Effects of Iron-Loaded Biochar on the Anaerobic Co-Digestion of Food Waste and Sewage Sludge and Elucidating the Mechanism Thereof
Round 1
Reviewer 1 Report
Attached
Comments for author File: 
Comments.pdf
Author Response
Re: Effects of Iron-Loaded Biochar on the Anaerobic Co-Digestion of Food Waste and Sewage Sludge and Elucidating the Mecha-nism Thereof
Wenxu Lu, Guanyong Deng, Xiaoge Cheng and Wan Wang*
1 School of Chemistry and Chemical Engineering, Guizhou University, Guiyang, Guizhou 550025, China
* Correspondence: [email protected]; Tel.: 0086-18785068727
Dear Editor,
Thank you for your consideration on the above manuscript as a revision. The manuscript has now been revised in light of the reviewers’ comments. All matters raised by the reviewer have now been addressed. All revisions made in response to specific referees’ comments are shown with yellow in the revised version. Our responses to the reviewers’ comments are listed below.
Yours faithfully
Dr. Wan WANG
Chemistry and Chemical Engineering
Guizhou University
Guiyang 550025
China
Email: [email protected]
Reviewer 1
1.Lines from 28… Please, specify, that this food waste amount in China.
Response: Thank your comments. It has been specially marked in the article to indicate the production of Chinese food waste
- Line 33: This a general statement that (Anaerobic digestion is a cost-effective technology that can convert food waste and sludge into methane). You should cite more articles to confirm this trend of
scientific work such as DOI: 10.21608/EJCHEM.2021.67579.3493
Response: Thank your suggestion. More references have been cited to confirm this trend.
3.Line 55: The literature in this study should be improved by mention more studies confirm this trend of working and these articles could help you :https://doi.org/10.1016/j.renene.2022.02.087
Response: Thank your comments. This improved working trend has been confirmed by adding more references
- Line 104: This statement is not correct, check it.
Response: Thank your comments. Sentence has been restructured
- Line 118: Write more details on the method of the analysis of VFA.
Response: Thank your suggestion. Already added more details on the method of the analysis of VFA.
- Line 156: Convert the units of volatile fatty acids to g/L not mg/L
Response: Thank your suggestion. Unit has been converted
- Line 181: delete one of the mL, you write it 2 times.
Response: Thank your comments.It has been removed in the revision
8.Line 191: This a general statement that (DIET transfer efficiency and improves anaerobic digestion performance). You should cite more articles to confirm this trend of scientific work such as DOI: https://doi.org/10.1016/j.biombioe.2022.106499
Response: Thank your suggestion. Related literature on trends in direct interspecies electron transfer rates has been added to the article.
- The article needs a thorough review of the English language.
Response: Thank your suggestion. Article has been professionally polished, Proof is below.
Author Response File: Author Response.pdf
Reviewer 2 Report
The paper is sufficient in its hypothesis and scientific approach. The experimental set up and chosen analytical methods were appropriate. However, some minor revisions have to be made before publication. First, some grammatical and language errors were made in the text. Second and most importantly, the BC-Fe has to be described more in detail in the paper. It is unclear how the biochar was made and how it was impregnated with the iron. That makes the comparison between BC-Fe and BC+Fe impossible to understand. The chosen materials have to be described more in depth.
Another question that occurred while reading was, why the hydrogen content wasn't measured. As the paper compares the methanogenesis to the hydrolysis process, a measurement of hydrogen as a parameter of hydrolysis might have been of interest.
Other revision comments can be found in the attached document.
Comments for author File: Comments.pdf
Author Response
Re: Effects of Iron-Loaded Biochar on the Anaerobic Co-Digestion of Food Waste and Sewage Sludge and Elucidating the Mecha-nism Thereof
Wenxu Lu, Guanyong Deng, Xiaoge Cheng and Wan Wang*
1 School of Chemistry and Chemical Engineering, Guizhou University, Guiyang, Guizhou 550025, China
* Correspondence: [email protected]; Tel.: 0086-18785068727
Dear Editor,
Thank you for your consideration on the above manuscript as a revision. The manuscript has now been revised in light of the reviewers’ comments. All matters raised by the reviewer have now been addressed. All revisions made in response to specific referees’ comments are shown with red in the revised version. Our responses to the reviewers’ comments are listed below.
Yours faithfully
Dr. Wan Wang
Chemistry and Chemical Engineering
Guizhou University
Guiyang 550025
China
Email: [email protected]
Reviewer 2
1.Lines from 20，42.00%’ Decimals not nessecary.
Response: Thank your comments. It's accurate to one decimal place
2.Lines from 20，what does the 'research mechanism' mean.clarify.
Response: Thank your comments. The research mechanism is that the concentration of coenzyme F420 in the following text increases, which means that the activity of methanogens increases.
- Line 28: ‘my country’Better to write the name of the country,to avoid having to look up your whereabou.
Response: Thank your suggestion. Country names have been identified in the manuscript
4.Line 29, in what time period?
Response: Thank your suggestion. No specific time period is mentioned in the reference
5.Line 30, in 2022?
Response: Thank your suggestion. No specific age is mentioned in the reference
- Line 34: and as low as? shoud be a range not a max value .Is food waste collected seperately.
Response: Thank your suggestion. Since food waste is affected by factors such as region, season, time, and customs, there is no clear data on the organic content range of food waste in China.
- Line 36: ‘the low 36 content of organic matter in sludge’.How much is low?
Response: Thank your suggestion. The range of sludge organic content has been clarified
- Line 44: sentence structure
Response: Thank your suggestion. The structure of the sentence has been modified
- Line 65: over what?
Response: Thank your comments. sentence has been deleted.
10.Line 72: what are the benefits of treat sludge and food wasters together? Are these usual streams in biogas plants?
Response: Thank your suggestion. The advantage is that it can balance the carbon and nitrogen ratio, adjust the organic content, and improve the conversion rate. Anaerobic digestion of food waste and sludge is the mainstream in the laboratory.
- Line 80: reptition.
Response: Thank your suggestion. Sentence has been restructured
- Line 86:Why these ration?
Response: Thank your suggestion. Refer to the actual food waste content comparison.
- Line 86:Not a full sentence.
Response: Thank your suggestion. Sentence has been perfected
- Line 86: Of what? The actual description of the Fe-BC is missing here. That has to be added. How was the Fe-Biochar made. What was the inital material of the Biochar and how was it impregnated with iron?
Response: Thank your suggestion. The preparation of Fe-BC is mentioned below.
- Line 86: Does not sound like it is written for a scientific paper but more like an excerpt from a experimental setup description.
Response: Thank your suggestion. Sentences have been restructured.
- table 1, In the detection method, only the experimental method used in the experimental discussion part is described in detail.
Response: Thank your comments. In the detection method, only the experimental method used in the experimental discussion part is described in detail.
- Line 112:‘TS、VS’ Abbreviations should be spelled out at least once in the text
Response: Thank your comments. full noun has been added.
- Line 112: Not a proper sentence.
Response: Thank your comments. Sentence has been restructured
- Line 165:‘optimal range’ Where is the optimal range and can this be seen in the figure?
Response: Thank your comments. The optimum pH range is 6.8-7.8.
- Figure 1 c, Use the same colors every time. That would make it easier to interpret the graph
Response: Thank your comments. The color of the picture has been unified
- Figure 1 d, Why not the same colors as before? Would make the gaphs easier to read.
Response: Thank your comments. The color of the picture has been unified.
- Line 218: Not clear, what the difference is
Response: Thank your comments. Fe+BC is iron and carbon added together. Fe-BC is the addition of iron-loaded biochar.
- Line 231: Of what biochar? To what biochar are you comparing?
Response: Thank your comments. Biochar made from corn stover.
- Line 238: Fe+BC?
Response: Thank your comments. Fe+BC is iron and carbon added together.
- Line 290: best measured.
Response: Thank your comments. Changed to best measured
Author Response File: Author Response.pdf
Reviewer 3 Report
Review report of the manuscript: sustainability-1790946
Entitled:
"Study On The Performance And Mechanism Of Iron-Loaded Biochar For Combined Anaerobic Digestion Of Food Waste And Sludge"
1) There are some typographical errors in the paper and authors should be corrected them in the revised version.
2) What is the advantages of the proposed material compared with the conventional ones used? And/or the use of proposed material is economically? Please provide cost analysis of this material and compared it with conventional ones.
3) Section 2, there are no information about statistical data analysis, software used for fitting kinetics, drawing figure, etc. How many replicates for each assay? The replications should be explained in detail. The Statistical analyses were performed by what? Please describe it carefully in the paper.
4) Authors are talking about biochar. I highly recommend the authors to introduce biochar properties used in this study. How the biochar properties were determined? Could you specify the methods with references added?
5) Section 2.1. The parameters analyzed needs to be more described in details (the sludge sampling methods including the size of samples, geometry, distance of sample, ….). The process of samples treatment before determination of characteristics is missing. What was the time (duration) between sampling and determination of characteristics? What is the opinion of the authors that how the parameters and characteristics of food waste and sludge can change with the time after the sampling?
6) Author should present the simplified scheme for the processes involved in the performance of anaerobic digestion system by developed material.
7) Section 2.2. Hypothesis and justification of the selection of the concentration of Fe-BC are not explicitly mentioned in the material and methods.
8) Referrals should be in accordance with the journal's format.
9) In general, legends of tables and figures are not all self-explainable. Remember that tables and figures must be self-explanatory. That is, all statistics and abbreviations used must be clearly explained. All tables and figures must present comparison letter and standard error and suitable statistical analysis when appropriate.
Author Response
Re: Effects of Iron-Loaded Biochar on the Anaerobic Co-Digestion of Food Waste and Sewage Sludge and Elucidating the Mecha-nism Thereof
Wenxu Lu, Guanyong Deng, Xiaoge Cheng and Wan Wang*
1 School of Chemistry and Chemical Engineering, Guizhou University, Guiyang, Guizhou 550025, China
* Correspondence: [email protected]; Tel.: 0086-18785068727
Dear Editor,
Thank you for your consideration on the above manuscript as a revision. The manuscript has now been revised in light of the reviewers’ comments. All matters raised by the reviewer have now been addressed. All revisions made in response to specific referees’ comments are shown with green in the revised version. Our responses to the reviewers’ comments are listed below.
Yours faithfully
Dr. Wan Wang
Chemistry and Chemical Engineering
Guizhou University
Guiyang 550025
China
Email: [email protected]
Reviewer 3
- There are some typographical errors in the paper and authors should be corrected them in the revised version.
Response: Thank your comments. Corrected in revision
- What is the advantages of the proposed material compared with the conventional ones used? And/or the use of proposed material is economically? Please provide cost analysis of this material and compared it with conventional ones.
Response: Thank your suggestion. Since this research is only carried out in the laboratory stage for the time being, it is difficult to carry out some economic cost analysis of mass production.
3 Section 2, there are no information about statistical data analysis, software used for fitting kinetics, drawing figure, etc. How many replicates for each assay? The replications should be explained in detail. The Statistical analyses were performed by what? Please describe it carefully in the paper.
Response: Thank your suggestion. A detailed explanation of this section has been added.
- Authors are talking about biochar. I highly recommend the authors to introduce biochar properties used in this study. How the biochar properties were determined? Could you specify the methods with references added?
Response: Thank your suggestion. Some characteristics of biochar are tested by a third-party professional testing organization, so the specific parameters are not described.
5) Section 2.1. The parameters analyzed needs to be more described in details (the sludge sampling methods including the size of samples, geometry, distance of sample, ….). The process of samples treatment before determination of characteristics is missing. What was the time (duration) between sampling and determination of characteristics? What is the opinion of the authors that how the parameters and characteristics of food waste and sludge can change with the time after the sampling?
Response: Thank your suggestion. The prepared food waste is shredded and stored at -20 degrees Celsius, so its properties do not change over time. The sludge is taken from the sewage treatment plant, and its particles, water content and flora are relatively stable.
- Author should present the simplified scheme for the processes involved in the performance of anaerobic digestion system by developed material.
Response: Thank your suggestion. Figure has been added.
- Section 2.2. Hypothesis and justification of the selection of the concentration of Fe-BC are not explicitly mentioned in the material and methods.
Response: Thank your suggestion. The addition concentration of Fe-BC was obtained by analyzing the data in ref. The results show that the gas production has an inflection point, indicating that the assumption is valid.
- Referrals should be in accordance with the journal's format.
Response: Thank your comments. Referrals have been revised according to journal standards.
- In general, legends of tables and figures are not all self-explainable. Remember that tables and figures must be self-explanatory. That is, all statistics and abbreviations used must be clearly explained. All tables and figures must present comparison letter and standard error and suitable statistical analysis when appropriate.
Response: Thank your comments. The table headers and legends have been revised to increase their self-explanatory character. The first occurrence of an abbreviation is explained in the manuscript.
Author Response File: Author Response.pdf
Round 2
Reviewer 3 Report
Dear editor,
Thanks for giving me the opportunity to evaluate this paper. I read the revised manuscript. In my point of view, the results of this kind of research could be interesting and useful. The authors applied all comments point by point and I confirm their revision. The added information is important and useful and led to improvements in the manuscript. I accept the revised manuscript in this present form. I concur; the final decision is accepted for publication.
