Optimization of a Textile Effluent Treatment System and Evaluation of the Feasibility to Be Reused as Influents in Textile Dyeing Processes

Round 1

Reviewer 1 Report

The paper written by Casaperalta et al. presented an innovative optimization of a treatment process for waste effluent containing azo dyes for textile industries. By introducing multiple revisions, including using post-combustion CO2 to acidify the solution, applying multiple filters with proper arrangements, trying new types of flocculating agents, as well as reusing effluents as influents for further dyeing, the authors successfully improved the water quality of the effluents with most of the water quality related parameters are significantly improved. The experiment is carefully designed and the study is thorough. I believe this is a great paper suitable to be published on Sustainability. 

Detailed comments:

1. In table 2, the authors may report the absorbance of the untreated effluent. If it exceeds the upper detection limit of the UV-VIS, the solution should be diluted and measured, and report the corresponding values (assuming the beers law still holds true)

2. In table 3, why the testing conditions of different flocculants are different? A direct comparison may not be made between them.

3. In section 3.4, why the hardness of the water sample drops? Is it due to the CO2 reactions or the flocculants？ Please specify.

4. Though the process may use CO2 and reduce some of the emissions, and improve the water quality, it seems that higher energy inputs may also be required to perform such process innovations. It is suggested that the authors should comment on the energy consumption associated with such process revisions.

Author Response

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Author Response File: Author Response.pdf

Reviewer 2 Report

The manuscript: "Reactive azo dyeing process: optimization of a textile effluent treatment system and evaluation of the feasibility to be reused as influents in textile dyeing processes" by López-Casaperalta et al introduces an important topic that fits the Journal of Sustainability and its audience.

Generally speaking, the manuscript is well-written and it adds a lot to the scientific community. The authors touch on the optimization parameters for any textile dyeing processes, including; suspended solids, temperature and pH, total solids and turbidity, and total hardness and conductivity. The approach of the study is clear and understandable. Here is my constructive feedback on this nice piece of work:

1.       The title reads "Reactive azo deying process", however, the authors did not confirm the existence of such molecules in the characterization section. Either this shall be confirmed in the results section or simply remove these words from the title.

 

2. There is a sort of gap between research and industry that shall be pinpointed between lines 39 – 53. Recent intensive research work has been done on many conventional (such as adsorption) and unconventional (such as nanotechnology) treatment methods for purifying such effluents. Experimental and computational modeling techniques on many deying molecules underpinned the mechanistic insights of such promising treatment techniques. This shall be addressed smoothly and comprehensively, so the authors can introduce the goal of their case study. The authors may see these recent works in this domain:

 

-          Emerging dyeing model molecules: https://doi.org/10.1007/s11356-022-21368-7

-          Textile Effluent: https://doi.org/10.1038/s41598-020-65334-0

-          Textile Effluent: https://doi.org/10.1002/tcr.202000153

-          Conventional deying model molecules: https://doi.org/10.1039/C9RA07001J

 

3.       I struggled reading Figures 1 – 3 on my hard copy. So, a better resolution is needed to increase the clarity of these informative figures.

 

4.       For Table 2, on what basis the authors listed the optimized characteristic parameters? Please add a few lines/sentences after line 162 to highlight these results.

5. Has anyone done such a study in the open literature? Please check and compare.  

 

6.       Conclusions: Please summarize the main findings in this section.     

 

 

  

Author Response

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Author Response File: Author Response.pdf

Reviewer 3 Report

The manuscript is meaningful and interesting that could be accepted for publication after the following amendment. The Introduction part needs to be further refined. I hope that these changes will help to improve your article and make it a document of great scientific interest.

1.     In the introduction page 2 line 77, published papers should be cited for the removal of organic dyes by these methods such as: https://doi.org/10.1016/j.seppur.2019.115961, doi:10.1088/1755-1315/958/1/012011 and https://doi.org/10.1016/j.psep.2017.11.005 .

2.     Please rewrite the last paragraph in the introduction to show the novelty of this work and importance in practical application.

3.     Abstract is correct in terms of content but should be improved in its structure. Authors should first explain the object of the research, then mention the methodologies and techniques used. They can also include a summary of the results and conclusions. In this way, a reader will be able, from this section, to classify the research and determine whether it is useful to him or her.

4.     The entire manuscript needs a good deal of work in improving its English usage so that it becomes much more readable.

5.     Please make sure your conclusions section underscores the scientific value-added of your paper, and/or the applicability of your findings/results. Highlight the novelty of your study. The current form was written as abstract not conclusion please revise.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Round 2

Reviewer 3 Report

 The paper has been revised well and the issues were addressed carefully. Therefore, I recommend the acceptance of the paper.