Tailing Ash for the Removal of Methylene Blue from Aqueous Solutions by Batch Adsorption

Round 1

Reviewer 1 Report

Review of the manuscript ID: Processes-2405208; entitled: Tailing Ash for the Removal of Methylene Blue from Aqueous  Solutions by Batch Adsorption

But there are major revisions to be made before likely publication as per the following comments raised as below:

The novelty of work must be more illustrated at the end of introduction section. The following references are helpful in filling this gap: https://doi.org/10.3390/app12157587; https://doi.org/10.1080/01496395.2019.1676785, https://doi.org/10.1016/j.psep.2022.12.028,

https://doi/10.1021/acsomega.2c03755

- The methodology used in this study should revised, because it has not been completely clarified.

- Page 03, line 110 qe is the adsorption capacity at equilibrium. The authors can also define Ct and Qt are at function of time rather than at equilibrium

- page 05, line 148 BET analysis result, authors should add the figure of P/P0 vs ….

- Error bars should be included in Fig. 5

- Page 09, line 228-278, authors need to give more detaills about the effect of pH on the adsorption mecanism and they should give a mecanism which can illustrat the adsorption of MB on the adsorbent.

- The authors should add information about the number of replicates for all experiments (including preparation of the solid adsorbent material and MB concentration determination), hence the corresponding standard deviation.

- It would be helpful to mention the specific conditions under which the adsorption experiments were conducted in the abstract (e.g. initial dye concentration, adsorbent dosage, etc.)

- To determine the efficiency of the synthesized material, it is better to calculate the MB removal efficiency and compare it with data from the literature In order to elucidate the possible mechanism of MB removal.

- The authors investigated only the linear regression adsorption models. By using the non-linear forms, the analysis of experimental data is more precise and accurate.

- The thermodynamic study is very important and authors have to add it

- The quality of the all figures need to be improved

- The conclusion section is very poor, the authors should rewrite this section according to the main objectives of the investig

Author Response

Please see the attachment. 

Thank You

Author Response File: Author Response.docx

Reviewer 2 Report

The study shows that modified Shankanay natural zeolites have a great potential as a low-cost adsorbent material for purifying water from heavy metals. Please make the following modifications before publishing.

1.      What are the advantages of Zeolites as an adsorbent?

2.      The author should conduct a material stability test.

3.      What are the factors that affect the adsorption effect in this study?

4.      The flowing adsorbents for contaminants should be compared in this work (10.1016/j.clay.2022.106686, 10.1021/acsami.1c22035, 10.1016/j.seppur.2021.120386 ).

5.      Although there are many experimental data in this work, there is insufficient understanding of the experimental mechanism.

Minor editing of English language required

Author Response

Please see the attachment

Thank You

Author Response File: Author Response.docx

Reviewer 3 Report

The study evaluates the performance of tailing ash for removal of methylene blue pollutant from aqueous solution. There are no new important scientific findings presented, but the study seems to be properly done and the results can be important for possible applications in technology of waste processing and environment remediation.

 

1. The notation "thermal tailing ash" should be explained clearly, to be distinguished from the "tailing ash" used in the experiments.

2. line 58: silica gel is not a waste product.

3. The grammar should be checked throughout the text. Many inaccuacies can be found, e.g. line 63 "date", line 233 |"higest" , line 308 "was evaluate".

4. A table with comparison to other low cost sorbents for MB should be included in the paper.

Fine

Author Response

Please see the attachment

Thank You

Author Response File: Author Response.docx

Round 2

Reviewer 1 Report

The "Introduction" section needs a major rewrite. The following references are useful to cover this gap :

 https://doi.org/10.3390/app12157587.

https://doi.org/10.3390/separations10010057

Author Response

Thank you for the comment and suggestion. We have revised the manuscript according to the comment. . Our responses are given in a point by point manner as attached.

Author Response File: Author Response.pdf

Reviewer 2 Report

Accept in present form

Author Response

Thank you for the acceptance.

Reviewer 3 Report

The revised version contains improvements but also many omissions. It can be suitable for publication after a major revision.

1. In some figures, data for control samples are shown. What was the control? this should be explained.
2. lines 146-149 and 163-166 are the same. Must be corrected.
3. Check and unify the various versions of writing the Tempkin/Temkin isotherm.
4. Figure 17 - add units to all axes.
5. Figure 18 - check units of q_e.
6. Unify the parameters C_e and q_e, usage of lower index e, or not. For example, lines 465 and 467.
7. Table 6. Check annotation and units of the MB removal column.
8. The removal percentages depend on many variables. Therefore, these numbers as listed in Table 6 are not useful for comparison. Please add a column with values of q_max obtained in different studies, and, optionally, another column that lists the most important parameters of those experiments.
9. Add for comparison traditional sorbents for methylene blue removal from recent studies:
https://doi.org/10.3390/pr10040705
https://doi.org/10.1016/j.matpr.2020.07.192
https://doi.org/10.1016/j.chemosphere.2020.127737

Minor imrpvements are needed.

Author Response

Thank you for the comments and suggestions. We have revised the manuscript according to the comments. Our responses are given in a point by point manner as attached.

Author Response File: Author Response.pdf

Round 3

Reviewer 3 Report

The paper can be accepted for publication.