Ecologically Friendly Building Materials: A Case Study of Clay–Ash Composites for the Efficient Management of Fly Ash from the Thermal Conversion of Sewage Sludge

Round 1

Reviewer 1 Report

The study is good, but the authors still need to improve the manuscript for more clarity. The suggestions are as follows:

1. Please revise the title as there are some minor grammar errors.

2. Please reduce the paragraphs in the introduction.

3. Provide the significance of the current work in the last paragraph of the introduction.

4. In Table 1 and all tables please use "." instead of "," between values.

5. Correct caption of Figure 2. Also, replace the Figure as it is blur.

6. Please remove this from lines 217-218 and add it to the acknowledgment. "The investigations were conducted in two institutions: Warsaw University of Life Science (Institute of Civil Engineering) and Main School of Fire Service in Warsaw. "

7. Figure 4 is a blur. please replace. 

8. All Figures are blur. Please update with high quality.

9. In Figure 10, use "." instead of "," between values.

10. Similarly, for all Figures and Tables, please correct the mistake of "." before decimal. 

11. Add a discussion section before the conclusion related to the practical implementation of the current work.

12.  Add future recommendation. 

Minor editing of English language required

Author Response

Dear Reviewer,

Thank you very much for all your comments. We have carefully reviewed each of them and made significant improvements to our article based on your valuable feedback. We sincerely hope that these revisions address any concerns and meet your expectations.

In the appendix, we provide a detailed response to each of your points to ensure transparency and clarity regarding the changes we have implemented. We believe that our research is now presented clearly, and the article has been meticulously revised.

We appreciate your thorough review and look forward to any further feedback you may have

Sincerely,

Authors

Author Response File: Author Response.pdf

Reviewer 2 Report

The paper is of interest and is recommended to publish after revision.

The main points of revising the manuscript are as follows:

Line 1: Please indicate the type of paper. Article?

Neither Chapter 2.2 (Research methods) nor Chapter 3.2 (Title untranslated) reveal the parameters of leaching procedure used, including its duration, water type used, its temperature etc. There is no comparison of leaching data obtained with that set by regulations. For example, in the US the standard Toxicity Characteristic Leaching Procedure (TCLP) is followed for hazardous waste and the results of tests are compared with limits set by authorities.

Chapter 3.2: Please translate its title to English.

This chapter is also missing data on test protocols which were followed for analysis of toxicity.

Conclusion 5 is incorrect, there is some leaching of metals (see data of Table 8) and the conclusion can significantly differ from that of manuscript depending on the regulatory limits and test protocols established to determine the toxicity of materials.

Author Response

Dear Reviewer,

Thank you very much for all your comments. We have carefully reviewed each of them and made significant improvements to our article based on your valuable feedback. We sincerely hope that these revisions address any concerns and meet your expectations.

In the appendix, we provide a detailed response to each of your points to ensure transparency and clarity regarding the changes we have implemented. We believe that our research is now presented clearly, and the article has been meticulously revised.

We appreciate your thorough review and look forward to any further feedback you may have

Sincerely,

Authors

Author Response File: Author Response.pdf

Reviewer 3 Report

Dear Authors,

The manuscript provides a study, about Ecologically friendly building materials on the example of clay- ash composite as a good management of fly ashes from thermal conversion of sewage sludge. This is a very interesting topic, considering the environmental impact of the construction sector and the need to reduce the use of raw materials as well as waste and pollutant emissions in order to move towards sustainable development.

The reviewer is of the opinion that although the study is of interest, the article fails to understand the process and methodology followed. In the explanation of the experiment, it is not clear what steps have been followed or how the samples have been treated. The results should be presented in a more user-friendly way; it is not clear what the objective is.

Other suggestions are mentioned below:

·       The title of paragraph 2 is missing

·       Where it is proposed to use this material, it is important to determine its use in order to know what properties should be required of it.

·       What do the authors mean when they refer to additive in the text? Are they referring to ash? Traditionally in materials science the term additive is used for "chemicals" that are added in small proportions to improve some of the properties of the material, whereas addition is added in larger quantities and is intended to replace part of one of the components that make up the material. Therefore, from my point of view, considering, the ash replaces 40% of the clay it should be an addition not an additive.

·   When the dimensions of an element are expressed in the form of multiplication and the unit is not put after each number but at the end, the unit representing the multiplication must be put, e.g. in the case of 4.0 x 4.0 x 4.0 cm, should be used 4.0 cm x 4.0 cm x 4.0 cm or 4.0 x 4.0 x 4.0 cm³

·       To express decimal numbers, the authors should always use the same criteria or full stops or commas, e.g. in the text they use full stops while in table 1 they use commas.

·   In section 2.1, although reference is made to a previous study, the proportion of water used in the mixture should be indicated or if other components have been added, such as some type of basic solution, silicates, etc. It should also be specified if the drying process is air-dried, how long it is left to dry, under what conditions of temperature and humidity, etc.

·       Figure 3 is not referred in the text.

·   In the reviewer’s opinion, sections 2.2 and 2.3, which refer to the characteristics of the materials, should be placed before 2.1. In this way, the conditions of the materials used would be explained first and then how the sample was taken.

·       A section should be added describing the tests to be performed on the samples of the proposed material and what the test is for. The number of samples manufactured per type and how many are used in each test should also be defined. Also which type of sample shape and dimensions was used in each test.

·       In table 2 a bracket is missing in the bulk density units.

·       Should be improved the quality of Figure 5.

·       Where the firing process is explained, this is how the setting of the mixture is achieved.

·       In the results the tested material types are not named the same as in section 2, in this part they are called clay, composite Łódź, and composite Warsaw, while in section 2 they are mentioned as 0-i, 1-i and 2-i.

·       In the results section, a lot of information is given in a not very user-friendly way so that it is difficult to follow the discussion and to understand the reason for the conclusions.

Author Response

Dear Reviewer,

Thank you very much for all your comments. We have carefully reviewed each of them and made significant improvements to our article based on your valuable feedback. We sincerely hope that these revisions address any concerns and meet your expectations.

In the appendix, we provide a detailed response to each of your points to ensure transparency and clarity regarding the changes we have implemented. We believe that our research is now presented clearly, and the article has been meticulously revised.

We appreciate your thorough review and look forward to any further feedback you may have

Sincerely,

Authors

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Accept

Minor editing required.

Author Response

Dear Reviewer,

Thank you very much for your review, which has greatly contributed to the significant improvement of our article. The English language has been thoroughly checked once again. We appreciate the acceptance of the article.

Best regards,

Authors

Reviewer 3 Report

Thanks to the authors for their efforts to improve the article.

I have only a few small recommendations:

Instead of putting degrees Celsius indicate it with the symbol.

The legend in figures 8 and 9 is not clear.

Author Response

Dear Reviewer,

Thank you very much for your review, which has significantly contributed to the improvement of our article. Following your comments, we have corrected the Celsius degree markings and the description beneath Figures 8 and 9. We sincerely appreciate the acceptance of our article.

Best regards,

Authors