Oxidative Degradation of Pharmaceutical Waste, Theophylline, from Natural Environment

Round 1

Reviewer 1 Report

The authors indicate that the concentrations used are higher than those found in the medium in order to follow the HPLC process, but as the concentration values are not realistic, they may influence the results.

They should indicate the characteristics of the hydrogen peroxide used in the experiments.

Author Response

Please see the attachment.

Author Response File: Author Response.docx

Reviewer 2 Report

General Comments. 

1. The document, when analyzed on Plagiarisms software, i.e., Turnitin, is showing 18%. As per my view, it must be lower down up to 14% or so for an article. Self-Plagiarisms are also not accepted more than 2.5%.
2. The tables and figures used are not clear and can be enhanced. Heading must be with sequential numbers like 1.0, 1.1, 1.2, etc. 
3. In reference section some reference is de-shaped, may be due to formatting. They are also needed to be corrected as per journal format.
4. The introduction must be reduced to one and a half pages.
5. The title needed significant modification.
6. The numbering of content must correct.
7. The manuscript requires an extension of the literature.
8. The manuscript does not illustrate great attention and activity in the field.
9. Tables also contain few references.
10. Please enhance the manuscript on analysis of earlier mention issues.
11. The figure number is distorted and can be rechecked.
12. Graphical Abstract need major revision.
13. For the text clarity, would you refrain from using additional words, mostly meaningless filler words, which can be omitted or some archaic words see, e.g. "respectively", "thus", "hence", “therefore", "furthermore", "thereby", "basically,", "meanwhile", "wherein", "herein", "Nonetheless", "Perceivably," etc.? Some more improvements are needed as follows:

 

1. In the introduction, you need to connect the state of the art to your paper goals. Please follow the literature review by a clear and concise state of the art analysis. This should clearly show the knowledge gaps identified and link them to your paper goals. Please reason both the novelty and the relevance of your paper goals. Clearly discuss what the previous studies that you are referring to. What are the Research Gaps/Contributions? Please note that the paper may not be considered further without a clear research gap and novelty of the study.
2. Please underscore the scientific value-added to your paper in your abstract. Your abstract should clearly state the essence of the problem you are addressing, what you did and what you found and recommend. That would help a prospective reader of the abstract to decide if they wish to read the entire article.
3. Material and Methods section: More specific details are needed to be added with use of latest reference. Chemical and synthesis part need more detailed must be more specific. Grades of chemical ,type of machine/instrument used ,its make etc must be specifically been mentioned.

3.1. In your discussion section, please link your empirical results with a broader and deeper literature review. Like why the adverse effect of NO₃⁻ on the degradation of  theophylline is more pronounced ?

3.3. Product analysis by LC-Q-TOF MS: each statement made in generally must be followed by citation. Don’t use broader view, better narrow down your view which authors wanted to present with respect to current study. Scheme 1 must be more precise showing the mineralization path. Better to use one color.

4. 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.In addition to summarizing the actions taken and results, please strengthen the explanation of their significance. It is recommended to use quantitative reasoning comparing with appropriate benchmarks, especially those stemming from previous work.
5. Please consult the journal's reference style for the exact appearance of these elements, and use of punctuation and capitalization. Bibliography style is not always consistent, please check the reference section carefully and correct the inconsistency.
6. Please eliminate those multiple references. After that please check the manuscript thoroughly and eliminate ALL the lumps in the manuscript. This should be done by characterizing each reference individually. This can be done by mentioning 1 or 2 phrases per reference to show how it is different from the others and why it deserves mentioning.
7. Please eliminate the use of redundant words. Eg. In this way, Recently, Respectively, therefore, currently, thus, hence, finally, to do this, first, in order, however, moreover, nowadays, today, consequently, in addition, additionally, on the other hand, furthermore. – Please revise all similar cases, as removing these term(s) would not significantly affect the meaning of the sentence. This will keep the manuscript as CONCISE as possible. Please check ALL.

Avoid beginning or end a sentence with one or a few words, they are usually redundant. E.g. Today,. Avoid beginning a sentence with a conjunction term, e.g. And, Which, Where, Because.

8. Please check if you have cited each Eq./Fig./Table/Section with its SPECIFIC NUMBER you referred in the TEXT? E.g. It should be stated in the text: …..as shown in Fig. 1 (Fig. capitalize). Please avoid stating ambiguous referencing e.g. …...is as follow…; based on the above/below table/fig.
9. Please use SI unit. E,g, m instead of meter, t instead of tons. d instead of day, y instead of years or yr, h instead of hours, M instead of million, kg instead of kilogram (including those in figures/tables) and leave a space between the value and unit.
10. Corresponding author should use institutional Email ID.

Author Response

Please see the attachment.

Author Response File: Author Response.docx

Reviewer 3 Report

This manuscript reports the degradation of a model pharmaceutical compound, theophylline, from natural environment with photo-irradiation experiments in the presence of varying H₂O₂ concentrations. Controlled experiments were reported aiming to quantify the effects of inorganic compounds (NaNO₃, KH₂PO₄ and ZnSO₄). These inorganic compounds in the medium seems negatively affect the degradation due to hydroxyl radicals (•OH) scavenging. Furthermore, the efficiency of H2O2/photolysis in river water seems largely reduced with very little reduction in the total organic carbon (TOC). This study also proposed mineralization pathways of theophylline on its reaction with •OH with the help of high-res MS.  This manuscript concluded that it is viable to use H₂O₂ to induce the degradation of this theophylline.

 

The story is clear, the data analysis is solid, and the presentation of the manuscript is good. I recommend publishing in the present form with a few minor, and editorial revisions.

 

Minor Comments:

Line 427 to 429: “The present, ultraviolet-based, degradation strategy is demonstrated to be very effective against significantly photo-stable compounds, such as theophylline and very likely other similar CECs, and there by resists the transportation of toxic pollutants into other valuable environmental resources, such as the air and soil.”

 

Since the focus of this study is theophylline, speculation of similar CECs is not appropriate. Please edit to make sure that it’s clear that “very likely other similar CECs” is just speculation and need further investigation.

 

 

Editorial comments:

 

Similar color patterns are used in the figures in the manuscript. However, they are not representing the same things. I recommend add legend to the figures so that readers don’t have to refer to the captions for these figures.

 

There are a lot of missed spaces in the manuscript. Please review and fix these in the final proofreading.

Line 222 “KH2PO4.Although”  Line 222.

Line 328 “× 10-4 mol dm-3H2O2(black).”

Author Response

Please see the attachment.

Author Response File: Author Response.docx