Relevance of Pyrolysis Products Derived from Sewage Sludge for Soil Applications
, Diana Bošanská 1, Vladimír Turčan 1, Martin Pipíška 1, Christoph Pfeifer 2 and Gerhard Soja 2,3Round 1
Reviewer 1 Report
The topic is of interest in the field of waste management. The subject is appropriate to be considered by Agriculture. Yet, the manuscript cannot be considered for publication in its present form. I recommend a major revision, based on the point-by-point comments given below.
- L51-54 If the organic waste were not treated, it is difficult to be allowed for agricultural use, thus, I suggest to revise the statement.
- I suggest to simplify the front part of the introduction, and add new contents about the research advance on your topic and highlight your innovation.
- 1 did not provide too much information, so please revise it or delete it.
- What are the characteristics of the initial sewage sludge?
- In the discussion part, the author compared with a lot of previous studies, but what is the good standard of each parameter is not state clearly.
Author Response
Reviewer's comment:
The topic is of interest in the field of waste management. The subject is appropriate to be considered by Agriculture. Yet, the manuscript cannot be considered for publication in its present form. I recommend a major revision, based on the point-by-point comments given below.
Author's reply:
Dear reviewer, on behalf of the entire authors' team, I would like to thank you for your valuable advice and valuable comments that improved the overall form of our manuscript. We respond to your comments in the individual paragraphs.
Reviewer's comment:
L51-54 If the organic waste were not treated, it is difficult to be allowed for agricultural use, thus, I suggest to revise the statement.
Author's reply:
The authors do not argue that untreated wastes do not only have benefits for soil applications. In the text, we then elaborate on this issue and point out the negatives that applications of treated organic materials entail.
Reviewer's comment:
I suggest to simplify the front part of the introduction, and add new contents about the research advance on your topic and highlight your innovation.
Author's reply:
Accepted, text has been modified and new research with corresponding references has been added.
Reviewer's comment:
Fig.1 did not provide too much information, so please revise it or delete it.
Author's reply:
Accepted, figure has been deleted.
Reviewer's comment:
What are the characteristics of the initial sewage sludge?
Author's reply:
The lack of information regarding the input material is due partly to the intention of the publication, namely to assess the suitability of the already prepared pyrolysis material based on sewage sludge and not the native sewage sludge itself. The material was prepared in the framework of the scientific project Bau einer PYREG® Anlage zur Klärschlammbehandlungauf der Kläranlage Linz-Unkel KfW-A.: NKa3 003004 (Umwelt innovations program) in Linz am Rhein, for which an output report exists and is available to the public, in which all the above-mentioned information is presented (heavy metals content). During project realization, several hundred of kilograms of material has been produced in period of several months. Input feedstock varied in time. Sample of pyrolyzed sludge used in our work represents representative sample (sampling of mixed sample, preparation of laboratory sample, quartering technique), therefore it is not relevant to state misleading characteristics of input sewage sludge.
Reviewer's comment:
In the discussion part, the author compared with a lot of previous studies, but what is the good standard of each parameter is not state clearly.
Author's reply:
Mentioned good standard does not exist for sewage sludge-derived pyrolysis products. According still valid EBC (European Biochar Certificate) the pyrolysis of non-plant biomasses such as sewage sludge, livestock manure, manure containing biogas digestates or bones and slaughterhouse wastes may also produce valuable raw materials that could be used in the interests of the bioeconomy and climate protection. It is planned to include these raw materials in the EBC feedstock list following a key review publication about the product safety and conditions of use.
Reviewer 2 Report
it is a relevant topic for both sustainable agriculture and a healthy environment. the introduction is well written, it plunges us into agro-environmental problems and challenges. the methodology could be improved if the authors add the extraction of Pah compound the discussion is rich and explains almost all the results, however the part on %C,N and H deserves to be improved
Author Response
Reviewer's comment:
It is a relevant topic for both sustainable agriculture and a healthy environment.
Author's reply:
Dear reviewer, on behalf of the entire authors' team, I would like to thank you for your valuable advice and valuable comments that improved the overall form of our manuscript. We respond to your comments in the individual paragraphs.
Reviewer's comment:
The introduction is well written, it plunges us into agro-environmental problems and challenges.
Author's reply:
Thank you for your valuable comment.
Reviewer's comment:
the methodology could be improved if the authors add the extraction of Pah compound
Author's reply:
Accepted, the details of methodology of PAHs compounds extaction have been added
Reviewer's comment:
The discussion is rich and explains almost all the results, however the part on %C,N and H deserves to be improved.
Author's reply:
Accepted, information in discussion has been added.
Reviewer 3 Report
To improve this article, consider the comments below:
Comments:
1. Line 24 - explain the abbreviation PK
2. Lines - 100 - 136 - the text should not be written in italics
3. X°C (e.g. lines 17, 161, 179, 317) or X °C in other lines - unify
4. Figure 2 - Should the values shown on the left and right side of the figure have the same values?
Author Response
Reviewer's comment:
To improve this article, consider the comments below:
Author's reply:
Dear reviewer, on behalf of the entire authors' team, I would like to thank you for your valuable advice and valuable comments that improved the overall form of our manuscript. We respond to your comments in the individual paragraphs.
Reviewer's comment:
Line 24 - explain the abbreviation PK
Author's reply:
Thank you, this typo has been corrected.
Reviewer's comment:
Lines - 100 - 136 - the text should not be written in italics
Author's reply:
Thank you, text has been modified.
Reviewer's comment:
X°C (e.g. lines 17, 161, 179, 317) or X °C in other lines – unify
Author's reply:
Thank you, text has been corrected and unified.
Reviewer's comment:
Figure 2 - Should the values shown on the left and right side of the figure have the same values?
Author's reply:
Thank you, data show fractionation of bound phosphorus in PM determined by sequential extraction with the order of steps: H2O-extractable P (I), NaHCO3-extractable P (II), NaOH-extractable P (III), HCl-extractable P (IV), and residual (non-extractable) P (V). Left side in mg/g and right side in % from total P content in sample. The scale is correct.
Reviewer 4 Report
This is the review of the manuscript entitled “Relevance of pyrolysis products derived from sewage sludge for soil applications”. The authors present an topic being in line with the mission of the Agriculture. It seems to be an interesting work.
In my opinion the authors should explain of the reason of "sieved to fraction of 0.5-1 mm"
Furthermore the lack of basic research of sewage sludge: grain size distribution, fractions of heavy metals according to BCR procedure, another heavy metals (for instance chrome) and properties of used soil.
Author Response
Reviewer's comment:
This is the review of the manuscript entitled “Relevance of pyrolysis products derived from sewage sludge for soil applications”. The authors present an topic being in line with the mission of the Agriculture. It seems to be an interesting work.
Author's reply:
Dear reviewer, on behalf of the entire authors' team, I would like to thank you for your valuable advice and valuable comments that improved the overall form of our manuscript. We respond to your comments in the individual paragraphs.
Reviewer's comment:
In my opinion the authors should explain of the reason of "sieved to fraction of 0.5-1 mm"
Author's reply:
The main reason why we used this fraction was to maximize the proportion of this fraction of the recovered material. Also, for the field application of pyrolyzed materials it is more acceptable to avoid dust particles. The choice of fraction is equally related to our experience with this type of material in soil experiments.
Reviewer's comment:
Furthermore the lack of basic research of sewage sludge: grain size distribution, fractions of heavy metals according to BCR procedure, another heavy metals (for instance chrome) and properties of used soil.
Author's reply:
The lack of information regarding the input material is due partly to the intention of the publication, namely to assess the suitability of the already prepared pyrolysis material based on sewage sludge and not the native sewage sludge itself. The material was prepared in the framework of the scientific project Bau einer PYREG® Anlage zur Klärschlammbehandlungauf der Kläranlage Linz-Unkel KfW-A.: NKa3 003004 (Umwelt innovations program) in Linz am Rhein, for which an output report exists and is available to the public, in which all the above-mentioned information is presented (heavy metals content).
