost made from bakery wastes.

The topic is interesting, the approach is well described. Results are statistically analyzed and look to be logical and reliable. The conclusion is well written, supported by the achieved results.

Here are some comments:

1. The introduction is weakly written and should be thoroughly revised. Please describe the problem, then provide a comprehensive and relevant literature review. Demonstrate the novelty of your approach in comparison with other studies, and then describe the objectives of your study clearly.

2. Sections 2.6.4, and 3.1.6: The method used for measuring odor does not seem to be based on any internationally accepted standard. There are several standards and methods for measuring odor. Bax et al. (2020) has recently published an informative review paper on the different methods for measuring odor and their applications. The work can be accessed for free here: https://doi.org/10.3390/atmos11010092
Please note that the mentioned paper is not authored by me, and I am not asking authors to cite it unconditionally. However, I do strongly recommend the authors to check the paper and revise their methodology and results as required.

In conclusion, I found this paper informative. In my opinion, the only major weak point of this work is the methodology and results for measuring odor, which should be revised before the paper is considered for publication.

Author Response

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Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

1. Introduction

• Line 40: add reference. How the bakery compost related to the pesticides, wind erosion etc.?
• Have other studies done something like this study? What are their results? Give some examples How you come up with your idea in this study?

For this question, in your cover letter, you said no related using bakery waste. However, if you type in “bakery waste”, “bakery waste compost”, there are so many different studies have published. I highly suggest do more dig in in the literature review part to make your study more conversing.

 

2. M & M

• Incorporate 2.7 to the rest of M&M instead of separating it as a single section.
• With only two replicates in the phytotoxicity trial, how can you conduct statistical analysis, normally, we’ll need at least three replicates in trial to make the data analyzable and the result convincing.

In your cover letter, you said: “Three replicates were done for all the experimental trials. But it was misunderstood that one sample replicated two times, hence the total will be three samples. Correction has been done in 2.7.” In the revised manuscript 2.7, you wrote “Three replicates per sample were done”. I’m confused, please check if this study is done correctly with three replicates per sample.

 

3. Results and discussion

• Add reference to Line 214-218.
• Add significant difference in all the table or figures if applicable, add SE in tables.

In your cover letter, you said “Standard error has been added to the Temperature profile graph (Figure 1). Significant difference has been added for the Table 1”, but in fact, although SE were added, no significant difference has been added for any of the tables or figures. I was concerned about the replicates, if you have three replicates, you should be easily conducting the significant difference by comparing each treatment.

      

Reviewer 2 Report

The changes and revisions are acceptable.

Just a minor comment for figures 1 and 2: It is difficult to see the trends. I suggest you limit the y-axis range to 20-50℃ and 3-8.5 or 9 for figures 1 and 2 respectively.