Evaluation of Portable Rhodamine B Analyzer for Monitoring OH Radical Scavenging Demand in Ultraviolet Advanced Oxidation Processes

Round 1

Reviewer 1 Report

Manuscript ID: sustainability-1457702
Title: Evaluation of portable Rhodamine B analyzer for monitoring OH radical scavenging demand in ultraviolet advanced oxidation processes

Reviewer comments

It is a well-executed and clearly described study that has practical application in evaluating municipal water quality. The proposed method is relatively simple, but the well-known chemistry of rhodamine B scavenging radicals can be applied in practical applications. The authors demonstrated the application of the RhB-H2O2-UV system in the evaluation of water quality in four different sites, which was tracked for a year. The calibration of the system and the differences in the radical scavenging demand were performed using water samples from four different sites. Under controlled concentrations of H2O2 and UV intensity, there were clearly discernable differences between tested samples. This manuscript describes a complete package solution that can be readily deployed to aid water quality evaluation in any similar environment.

Author Response

English language and style are fine/minor spell check required

• Thank you for your insightful comments and suggestions. The revised manuscript was reviewed by a native speaker again. After review, we carefully check the manuscript.

Reviewer 2 Report

This article describes the development of portable OH radical scavenging demand analyzer, and it can be used to measure water quality indicators that influence the generation of OH radicals from UV/hydrogen peroxide reactions to determine UV dose and hydrogen peroxide injection concentrations. It is of great significance to monitor water treatment indicators, and it makes water quality monitoring more convenient. In addition, this article has been very well written and nicely put together with a lot of care and it is also evident that the authors have attempted to be very thorough.

1. The portable instrument we usually define can be easily carried. Can the author provide the specific size and weight of the whole instrument in the article, preferably in Figure 1, and it helpful to evaluate whether it is easy to carry. In addition, what is the mean of “…can be installed and operated on site...”
2. In Figure 2, the data in the calibration curves does not contain the original point, please delete it.
3. Please remake the Figure 3. In all figures, I think the number of the picture should be placed in the upper left corner.
4. Figure 6 should be remaked.
5. 5. Authors need to check your English and spelling.

Author Response

1. The portable instrument we usually define can be easily carried. Can the author provide the specific size and weight of the whole instrument in the article, preferably in Figure 1, and it helpful to evaluate whether it is easy to carry. In addition, what is the mean of “…can be installed and operated on site...”

     --> Thank you for your insightful comments and suggestions. We added the size of the instrument.(Lines 90~91) As shown in Figure 6, the OH radical scavenging demand showed different deviations depending on the location and time. These deviations affect the UV dose and the hydrogen peroxide injection concentration. Therefore, since the portable OH radical index measuring device presented in this study needs to be measured in the field, a device with a relatively small size was developed.

 

2. In Figure 2, the data in the calibration curves does not contain the original point, please delete it.

    --> We add the value of blank sample in figure 2 and manuscript. (Lines 159, 164)

 

3. Please remake the Figure 3. In all figures, I think the number of the picture should be placed in the upper left corner.

   --> We revised the location of picture number.

4. Figure 6 should be remaked.

   --> We revised the figure 6 as a bar graph for easier understanding by the reader.

5. Authors need to check your English and spelling.

   --> The revised manuscript was reviewed by a native speaker again. After review, we carefully check the manuscript.

Reviewer 3 Report

Minor issues like:

In page 2, line 51, the authors did not give the meaning of the abbreviation for ROH,UV. 

In line 56, the authors wrote an method instead of a method.

Author Response

1. In page 2, line 51, the authors did not give the meaning of the abbreviation for ROH,UV. 

   --> Thank you for your insightful comments and suggestions ROH and UV concept explanations and previous papers were presented. We added the meaning of the R_OH,UV. and reference. Rosenfeldt and Linden reported a measuring method for the ⦁OH scavenging demand using the R_OH,UV concept. R_OH,UV is defined as the ⦁OH exposure per UV dose. (Lines 44~45)

 

   2. In line 56, the authors wrote an method instead of a method.

   --> We revised the mistyping. Thank you.