Sewage Sludge Bottom Ash Characteristics and Potential Application in Road Embankment
Round 1
Reviewer 1 Report
Manuscript sustainability-653664 reports a well-done study and is of great interest. Manuscript has a correct structure and includes clear descriptions and explanations of the experimental design. The manuscript has valuable data. It presents data in an easy to follow way. The analytical approach is appropriate and the conclusions are coherent with the data and give some perspective for future studies. The style and the English language are fine, text requires a minor spell check.
Unfortunately, the manuscript has a single significant issue. Aim of the paper is to assess the use of SSA as material for sustainability-related applications in civil engineering. But as the author writes: "… possibility of leaching of heavy metals from the waste because their content is much higher than in uncontaminated soils.” SSA is not an environmentally friendly material. I suggest the author to change the target of the manuscript. The paper is well written and contains interesting data, but the purpose proposed in the introduction/abstract is not applicable.
Author Response
Dear Sir,
I would like to thank for the positive assessment of my paper in the first part of the review.
In replay to the individual comment about change the aim of may paper - in my opinion it is not necessary. Please take into consideration my explanation.
As I wrote in my paper, a major component of sustainability-related applications in civil engineering should be focused on alternative construction materials by using environmentally friendly materials, concentrating on the use of recycled waste materials. "… possibility of leaching of heavy metals from the waste because their content is much higher than in uncontaminated soils” does not exclude the use of SSA from the combustion of sludge in a grate furnace. The SSA should be incorporated into an embankment in a special way, where it should be assembled in a space isolated from groundwater and rainwater. The lower isolation layer at a high groundwater table, and an upper layer of the embankment in the freezing area should be protected by chemical stabilization, which was carefully described in my paper. Chemically stabilised soil is practically impermeable.
Additionally, please pay attention, that I wrote: "In the analysed aqueous extract only lead concentration insignificantly exceeds the one most frequently quoted for natural soil solutions or groundwater [25]. Despite the high content of copper and zinc, their leaching was not high...". The possibility of leaching of heavy metals concerns every waste even characterised by contents non exceeding ranges for unpolluted soils. It should be remembered that unused waste will be stored in waste landfills, where it can also affect the environment.
For better explanation I have added statements in the Abstract and have rearranged chapter 2.1. New text is in red, rearranged - in blue.
Text was checked and minor errors were improved.
I would like to add that I am a civil engineer with an extensive experience in the use of man-made soils in the earth structures. Among other things, I am the author of two books (in Polish) devoted to this topic. Both were quoted in my paper.
Yours faithfully,
Katarzyna Zabielska-Adamska
Reviewer 2 Report
The sewage sludge ash is abbreviated as SSA, but the sewage sludge ash is also called as sewage sludge bottom ash, municipal sewage sludge bottom ash, municipal sewage sludge thermally converted, municipal sewage sludge incineration product and waste etc., please unify the presentation of SSA in the text.Author Response
Dear Sir,
Thank you very much for positive review of my paper. Thanks to given remarks my paper can be more comprehensible and valuable. In replay to the individual comment about unification the presentation of SSA in the text, I would like to ensure that I have tried to do it in all possible places. SSA in literature and my paper concerns not only for fly ash form fluidised bed furnace, but for bottom ash from conventional furnace. "Waste" has been used only for avoiding repetitions (especially in the Abstract).
Yours faithfully,
Katarzyna Zabielska-Adamska
Reviewer 3 Report
I have no comments
Author Response
Dear Sir,
Thank you very much for positive review of my paper.
Yours faithfully,
Katarzyna Zabielska-Adamska
Round 2
Reviewer 1 Report
Dear author,
Your manuscript is of high value and well made. But I still maintain that the purpose of the research and consequently the title of the manuscript must be changed.
Please let me give you a little suggestion. This is a peer-review, so it is not necessary to respond to reviewers' comments by highlighting your curriculum vitae. I repeat, your manuscript is excellent and I recognize its value.
Author Response
Dear Sir,
I would like to thank for all remarks on my manuscript.
Yours faithfully,
Katarzyna Zabielska-Adamska
