Cellulose-Based Waste in a Close Loop as an Adsorbent for Removing Dyes from Textile Industry Wastewater

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

Dear authors,

The manuscript was well written, it is well aligned with the scope of the journal, and it clearly contributes to the field. The results were comprehensive, contextualized with the literature and presented in a compelling way.

 

I only have a few comments/questions:

1)      Regarding the activation of the materials with KOH (lines 92-96), how was the form of the KOH and how was the mixing with the materials? KOH usually comes in pellet, flake or powder form. Was the material separated from KOH after the treatment? Or the optical photographs (1c and 1f) is exactly what came out of the KOH treatment?

2)      The source of the dyes was not described in the Materials section.

3)      What was the relative proportion (%) of the cotton/polyester yarn? (line 87) Are there reports in the literature with different relative proportion of cotton/polyester?

4)      No information was given about the real wastewater samples (W1, W2, and W3) – where are they from? How were they collected? Any physical properties? Any compositional information (metal, total organic content, etc)? Since this work focuses on methylene blue and methyl orange, is there an estimate of how much of these dyes are present in the samples? You could determine that with a calibration curve.

5)      Figure 1e: two pictures were shows at the same scale, but the materials showcased have totally different sizes. Is the scale bar correct? It seems like the picture on the right has a higher magnification, hence the scale would not be 2 um.

6)      “The immeasurable surface area may be the consequence of the presence of condensed material, visible in Figure 1e” (lines 200-201). Can you edit figure 1e including arrows to show your observation, highlighting the difference between the cotton material shown in 1b?

7)      “Optimal parameters of adsorption obtained in previous experiments”… (lines 390-392). No reference was provided here, are you referring to a previous publication or a previous section of this work? What are the optimal parameters? That is unclear.

8)      The figures 3, 4, 5, 6, 7 and 8 have no standard deviation, and it wasn’t mentioned in section 2 if the experiments were done in triplicate, in order to have enough statistical representation. This is particularly critical when subtle behaviors are being explained based on a slight variation of data. For example, in Figure 7b, the Cott/PESac sample was the only one that had an ascending curve (with minimal slope). Similarly, the curves Cott and Cott/PES in Figure 7a, as well as the curves Cott and Cottc in Figure 7b all have minimal slope. Are those measurements statistically different so that you can make that conclusion? Or the variability would show that they’re actually “flat” and not statistically different? Error bars would help to prove or disprove that, and they’re standard practice in the literature.

Author Response

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Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

1.       I propose changing the title of the article to: Cellulose-based waste in a close loop as an adsorbent for removing dyes from textile industry wastewater.

2.       Chapter Abstract should be corrected. This chapter should include information chronologically: the purpose and scope of the research, the research period, a short research methodology and the most important conclusions.

3.       The purpose of the work (line 71-73) is not very clear: what does it mean "as adsorbents and precursors for obtaining carbon adsorbents for wastewater treatment"? – the purpose of the work should be described more precisely.

4.       The text in lines 73-82 should be placed in the "materials and methods" chapter.

5.       Patterns No. 1 and No. 3 are missing a unit.

6.       A logarithmic scale should be used in figures (Figure 3). The current linear scale makes it impossible to accurately read the values in figures a and b.

7.       The Conclusion chapter should result from the analysis carried out. Some of the text in this chapter is suitable for Introduction. This section needs to be improved.

 

General comment: In my opinion, the presented research results are interesting. The text of the publication should be corrected in accordance with the comments proposed in points 1-7.

Author Response

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Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

The article analyzes the use of waste cotton yarns for the production of adsorbents, their possible use in the textile waste sector, and the reduction of dye pollution in wastewater from the same sector. In this regard, the adsorption properties of cotton-based adsorbents for the adsorption of selected organic dyes from water such as methylene blue and methyl orange are studied in detail.

This topic holds significant scientific and industrial relevance.

The manuscript demonstrates a well-organized structure and clarity in writing. It effectively integrates results from various analyses and provides detailed explanations of relevant phenomena. According to my opinion, this paper is accepted with minor revision. In addition, the authors are suggested to address the following two comments to meet the requirements of the Journal.

 

1.     Lines 77-78. “Methylene blue (MB) was selected as a model of cationic and methyl orange (MO) as a model of anionic dye.” Indicate in the text the reason that led to the choice of these two components for the experimental study.

 

2.    Many of the tables presented in the manuscript and supplementary material contain results with numerous significant digits. If such precision is unnecessary or unattainable, it would be advisable to reduce the number of digits.

Author Response

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Author Response File: Author Response.pdf