Evaluation of the Performance of a Nitrogen Treatment Plant in a Continental Mediterranean Climate: A Spanish Pig Farm Case Study

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

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The study “Evaluation of a pig slurry nitrification-denitrification plant  over 4 years: a case of study in a Continental Mediterranean Climate in Spain”  presents a four-year evaluation (2020–2024) of an integrated climate mitigation project on a pig farm in Á vila, Spain. According to the authors, it aims  to technical feasibility and environmental benefits of reducing retention times in housing pits, separating solids and liquids, treating the liquid fraction via nitrification-denitrification (N-DN) and assess the plant performance under varying coditions. The study presents some interesting results  but I have a few concerns.

1. The authors claim to evaluate the environmental benefits of the proposed SEP=NDN system. Despite the inclusion of a detailed section on technical details on correlations of process parameters on removal efficiencies, it lacks a real environmental assessment (or GHG assesment) of the proposed trajectory to conventional practices. For example, the important N2O emissions during NDN is not discusses. This need to be included to strengthen the climate claim.

2.  I think the result section on the correlation and removal efficiencies is too lenghty and repetitive. Should be shortened.

3.  The 4 year analysis on a full scale plant is a strength of the study. I think the authors can strengthen this asset. Multi year anaylysis on a full scale plant opens the door for a proper cost-benefit analysis/environmental assesment which also adresses risk because of inter-year variability. The authors should consider to go beyond a purily desciptive analysis based on correlations etc. Adding for exemple the GHG analysis and link it to the operational parameters can be an option.

4 . The proposed technology route is not innovative. Other full-scale studies such as Vingerhoets et al. (2024) go beyond this SEP=NDN trajectory by adding nutrient recovery before NDN and reducing the possibility of N2O formation in NDN. The authors can consider to compare their results to existing studies and how nutrient recovery could affect their observations

5. The axis of figure 3 is not readable. Important to understand the results.

 

Vingerhoets, R., Sigurnjak, I., Spiller, M., Vlaeminck, S. E., & Meers, E. (2024). Enhancing swine manure treatment: A full-scale techno-economic assessment of nitrogen recovery, pure oxygen aeration and effluent polishing. Journal of Environmental Management, 356, Article 120646. https://doi.org/10.1016/j.jenvman.2024.120646

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Author Response

Francisco San José Barreno
College of Arts and Sciences
Catholic University of Ávila
C. de los Canteros, S/N
05005 Ávila
Spain

Renee Liu

Journal Manager

Nitrogen

 

Ávila, July 2025

 

Dear Ms. Renee Liu,

 

Please find the reviewed version of the research article entitled “Four-Year Operational Performance of a Nitrogen Treatment Plant in a Continental Mediterranean Climate: A Spanish Pig Farm Case Study” by L. Escudero-Campos et al. (nitrogen-3731528).

This version has undergone a comprehensive revision, including changes according to the comments posed by the reviewers. We have chosen a more precise title for the work, we have improved the sections that the reviewers have considered either by rewriting them or adding more information, we have included additional figures to help in the understanding of the operation of the nitrogen treatment plant, and finally, the manuscript has been revised by an English native speaker.

We also enclose our response to the reviewers’ comments and the changes made to the original manuscript, in red.

We hope this version of the article fulfills the requirements and can be suitable for publication in the Nitrogen journal. Furthermore, we want to express our gratitude to the reviewers for the time spent reviewing this manuscript and the suggestions provided, which have enabled us to improve the article.

Please, address all correspondence concerning this manuscript to fjose.sanjose@ucavila.es .

Thank you for your consideration.

 

Yours sincerely,

Francisco J. San José, et al.

 

 

Dear editor and reviewers,

 

In response to the comments provided by each reviewer, we provide the following letter explaining, debating, and presenting the changes made to our manuscript that we have considered to be adequate. We would like to thank all reviewers for the time spent reviewing this manuscript and their valuable and constructive comments to improve our work.

 

 

Reviewer 1

The study “Evaluation of a pig slurry nitrification-denitrification plant over 4 years: a case of study in a Continental Mediterranean Climate in Spain” presents a four-year evaluation (2020–2024) of an integrated climate mitigation project on a pig farm in Á vila, Spain. According to the authors, it aims to technical feasibility and environmental benefits of reducing retention times in housing pits, separating solids and liquids, treating the liquid fraction via nitrification-denitrification (N-DN) and assess the plant performance under varying conditions. The study presents some interesting results but I have a few concerns.

The authors claim to evaluate the environmental benefits of the proposed SEP=NDN system. Despite the inclusion of a detailed section on technical details on correlations of process parameters on removal efficiencies, it lacks a real environmental assessment (or GHG assessment) of the proposed trajectory to conventional practices. For example, the important N2O emissions during NDN is not discusses. This need to be included to strengthen the climate claim.

Thanks for the appointment. We have added a new section in the manuscript (Section 3.1.6. GHG emission analysis), including this assessment. The following table summarizes the N₂O emissions and the reduction between the conventional practices and the employment of the NDN plant.

YEAR	CONVENTIONAL PRACTISE (t CO2 eq)	WITH NDN (t CO2 eq)	%
2020	70,42	27,18	61,41 %
2021	199,2	50,11	74,84 %
2022	278,71	33,34	88,04 %
2023	220,65	52,67	76,13 %

Also, we have included a table that encompasses data including other GHGs: CH₄, N₂O, and NH₃.

YEAR	CONVENTIONAL PRACTISE (t CO2 eq)	WITH NDN (t CO2 eq)	EMISSION REDUCTION (t CO2 eq)	%
2020	152	19	133	87,5 %
2021	522	28	494	94,64 %
2022	675	17	658	97,48 %
2023	293	34	259	88,40 %

 

I think the result section on the correlation and removal efficiencies is too lenghty and repetitive. Should be shortened.

Thanks for the suggestion. The results section has been summarized to avoid being repetitive, and we have included more information in response to other reviewers' comments.

The 4-year analysis on a full-scale plant is a strength of the study. I think the authors can strengthen this asset. Multiyear analysis on a full scale plant opens the door for a proper cost-benefit analysis/environmental assessment which also addresses risk because of inter-year variability. The authors should consider to go beyond a purely descriptive analysis based on correlations etc. Adding for example the GHG analysis and link it to the operational parameters can be an option.

Thank you for the suggestion. In this case, we have included greenhouse gas (GHG) data calculated using the calculator provided by the Spanish Ministry for the Ecological Transition (MITECO) on Section 3.1.6. GHG emission analysis. We have added a summary of the emissions reduced thanks to the implementation of the NDN technology on the farm in the following table. These data have been certified annually by an external certification body and registered on the MITECO platform.

YEAR	CONVENTIONAL PRACTISE (t CO2 eq)	WITH NDN (t CO2 eq)	EMISSION REDUCTION (t CO2 eq)	%
2020	152	19	133	87,5 %
2021	522	28	494	94,64 %
2022	675	17	658	97,48 %
2023	293	34	259	88,40 %

 

4 . The proposed technology route is not innovative. Other full-scale studies such as Vingerhoets et al. (2024) go beyond this SEP=NDN trajectory by adding nutrient recovery before NDN and reducing the possibility of N2O formation in NDN. The authors can consider to compare their results to existing studies and how nutrient recovery could affect their observations

We appreciate this comment. We found the referenced article highly relevant and have cited it accordingly in the revised manuscript.

Thank you for the reference. We have reviewed that manuscript, and it is indeed interesting to see how the combination of physico-chemical processes with biological treatment can enhance slurry management. The plant studied in that paper demonstrates higher removal efficiencies compared to the one analyzed in our work. It is clear that the recovery of nitrogen (N) and phosphorus (P) prior to the NDN treatment significantly improves overall performance. In our case, we achieved average removal efficiencies of 83.84% for nitrogen, 38.31% for phosphorus, and 80.11% for COD. These results fall short of those reported in the referenced study, which achieved removal efficiencies of 95% for nitrogen, 99% for phosphorus, and 99% for COD.

This comparison has been added to the Discussion section.

5. The axis of figure 3 is not readable. Important to understand the results.

We sincerely appreciate the suggestion. The relevant information from Figure 3 and the subsequent figures is already described in the text; therefore, we have decided to remove them from the main manuscript and provide them as supplementary material. Instead, we have incorporated additional content in response to other reviewers' comments, including figures that are more readable and informative.

 

We are very grateful to the reviewers for the time they have taken to evaluate our research. We very much appreciate their opinion and constructive criticisms regarding this early version of our manuscript. All comments on the document provided have been gratefully received and the content of our document has been modified accordingly.

We hope that with this letter and the changes made to the manuscript, we have arranged the issues that were present before. With these changes, we hope that the article now meets the requirements of the editor and reviewers of Nitrogen Journal.

Thank you greatly for your time.

On behalf of myself and my co-authors,

 

Yours sincerely,

Francisco J. San José.

Reviewer 2 Report

Comments and Suggestions for Authors

The research group carried out a four-year evaluation of the operation of the swine manure treatment plant and presented the interesting findings in the manuscript. Please check my comments and suggestions below.

1. The authors didn't present the evaluation results properly in a journal article style.  
2. The abstract doesn't meet the requirements per the author's instructions.
3. Keywords: Agricultural effluents can be changed to agro-industrial effluents.
4. The authors need to demonstrate the performance of the four-year operation in time series and significant results in the Results section, e.g., the water quality of effluents in different seasons and/or at different operation stages, and then present the correlation results. So far, the authors have mostly presented and discussed the correlation results heavily.
5. The legends of the correlation matrix are not clear in most figures, and are missing in Figures 8 and 9.
6. Some appreciations are not used in the manuscripts.
7. An issue with some typos.

Author Response

Francisco San José Barreno
College of Arts and Sciences
Catholic University of Ávila
C. de los Canteros, S/N
05005 Ávila
Spain

Renee Liu

Journal Manager

Nitrogen

 

Ávila, July 2025

 

Dear Ms. Renee Liu,

 

Please find the reviewed version of the research article entitled “Four-Year Operational Performance of a Nitrogen Treatment Plant in a Continental Mediterranean Climate: A Spanish Pig Farm Case Study” by L. Escudero-Campos et al. (nitrogen-3731528).

This version has undergone a comprehensive revision, including changes according to the comments posed by the reviewers. We have chosen a more precise title for the work, we have improved the sections that the reviewers have considered either by rewriting them or adding more information, we have included additional figures to help in the understanding of the operation of the nitrogen treatment plant, and finally, the manuscript has been revised by an English native speaker.

We also enclose our response to the reviewers’ comments and the changes made to the original manuscript, in red.

We hope this version of the article fulfills the requirements and can be suitable for publication in the Nitrogen journal. Furthermore, we want to express our gratitude to the reviewers for the time spent reviewing this manuscript and the suggestions provided, which have enabled us to improve the article.

Please, address all correspondence concerning this manuscript to fjose.sanjose@ucavila.es .

Thank you for your consideration.

 

Yours sincerely,

Francisco J. San José, et al.

 

1.- The research group carried out a four-year evaluation of the operation of the swine manure treatment plant and presented the interesting findings in the manuscript. Please check my comments and suggestions below.

2.- The authors didn't present the evaluation results properly in a journal article style.

Thank you very much for your comment. We have revised the manuscript to present the evaluation results in a format more appropriate for a journal article, aiming to improve clarity, structure, and alignment with academic standards.

3.- The abstract doesn't meet the requirements per the author's instructions.

Thank you for your feedback. We have revised the abstract to ensure it fully complies with the journal's guidelines. The updated version now clearly states the background, the employed methods, main results, and conclusions of the study, providing a concise and comprehensive summary in line with the required format. Additionally, the revised abstract adheres to the 200-word limit specified in the author instructions.

4.- Keywords: Agricultural effluents can be changed to agro-industrial effluents.

Thank you very much for your suggestion. We have replaced the keyword Agricultural effluents with agro-industrial effluents in the manuscript.

5.- The authors need to demonstrate the performance of the four-year operation in time series and significant results in the Results section, e.g., the water quality of effluents in different seasons and/or at different operation stages, and then present the correlation results. So far, the authors have mostly presented and discussed the correlation results heavily.

Thank you for the observation. We have revised and improved the Results section by summarizing all the information related to the correlations and adding further details on the statistical distribution of the removal efficiencies throughout the different months of the year.

6.- The legends of the correlation matrix are not clear in most figures, and are missing in Figures 8 and 9.

We sincerely appreciate the suggestion. The relevant information from figures 8 and 9, and other figures with correlacion information, is already described in the text; therefore, we have decided to remove them from the main manuscript and provide them as supplementary material. Instead, we have incorporated additional content in response to other reviewers' comments, including figures that are more readable and informative.

7.- Some appreciations are not used in the manuscripts.

Thank you very much for the suggestion, we may have made changes to address this.

8.- An issue with some typos.

Thank you for pointing that out. We have carefully revised the text and corrected all typographical errors.

We are very grateful to the reviewers for the time they have taken to evaluate our research. We very much appreciate their opinion and constructive criticisms regarding this early version of our manuscript. All comments on the document provided have been gratefully received and the content of our document has been modified accordingly.

We hope that with this letter and the changes made to the manuscript, we have arranged the issues that were present before. With these changes, we hope that the article now meets the requirements of the editor and reviewers of Nitrogen Journal.

Thank you greatly for your time.

On behalf of myself and my co-authors,

 

Yours sincerely,

Francisco J. San José.

Reviewer 3 Report

Comments and Suggestions for Authors

The manuscript titled "Evaluation of a pig slurry nitrification-denitrification plant over 4 years: a case of study in a Continental Mediterranean climate in Spain".

 

The researchers examined the treatment efficiency of an SBR plant for treating pig slurry under specific conditions in the Continental Mediterranean climate in Spain. The study offers useful insights for readers in the field. It explores a new approach to improve pig slurry management, which could benefit the industrial-scale application of this system for daily use. However, the experimental design lacks clarity, the data analysis is poorly presented, and the presentation and discussion of results are unsatisfactory.

 

Comments:

 

Title:

• Use "a case study" instead of a case of study".

• The title should be revised to be more specific and concise, helping readers understand the main objectives of the study, as slurry nitrification-denitrification was likely not the only parameter investigated.

 

English language: requires a thorough review, as it is very poor.

 

Other comments:

- Abstract: needs update to briefly describe the study, its aims and objectives, the methodology (not in detail), main results, and conclusions. The abstract should summarise all sections briefly.

- Line 53-54: The statement is unclear. Please clarify it.

- Line 150: The terms “reception” and “homogenization” tanks are not typical in wastewater treatment systems; probably you mean presedimentation and equalisation tanks.

- Lines 157 and 162: Review terms “primary separation” and “secondary separation”, using formal terminology.

- Lines 168-234: This section is confusing and written in a non-standard style. SBR systems are well known; please review and rewrite this section briefly, highlighting any key features that differ from conventional designs.

- Lines 244-305: Clarify which methods were used; this section should focus on methodology. Describe the sampling procedure and analysis, referencing the standard methods applied.

- Section 2.5.3: Limit to mentioning the statistical analysis performed without excessive detail.

- Results section: It currently only presents statistical analysis. Avoid only showing parameters over time; instead, include the characteristics of raw samples and consider incorporating comparative tables with literature values under similar or different conditions for a more comprehensive discussion.

- Add a table in the results or discussion section comparing influent and effluent characteristics with literature values.

- Lines 529 and 533: Specify the actual peak loading value when discussing it.

- Review relevant literature to see how other researchers describe and discuss similar results.

- Conclusion: Begin with the key conclusions of your study before proposing future research directions.

Comments on the Quality of English Language

English language is very poor needs major revision.

Author Response

Francisco San José Barreno
College of Arts and Sciences
Catholic University of Ávila
C. de los Canteros, S/N
05005 Ávila
Spain

Renee Liu

Journal Manager

Nitrogen

 

Ávila, July 2025

 

Dear Ms. Renee Liu,

 

Please find the reviewed version of the research article entitled “Four-Year Operational Performance of a Nitrogen Treatment Plant in a Continental Mediterranean Climate: A Spanish Pig Farm Case Study” by L. Escudero-Campos et al. (nitrogen-3731528).

This version has undergone a comprehensive revision, including changes according to the comments posed by the reviewers. We have chosen a more precise title for the work, we have improved the sections that the reviewers have considered either by rewriting them or adding more information, we have included additional figures to help in the understanding of the operation of the nitrogen treatment plant, and finally, the manuscript has been revised by an English native speaker.

We also enclose our response to the reviewers’ comments and the changes made to the original manuscript, in red.

We hope this version of the article fulfills the requirements and can be suitable for publication in the Nitrogen journal. Furthermore, we want to express our gratitude to the reviewers for the time spent reviewing this manuscript and the suggestions provided, which have enabled us to improve the article.

Please, address all correspondence concerning this manuscript to fjose.sanjose@ucavila.es .

Thank you for your consideration.

 

Yours sincerely,

Francisco J. San José, et al.

1.- The researchers examined the treatment efficiency of an SBR plant for treating pig slurry under specific conditions in the Continental Mediterranean climate in Spain. The study offers useful insights for readers in the field. It explores a new approach to improve pig slurry management, which could benefit the industrial-scale application of this system for daily use. However, the experimental design lacks clarity, the data analysis is poorly presented, and the presentation and discussion of results are unsatisfactory.

We thank the reviewer for his constructive comments and valuable feedback.

In response to the concerns regarding the experimental design, we have revised the Materials and Methods section to improve clarity and provide a more detailed description of the operational conditions of the NDN plant and the sampling strategy of the SBR system.

Additionally, we have modified the Results section to enhance the presentation and interpretation of the data. The data analysis has been significantly improved by including a temporal study of the main variables and a clearer presentation of the data distribution. These changes aim to provide a more comprehensive understanding of the system's performance over time and under the specific experimental conditions. We hope these revisions address the reviewer’s concerns and improve the overall quality of the manuscript..2.- Title:

• Use "a case study" instead of a case of study".
• The title should be revised to be more specific and concise, helping readers understand the main objectives of the study, as slurry nitrification-denitrification was likely not the only parameter investigated.

Thanks for the suggestion, we have modified it in this new manuscript: “Four-Year Operational Performance of a Nitrogen Treatment Plant in a Continental Mediterranean Climate: A Spanish Pig Farm Case Study”. We trust that this new title will be more appropriate.

3.- English language: requires a thorough review, as it is very poor.

Thank you very much for the suggestion. The manuscript has been revised by an English native speaker.

 

4.- Other comments:

 

- Abstract: needs update to briefly describe the study, its aims and objectives, the methodology (not in detail), main results, and conclusions. The abstract should summarise all sections briefly.

Thank you for your feedback. We have revised the abstract to ensure it fully complies with the journal's guidelines. The updated version now clearly states the background, the employed methods, main results, and conclusions of the study, providing a concise and comprehensive summary in line with the required format. Additionally, the revised abstract adheres to the 200-word limit specified in the author instructions

- Line 53-54: The statement is unclear. Please clarify it.

Thank you for pointing that out. We have rewritten the statement to improve clarity. The revised version now reads: “NVZ areas represent a significant extension in Castilla y León, the Spanish region where the study NDN plant is located, encompassing over 14,000 km² (nearly 20% of the region's total area) and including close to 400 municipalities.”

- Line 150: The terms “reception” and “homogenization” tanks are not typical in wastewater treatment systems; probably you mean presedimentation and equalisation tanks.

Thank you for your observation. We agree that the terminology could lead to confusion. In response, we have replaced the term "homogenization tank" with "equalization tank", which is more widely used in the context of wastewater treatment systems.

Regarding the "reception tank", this term was used to refer to the point where the pig slurry first arrives at the treatment plant. We have clarified this in the text to avoid misunderstanding.

- Lines 157 and 162: Review terms “primary separation” and “secondary separation”, using formal terminology.

Thank you for your observation. To address this issue, we have revised the terminology in the manuscript and replaced the word “separation” with “filtration”, which more accurately reflects the processes involved. We believe this change improves the technical precision and consistency of the text.

- Lines 168-234: This section is confusing and written in a non-standard style. SBR systems are well known; please review and rewrite this section briefly, highlighting any key features that differ from conventional designs.

Thank you for your comment. We have rewritten the section to provide a clearer and more concise explanation of the SBR process. We hope the revised section now meets the expected standards and improves the reader’s understanding.

- Lines 244-305: Clarify which methods were used; this section should focus on methodology. Describe the sampling procedure and analysis, referencing the standard methods applied.

Thank you for your valuable comment. We acknowledge that the original version of this section lacked sufficient methodological detail. In response, we have revised the section to clearly specify the methods used, including a detailed description of the sampling procedure and analytical methods applied.

We now indicate the sampling points, frequency, and type of samples collected, and have included references to the standard methods used for the analysis of key parameters. These revisions aim to ensure that the methodology is transparent, reproducible, and in line with accepted scientific practices

- Section 2.5.3: Limit to mentioning the statistical analysis performed without excessive detail.

Thank you for your comment. The details regarding this aspect are now clearly described in Section 2.5.4 of the revised manuscript.

- Results section: It currently only presents statistical analysis. Avoid only showing parameters over time; instead, include the characteristics of raw samples and consider incorporating comparative tables with literature values under similar or different conditions for a more comprehensive discussion.

Thank you for the observation. We have revised and improved the Results section by summarizing all the information related to the correlations and adding further details on the statistical distribution of the removal efficiencies throughout the different months of the year

- Add a table in the results or discussion section comparing influent and effluent characteristics with literature values.

Thank you for the helpful suggestion. In response, we have added a table in the Discussion section which compares the influent and effluent characteristics observed in our study with relevant literature values

- Lines 529 and 533: Specify the actual peak loading value when discussing it.Thank you very much for the suggestion, we may  have made changes to address this- Review relevant literature to see how other researchers describe and discuss similar results.

We appreciate this valuable recommendation. In response, we have expanded the Discussion section by reviewing and integrating relevant literature to contextualize our results more thoroughly. We now discuss how similar patterns and findings have been interpreted in other studies, highlighting agreements and differences to strengthen the interpretation of our data. This additional context provides a clearer understanding of the implications of our results in relation to existing knowledge.

Conclusion: Begin with the key conclusions of your study before proposing future research directions.

We appreciate the reviewer’s suggestion. We have revised the Conclusion section to begin with a clear summary of the key findings of our study before outlining the proposed directions for future research, in accordance with the recommendation

 

 

 

We are very grateful to the reviewers for the time they have taken to evaluate our research. We very much appreciate their opinion and constructive criticisms regarding this early version of our manuscript. All comments on the document provided have been gratefully received and the content of our document has been modified accordingly.

We hope that with this letter and the changes made to the manuscript, we have arranged the issues that were present before. With these changes, we hope that the article now meets the requirements of the editor and reviewers of Nitrogen Journal.

Thank you greatly for your time.

On behalf of myself and my co-authors,

 

Yours sincerely,

Francisco J. San José.

Round 2

Reviewer 3 Report

Comments and Suggestions for Authors

Please review my comments and make the necessary updates to the manuscript. Thank you.

   

يرجى قراءة تعليقاتي وتحديث المخطوطة وفقًا لذلك.

 

Comments on the Quality of English Language

Can be improved.

Author Response

Dear Editor and Reviewers,

 

In response to the comments provided by each reviewer, we humbly reply, explaining and presenting the changes made to our manuscript that we consider to be adequate. We would like to thank all reviewers for their valuable time and constructive comments, which have improved our work.

 

Reviewer 3

Compared to the previous version, this revised version has been well improved, including various updates in response to comments by the three reviewers. I do have 3 major comments that I would like them to account for in the resubmission:

1 Change the number of significant digits to 2 in the presented percentages as the current presentation of percentages suggest far too much precision. For example, change in the abstract the sentence: Annual emission reduction was measured and the results showed annual reduction of 75% in N₂O emissions and up to 92% in total GHG emission. Annual average reduction was 75%COD, up to 98% NH3 or 80% N. So, change 75.10 to 75; 92.00 to 92 etc. This holds for the whole paper (see also the numbers in Table 1 and Table 2, which also includes far too much precision).

We appreciate the reviewer’s suggestion regarding the number of significant digits used in reporting percentages. Following the recommendation, we have revised the text throughout the manuscript to limit the reported percentages to two significant digits, reflecting a more appropriate level of precision.

2 Check numbering. The results section starts with 3.1.2 instead of 3.1.1. and section 3.1.6 occurs two times.I would also announce figures before the figure is given. Now it starts with the figure and then the text.

Thank you for pointing out the issues with section numbering and figure placement.

• The section numbering has been thoroughly reviewed and corrected throughout the entire manuscript. All sections follow a consistent and logical sequence across the paper.
• Regarding figure placement, we have revised the manuscript to ensure that all figures are now properly introduced in the main text before they appear. This improves readability and ensures that readers are guided contextually to each figure.

We appreciate this helpful observation, which contributed to improving the overall clarity and structure of the manuscript.

3 Check part of the abstract. The sentence: "going deeper in temperature-reduction relationship there are less N, Nh3 or NOx reduction efficiency in summer months" is unclear and it is not proper English. Furthermore, the following sentence "The annual emission reduction was 75.10% in N₂O emissions and up to 92.00% in total GHG" is a repetition and can be deleted

Thank you for your valuable comments regarding the abstract. It has been revised and rewritten to improve language quality and overall readability, ensuring that the key findings are communicated more clearly and concisely.

 

We are very grateful to the reviewers for the time they have taken to evaluate our research. We highly appreciate their opinion and constructive criticisms regarding this early version of our manuscript. All comments on the document provided have been gratefully received, and the content of our document has been modified accordingly.

We hope that with this letter and the changes made to the manuscript, we have addressed the issues that were present before. With these changes, we hope that the article now meets the requirements of the editor and reviewers of Nitrogen Journal.

Thank you greatly for your time.

On behalf of my co-authors and myself.

 

Yours sincerely,

Francisco J. San José.