Chlorine vs. Sodium Chloride Regeneration of Zeolite Column for Ammonium Removal from an Explosives Impacted Mining Wastewater
Round 1
Reviewer 1 Report
General comments:
1. Review all “ammonia” in the text and consider using “ammonium” when needed (for example in line 36: ammonium nitrate. As you explain, the IE column is interacting with ammonium, not ammonia.
2. Plots in graphs should be shown without lines and never using smoothed lines. Lines are used for models or regressions. Please use only dots.
3. Figures showing the same experiment could be placed one next to the other, so in the same lines (reducing the size). This would help the reader to follow the comments and to reduce the extent of the article.
4. Please make sure the order of the species in the legend of the figures are always the same.
5. In general, the text is too long, there are ideas that are commented several times in different sections and many explanations could be simplified and reduced.
6. A cost comparison of the two regeneration options would help in the final discussion and conclusions. Also, safety and practical issues for the practical implementation. This is missing in the article and should be improved.
Specific comments:
Tittle: consider changing “salt” by “sodium chloride” and changing “ammonia removal” by “ammonium removal”
Line 24. SIR-600 is mentioned but it has not been introduced yet. Can be removed
Line 48. I do not agree with the sentence “limited chemical supply needs”. IE needs chemicals for regeneration. This sentence should be quantified or include a reference. As it is now it is not credible.
Line 66. NH4+-N is mentioned. Why is it mentioned like this if you always use ammonia or TAN to refer to it? In fact , NH4+-N is not a nitrogen specie, it is a way of quantifying it.
Line 94. Please introduce a title for the following paragraphs, for an easier reading.
Line 163. Consider introducing a table with the summary of the experiments, the experimental conditions, and the names of the experiments. It will help the reader a lot.
Line 185. No need to repeat “1000 ppm as free Cl2”. This is already explained in the previous sections.
Line 187-189. No need for this information. This is already explained in the previous sections.
Line 198. This comparison is repeated four times in the text, with the same arguments. Please do it in a way that it is compared just once.
Line 205. In this position Figure 1 an Figure 2 could be shown.
Line 214. Specify the range reported in the literature.
Line 215. You say that the column achieves higher TAN:K ratios. Please specify what are you comparing with.
Line 221. Specify “data not shown” if it is the case.
Line 245. Info already explained in materials section. Could be removed from here or introduced in a different way.
Line 251. Figures 3 and Figure N-1 could be shown together in the main text.
Line 281. I can see a repetition of Figure 4.
Line 296-298. This explanation seems contradictory with equations 1 and 3. In all cases reaction of chlorine and ammonia are considered but they are introduced without any relation among them.
Line 354. Improve “10-9”.
Line 359. Indicate “data not shown” if it is the case.
Line 365. Figure N-2 could be moved to the main article.
Line 413. Figure 2b?
Line 423. Indicate “data not shown” if it is the case.
Line 423. The SS breakthrough data was used…” this is an example of text that can be removed or summarized. This has been explained many times before.
Line 470. Figure 3 and Figure 8?
Line 489. “some of the ammonia” or “most of the ammonia”?
Line 494. Figure 5?
Line 495. Figure 4?
Line 495 “was essentially the same”. I can see a difference of 28% which is not “the same”
Line 497. Is equation 3 useful to predict the reaction time? Not sure
Line 505. Figure 5?
Line 519. “one could also the collect the..” review this sentence.
Line 531-532. Please quantify this conclusion.
Line 534. Please quantify this conclusion.
Line 537. Please quantify “limited combined chlorine generation”.
Line 541. “smaller but significant” seems contradictory. Please be more specific.
Line 547. Probably with a different experimental set-up the nitrogen could be quantified. Do not use this as an argument for further research.
Author Response
Thanks for the thorough review and comments.
Author Response File: 
Author Response.docx
Reviewer 2 Report
The present manuscript entitled “Chlorine vs Salt Regeneration of Zeolite Column for Ammonia Removal from an Explosives Impacted Mining Wastewater” brings some insights about the removal of ammonia by Zeolites. However, before accepting the work for publication, the authors need to revise as per the following.
1. Introduction section, I see there is no order in terms of introducing the subject, discussing the problem, solution to that problem etc. Therefore, the authors need extensive revision of this part.
2. There are so many English grammatical corrections, in the Introduction section and also other sections of the manuscript.
3. In the Results and Discussion section, there is no information about the physical characteristics of the adsorption bed material. It is highly required to have the physical properties so as to connect to the final performance.
4. There is no experimental proof for the regeneration of materials like chlorine and TAN. The authors need to provide spectrographical proof for the confirmation of their findings.
5. Overall, there are so many hypothetical predictions/assumptions from the trend of analysis, the authors need to provide graphical evidence for the confirmation.
Author Response
Please see response in attached file.
Author Response File: Author Response.docx
Round 2
Reviewer 2 Report
I see that the changes made are seems to be ok. The work can be accepted for publication in its present form. In actual, I was analyzing the work in some perspective and so made some comments according to that, which the authors did not agreed. I do agree with them and conclude that their vision is better than my analysis about the topic and its results. Therefore, I must accept this work in the presented form.
