Coagulated Mineral Adsorbents for Dye Removal, and Their Process Intensification Using an Agitated Tubular Reactor (ATR)

Round 1

Reviewer 1 Report

In my opinion the paper needs minor revision.

It is well written and organized. It is aimed at the adsorption of anionic direct dye on various mineral types with and without the secondary coagulation of iron hydroxide (‘FeOOH’) in both a bench stirred tank, as well as an innovative agitated tubular reactor. It's valuable article. The special interest of readers concern agitated tubular reactor. However some corresctions are necessary:

1) Dye physicochemical characteristics and strusture must be added.

2) There is no information about mineral samples of bentonite, kaolin, talc, clinoptilolite zeolite and calcium carbonate - it maus be added, i.e. properties, total capacit, working pH and temperature, etc.

3) Description of interactions between adsorbents and dye mus be added.

Author Response

Please see the attachment 

Author Response File: Author Response.docx

Reviewer 2 Report

Dear authors,

thank you for the well written manuscript. Minor modifications are required from my point of view:

Introduction: It may be worth to breifly discuss extraction methods such as extraction centrifuges (https://www.mdpi.com/2305-7084/3/1/17) as another option.

Figure 3: It would be helpful for interpretation to show the correlation of Experimental data and fit in a digram with logarhythmic time scale as the intersting data points are within the first 50 minutes.

Figure 9c) which is supposed to show the outlet tubing from the ATR is not very explicit in showing the settling effect. Maybe you can increase the scale of the photo.

Some of the text references were 'not found' in the text available for me. Please correct if this is a general issue.

Regards

 

 

Author Response

Please see the attachment.

Author Response File: Author Response.docx

Reviewer 3 Report

Comments for authors consideration are as follows:

1. The given abstract does not deduce the justification of the work theme. Normally an abstract should state briefly the purpose of the study undertaken and meaningful conclusions based on the obtained results. Hence, this needs rewriting. I would expect a brief, yet concise, quantitative description in the abstract.
2. The list of keywords needs to be updated. Avoid the redundant terms which are already coated in the title and abstract.
3. The level of English is poor. Throughout the whole manuscript, the sentences are badly worded and unnecessarily lengthy. Authors are advised to get help from native English expert or professional language service for clear and concise readability.
4. The introduction is lacking recent literature on the impact of environmentally-related contaminants with rising toxicity concerns. Add a paragraph about it.
5. Figure 1 is superficial and should be extended by considering all necessary information.
6. What was the sample size? It needs to be clearly mentioned. Add a footnote explaining the coated values were taken from the duplicate/triplicate samples.
7. L211, 261, 314, 395 - Error! Reference source not found.,???
8. Figures 3, 4, 7, 8, 10 – lacking error bars.
9. L377 - Figure 112? Typo error.
10. All Figures are badly constructed. The sample size is not evident, bars are lacking standard errors.
11. How about the toxicity aspects of treated samples? More data should be added on the toxicity of the treated and untreated samples.

Author Response

Please see the attachment.

Author Response File: Author Response.docx

Round 2

Reviewer 3 Report

The revised version reads well. However, this reviewer is not able to see any change/updates as none of them were marked properly. Authors are advised to mark the changes with a different color or submit a tracked version to clearly identify the improvements.

Other irregularities:

L152 - centrifuged at 12,000 RPM, and throughout the manuscript. It is not correct to indicate the rpm in scientific work. The authors should mention RCF/g or provide information about the used rotors.

Units are given with different expressions, the whole manuscript is lacking consistency. L19 “min”, L24 “min-1”, L121 “minutes”, L129 “minutes”, L202 “mins” and throughout.  The unit presentation should be unified in the whole manuscript.

I am not satisfied with the toxicity aspects of treated samples. More data should be added on the toxicity of the treated and untreated samples.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf