Resource Cycling: Application of Anaerobic Utilization Methods
Round 1
Reviewer 1 Report
The authors had the intention to present a review paper considering the anaerobic waste disposal methods. Despite the interest of the topic addressed, the authors presented a document with several limitations, that in my opinion not suitable for publication on MDPI Sustainability. The limitations are related to the structure, absence of study objectives, the contents are not organized considering the presented topic. Also, the conclusion is not related to the contents presented (anaerobic organic waste) and the authors introduce the problem of the presence of plastics in waste as a problem, focusing on their treatment. The authors limited themselves to describing the phases of anaerobic digestion, and characterizing them.
Author Response
The article has been revised according to the recommendations of other reviewers. I suggest you read the revised version of the article. Thanks for the constructive review. Your comments and suggestions have provided invaluable assistance in finalizing the article.
Reviewer 2 Report
Dear authors, I appreciate your well written review on “Resource cycling: A review of anaerobic waste disposal methods”. The review is well organized, the topic of research is good. It's an important work, and the review has been well prepared. Below is my assessment on the of the submitted review. Based on the these; the manuscript can be accepted for publication after the major revisions are addressed.
Comments:
Line 8: This sentence is unclear
Please consider changing the keywords list and use synonyms.
Line 83: The authors should include a paragraph describing what they want to show in the rest of this review.
Line 138: What is the meaning of 6.6…7.6
Line 370-436: Rework on your conclusion, the authors should show what's new in this review and try to be more concise. Please note you only need to place your conclusion and not keep putting results, because these have already been presented previously in the review.
I highly recommended to add “A Future Prospects” in a separate section to allow readers to express their thoughts on the future of this research.
The number of factors affecting anaerobic digestion of organic substrate is relatively large, so that the key content is not easy to focus on. Therefore, a mechanism diagram or pattern diagram is suggested to add in the review to present these factors and the process outputs.
Kind Regards,
Author Response
Line 8: This sentence is unclear
- This sentence have been corrected: Human activity and modern production contribute to the formation of a certain amount of waste that can be recycled to obtain useful products and energy sources.
Please consider changing the keywords list and use synonyms.
- The keywords list have been corrected: anaerobic digestion; biogas; recource; recycling; waste
Line 83: The authors should include a paragraph describing what they want to show in the rest of this review.
- The paragraph have been included:
A wide range of different raw materials is suitable for anaerobic digestion. This process of biological conversion is based on microbial decomposition of organic matter in the absence of oxygen. Summing up the data on anaerobic digestion of organic substrates, it can be concluded that biogas is one of the most promising sources of bioenergy, since it is the product of a cheap and environmentally safe method of recycling various waste. Anaerobic digestion reduces greenhouse gas emissions, reduces household use of coal, oil, natural gas and wood; increases the safety of sewage (anaerobic digestion kills pathogenic microorganisms due to high temperatures and anaerobic regime); increases soil fertility through the use of unconventional fertilizers based on digestate, reduces discomfort from unpleasant odors and flies.
Line 138: What is the meaning of 6.6…7.6
– The changes have been made: 6.6–7.6
Line 370-436: Rework on your conclusion, the authors should show what's new in this review and try to be more concise. Please note you only need to place your conclusion and not keep putting results, because these have already been presented previously in the review.
– The changes have been made
I highly recommended to add “A Future Prospects” in a separate section to allow readers to express their thoughts on the future of this research.
- The changes have been made.
- Future prospects
The large amount of waste generated in the world is an attractive sustainable source for industrially important chemicals. Known green recycling technologies are used to minimize waste disposal and protect the environment in general. In doing so, various types of waste can be converted into valuable chemicals and fuels.
Increasing recycling of food and plastic waste is curbing the growth of landfills in many parts of the world. Waste valorization is an attractive concept that is gaining popularity in many countries due to the rapid increase in waste generation. For this reason, researchers are not only developing valorization strategies, but are also focusing on developing more environmentally friendly materials using a range of green technologies.
The development of methods for converting various raw materials into valuable products, including chemicals, biomaterials and fuels, is being traced in research, highlighting the significant potential of advanced waste valorization strategies. Incorporating such processes into future value-added and fuel treatment plants is an important contribution to achieving the world's highest priority goal, sustainable development. But the most important issue now, which needs to be addressed for the sake of future generations, is that the understanding of waste as worthless must give way to a society understanding of waste as a valuable resource. A resource that entails significant complexity due to its inherent diversity and volatility can simultaneously provide an infinite number of innovative solutions and end product alternatives through advanced valorization strategies. Developing innovative sustainable alternatives that will lead to a more sustainable society and economy will require a collaborative effort across a range of sciences, from engineering to biochemistry, biotechnology, environmental sciences, law and economics.
The number of factors affecting anaerobic digestion of organic substrate is relatively large, so that the key content is not easy to focus on. Therefore, a mechanism diagram or pattern diagram is suggested to add in the review to present these factors and the process outputs.
- – The changes have been made.
Reviewer 3 Report
1. Please re-consider the title of the manuscript. This article focuses on the production and utilization of bigas, it is actally a part of "anaerobic wast disposal methods" .
2. The abstract need to be re-organized. Should be more concise and stress the key point.
3. Too much paragraphs in the Introduction, some of them can be combined.
4. Please re-plot Figure 3.
5. Same problem with the abstract, the conclusion needs to be re-organized. Should be more concise and stress the key point.
Author Response
- Please re-consider the title of the manuscript. This article focuses on the production and utilization of bigas, it is actally a part of "anaerobic wast disposal methods".
– The authors disagree. Biogas in the article is given only 3 pages, while the volume of the article is 10 pages without a bibliography. In addition, the article says that biogas is one of the possible products of anaerobic digestion.
- The abstract need to be re-organized. Should be more concise and stress the key point.
– The changes have been made.
- Too much paragraphs in the Introduction, some of them can be combined.
– The changes have been made.
- Please re-plot Figure 3.
– The changes have been made.
- Same problem with the abstract, the conclusion needs to be re-organized. Should be more concise and stress the key point.
– The changes have been made
Reviewer 4 Report
Review report:
Title: Resource cycling: A review of anaerobic waste disposal methods
Authors: Irina N. Vikhareva, Guliya K. Aminova, Aliya K. Mazitova
Manuscript ID: sustainability-1769394
Recommendation: Minor revision
Comments:
This paper reviews the topic of resource recycling with a focus on anaerobic waste disposal and biogas production. The article discusses a wide variety of topics including the process of anaerobic digestion, impact of various process variable, production of biogas and digestate and their application, and the geographical distribution of biogas production around the world.
Overall, the article is well written and provides a good amount of information. I will recommend its publication with minor revisions.
A few comments that needs to be addressed before publication:
1) The English of the article needs a little improvement. The authors use too many short paragraphs, quite a few which could be clubbed together into single paragraphs. For example, the paragraphs starting in Line 112, 114, 118 and 124 can be combined into one single paragraph as all of them talks about thermophilic fermentation. This is just one example, but similar issue exists throughout the article. The authors need to address this issue for better readability of the article.
2) Line 40: “Hydrolysis. At the first…..” should be “Hydrolysis: At the first…..”.
3) Line 48: “Acedogenesis. At the second…..” should be “Acedogenesis: At the second …..”
4) Line 54: “Acetogenesis. At the third…..” should be “Acetogenesis: At the third…..”
5) This being a review article, the cited author’s names should be included in the article whenever appropriate. For example, in Line 129, instead of- “Changes in the toxicity of oil…….[56]”, the authors should consider to write- “Kaya et al. studied changes in the toxicity of oil…..[56]”
6) Line 100 and 102: Remove the periods after the word “dry”
7) Font size of the texts in Figure 1-4 are too small to read. Please increase the font size of these texts.
Author Response
1) The English of the article needs a little improvement. The authors use too many short paragraphs, quite a few which could be clubbed together into single paragraphs. For example, the paragraphs starting in Line 112, 114, 118 and 124 can be combined into one single paragraph as all of them talks about thermophilic fermentation. This is just one example, but similar issue exists throughout the article. The authors need to address this issue for better readability of the article.
– The changes have been made.
2) Line 40: “Hydrolysis. At the first…..” should be “Hydrolysis: At the first…..”.
3) Line 48: “Acedogenesis. At the second…..” should be “Acedogenesis: At the second …..”
4) Line 54: “Acetogenesis. At the third…..” should be “Acetogenesis: At the third…..”
– The changes have been made.
5) This being a review article, the cited author’s names should be included in the article whenever appropriate. For example, in Line 129, instead of- “Changes in the toxicity of oil…….[56]”, the authors should consider to write- “Kaya et al. studied changes in the toxicity of oil…..[56]”
– The changes have been made.
6) Line 100 and 102: Remove the periods after the word “dry”
– The changes have been made.
7) Font size of the texts in Figure 1-4 are too small to read. Please increase the font size of these texts.
– The changes have been made.
Reviewer 5 Report
-
Author Response
The article has been revised according to the recommendations of other reviewers. I suggest you read the revised version of the article. Thanks for the constructive review. Your comments and suggestions have provided invaluable assistance in finalizing the article.
Round 2
Reviewer 2 Report
The authors have addressed my comments, many thanks for their contribution
Author Response
Thank you for your review.
Reviewer 3 Report
I still think the title is not appropriate. As checked, the main content of 4 sections are about biogas, while only 1 section focus on biogas residue. The authors insisted biogas is only one of the productes, but it makes me think that biogas residue is more like a byproduct of biogas production.
Author Response
Thank you for your review.
Tittle was changed: Resource cycling: application of anaerobic utilization methods.
Reviewer 5 Report
The changes made to the article are appropriate. I recommend that this paper be accepted for publication.
Author Response
Thank you for your review.
Round 3
Reviewer 3 Report
Accept.
