Review Reports

Round 1

Reviewer 1 Report

Dear Authors

I attach my comments to yours manuscript

Comments for author File: Comments.pdf

Author Response

Dear Reviewer:

        Thank you for your comments concerning our manuscript entitled “different adsorption behavior and mechanism of anionic azo dyes on Polydopamine-Polyethyleneimine modified thermoplastic polyurethane nanofiber membranes” (Manuscript number: water-2004838). Those comments are all valuable and very helpful for revising and improving our paper, as well as the important guiding significance to our researches. We have studied comments carefully and have made correction which we hope meet with approval. Revised portion are marked in red in the paper. The point-by-point responses to your comments are provided. Please see the attachment！

We sincerely hope that the modified manuscript is acceptable for publication and look forward to your decision. Finally, thank you very much for your comments and suggestions again.

Best Regards!

Yours sincerely,

Jiaoxia Sun

E-mail address: sjx@cqu.edu.cn

Chongqing Jiaotong University

November 14, 2022

Author Response File: Author Response.docx

Reviewer 2 Report

This paper focus on wastewater treatment to mitigate azo dyes pollution by means of adsorption on the polydopamine-polyethyleneimine modified thermo-plastic polyurethane nanofiber membranes. Generally speaking, the considered topic is interesting and important, especially from ecological point of view. However, the quality of the work in its present form is not suitable for publication in Water or another professional journal. There is a large number of flaws that must be reviewed, and redone before the manuscript has been considered for publication.

 

The most important of them are specified below:

1.       The novelty of the article should be emphasized in the Introduction section.

2.   Experimental part: Detailed characteristics of the adsorbents used should be provided and discussed: Textural parameters (surface are, pore volume, pore size distribution, mean pore diameter); Content of surface functional groups of acidic and basic character (determined via Boehm method or by potentiometric titration); pH value of water extracts as well as pH_pzc.

3.       There is no justification why these 3 dyes were selected for the research and not the others. e.g. anionic and cationic.

4.     Please explain why during investigation of the pH effect on the sorption capacity towards dyes, a different volume of solution was used for CR (50 mL) than for SY and MO (20 mL)?

5.   Why the equilibrium isotherms and adsorption kinetics was studied only for Congo Red? All dyes should be tested in the same manner.

6.       Eq. 7 – there is no “c” in the formula. Please correct the description below (line 175).

7.       Effect of the temperature as well as adsorbent dose on sorption capacity should be also checked.

8.   The effectiveness of removal of the dyes from water solutions should be calculated.

9.     Why only NaOH was used as the desorbing agent? And not, for example, HCl or pure H₂O?

10.    The quality of the Figures is terrible. This must be corrected.

11.    Fig. 5 – The unit of binding energy is [eV], not [ev].

12.    XPS results: C 1s peak should be also showed and analyzed.

13. Figure 10: The mechanism of dyes adsorption should be fine-tuned. p-p interactions should be also considered. Conclusions regarding electrostatic interactions should be based on the determined pH_pzc values.

Taking into account all the above objections, I do not recommend publication of this paper, at its present form. A major revision is needed.

Author Response

Dear Reviewer:

        Thank you for your comments concerning our manuscript entitled “different adsorption behavior and mechanism of anionic azo dyes on Polydopamine-Polyethyleneimine modified thermoplastic polyurethane nanofiber membranes” (Manuscript number: water-2004838). Those comments are all valuable and very helpful for revising and improving our paper, as well as the important guiding significance to our researches. We have studied comments carefully and have made correction which we hope meet with approval. Revised portion are marked in red in the paper. The point-by-point responses to your comments are provided. Please see the attachment！

        Finally, thank you very much for your comments and suggestions sincerely again.

Best Regards!

Yours sincerely,

Jiaoxia Sun

E-mail address: sjx@cqu.edu.cn

Chongqing Jiaotong University

November 14, 2022

Author Response File: Author Response.docx

Round 2

Reviewer 2 Report

In the current version, the article can be accepted for publication.

However, the manuscript needs to be checked for linguistic correctness and text editing.

Figure 8 needs to be corrected - as only an empty frame is visible.