Rainwater Quality Analysis for Its Potential Recovery: A Case Study on Its Usage for Swimming Pools in Poland
Round 1
Reviewer 1 Report
Dear authors,
please find my comments in the attachment.
Sincerely Yours
Comments for author File: 
Comments.pdf
Author Response
We would like to thank all the Reviewers for their valuable help in improving our manuscript. As can be seen in the revised text, their comments, remarks, and suggestions have been taken into account during the revision. Detailed responses to reviewers are summarized in the attached files, and the changes are marked in red in the uploaded revised version of the manuscript.
The reviewers suggested that we should include lots of information related to the types of swimming pools in Poland, including the water quality standards. This information has not been previously available in English and we are hoping that by enriching our paper with this information it will find more readers.
The point-by-point response to the reviewer 1's comments is upload as a .pdf file. Please see the attachment. Our answers are marked in red.
Author Response File: Author Response.pdf
Reviewer 2 Report
The research undertakes a study pertaining to a well-researched area of water management for rainwater harvesting for specific use in swimming pools. The discussion of results related to the analytical compounds/water quality parameters must be coherently discussed. Authors must discuss the implication of location impact of other environmental factors impacting the final quality. Just assuming pre-treatment prior to swimming pool use would take care of the requisite standards is not good enough. Literature reports in terms of removal efficacy of these detected compounds must be discussed and potential solution must be identified.
For Table 2: Authors must clearly state more details about the methods and experimental parameters, instruments used etc so that the data can be reproduced.
The english language needs improvement in terms of concise writing.
example: From Line 151-158, one long sentence cannot be a stand alone paragraph. Break it down.
Author Response
We would like to thank all the Reviewers for their valuable help in improving our manuscript. As can be seen in the revised text, their comments, remarks, and suggestions have been taken into account during the revision. Detailed responses to reviewers are summarized in the attached files, and the changes are marked in red in the uploaded revised version of the manuscript.
The reviewers suggested that we should include lots of information related to the types of swimming pools in Poland, including the water quality standards. This information has not been previously available in English and we are hoping that by enriching our paper with this information it will find more readers.
The point-by-point response to the Reviewer 2’s comments is upload as aPDF file. Please see the attachment. Our answers are marked in red.
Author Response File: Author Response.pdf
Reviewer 3 Report
Specific Comments:
1. Was the color of water examined and analyzed in this study? Please comment on the color of rainwater in the samples collected in this study. Also, is the color of water a parameter that should be controlled according to the standard for swimming pools in Poland?
2. Table 3 shows that the water pH in R2, R3, R4 and R5 are lower than the minimum recommended pH values according to the standards for swimming pools (Table 4). Please comment on this issue and recommend methods for the adjustment of water pH.
3. Line 184: The sentence on this line is confusing since, as reported in Table 4, the pH range of 6.5 – 7.6 is the pH recommendation according to the water quality standards for swimming pools, not the pH values of rainwater samples collected in this study.
4. What is the recommended Zn value based on the water quality standards for swimming pools in Poland? Please add this information to the manuscript.
5. The statements on lines 216-285 are better suited for the Introduction section of the manuscript, and should be moved to that section.
6. Line 254: Please correct the unit (mL).
7. Table 5 should include a column to present the concentrations of identified organic micropollutants in the collected samples.
8. What is the annual volume of water commonly used in swimming pools in Poland? How important would the use of harvested rainwater be in supplying the required amount of water for swimming pools?
9. Results and Discussion section: What treatment methods do the authors recommend for the removal of detected micropollutants from the harvested rainwater? Comments on this issue should be added to the manuscript.
10. Please comment on the applicability and commercial viability of the recommend treatment methods for the removal of micropollutants in an effort to use rainwater for swimming pools. Comments on these issues should be added to the R&D section and will improve the quality of manuscript.
The manuscript contains minor grammatical errors that should be corrected.
Author Response
We would like to thank all the Reviewers for their valuable help in improving our manuscript. As can be seen in the revised text, their comments, remarks, and suggestions have been taken into account during the revision. Detailed responses to reviewers are summarized in the attached files, and the changes are marked in red in the uploaded revised version of the manuscript.
The reviewers suggested that we should include lots of information related to the types of swimming pools in Poland, including the water quality standards. This information has not been previously available in English and we are hoping that by enriching our paper with this information it will find more readers.
The point-by-point response to the Reviewer 3’s comments is upload as a PDF file. Please see the attachment. Our answers are marked in red.
Author Response File: Author Response.pdf
Reviewer 4 Report
The article is focused on investigating the potential use of rainwater for filling swimming pools, particularly in the context of water quality and the formation of disinfection by-products. The authors discuss the growing issue of water stress and scarcity, particularly in European regions, and highlight the importance of sustainable water management strategies. They emphasize the underutilized potential of rainwater as a source of water and its relevance in mitigating water shortages and floods.
The article proceeds to outline the methodology employed for the study, including the collection and analysis of rainwater samples from different locations in the Upper Silesia Region of Poland. The authors conducted a comprehensive analysis of various water quality parameters, including nutrients, metals, and semi-metals. They also performed non-target chromatographic analysis to identify a range of organic micropollutants present in the rainwater samples.
The findings of the study are summarized and discussed, highlighting key aspects:
Rainwater as a Resource: The study supports the idea that rainwater harvested from roofs could serve as a valuable source of water for swimming pools, particularly in line with European policies focused on sustainability and green initiatives.
Water Quality Parameters: The authors found that certain water quality parameters such as pH and nitrate levels were in accordance with Polish standards for swimming pools. Turbidity levels exceeded the permissible limit, but the water treatment processes used in swimming pools could effectively address this concern.
Metal Contamination: The presence of metals in rainwater, specifically zinc, is noted as a potential concern. The study indicates that toxic by-products could form when chlorine compounds are introduced, raising questions about the compatibility of rainwater with swimming pool disinfection practices.
Organic Micropollutants: The presence of various organic micropollutants in rainwater is highlighted. The authors emphasize the potential risks associated with these compounds, including the formation of disinfection by-products like trihalomethanes (THMs) and chloroform when the rainwater is disinfected for use in swimming pools.
Limitations and Implications: The authors acknowledge limitations in their study, particularly regarding the microbiological parameters. They argue that the heavy disinfection practices in swimming pools would likely address microbiological concerns, making them less relevant to the study's main focus.
In conclusion, the authors suggest that while rainwater could be a viable source for filling swimming pools, potential challenges related to metal contamination and organic micropollutants need to be carefully considered. The study underscores the importance of water quality monitoring, appropriate treatment methods, and regulatory standards when considering rainwater reuse for specific applications like swimming pools.
However, there are a few potential gaps or areas that could be further addressed or explored:
- While the study acknowledges that the focus is on physico-chemical parameters and not on microbiological parameters, it's important to recognize that microorganisms can play a significant role in water quality and health considerations, especially in a setting like a swimming pool. It would be valuable to briefly discuss how the study accounts for potential microbial risks and how disinfection practices would address these concerns.
- The study was conducted over a relatively short period (from April to June 2023). Rainwater quality can vary significantly across seasons, weather patterns, and regions. A more extensive sampling period could provide a better understanding of the variability of rainwater quality and its implications for different end uses.
- The study discusses the presence of various organic micropollutants, some of which are toxic or have health implications. However, a more comprehensive risk assessment could be valuable. This assessment could consider exposure pathways (oral, inhalation, dermal contact), potential health effects, and ways to mitigate these risks in the context of swimming pool use.
- The article focuses on the potential use of rainwater for swimming pools. However, it might be useful to compare the water quality of rainwater with other potential sources (e.g., tap water or well water) that are commonly used for pool filling. This would provide context for the suitability of rainwater compared to existing practices.
- While the study identifies potential contaminants, it doesn't elaborate on how these pollutants might behave once introduced to a swimming pool environment. Understanding how pollutants interact with pool disinfectants, how they might degrade or transform, and whether they could contribute to the formation of new disinfection by-products within the pool water is important.
Finally, the concern about DBP formation and associated health risks is not unique to rainwater. Indeed, the formation of THMs and other DBPs is a well-known issue in chlorinated water treatment, including tap water. By raising this question, the authors highlight the need for a comprehensive risk assessment across various water sources, taking into account the potential DBP formation and associated health effects.
The potential for DBP formation exists whenever water is disinfected with chlorine. Thus, the challenge is not isolated to rainwater. Water treatment processes for both tap water and harvested rainwater must consider strategies to mitigate DBP formation. This could involve optimizing chlorine dosing, considering alternative disinfection methods (such as ozone or UV treatment), or implementing advanced treatment techniques that target specific organic contaminants.
The authors rightly emphasize that swimmers can be exposed to DBPs through multiple pathways, including oral ingestion, inhalation of volatile compounds, and skin contact. This exposure pathway concern is applicable to all sources of water used in swimming pools, not just rainwater. Ensuring proper water treatment and maintenance practices, as well as monitoring water quality, are essential for minimizing health risks to swimmers.
Author Response
We would like to thank all the Reviewers for their valuable help in improving our manuscript. As can be seen in the revised text, their comments, remarks, and suggestions have been taken into account during the revision. Detailed responses to reviewers are summarized in the attached files, and the changes are marked in red in the uploaded revised version of the manuscript.
The reviewers suggested that we should include lots of information related to the types of swimming pools in Poland, including the water quality standards. This information has not been previously available in English and we are hoping that by enriching our paper with this information it will find more readers.
The point-by-point response to the Reviewer 4’s comments is upload as a PDF file. Please see the attachment. Our answers are marked in red.
Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
Dear authors,
please find comments in the attachement.
Comments for author File: Comments.pdf
Author Response
We would like to thank all the Reviewers for taking the time to re-review our manuscript and for all valuable comments that allowed us to improve it even further. As can be seen in the revised text, their comments, remarks, and suggestions have been taken into account during the second round of revision. Detailed responses to reviewers are summarized in the attached files, and the changes are marked in red in the uploaded revised version of the manuscript.
The point-by-point response to the Reviewer 1's comments is upload as a .pdf file. Please see the attachment. Our answers are marked in red.
Author Response File: Author Response.pdf
Reviewer 3 Report
Comments on the revised version of manuscript:
The authors have responded to my questions and incorporated my comments. The quality of manuscript has been improved after the revision, and it can be accepted for publication in the present form.
Author Response
Thank you for taking the time to re-review our manuscript and for all your valuable comments that allowed us to improve it. We are grateful for the positive feedback.
Reviewer 4 Report
Small issues must be corrected, such as the following:
Page 12, line 404 - Should it be NO2 or NO3?;
Page 12, line 414 - A lower pH favors the disinfection process and not the opposite;
Page 12, line 432 - It is not clear that the NTU scale is only up to 10, when a much lower scale could be constructed or a nephelometric reader could be used. The usefulness of Figure 5 is also not understood;
Page 17, table 6 - remove the division symbol by a dash, the same occurs in the text;
Finally, the conclusions must clearly state whether it is possible and desirable, both from an environmental and economic point of view, to use rainwater to fill public and private swimming pools and whether there are obstacles to its use.
Author Response
We would like to thank all the Reviewers for taking the time to re-review our manuscript and for all valuable comments that allowed us to improve it even further. As can be seen in the revised text, their comments, remarks, and suggestions have been taken into account during the second round of revision. Detailed responses to reviewers are summarized in the attached files, and the changes are marked in red in the uploaded revised version of the manuscript.
The point-by-point response to the Reviewer 4's comments is upload as a .pdf file. Please see the attachment. Our answers are marked in red.
Author Response File: Author Response.pdf
