Dynamic Failure Risk Assessment of Wastewater Treatment and Reclamation Plant: An Industrial Case Study
Round 1
Reviewer 1 Report
This manuscript is about the dynamic failure risk assessment of wastewater treatment. I think that only the text editing of the manuscript should be done.
Author Response
Dear Reviewer,
Thank you for taking the time to review this article and provide your crucial feedback. We have found your review helpful in improving the manuscript. We have revised it accordingly. We hope the revised version will meet your expectations and you will find the work suitable for publication.
Author Response File: 
Author Response.docx
Reviewer 2 Report
In general, the document is well written, but it is essential to clearly highlight the novelty of the proposal.
Considering the relevance of the practical case, the procedure for obtaining the probabilities must be described in detail, since in the first instance there is no robustness in its development.
When talking about reliability, how is it possible to have a fixed value per year? what is its meaning?
For the second period, where it is forecast until the year 2030, the reliability increases considerably, what happens to the wear of the equipment? What about maintenance policies? What about asset acquisition and renewal policies?
how can these results be qualitatively and quantitative justified?
As summary, It is necessary to delve deeper into how this concept of reliability is modeled and its mathematical relationship with the probabilities obtained and the Bayesian networks applied.
Author Response
Dear Reviewer,
Thank you for taking the time to review this article and provide your crucial feedback. We have found your review helpful in improving the manuscript. We have revised it accordingly. We hope the revised version will meet your expectations and you will find the work suitable for publication.
Author Response File: Author Response.docx
Reviewer 3 Report
Comments are attached
Comments for author File: 
Comments.pdf
Author Response
Dear Reviewer,
Thank you for taking the time to review this article and provide your crucial feedback. We have found your review helpful in improving the manuscript. We have revised it accordingly. We hope the revised version will meet your expectations and you will find the work suitable for publication.
Author Response File: Author Response.docx
Reviewer 4 Report
This manuscript deals with the analysis of system failure and the potential outcomes and mitigation measures due to many risks and uncertainties during the operation period of a wastewater treatment plant. The analysis used a systematic dynamic risk assessment approach. It was found that a dynamic Bayesian network can be effectively used in this context, capturing complex interactions between failure contributory factors and forecasting the upcoming failure likelihood using a prediction inference.
After reading carefully, I would recommend this manuscript for publication in Safety after minor corrections.
(1) Line 460-462: This paragraph should be deleted.
(2) References: There are many references are not properly cited. For instance, volume and pages are missing in Refs No. 8, 9, 10, 17, 18, 19, 20, 21, 23, 24, 25, 28, 29, 30, 31, 32, 35, and 36. Authors should check all references and present them properly.
Author Response
Dear Reviewer,
Thank you for taking the time to review this article and provide your crucial feedback. We have found your review helpful in improving the manuscript. We have revised it accordingly. We hope the revised version will meet your expectations and you will find the work suitable for publication.
Author Response File: Author Response.docx
Reviewer 5 Report
Current paper discusses various factors that can detrimentally affect the performance of a wastewater treatment plant (WWTP), which is considered a risk of not fulfilling the effluent requirements. To ensure the quality of treated wastewater, there were analyzed system failure causes and their potential outcomes and mitigation measures through a systematic dynamic risk assessment approach. This work shows how a dynamic Bayesian network (DBN) can be effectively used in this context.
A total of 15 years time frame (2016-2030) has been considered in this work. The first 6 years' 20 data have been used to develop the DBN model and to identify the crucial risk factors that are further used to reduce the risk in the remaining 9 years. The risk increased from 21% to 42% in 2016– 22 2021
Some remarks can be made on MS quality:
1. This paper presents the latest developments on the contaminated wastewater treatment. High DO consumption is problematic in energy crisis conditions involving high electricity consumption and can be failure cause, so it needs description how to diminish DO needs? Comparable datasets should be shown with their parameters introduced at different risk-low levels and high ones to see the different removal rates at different stages with failures.
There is bad wording in sentences needed is correct units.
In literature review, reference could be placed at the end not at beginning. More info on Bayesian modelling need to be show instead of other modelling approaches, which You did not use actually.
Some sentences belongs to materials section not results.
Specify the scheme composition in Graph abstract and increase readability of Figures/sharpness. Why abbreviations was not provided with meaning at first appearance.
2. Work should show how much of wastewater loads could be recycled, treated to safer compounds– Give standard deviation of your resultant pollutants’ removals rates, mean, max (Fig. 8, 9) etc and min in separate table of results.
3. Needs descriptions about the parameters measured and given (their meanings in full after first appearance)
4. Some used phrases needs some revision to enhance English quality.
5. There should be replaced data on tables and add the Figures instead for better graphical overview.
7. Hypothesis and clear aims are missing.
8. Check that if your statements has not been backed up with reasoning why were as extensively studied field as wastewater treatment
for research, compared to other studies the novelty to be added.
9. End of Introduction does belong to Methods and Results section rather, not stating Literature anymore.
10. Results section should start with introductory to results, before giving all numerals and Figures. Only few studies were selected for inclusion in the manuscript as comparative study, could more studies be included and most novel studies involved?
Literature has shown different environmental treatments to be solved for more economic way, which could be shown: DOI: https://doi.org/10.3390/w13111522, https://doi.org/10.3390/w13141969, https://doi.org/10.3390/w14020242, https://doi.org/10.3390/w13152136 , https://doi.org/10.3390/w13081095, https://doi.org/10.1016/j.scitotenv.2021.149133
11.Figures quality is bad and they could improve their amount and sharpness, Fig. 1 should show the meaning of ABC, on caption. Waste’s removals failures could need to be added simultaneously from tables to tests result graphs. Sharpen graphs up, too. Error bars on Figs showing error ranges and significant difference need to be added correctly to every new figure
12. The choice of other researches for making research comparisons needs to be justified.
13. Aims should be followed in results and conclusion sections answering to stated aims.
14. Check spacing addition after units and numerals
Reference style should be unified some places used different style.
Author Response
Dear Reviewer,
Thank you for taking the time to review this article and provide your crucial feedback. We have found your review helpful in improving the manuscript. We have revised it accordingly. We hope the revised version will meet your expectations and you will find the work suitable for publication.
Author Response File: Author Response.docx
Round 2
Reviewer 2 Report
All the first review comments are well covered.
Reviewer 3 Report
Dear authors
The paper is acceptable in present form.
Reviewer 4 Report
This manuscript has been well revised based reviewer's comments and suggestions. Thus, this revised manuscript should be accepted for publication in Safety.
Reviewer 5 Report
Check language qualities and revise errors. Check the correct referencing style (Ref at the end of sentence). Literature review can be around 2 pages not more. Figure 9, 10 needs error bars addition, elsewere Figures, too
Fig. 5: sand filtration "n" is separately, revise
check correctness of word "ageing"
