Wastewater Treatment by Catalytic Wet Peroxidation Using Nano Gold-Based Catalysts: A Review
, Ricardo M. Silva 1, Sónia A.C. Carabineiro 2, F.J. Maldonado-Hódar 3 and Luís M. Madeira 1Round 1
Reviewer 1 Report
Comments and Suggestions
The authors presented a good review on the topic “Catalytic wet peroxidation using nano gold-based catalysts for wastewater treatment”. The article is well written and authors showed a review of the main advanced oxidation processes used, namely CPWO, catalysts preparation methods and, the effect of catalysts properties, as well as the influence of the operating conditions in the efficiency of CPWO.
In the reviewer’s opinion, the paper should be published in Catalysts after minor revisions, according the comments below:
1. The structure of the work seems unbalanced. The index and abbreviations have a too large size and different font than normal text. Tables are also an inadequate proportion to the text. Some chemical reactions such as equations (1, 6, 7, 9, 11-14) are written differently from other reactions. Table 3 (page 13) should be further condensed occupying less space. It should actually be Table 2 because there is another Table 3 on page 21 (please correct)! Table 4 on page 31 should also be presented in a more condensed form.
2. On page 3 the authors should remove the spacing between the words "h" and “n”;
3. In the last paragraph of the Introduction, authors should include also a description of the influence of the materials properties beyond the operative conditions, as this effect is discussed in section 5.1;
4. Authors should standardize the font throughout the document; for example, equations 18 and 19 have different letter size.
5. In the 2nd paragraph of page 6, remove the spacing between words “the” and “installation”;
6. In 1st paragraph of page 8 change “next section” by “next sections” and authors should include, after “discuss”, “the nano gold-based catalysts preparation methods and”;
7. In Figure 4 a), a) appears with green background - please remove that strange background color;
8. On page 19 add a hyphen after C/C0;
9. In caption of Figure 5, remove one endpoint;
10. On page 20 the authors refer the Au/D catalyst but this is not designated in the document and not shown in the abbreviation list. Please add it;
11. Figure 7b) should appear next to 7a);
12. Figures 7a, 8a and 11 would look better with the bars on solid colors
13. In caption of Figures 10 and 12, there is an extra line after “better”; please remove and put all in the same sentence
14. In 1st paragraph of page 27 remove the spacing between “degradation” and “by”.
Author Response
Comment: The authors presented a good review on the topic “Catalytic wet peroxidation using nano gold-based catalysts for wastewater treatment”. The article is well written and authors showed a review of the main advanced oxidation processes used, namely CPWO, catalysts preparation methods and, the effect of catalysts properties, as well as the influence of the operating conditions in the efficiency of CPWO.
In the reviewer’s opinion, the paper should be published in Catalysts after minor revisions, according the comments below:
Answer: We thank to the reviewer for the positive comments on our manuscript.
Comment: 1. The structure of the work seems unbalanced. The index and abbreviations have a too large size and different font than normal text. Tables are also an inadequate proportion to the text. Some chemical reactions such as equations (1, 6, 7, 9, 11-14) are written differently from other reactions. Table 3 (page 13) should be further condensed occupying less space. It should actually be Table 2 because there is another Table 3 on page 21 (please correct)! Table 4 on page 31 should also be presented in a more condensed form.
Answer: The referee is absolutely right. However, some of these discrepancies resulted from the editorial team edition, whom has made some changes in our manuscript when adapting to the journal template.
We have now standardized the letter size and font throughout the whole manuscript (doc file) including contents, abbreviation sections, chemical reactions and tables.
The table in page 13 was renumbered to Table 2. Tables 2 and 4 were condensed as the reviewer suggested.
Comment: 2. On page 3 the authors should remove the spacing between the words "h" and “n”;
Answer: We thank the reviewer for alerting to this problem. The spacing between the words "h" and “n” was removed in the doc file.
Comment: 3. In the last paragraph of the Introduction, authors should include also a description of the influence of the materials properties beyond the operative conditions, as this effect is discussed in section 5.1;
Answer: As the referee suggested, we have now included the influence of the catalysts properties in the last paragraph of the Introduction section.
Comment: 4. Authors should standardize the font throughout the document; for example, equations 18 and 19 have different letter size.
Answer: As mentioned in the answer to the first comment, the font and letter size were standardized throughout the manuscript.
Comment: 5. In the 2nd paragraph of page 6, remove the spacing between words “the” and “installation”;
Answer: The referee is right and the spacing between “the” and “installation” was removed in the new version of the manuscript.
Comment: 6. In 1st paragraph of page 8 change “next section” by “next sections” and authors should include, after “discuss”, “the nano gold-based catalysts preparation methods and”;
Answer: The sentence was included in the last paragraph of section 3 as proposed.
Comment: 7. In Figure 4 a), a) appears with green background - please remove that strange background color;
Answer: That was a strange feature appearing in the pdf version. Actually, the green background colour of a) does not appear in the Word version of manuscript; we will pay attention to this also in the proofs, if the manuscript is accepted for publication.
Comment: 8. On page 19 add a hyphen after C/C0;
Answer: The hyphen was added after C/C0, as suggested.
Comment: 9. In caption of Figure 5, remove one endpoint;
Answer: The extra endpoint was deleted, as suggested.
Comment: 10. On page 20 the authors refer the Au/D catalyst but this is not designated in the document and not shown in the abbreviation list. Please add it;
Answer: The Au/D catalyst designated in section 5.1 is actually Au/FH2 that is in the list of abbreviations. Thus, in the tenth paragraph of such section, the catalyst designation was now corrected.
Comment: 11. Figure 7b) should appear next to 7a);
Answer: We corrected this. In the new version of manuscript, Figure 7b appears next to 7a).
Comment: 12. Figures 7a, 8a and 11 would look better with the bars on solid colors
Answer: We understand the reviewer suggestion. However, if the manuscript is printed in a black & white printer, the series can become very similar/hard to distinguish. So, we decided to keep the figures with one of the series with some texture.
Comment: 13. In caption of Figures 10 and 12, there is an extra line after “better”; please remove and put all in the same sentence
Answer: The extra line in captions of Figures 10 and 12 was removed.
Comment: 14. In 1st paragraph of page 27 remove the spacing between “degradation” and “by”.
Answer: The spacing between “degradation” and “by” was deleted – see the fifth paragraph of section 5.2.3.
We thank the referee again for all comments and suggestions.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
The review presents an overview of oxidative processes for wastewater treatment and discusses the potential of gold catalyst, when efficiently used in CWPO processes, pretending to contribute to evolution and optimization of catalytic wet peroxidation in field application. The work is interesting, brings some novelty and highlights interesting features of the technology. It is reasonably well written, but can be improved by a final review by a british native. It would recommend also to check and avoid repetitive sentences.
Author Response
Comment: The review presents an overview of oxidative processes for wastewater treatment and discusses the potential of gold catalyst, when efficiently used in CWPO processes, pretending to contribute to evolution and optimization of catalytic wet peroxidation in field application. The work is interesting, brings some novelty and highlights interesting features of the technology. It is reasonably well written, but can be improved by a final review by a british native. It would recommend also to check and avoid repetitive sentences.
Answer: We thank the referee for the positive comments. The text was completely revised and the English was improved throughout the whole manuscript (such modifications were however not highlighted, to avoid making the document difficult to check).
We thank the referee again for the comments and suggestions.
