Anaerobic Co-Digestion of Food Waste with Livestock Manure at Ambient Temperature: A Biogas Based Circular Economy and Sustainable Development Goals
Round 1
Reviewer 1 Report
This study explores the start-up process without using a well-adapted inoculum and at ambient temperatures well below mesophilic range and the effects of different ratios of substrate on AD’s biogas production paying special attention to effect of the seasonal temperature change. The conclusion drawn from the study is useful for implementing the sustainable goals through household biogas production in areas where access to well-adapted inoculum and heated equipment are limited. A minor revision addressing the following is recommended:
- Line 19 Acronym VS (Volatile Solid) was used without first defining it when it first appeared.
- Line 155 OLR stands for Organic Loading “Rate” not “load”
- Line 155 162 171, etc. “VS/L/day” using day is better than d; some have subscript a but some don’t, does it mean “added”?
- Is there a compelling explanation as to why goat manure works better a co-substrate in this study? Is it its physio-chemical properties such as composition etc., or its containing microorganisms?
Author Response
Reviewer 1:
Comments and Suggestions for Authors
This study explores the start-up process without using a well-adapted inoculum and at ambient temperatures well below mesophilic range and the effects of different ratios of substrate on AD’s biogas production paying special attention to effect of the seasonal temperature change. The conclusion drawn from the study is useful for implementing the sustainable goals through household biogas production in areas where access to well-adapted inoculum and heated equipment are limited. A minor revision addressing the following is recommended:
- Line 19 Acronym VS (Volatile Solid) was used without first defining it when it first appeared.
Response: Defined Acronym
- Line 155 OLR stands for Organic Loading “Rate” not “load”
Response: Corrected
- Line 155 162 171, etc. “VS/L/day” using day is better than d; some have subscript a but some don’t, does it mean “added”?
Response: VSa= VSadded , revised the unit throughout the paper
- Is there a compelling explanation as to why goat manure works better a co-substrate in this study? Is it its physio-chemical properties such as composition etc., or its containing microorganisms?
Response: Since, the microbial study isn’t conducted during this experiment, we don’t have enough evidence to claim that the co-substrate containing goat manure possessed well adapted or greater population of microorganisms. Based on this study, it is evident that the physio-chemical properties of goat manure were more suitable as the properties like pH, C: N lie within an acceptable range for AD process.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
The "ambient temperatures" should be added to the tittle
Anaerobic digestion, circular economy and sustainable development goals indicators analysis (Tab 6) should be mentioned in the abstract and in conclusion
Conclusion is longer than abstract, it must be shorter
add this idea:
Each co-substrate performed under specific experimental conditions, this feature provides decision makers with diverse alternatives to implement a sustainable organic waste management system, conveying sufficient technical details to draw up appropriate designs for the recovery of various types of organic residue (DOI: 10.3390/foods10102353)
Author Response
Comments and Suggestions for Authors
Reference can be improved.
Response: Few references formatting improved.
The "ambient temperatures" should be added to the tittle
Response: Added
Anaerobic digestion, circular economy and sustainable development goals indicators analysis (Tab 6) should be mentioned in the abstract and in conclusion.
Response: Added in the abstract “Therefore, selecting suitable co-substrates with an optimized mixing ratio can promote several key indicators of a biogas-based circular economy towards achieving sustainable development goals 2, 3, 5, 6, 7, 9, 13 and 15” and in the conclusion it was already mentioned “It can be inferred from this research that anaerobic co-digestion of food and livestock waste with an appropriate model could potentially demonstrate pathways to a biogas based circular economy towards achieving sustainable development goals”.
Conclusion is longer than abstract, it must be shorter
Response: Cut down the conclusion section as can be seen in track change version.
add this idea:
Each co-substrate performed under specific experimental conditions, this feature provides decision makers with diverse alternatives to implement a sustainable organic waste management system, conveying sufficient technical details to draw up appropriate designs for the recovery of various types of organic residue (DOI: 10.3390/foods10102353)
Response: Added as can be seen in the track change version. “Furthermore, this research will also provide diverse options to decision makers for implementing a sustainable organic waste management system along with relevant technical details to develop appropriate designs for resource recovery [71]”.
Author Response File: Author Response.pdf
