Passive Detection of Phosphorus in Agricultural Tile Waters Using Reactive Hybrid Anion Exchange Resins
Round 1
Reviewer 1 Report
Paper is well written, English language is good, the topic is interesting.
Just few corrections should be made:
Title 2.10.3 should be written in more detail, e.g.:
The load of phosphorus loss
Title 3.3. should be moved below the Fig.4
L431: Figs. 10and - before "and" should be space
Some explanation of Fig.8 should be added.
Conclusion, L500-502: it is not common to cite literature in Conclusion. Rephrase the sentence in these lines.
Author Response
Reviewer 1
Paper is well written, English language is good, the topic is interesting.
Just few corrections should be made:
Title 2.10.3 should be written in more detail, e.g.: The load of phosphorus loss
Response: It was edited to “The load of phosphorus loss in tile lines”.
Title 3.3. should be moved below the Fig.4
Response: The location of the fig 4 was set by the editorial office. We have no control over this.
L431: Figs. 10and - before "and" should be space
Response: A space was added.
Some explanation of Fig.8 should be added.
Response: thank you for your comments. We added the explanation in the section 3.3.3.
According to the result of calibration experiments and water flow rate in each tile line (Fig. 8), the passive-sampled P in the hybrid resins was converted into the average concentration of DRP in tile water using on the laboratory sampling rate and the field sampling rate. The flow rate showed that there are several storm events (flow rate > 0.5L /s) during the study period (Fig. 8).
Conclusion, L500-502: it is not common to cite literature in Conclusion. Rephrase the sentence in these lines.
Response: Although we appreciate the comments, we feel that our sentence reflects to the implications and future study needs.
“It should be further studied whether the predicted DRP in the passive sampling was affected by particulate P, since a considerable amount of particulate P in tiles is released during storm events [61–63]. “
The conclusion is a paragraph above. We feel that these references are acceptable in this section.
According to the guideline, conclusion is not mandatory. So we edited the sub section title from “conclusion” to “Conclusion and Future Implications”. This should accommodate your question.
Reviewer 2 Report
I prepared the manuscript review Passive detection of phosphorus in agricultural tile waters using reactive hybrid anion exchange resins written by
Zhe Li, Maria Librada Chu, Lowell Gentry, Ying Li, Corey Mitchell and Yuji Arai
The study is clear and adequately described. I propose to publish.
Author Response
Thank you for your time to review.
There was no comments. It was recommended
Reviewer 3 Report
this is a very good manuscript! the monitoring of phosphorous in fresh water system is important to avoid eutrophication. I miss a comparison of labour and expense if you use ordinary sampling and this passive method. There are other methods for measuring the amount of P coming to a wetland see Water 2016, 8(11), 544. I do not think that all people that like to monitor the P release can fix this resin so I suppose that there will be a comercially available product in the future? Is it possible to catch other nutrients at the same time?
Comments for author File: 
Comments.pdf
Author Response
See our reply to annotation in PDF. Our response to the general comments is below
Comments and Suggestions for Authors
this is a very good manuscript! the monitoring of phosphorous in fresh water system is important to avoid eutrophication. I miss a comparison of labour and expense if you use ordinary sampling and this passive method. There are other methods for measuring the amount of P coming to a wetland see Water 2016, 8(11), 544. I do not think that all people that like to monitor the P release can fix this resin so I suppose that there will be a comercially available product in the future? Is it possible to catch other nutrients at the same time?
Response: Thank you for your comments. In the intro, a comparison expense between this and a sensor were mentioned but we did not mention it about labor. We mentioned about the labor between two techniques.
We appreciate the reference, but in this paper, they used “automatic flow-proportional water sampling in the inlet and outlet of three created wetlands”. If we want to monitor P in all waterbodies in state(s), it is too expensive to purchase and deploy Auto samples. This is our point. Our method (resin bags) is very inexpensive. We already justified it in the introduction section. See below.
“…………..However, due to the high cost of flow monitoring equipment and intensive sample analysis, it is not feasible to comprehensively assess P loads in agricultural drainage ditches and tile lines throughout the Midwestern United States [5] because of the cost. Therefore, it is ideal to develop a quick, easy, and inexpensive technique that could be used to monitor the P concentrations in agricultural waters during critical wet seasons when a large quantity of P is discharged from agricultural fields.”
If other nutrients/contaminants strongly react with iron oxides, Yes, it is possible to monitor it with P. We edited the last sentence to:
“……The technique might be of interest to a large-scale monitoring project to understand and manage P loss and other dissolved contaminants, which have strong attraction to iron oxides, in watersheds and or a river basin.”
Author Response File: Author Response.pdf
