Converting Municipal Solid Waste Incineration Fly Ash and Municipal Sludge into Environmentally Compatible Alkali-Activated Material

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

Dear authors,

Thank you for an extremely detailed and thoughtful paper, which was a pleasure to read.

You can improve your certainly very high-quality work if:

1. In the abstract, add 1-2 more sentences aimed at the key findings of the paper,

2. In the introductory part, you add several global examples of municipal solid waste management, with a focus not only on landfilling and incineration, because MSW in particular is also suitable for some other treatment methods. In addition, make a brief overview of the trends in the amount of waste generation per capita, or use some similar parameter

3. Avoid mixing the terms MSW and garbage, use MSW only

4. The statement given on line 54 should be expanded with an additional focus on reference under number 19 or similar usage. MS must not contain heavy metals in significant concentrations, and if it does, it indicates a certain failure of CEPI. In any case, MS should be seen as a resource that is gaining more and more importance, so on the example of the EU, there are more and more initiatives aimed at the use of MS as fertilizer

5. The methodological-experimental part of the work is excellent, just make a more substantial announcement of the results - like SEM analyses, etc.

6. The only serious objection concerns the conclusion, which in its current form is very scarce and does not follow the scope of your work. The conclusion needs to be expanded with more quantitative elements that you certainly have in abundance in your work. It is also necessary to give a reference in the conclusion to where AAMs would be specifically used and with which environmental media they would be compatible. In connection with this, it is necessary that in the introductory part of the work you make a review of the possible amount of AAMs that would be generated if your approach were to be applied entirely at the national level.

Best Regards

 

 

Author Response

请参阅附件。

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

In this paper, an environmentally friendly alkali-activated material was prepared by using municipal solid waste incineration fly ash and municipal sludge, and the properties of material prepared under different proportions of fly ash and sludge were investigated in detail, which has positive significance for the resource utilization of fly ash and sludge. However, there are still the following problems in this paper, which need further consideration and improvement.

(1) What is the purpose of judging the fluidity? What is the effect of the fluidity of fly ash sintering on the properties of cementing materials?

(2) In the precursor, the flow temperature is the lowest when the fly ash-to-MS mass ratio is 60%, but SEM shows that the precursor is not the most uniform and dense under this condition. Is there a contradiction?

(3) In section 3.3, “Overall, the amorphous hump after activation increased as the MS proportion increased” it is not intuitively reflected in the figure. Is there any other characterization method to support this conclusion?

(4) What is the basis for the EDS point scan in Figure 7? Is the sampling point in the picture representative?

(5) The phase labeling in Figure 5 and Figure 8 is messy, it is suggested to modify.

(6) Excessive citation of references, especially in the introduction section. It should be avoided consecutive references, such as [29-32].

(7) The format of references is inconsistent, such as [22-25] and [51, 53, 54].

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

The manuscript presents a comprehensive study on converting municipal solid waste incineration fly ash (MSWI-FA) and municipal sludge (MS) into environmentally compatible alkali-activated materials (AAMs). The work is extensive, demonstrating a significant research effort and demonstrating good innovation. However, there are a few minor issues that require attention to further improve the manuscript. My review comments are as follows:

1. The current discussion on MSWI-FA disposal methods is informative but could benefit from including more recent literature. Specifically, citing recent studies such as 10.1016/j.cej.2023.144731 and 10.1016/j.cej.2023.143344 would strengthen the context and position your work within the latest advancements in the field.
2. • The reaction mechanism between municipal sludge and fly ash is not sufficiently detailed in the manuscript. A clearer elaboration on how these two waste streams interact and the specific chemical/physical processes involved would significantly enhance the scientific rigor of the work. Furthermore, the conclusions should reflect this mechanism more explicitly, demonstrating a thorough understanding of the underlying processes.
3. • The resolution and clarity of Figures 7, 10, and 13 are insufficient, with some fonts appearing too small to read easily. Enhancing the quality of these figures, including increasing font sizes where necessary, would improve the accessibility and readability of the data presented.
4. • The sizes of the figures vary throughout the manuscript, which can disrupt the flow of reading. Adjusting the figure sizes to be uniform would enhance the overall professionalism and visual appeal of the paper.

In summary, the work presented in this manuscript is valuable and demonstrates considerable research effort. Addressing the above-mentioned points would further strengthen the scientific merits and accessibility of the research, making it more suitable for publication in a high-impact journal. I look forward to reviewing the revised version of the manuscript.

Comments on the Quality of English Language

1. • While the overall English expression is acceptable, there are opportunities for improvement to enhance readability and fluency. Engaging a native English speaker or professional editor to proofread and polish the text would likely result in a more polished final manuscript.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Round 2

Reviewer 2 Report

Comments and Suggestions for Authors

The authors have addressed my concerns.

Reviewer 3 Report

Comments and Suggestions for Authors

all comments have been addressed