Life Cycle Assessment of Green Space Irrigation Using Treated Wastewater: A Case Study

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

In this work, the authors investigated the environmental implications of using TWW for lawn irrigation in the city of Viseu. I recommend improving the resolution of the figures and the labels of the axes. In the conclusion, the authors should elaborate on the impact of the results for the city of Viseu.

Author Response

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Author Response File: Author Response.docx

Reviewer 2 Report

Comments and Suggestions for Authors

In this paper, the method of life cycle assessment (LCA) was used to evaluate the environmental impact of green space irrigation with treated wastewater. It is proved that the use of treated wastewater for green space irrigation is feasible in the environment, and has a positive impact on human health and ecosystem. This provides a scientific basis for wastewater reuse and is of great significance for water resources management and sustainable development.

The article has the following problems that need to be further improved:

1. The specific technologies and measures in the process of wastewater treatment are briefly mentioned in the chapter, but there is no in-depth discussion. It is suggested that the types, treatment technologies and measures of wastewater should be explained and analyzed in more detail in the part of materials and methods, so that readers can better understand the practical application and popularization value of the research.

 

2. The article does not consider the impact of the sewage treatment process in the system boundary of the life cycle assessment (LCA). It is recommended to add this discussion in the discussion section to explain the possible impact on the results.

 

Author Response

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Author Response File: Author Response.docx

Reviewer 3 Report

Comments and Suggestions for Authors

This paper provides a comprehensive Life Cycle Assessment (LCA) of using treated wastewater (TWW) for irrigation in Viseu, Portugal. The study is well-structured and presents a clear objective, thorough methodology, and detailed results. However, several areas need improvement to enhance clarity and depth.

My suggestions and comments are presented as follows:

-Lines 41-45: Can the authors elaborate on the limitations and challenges of the technological advances mentioned (seawater desalination and dam construction) in the context of water reuse? How do these technologies compare to treated wastewater reuse in terms of cost, efficiency, and environmental impact?

-Lines 46-57: Are there specific examples or case studies from other regions or countries where the use of treated wastewater for irrigation has been successfully implemented? How do these examples compare to the situation in Viseu?

-What are the potential environmental and health risks associated with the use of treated wastewater, and how are these risks managed or mitigated in this study?

-Lines 58-69: Could the authors provide more detailed information on the regulatory and policy frameworks in Portugal that support or hinder water reuse initiatives? How do these frameworks compare to those in other EU countries?

-Throughout the Introduction, there are several broad statements about the benefits of treated wastewater reuse. Could the authors provide more specific data or evidence from previous studies that quantify these benefits, particularly in terms of environmental and economic impacts?

-How does this study build upon or differ from the previous LCA studies on wastewater reuse highlighted in the review?

-Lines 95-101: Can the authors provide more detailed information about the climate of Viseu and how it influences irrigation needs throughout the year?

-The quality parameters of TWW are listed in Table 1. How do these parameters compare to the requirements for safe and effective irrigation of green spaces?

Have there been any observed impacts on soil health, plant growth, or biodiversity in the areas irrigated with TWW compared to those irrigated with tap water?

-Lines 135-150: Can the authors provide more details about the specific environmental impact categories considered in this LCA study? Why were these particular categories chosen?

-Lines 151-161: How might the inclusion of water treatment and facility construction processes change the environmental impact results of this study?

The system boundary diagram (Figure 2) is helpful, but can the authors provide a more detailed explanation of each included process, particularly the avoided use of chemical fertilizers?

-The normalization of flows is mentioned but not detailed. Can the authors explain the normalization process and its significance in the context of this study?

- Lines 269-278: How do these findings compare to other studies or practices in regions with similar climates and water scarcity issues?

- Lines 279-297: What potential solutions or mitigation strategies can the authors suggest to reduce the negative environmental impacts related to TWW transport and electricity consumption?

Can the authors provide a more discussion that includes both the positive and negative environmental impacts of using TWW for irrigation?

-Lines 298-312: Can the authors expand the comparison with other studies to include a broader range of impacts and more examples from different regions or contexts?

How do the findings of this study align with or differ from those of other studies, and what are the implications for future research and practice?

General suggestions to improve the discussion:

-What are the main limitations of this study, and how might they impact the overall conclusions and recommendations?

-Are there any plans to conduct follow-up research or implement pilot projects to further validate and expand on these findings?

-How can the study findings inform broader regional or national strategies for sustainable water management and reuse?

 

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Round 2

Reviewer 3 Report

Comments and Suggestions for Authors

The revised manuscript is sufficient. The quality of the manuscript has been improved and it can be published in present form.