Odor Characteristics and Concentration of Malodorous Chemical Compounds Emitted from a Combined Sewer System in Korea
Round 1
Reviewer 1 Report
A lot of corrections have been made in the resubmitted manuscript. However, additional corrections and reconsiderations should be necessary.
1. Is “0.32 mm (I.D.)” in Table 1 correct?
2. Two “(CH3)2S” standard gas concentrations are shown in Table 1. Either of the two might be “(CH3)2S2”.
3. Is the unit of the threshold limit values “ppm” in Table 4 correct?
4. The unit of the concentration of odorous compounds is not shown in Table 5.
5. The values in Table 5 and Table 7 should be given to appropriate significant figures.
6. What does “the COI method can obtain more stable results than the OOI method” in line 293 mean? The lower coefficient of variation does not mean better odor intensity estimation. The odor intensity estimation which can reproduce the onsite odor intensity observation is desirable.
7. Reference numbers in Table 9 should be corrected.
Author Response
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Author Response File: 
Author Response.pdf
Reviewer 2 Report
The authors have carried out an extensive revision of the paper and my questions have been satisfactorily addressed, given some limitations on the study. In my opinion, the paper can be accepted.
Author Response
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Author Response File: Author Response.pdf
Reviewer 3 Report
Please describe the chemical analysis method of Table 1 & 2 in text. The presentation of the results should be clearer. The results and discussions in the manuscript are too poor and unstructured to be understandable. Scientific innovation cannot be discovered in this study.
Author Response
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Author Response File: Author Response.pdf
Round 2
Reviewer 3 Report
I have no further questions.
Author Response
Since there are no more questions as the comments for the author, I would like to say thank you and replace the author's reply to reviewer.
In the meantime, thank you for kindly reviewing my manuscript.
This manuscript is a resubmission of an earlier submission. The following is a list of the peer review reports and author responses from that submission.
Round 1
Reviewer 1 Report
This paper reports and discusses the sewer odor characteristics in terms of sensory odor intensity and the concentration of individual sulfur compounds. Although the obtained data and analytical results are interesting, several points should be clearly explained or reconsidered.
1. A scale and a sewer flow direction should be added in the map of Figure 1.
2. How were panel members selected and considered to have normal olfaction?
3. The values in Table 4 should be given to appropriate significant figures. Does “5889 ppb” mean the value is correct to four significant figures?
4. The minimum value of MM, DMS and DMDS in Table 4 should be “N.D.” The explanations in the main text should be also reconsidered.
5. The COI was determined using Korean and Japanese correlation equations in Table 5. Are the explanatory labels of the odor intensity scale same between Korean and Japanese? If not, the comparison of the COI is inappropriate.
6. It is not clear why the COI of H2S was adopted in Table 7. What does “the calculated odor intensity estimated by the compounds concentration as an arithmetic percentile” mean?
7. Is “Average” in Table 7 correct?
8. The OOI and the COI were compared based on the RSD in Table 8. Is the RSD appropriate to compare two values?
9. The sentence “it was shown that the RSD between the observed odor intensity and the calculated odor intensity was 0 to 0.15” is not consistent with Table 8. The RSD ranged from 0 to 0.4 in Table 8 and not “much less than 1.”
10. Generally, the TOER is defined to be the product of odor concentration and odorous gas flow rate. In Table 10, the TOER seems to mean the summation of odor concentration.
Reviewer 2 Report
Comments to the Authors
One of my main concerns is the way of measuring and quantifying odours. In Europe, there is systematic regulation to give the number of odours, not only a degree. For me, it is very important to have some kind of equivalence between both systems, although qualitative. If not, there has a limited interest.
In other equivalent systems such as primary units of wastewater treatment plants, there are other compounds (not with S but with N) that are extremely bad odorants. I understand that S compounds are predominant, but the authors should justify why not to use a wider range of compounds.
Regarding this last comment, Table 5 with the correlations must be considered with care, and the authors should empathise this point, as in other ambient this correlations are not correct (composting, anaerobic digestion, landfills).
A point that is general in all the paper is the absence of Discussion. Although scarce, there several papers published in this field, especially with H2S, so it would be interesting to compare data.
Accordingly, the last part of the paper seems a technical report with a succession of Tables, which are practically nor commented neither discussed.
Reviewer 3 Report
The idea in this research is interesting. However, the qualities of data from the odor evaluation and the chemical analysis both are too poor. The data in the table 4,5,6 should now be presented as a graph after a comprehensive association or regression. Overall, I think the author should organize this interesting data more carefully.
