Achieving Partial Nitritation in Anammox Start-Up Environment

Round 1

Reviewer 1 Report

The manuscript presents some useful information in the field of wastewater treatment. However, some clarifications are required before consideration:

Please explain how you did that "The mean of each biochemical and physical parameter measurements over time were used for the statistical comparisons." ? what is the significant level? "The mean of each biochemical " how many samples? How many replicates? "measurements over time", what is the time step?

Figure 7: Why are the  N2-out in some data points negative values?

How do the authors know "significantly decreased", "No significant change" and "significant quantity" without conducting statistical analyses"? Would you please add the p-value?

Figure 5, please add the y-axis title. "percentage" is a unit, percentage of what?

"Error bars are the standard deviations calculated from
six samples" what do the authors mean by "six samples"? Is this a related measurement or what?

Some numbers are presented without unites. Please check the whole manuscript. Such as Line 259-260, "0.005", and "when DO/TAN was around 0.015 on day 34" please add the units.

Would you please highlight the take-home message in the conclusion section?

Author Response

Please see the attachment

Author Response File: Author Response.docx

Reviewer 2 Report

Dear authors,

Please consider the suggested comments to improve the quality of the current version of the manuscript:

1. The abstract needs to be incorporated with the gist of the complete work in the manuscript. In the current version of the abstract, only the summary of the work is mentioned in a very broad view. Instead, please include the specific details of the research study presented in the manuscript.
2. The abstract of a scientific paper should precisely mention the specific scientific question that is answered, and conclusions made based on the results. Please explain and provide the specifications of the scientific questions answered in the proposed study.
3. In the abstract, please include the details of the limitations of the previous research studies/technologies made in the proposed domain of study. Also, specify the scientific advancements made in the current/proposed study to overcome those limitations.
4. In the current version of the abstract, the scientific conclusions made based on the experimental results attained were not clearly mentioned (in lines 19-22). Please include the details of conclusions driven from the experimental results.
5. In the introduction, please include additional details of the peer studies performed on the ‘Partial Nitritation Anammox (PNA) process', to guide the reader to understand the importance of the study performed. Also, include corresponding references in the text when mentioning the details.
6. In the introduction, please include the knowledge gaps existing between the current proposed study and prior studies performed in this field. Very importantly, please specify the need for the current work presented in the manuscript.
7. In the last paragraph of the introduction, kindly include the details of the broader impacts on the study made and the results achieved. It is very important to provide the future scope of the study performed to make a strong impact on the readers of the research performed/Study proposed.
8. In the section-3 (Results and Discussion), the current version of the manuscript is only explaining and detailing the results (especially the plots in the figures- 4 & 6). However, please provide scientific reasoning for the results obtained. Please use the ongoing studies published by peers with appropriate references to support your arguments and statements.
9. Please use the proper format for writing and mentioning the mathematical equations. Kindly refer to the author's instructions to understand the formatting process during the submission of the manuscript. Please use the link below for author instructions: https://www.mdpi.com/journal/water/instructions
10. Please include more appropriate references from the studies that are performed more recently. In the current version of the manuscript, there are some references that are not recent publications.
11. Please revise the manuscript with English grammar. There are a few places that the manuscript needs to be improved with respect to English writing.

Author Response

Please see the attachment

Author Response File: Author Response.docx

Round 2

Reviewer 1 Report

The authors' response is sufficient

Reviewer 2 Report

Dear authors,
Thank you for updating the manuscript with recommended changes.

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

Please find the attached file.

Comments for author File: Comments.docx

Author Response

Please see the attachment

Author Response File: Author Response.docx

Reviewer 2 Report

The statistical analysis is not presented in the paper. Please provide the statistical analysis (p-value) along with the results. it will be better for the reader to see where this significant differences between the different HRT and the correlation with other treatments.
Also please add in the material and methods a subsection to talk about what type of statistical analysis was performed.
- Please add stander errors and stander division to the following figures 4 and figure 6.
-Figure 5: what type of error bars was added to the figure?
- The manuscript needs to be reviewed carefully. many mistakes are found, for example: DO was mentioned in the first then was defined, please correct this: "The operating conditions such as DO concentration as the ratio of dissolved oxygen 183 concentration (DO)"
-figure 4: please clarify in the text why c-N2-out in some data points were negative?

Author Response

Please see the attachment

Author Response File: Author Response.docx

Round 2

Reviewer 1 Report

The response provided by the authors is sufficient, the manuscript should be accepted.

Reviewer 2 Report

The manuscript presented data without any statistical analysis, and the experiment design lacks treatments duplication.