New System for Efficient Removal of Lignin with a High Proportion of Chlorine Dioxide

Round 1

Reviewer 1 Report

Comments and Suggestions for the Author

The manuscript entitled “Exploration of a New System for Efficient Removal of Lignin with a High Proportion of Chlorine Dioxide” deals with the high proportion chlorine dioxide is used to remove lignin more efficiently. The process parameters were optimized for efficient removal of lignin and reduce pollutant concentration. The manuscript submitted by Jiahao He et al. can be considered and will be accepted for publication in “sustainability” journal after a minor revision. The article is interesting to the scientists relevant to this area and the manuscript is well-written with all the essential information. The research article is worth to be published but needs some modifications (minor revision) before the manuscript can be accepted for publication.

 

Authors need following points to be included before the manuscript can be accepted for publication.  The comments and suggestions which need to be addressed carefully in the revised manuscript.

 

1.      The abstract should be reorganized. It should be more informative. Add some more important experimental results in the abstract instead of general statements.

2.      The utility of this study should be clearly highlighted in the manuscript and explain the real-time application of the chlorine dioxide with respect to large scale.

3.      The author should explain the innovation and novelty of the present research work in the introduction section.

4.      The authors should explain the methodology for finding the values of Kappa number, brightness and Lignin content in section 2.1, 2.5 and 2.6. with appropriate references. The author should remove the line in section 2.1 “Kappa number was 9.70, brightness was 45.89 %ISO. Lignin content of 1.455%” an incorporate in section 2.5 and 2.6 respectively.

5.      The authors should explain, why the pulp consistency was adjusted to 8% in section 2.2.

6.      The authors should include the kinetic studies for the removal of lignin using chlorine dioxide. It is very essential to study the mechanism of the process.

7.      The authors should explain the mechanism for the removal of lignin using chlorine dioxide.

8.      The authors should include the statistical analysis for the optimization of various process parameters using response surface methodology (RSM) and show the interaction between the response variable and independent variables with appropriate regression plots. 

9.      The authors should explain in section 3.4, why the chlorine oxide decomposition rate is increased with increasing temperature? And should specify the nature of the process at higher temperature.

10.  I recommend adding comparisons of specific experimental data obtained with the results of the authors of other works. It should be added in the tabular column format.

11.  The authors should add the economic assessment/cost analysis section in the present research studies. The cost analysis should be included for the removal of lignin in the bleaching process.

12.  Conclusion must be reorganized; it should be more concise and the authors should verify the language corrections in the entire manuscript.

13.   Some references are 1999 and below the years. The authors must delete the old references and should include the new references (After 2019) with the same concept. So that the research in this field was updated.

 I believe that the manuscript can be accepted for publication with above corrections.

Author Response

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Author Response File: Author Response.docx

Reviewer 2 Report

Title: Exploration of a New System for Efficient Removal of Lignin with a High Proportion of Chlorine Dioxide.

After careful evaluation of the submitted manuscript, I suggest the following points for the improvement of this manuscript.

1. Title of the manuscript is not clear. The word "of" repeated thrice in the title. This has to be corrected.

2. Abstract is very general. Include few numerical findings in the abstract.

3. What is the idea behind the image included before the introduction? What the authors are trying to explain from this image?

4. Include the complete description about the materials used in Section 2.1.

5. There is no much difference in the graphs presented in Fig. 2 and 3. This needs to be explained more.

6. How the error values have been calculated which is included in Fig. 9.

7. Several figures are poor in quality.

8. Language of the manuscript need to be improved.

Author Response

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Author Response File: Author Response.docx

Reviewer 3 Report

This work by He et al has reported a high proportion of ClO2 for bleaching, which has been named as the ‘new system’ by the authors. I agreed with that efficient bleaching with minimized AOX production and thus environmental impacts still represents a challenging issue for pulp and paper industry; However, some questions still remained before the further consideration for probable publication in Sustainability.

1. What is the novelty of this study?

2. In the abstract, the authors stated several times the ‘new system’, but it is not clear what is the new system and what is new in the system as compared with conventional bleaching technology. If only ClO2/lignin mass ratio selected to 4, which is much higher than conventional bleaching, it remained unclear to understand the experimental design in this study. To address this question, the previous work by the authors (Ref-25) and their mechanistic finding, and the rationale to carry out this study should be much emphasized.

3. As presented in the Introduction section, AOX is an important index to evaluate the environmental impacts of bleaching, but the AOX only slightly discussed in a sub-figure of Fig. 9. The discussion regarding the AOX of the bleaching reported in this study should be much improved.

4. What is the ‘sustainability’ issue this study has addressed on?

5. The meaning of Y-axis of Fig. 4a and the third panel in Fig. 9 is not understandable.

6. Fig. 6b and the second panel of Fig. 9 should be ‘The formation of AOX’.

7. Many typos in this manuscript should be corrected. For example, ‘removed ration’ should be ‘removal ratio’, ‘Fig. 4. a)’ should be ‘Fig. 4 (a)’, Fig. 8 legend is incorrect, ‘50% of lignin be removed in a short time’ should be ‘50% of lignin has been removed in a short time’ . The authors should check carefully the manuscript through and make sure all these types of typos have been corrected.

8. Where is Fig. 1?

 

 

 

Author Response

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Author Response File: Author Response.docx

Round 2

Reviewer 2 Report

I carefully evaluated the manuscript's revised version. The authors have significantly modified the updated version in response to the referees' suggestions. The parameters have been clearly defined, and the manuscript has become more fluent. As a result, I feel that the work, in its present form, is of sufficient quality to merit publication in this journal.

Author Response

    We greatly appreciate the reviewer’s positive and constructive comments, which have helped improve our manuscript a lot. At the same time, thank you for agreeing to accept our manuscript.

Reviewer 3 Report

Unfortunately, I failed to see the authors have appropriately addressed most of my qurestions. For example, for Q-1,  the authors responded that the novelty is the reduction of the formation of AOX, but in the Q-3, the authors denied to discuss more about AOX. For Q-2, the authors did not make any changes and my question still remained. For Q-4,  the authors responed the 'sustainability' issue is to replace plastics with paper, and I personally can not buy in this. This research is not about plastic replacement. I would suggest the authors to think 'sustainable and clean production' for this question. For Q-5, I do not think the authors well understood my question. 

Author Response

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Author Response File: Author Response.docx

Round 3

Reviewer 3 Report

For Q2, I do not buy in the statement of the previous finding (Ref-25) is "The molar ratio of different lignin model compound to chlorine dioxide consumption is not fixed". This is not even a scientific finding. Moreover, the authors said they responded in green color in the text, but I did not see any gree color highlighted. Moreover, the related place the authors revised in red color has many language problem. For example, 'the research is relatively small', what do you mean? And many other typos and grammar mistakes existed.  These problems araised my concerns about the author's academic attitude and they could not take my question seriously. Based on this, I would recommend a further correction of all these mistakes before it can be considered for publication. 

Author Response

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Author Response File: Author Response.docx