Digested Sludge Quality in Mesophilic, Thermophilic and Temperature-Phased Anaerobic Digestion Systems
Round 1
Reviewer 1 Report
The paper deals with an important topic from the perspective of the wastewater treatment and and the current and future need for ”Clean Water and Sanitation”. The research methods are described in detail and leave no room for interpretation or misunderstanding. The results are conclusive, being supported by the ideas presented in the ”Conclusions” section. Very good documentation, relevant for the subject of the paper.
Author Response
Please, see the attachment.
Reviewer 2 Report
The manuscript “Digested sludge quality in mesophilic, thermophilic and temperature-phased anaerobic digestion systems” is well written. This can be considered worth publishing in journal “water” after following modifications:
- Main finding/result should be added in the abstract.
- The objectives of the paper should be presented in a more clear way.
- The detail of all equipments used in this study should be given as (equipment name, model, company, country).
- The analytical method for biogas production and biogas quality measurement should be given in detail. Author should provide the GC operating parameters.
- The conclusion section needs modification, since the authors present a resume of what they have done and results obtained rather than highlighting the main achievements of the work.
- The authors can compare their results with previous studies in “tabular form” as a supporting data for better understanding.
Author Response
Please, see the attachment.
Author Response File: 
Author Response.pdf
Reviewer 3 Report
COMMENTS TO AUTHORS:
I have reviewed the manuscript entitled "Digested sludge quality in mesophilic, thermophilic and temperature-phased anaerobic digestion systems" by Iryna Lanko et al. The results of this paper were conducted in lab-scale reactors treating sewage sludges and were showed that the temperature-phased anaerobic digestion (TPAD) was the most beneficial, in terms of organic matter degradation efficiency, producing a digestate with high dewatering ability and pathogenic safety, with the lowest lower calorific value (LCV).
Despite the content is interesting, it is unclear about what was the main focus of this paper.
I would like to suggest MAJOR REVISION needed for this manuscript.
Major revision comments:
1.- In the introduction section:
1.1 The authors non-exposed the objectives of the research, and this part is confusing. From my point of view, the objectives of the research must be clearly incorporated in the revision version of the manuscript in the end of introduction.
1.2 The role of bacteria is essential in the whole process of anaerobic digestion, but nothing is discussed about them. Please improve it.
1.3 “AD consists of the biodegradation of organic matter under anaerobic conditions, leading to the production of biogas (mostly composed by methane) and a stabilised digestate”. Include some references at the end of this sentence and add more content on these concepts besides the role of microorganisms.
1.4 Moreover, some of the references in this section are old. Please, as far as possible, cite recent references of the last 3-5 years.
2.- The section of material and methods
2.1 Lines 235-239: This paragraph should be rewritten to clarify.
2.2 Lines 285-308: All of this information is too general and should be summarized.
Minor comments:
1.- Please check the bibliographic references not all have the proper format.
2.- Lines 32-34. This paragraph is too general and not inclusive. Please, it should be rewritten to clarify, and the authors could provide more references for improve it.
3.- Throughout the manuscript change "micro-organisms" for "microorganisms".
Author Response
Please, see the attachment.
Author Response File: Author Response.pdf
Round 2
Reviewer 2 Report
The authors have revised the manuscript accordingly.
Reviewer 3 Report
In general, the authors have addressed all the comments and concerns, in most of them, very nice responses. Thank you very much for your thorough explanations.
I recommend acceptance in the present form of research paper.
