Strategies for the Sustainable Management of the Organic Fraction of Municipal Waste

Round 1

Reviewer 1 Report

The manuscript presents an interesting case of study about the management of organic fraction of municipal waste in combination with others waste from biomass. This article could be published in Applied Sciences including some changes and an adequate revision of the guide for author of the journal. In mi opinion, the following aspects must be revised:

1) Abstract (Lines 18 and nexts): Is not clear why only mixture 1 and 3 are commented. What about mixture 2?

2) Line 44-46: The format is nos consistent with the rest of the text.

3) Line 70-79: Reference every option of composting and homogenize in a similar way. Which is the destination of the centralized composting?

4) Line 113-121: The format of the numeration is nos consistent. Initial capital letter or not.

5) Format paragraph line 150-153. The estructure in paragraph must be revised. There are several paragraph consist in only one sentence.

6) Part 2.2: Is not clear the mixture carried out. An explication about the reason to adopt these combination could be interesting.

7) Line 238: There are a simple point and two points followed. The denomination of Posidonia Oceanica is not consistent throughout the manuscript. Please revise it.

8) Table 3: Is not clear the diferences in every mixture. A evolutions diagram in a figure could be clearer. 

9) As a general comment, include novelty references could be interesting. A lot of claims are made without including the convenient background.

10) Conclusions must be rewritten. The introduction of this are very extensive and the aim of the manuscript are not responded. To reordered the ideas would be convinient. 

Author Response

Dear Reviewer,

First and foremost, I would like to thank the reviewer for the suggestions made that have improved the paper and clarified aspects for future researchers.

In answer to your comments

The manuscript presents an interesting case of study about the management of organic fraction of municipal waste in combination with others waste from biomass. This article could be published in Applied Sciences including some changes and an adequate revision of the guide for author of the journal. In mi opinion, the following aspects must be revised:

• Abstract (Lines 18 and nexts): Is not clear why only mixture 1 and 3 are commented. What about mixture 2?

Thanks a lot. This question has been solved in the text (lines 20-22).

• Line 44-46: The format is nos consistent with the rest of the text.

Yes, I have revised all the document, thank you.

• Line 70-79: Reference every option of composting and homogenize in a similar way. Which is the destination of the centralized composting?

Thanks a lot, this information really enrichens the text. It has been introduced in lines 71-90.

• Line 113-121: The format of the numeration is nos consistent. Initial capital letter or not.

Thank you very much, sometimes this happens because there are lines separated by a semicolon. I have changed all the paragraph with full stops and I have used a capital letter.

• Format paragraph line 150-153. The estructure in paragraph must be revised. There are several paragraph consist in only one sentence.

Yes, I apologise for that; it has been corrected.

• Part 2.2: Is not clear the mixture carried out. An explication about the reason to adopt these combination could be interesting.

Yes, this explanation is given in Part 3 supported by the experimental analytical data. We choose that mix considering the values of C/N that will provide a good composting process. The availability of the raw materials has also been taken into account. Mixture 2 was chosen in order to evaluate an extreme mixture without optimal parameters.

• Line 238: There are a simple point and two points followed. The denomination of Posidonia Oceanica is not consistent throughout the manuscript. Please revise it.

I apologise for this editing error. In relation to Posidonia oceanica (L.) Delile, it has been written using the correct Latin name throughout the document.

• Table 3: Is not clear the diferences in every mixture. A evolutions diagram in a figure could be clearer. 

This is a valuable suggestion. The data have been shown as a graph and is much clearer, thank you very much.

• As a general comment, include novelty references could be interesting. A lot of claims are made without including the convenient background.

Thanks a lot, yes I have included some new references in order to support some claims.

• Conclusions must be rewritten. The introduction of this are very extensive and the aim of the manuscript are not responded. To reordered the ideas would be convinient. 

The conclusions have been rewritten and reordered. Thank you for the comment.

Thanks a lot, best regards,

MD Gómez-López

Author Response File: Author Response.docx

Reviewer 2 Report

The authors discuss different ideas of composting waste materials in the municipality of Cartagena, Spain. A better structuring of the paper would be welcome. Sometimes general statements are intermingled with research specific statements. The two should be dealt with separately, not to hinder the train of thought. The experiments dealing with the composting in section 3.1 should be depicted in greater detail. Food wastes, pruning wastes and the seaweed P. oceanica are given as the major sources of biodegradable material. It would be good to have an indication of the availability of all 3 in Cartagena over one year (quantities). Especially for local composting, the availability of the materials in the right proportions would be essential to cut down on transportation - more thoughts on that would be welcome in the text. Also, P. oceanica is being advertised as a possible precursor for animal feed, limiting its availability in the future - some comment on that might be necessary. Pruning wastes seem to be very heterogeneous - how is that dealt with? Are there any other agricultural wastes that are not part of pruning wastes and are not utilized on the farms? Is there any biowaste stemming from the food industry that might come into the mix? Transport in local composting should not be set to zero unless it is self-composting (Table 8). How is the collection of P. oceanica done momentarily?  The allowed limits for heavy metals in fertilizer/compost obtained through composting should be given in Table 5. There is a lot of duplication in lines 185-207. The English of the manuscript must be improved. The references should be given in the required style (for all references).

Author Response

Dear reviewer,

First and foremost, I would like to thank the reviewer by for the suggestions done made that have improved the paper and clarified aspects for future researchers.

In answer of your suggestions:

The authors discuss different ideas of composting waste materials in the municipality of Cartagena, Spain.

A better structuring of the paper would be welcome. Sometimes general statements are intermingled with research specific statements The two should be dealt with separately, not to hinder the train of thought.

Thanks a lot. In order to follow this suggestion, I have tried to reorganise the information.

The experiments dealing with the composting in section 3.1 should be depicted in greater detail. Food wastes, pruning wastes and the seaweed P. oceanica are given as the major sources of biodegradable material. It would be good to have an indication of the availability of all 3 in Cartagena over one year (quantities). Especially for local composting, the availability of the materials in the right proportions would be essential to cut down on transportation - more thoughts on that would be welcome in the text. Also, P. oceanica is being advertised as a possible precursor for animal feed, limiting its availability in the future - some comment on that might be necessary.

Yes I agree with you when you read the section in detail, thanks for the suggestions.

In order to solve this, we have introduced the annual quantity of each residue in Cartagena. Some ideas about the management have been introduced in the text. Some references have been introduced about the use of Posidonia in ruminant feed and the effect on the metabolism and the cost of this (line 67-69).

 

 Pruning wastes seem to be very heterogeneous - how is that dealt with? Are there any other agricultural wastes that are not part of pruning wastes and are not utilized on the farms? Is there any biowaste stemming from the food industry that might come into the mix?

All the residues are heterogeneous if you consider different sources, and indeed it is a problem for the circularity, I agree with you. We point out the possibility of taking waste from agricultural pruning of citrus and fruits trees. The use of food industries waste could be another source, but this is beyond the responsibility of the municipality and should be transported from further away, thereby raising the carbon footprint.

 

Transport in local composting should not be set to zero unless it is self-composting (Table 8). How is the collection of P. oceanica done momentarily? 

Yes, of course, it is difficult to account for this, but we have tried to make an estimation of it. The collection of P. Oceanica is described in lines 197-203.

The allowed limits for heavy metals in fertilizer/compost obtained through composting should be given in Table 5.

Yes, thank you, the information has now been included in the table.

There is a lot of duplication in lines 185-207.

Yes, I apologise, it was an editing error.

The English of the manuscript must be improved.

The English has been thoroughly reviewed by a native English speaker/teacher.

The references should be given in the required style (for all references).

Yes, I apologise for that oversight. The references have been revised. 

Thanks a lot, best regards,

MD Gómez-López

Author Response File: Author Response.docx

Round 2

Reviewer 2 Report

The revision of the article reads much better than the original. Some small suggestions for improvement:

a.) in line 562 change: "from ... at" to "from... to"

b.) in line 551 please delete" "which implies good digestion and stabilization...." as this might confuse the reader.

c.) in line 554: not all countries use brown and green waste bins (a short definition of purpose for both is neeed)

d.) ref. 25: incorrect style. doi is missing

e.) ref. 26 is incomplete.

Author Response

Dear reviewer,

First of all, I would like to thank the reviewer for the new suggestions.

• in line 562 change: "from ... at" to "from... to"

 Thanks a lot, maybe English reviewer didnt see it

 

• in line 551 please delete" "which implies good digestion and stabilization...." as this might confuse the reader.

Thank you very much, yes, I think it is clearer now.

• in line 554: not all countries use brown and green waste bins (a short definition of purpose for both is neeed)

Thank you very much, yes, these colors are not really the same for all regions and countries, I have replaced the paragraph trying to clarify it, putting: "a collection of the same through a special biowaste container located in the points where there are the rest of containers, with a centralized composting plant"

• 25: incorrect style. doi is missing

Yes, sorry, I have corrected it, thank you

• 26 is incomplete.

Yes, sorry, I have corrected it, thank you

Thanks a lot, best regards,

MD Gómez-López

Author Response File: Author Response.pdf