Granular Natural Zeolites: Cost-Effective Adsorbents for the Removal of Ammonium from Drinking Water
Round 1
Reviewer 1 Report
The manuscript provides novel insights into the use of natural zeolites for removing ammonium from drinking water (or other water sources). Several conditions such as pH, media grain size, ammonium loading, etc. have been explored to evaluate the effect on the removal efficiency and kinetics.
Overall, this is a well written manuscript with the properly designed experiments, rationalization of data and strong correlation between the results and the conclusions drawn.
Minor revisions
1) Authors are requested to change the molecular formulae numbers to subscripts (e.g. NH4, where 4 should be a subscript) throughout the manuscript.
2) please check for typos (e.g. line 94, "remarkably" should be "remarkable"
3 ) Line 129 - 132, is visual inspection sufficient to ensure all the salts and excess adsorbed cations are washed off? at least conductivity of the washing liquid needs to be monitored.
Author Response
Please see the attachment
Author Response File: 
Author Response.pdf
Reviewer 2 Report
The manuscript provides an excellent insight into the suitability of granular natural zeolites as adsorbents for ammonium from drinking water. The abstract, introduction and context-setting part are written nicely. However slight improvement in methodology part are required, particularly the authors can slightly improve how treatment application was done and which design of experimentation was applied, for enhanced understanding of the readers. Why Langmuir model, Freundlich model were used, I mean why not others? Is there any specific scientific reason?
Results and discussion sections are ok, though slight improvement in English language may be made. Conclusion part is too lengthy, please rewrite in an abridged form. It look more like a summary.
Considering the importance of study and quality of manuscript, it may be accepted for publication after minor revisions.
Author Response
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Author Response File: Author Response.pdf
Reviewer 3 Report
A considerable amount of work has been done in this manuscript but the authors need to address some important queries prior to publication. The authors need to discuss a bit more their results, try to find and describe better the reasons for the level of performance of their adsorbent material for NH4 removal from drinking water and compare better with literature.
The authors should pay attention to the following comments:
-The authors need to discuss a bit more their results, try to find and describe better the reasons for the level of performance of their adsorbent material for NH4 removal from drinking water (It is known from the literature that zeolite has also been used as adsorbent material for NH4 removal from water) and compare better with literature. What's new in their studies?
- Please added the city and country to the instruments using in the studies.
- May be it should be studied the dosage of adsorbent material.
-It is necessary to add a comparative data cited in the literature regarding other possible adsorbent materials (adsorption capacity), used for NH4 removal from drinking water.
- Please perform the SEM/XRD analysis after adsorption studies.
- The manuscript may be accepted after minor revision
Author Response
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Author Response File: Author Response.pdf
Reviewer 4 Report
Authors presented the results obtained by study conducted in order to investigate the efficiency of ammonium removal by granular natural zeolite by adsorption. Experiments were performed using model solutions and various zeolite grain size, pH, contact time, initial ammonium concentration, and presence of competing ions.
The manuscript is well writen, amd obtained results are clearly presented.
Only several technical erors in text are noted.
Sugestions to authors for minor corrections in text are given in attached file.
Comments for author File: Comments.pdf
Author Response
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Author Response File: Author Response.pdf
