Carbon Emission Reduction of Reclaimed Water Use Substitution for Inter-Basin Water Transfer and Sustainability of Urban Water Supply in Valley Area

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

As for numerous literatures on resource, economic, and ecological impact of IBWT, this manuscript focused on the environmental impact of IBWT compared with reclaimed water use from the perspective of carbon emission. I think this is very interesting to sustainable water management.

 1. Introduction: this part is very expansive to the background for this study. Please add the contributions of this study.

 2. Section 2: in line 209 to 219, please distinguished what are the planning contents and what are the author's assumptions.

 3. Line 316, Please verify if the table for CE type source in Table 2 is correct? I think it should be table 4, not the table 3.

 4. Some Incorrect labeling of CO₂ should be correct.

 5. It should pay attention to the limitations of this study. Firstly, Because the economic costs and water quality of the two water supply methods are different, they actually meet different needs and purposes. Therefore, simply proposing their mutual substitution has certain limitations; Secondly, the research results of this manuscript are largely depended on the inclusion energy consumption of steps and projects of two water supply methods into the accounting process. Please give enough explanation why the first and second treatments of waste water treatment are considered as sunk costs. Thirdly, when waste water is treated into different levels of water quality, such as ecological water or drinkable water, its energy consumption varies. The author should pay attention to these points in discussion and conclusion.

 6. The CO₂ emissions from IBWT are relatively higher mainly due to the huge amount of electricity consumed for pumping stations to lift water. If the power supply structure is changed into clean energy，such as clean hydropower or wind energy, or combining pumped storage power stations, the CO₂ emissions of this energy consumption can be reduced. In addition, for the adjustment of Chongqing's power supply structure in 6Line 75, it should pay attention to the possibility of increasing the use of external clean energy, such as hydropower from Sichuan Province.

 7. there is no section 4.

 

 

Comments on the Quality of English Language

I think the English expression in this article is very fluent, only requiring minorl modifications.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

Manuscript ID: water-3058661

Title:  Carbon emission reduction of reclaimed water use substitution for inter-basin water transfer and sustainability of urban water supply in valley area
General Comments:

Originality: The authors used novel ideas in their research, which is appropriate for this journal.

Scientific Quality: The work titled "Carbon emission reduction of reclaimed water use substitution for inter-basin water transfer and sustainability of urban water supply in valley area" is very well structured and scientific and is written in a way that is easy to understand.

Relevance to this Journal's Field(s): The article is relevant because the objectives and scope align.

 

Therefore, this is an exciting research work. Some aspects need to be revised. My recommendation is a Major revision to fulfil the journal standards The specific comments are given below:

Comments 1: The abstract does not provide sufficient context about water scarcity and environmental degradation in the Chongqing municipality or the valley region. A brief overview of the problem's background would help set the stage for the study.

Comments 2: The abstract ends abruptly without a clear concluding statement highlighting the findings' significance or their broader implications. A strong concluding sentence would reinforce the importance of the study and its contributions to the field.

Comments 3: The introduction provides extensive background information on various water resource management strategies, but does not connect this information to the specific research focus on carbon emission reduction through reclaimed water substitution. A more focused narrative that ties the background information directly to the research question would be beneficial.

Comments 4: Although some previous studies are mentioned, the introduction could benefit from a more comprehensive review of existing literature on the topic. This would help situate the current study within the broader research context and highlight its unique contributions.

Comments 5: Figure 1 shows a schematic map of the Inter-basin Water Transfer project. This map should include geographical dimensions, specifically the latitudinal and longitudinal extents, as well as an appropriate scale.

Comments 6: The study does not appear to account for future changes in water demand, population growth, technological advancements, or climate change, all of which can influence the carbon emissions associated with water transfer and reclaimed water systems.

Comments 7: The emphasis on carbon emissions may overlook other critical factors in water resource management, such as water availability, quality, and the overall sustainability of water use practices. An explanation is needed to understand why these elements are being overlooked.

Reviewer’s Decision Comment: This paper was prepared with science in mind. After improvement, this might be okay, however, I firmly advise performing some major checks.

Best wishes

 

 

 

Author Response

Please see the attachment.

Author Response File: Author Response.pdf