Design, Scale-Up, and Construction of Drinking Water Recarbonization Fluidized Bed Reactor System
Round 1
Reviewer 1 Report
The study seems interesting and provides useful information to the decision-makers on the degree of lack of calcium and magnesium in drinking water. But it is vaguely written. Language is not proper, which makes understanding very difficult. The other concern is a novelty. Adding optimizing modeling tools could cover up the novelty aspects. The manuscript cannot be accepted in its current form. I think the following comments need to be addressed:
1. Abstract: add some quantitative information to the abstract. Abstract also does not give any design-related information or the effect of operating parameters.
2. Keywords--Avoid duplicating words used in your title. Be specific and use multi-word “key phrases” where possible.
3. Line 66--- Re-write “very popular hardening technique”. Replace “hardening” by “softening”.
4. Line 78--- Kindly check “remineralization” or “demineralization”.
5. Line 84---Reference papers [13,23] contain the same title “Improving Drinking Water Quality by Remineralisation”. Kindly check if it is the same or different.
6. Line 127--- Kindly elaborate it “PP 50035-2018”.
7. Line 149---"4.0 mm and water was 0,047m/s”. There should be uniform spacing between numbers and units. Use same pattern throughout the manuscript.
8. Figure 1 is blurred.
9. Line 187--- Figure 1 should be transferred after its discussion in the text as (Fig 1).
10. There is no uniformity in the link of figures in the text. Sometimes Fig. or Figures.
11. Line 206---What is this? “200 mg Mg/L”
12. The use of subscript and superscript needs to be reviewed throughout the manuscript.
13. Why didn’t authors mention the source of water? Because there are several issues encountered in real water source. Please explain.
14. Why authors didn’t discuss Figure 7, and 8?
15. Conclusion of study is missing.
Author Response
Please see the attachment.
Author Response File: 
Author Response.docx
Reviewer 2 Report
In this article, the authors present a summary of the results of several works on the design, scale-up and construction of a drinking water recarbonization system based on a fluidized bed reactor. If this article format is allowed by the Processes, then I definitely recommend this article for publication. The work is easy to read and has undoubted practical interest. I have comments (see pdf file) that should be addressed before being accepted for publication.
Good luck.
Comments for author File: 
Comments.pdf
Author Response
Please see the attachment.
Author Response File: Author Response.docx
Round 2
Reviewer 1 Report
The topic of the paper is interesting, but the paper has not been properly revised. In my opinion, the revision does not bring significant improvements in the manuscript. Overall, the revision is vaguely done. There are so many missing links, and the paper is currently very weak. The authors have addressed my previous comments 9, 10, 11, 14 and they didn't take into consideration the previous point related to Figure 6, 7, and 8 discussion. Even revised version contains many typo error such as Line 222- “hight”, Line 338-“ increas”, Line 352-“ „age“of”, Line 444-“ CO2was” etc. Therefore, this paper cannot be accepted without considering these issues.
Author Response
Response to Reviewer 1 Comments
2nd Revision
Point 1: The authors have addressed my previous comments 9, 10, 11, 14 and they didn't take into consideration the previous point related to Figure 6, 7, and 8 discussion.
Response 1: Added discussion of Figures 6, 7, and 8 to the text: The experimental results presented in Figures 6 and 7 indicate significant effect of recarbonization process on HCD particle size. Since HCD releases ions from their surface an average size of particles decreases and therefore both cumulative and differential particle size distribution is shift towards smaller diameters. Release of ions from the particles makes them more brittle and therefore the particles change the diameter also by attrition since the particles are in intensive mutual contact in fluidized bed. Presence of small particles formed due to attrition in the system improve water - solid particles contact what positively affects effectiveness of recarbonization process. On the other hand very small particles can be entrained from the fluidized bed reactor what decreases utilization of HCD for the process. Changes of particle shape caused mainly by attrition is presented in Figure 8. Fresh particles have sharp edges and due to fluidization and mutual contact of solids and HCD consumption the particles lose their sharpness and they are rather rounded. This phenomena affects fluidization characteristics of the HCD. Presented results indicated that the recarbonization process in three phase fluidized bed is very complex and it is difficult to predict the system behaviour using common methods. Therefore, long term experimentation at different process conditions is the only way how to design reliable equipment and sustainable process.
Point 2: Even revised version contains many typo error such as Line 222- “hight”, Line 338-“ increas”, Line 352-“ „age“of”, Line 444-“ CO2was” etc.
Response 2: Type errors, subscript and superscript were reviewed and corrected throughout the manuscript. The descriptions of the Y axes in Figures 3 and 5 have been corrected. Conclusions were extended.
The authors thank the reviewer for his patient and detailed reading and valuable comments and suggestions that helped to improve the quality of the manuscript.
Author Response File: Author Response.pdf
Round 3
Reviewer 1 Report
The manuscript has been revised well. All the comments have been considered in the revised version. Therefore, I recommend accepting this manuscript.
