Biogeochemical Permeable Barrier Based on Zeolite and Expanded Clay for Immobilization of Metals in Groundwater

Round 1

Reviewer 1 Report (Previous Reviewer 2)

The manuscript is much improved. The authors have done a great job of responding to comments all over the article and improving the English.  This manuscript will make a fine contribution to the literature as a research article. Thank you for all your efforts. I recommend to accept this article to publish in hydrology.

Author Response

Dear reviewer, thank you for the time devoted to our article.

Reviewer 2 Report (Previous Reviewer 1)

In this revised version, the authors made a lot of changes and adjustments, which significantly increased the manuscript's quality.

In my opinion, there are still some small errors which should be corrected. 

The most important of them consists of the absence of uncertainties as well as error bars. Both of them are absolutely necessary for a good quality paper. 

Please see the attached annotated pdf. file

My final recommendation: Accept after minor revisions

Comments for author File: Comments.pdf

Author Response

Dear reviewer, thank you for the time devoted to our article. All your comments have been taken into account and marked in the text.

point-by-point response

please, pay attention to the table format table1 line 104

Answer. Table format was corrected

ii. please include uncertainties to tab1 !!!!

Answer. uncertainties to tab1 were added

if possible, please add an URL line 111, 117, 153, 170,

Answer. All URLs were added

the same remark to table 2: for a higher scientific value pleas add the corresponding uncertainties line 239

Answer. uncertainties to tab1 were added

what do you mean - blue highlight ??? Line 261, 280-281, 345,

Answer. blue highlighting was removed

I would suggest this table to be moved to an Appendix. It contains only literature references, and no data. Line 351, tab 6

Answer. Table was moved to supplementary section (table 1-SI)

please, reformulate lines 370-371!

Answer. Done

for a better scientific value, please add the corresponding uncertainties to table 7, line 372. too many digits, 1.0 would be OK, please restrain the number of decimals.  please add error bars to line 374 to fig 4

Answer. Dear reviewer, thank you for your valuable comment. This table shows the calculated data of the phase saturation index in the PhreeqC 2.1 software (see line 226-231). We have changed the number of significant numbers after the decimal point, but unfortunately it is impossible to give error values based on these data. In the data given in the table, only a sign greater than or less than zero is significant. if the index value is less than zero, the formation of the phase is not predicted; if it is greater than zero, under our conditions, the phase can be thermodynamically stable. The same applies to Fig. 4. The value of the saturation index itself is not so important in this case. If its values are significantly higher than zero, then in general, we can talk about the high stability of the phase under the selected conditions. Thus, the uncertainties for these data are affected only from the uncertainties of the instrumental measurements given in Table 1.

please add error bars to fig 5

Answer. Done.

please do reference corrections everywhere the number of authors exceeds three.

Answer. Done.

Author Response File: Author Response.docx

This manuscript is a resubmission of an earlier submission. The following is a list of the peer review reports and author responses from that submission.

Round 1

Reviewer 1 Report

I have found the manuscript of interest as it proposes a new approach to the still  unresolved problem of environmental contamination by the product of chemical industry.

The manuscript presents new, original data, but the scientific quality could and should be significantly improved.

As the entire presentation is based on original experimental data, the authors should pay significantly more attention to quality assurance.

In this regard, the author should prove the quality of experimental data by providing a comparison with similar data obtained in the same conditions using Certified Reference Materials, and, what is most important, to provide for each experimentally determined data the corresponding total uncertainty.

Also, I would suggest the manuscript be revised by a native English speaker.

More remarks can be found in the attached annotated file.

My overall recommendation:  Reconsider after major revision 

 

Comments for author File: Comments.pdf

Reviewer 2 Report

The paper titled "BIOGEOCHEMICAL PERMEABLE BARRIER BASED ON ZEOLITE AND EXPANDED CLAY FOR IMMOBILIZATION OF CR, ZN, NI, CO, CU, MN, CD, SR, BA, PB IN GROUNDWATER" is interesting.

Due to some lack of presentation flow and writing style, the article will be difficult for the reader. I recommend to rewrite the article, revised by a native English speaker or professional to reconsider for publication. Herein, I have suggested the following remarks, believing that they can help authors to improve the updated version.
Please update the content of the abstract and introduction part.
1. It will be better to change the Title as BIOGEOCHEMICAL PERMEABLE BARRIER BASED ON ZEOLITE AND EXPANDED CLAY FOR IMMOBILIZATION OF HEAVY
METALS IN GROUNDWATER.
2. Line 18-20, the sentence “Using a sample of groundwater polluted with high levels of nitrate and sulfate, collected 18at a depth of 8-10 meters from the basin of the Siberian Chemical Plant multicomponent waste storage, the feasibility of creating a permeable biogeochemical barrier based on zeolite and expanded clay was studied.“is not clear. Rewrite this sentence.
3. Line 23-25, Specify the purpose of using the experiments of “Atomic absorption spectrometry, neutron activation analysis, confocal scanning microscopy, Fourier transform infrared spectroscopy, total organic carbon analysis, and thermodynamic modeling were employed in the present study.” A very short description of experimental results in the abstract can make more understandable for the readers.
4. In line 27-29, the sentence “An important aspect of the expanded clay loading process is the formation of biogenic deposits of iron sulfide, which act as a sorption-precipitation phase during the immobilization of the majority of metals.”is not clear, rewrite the sentence.
5. In line 31, write the full abbreviation of LECA as “lightweight expanded clay aggregate.”
6. In line 39-43, rewrite the sentence “While a variety of methods for 39the remediation of polluted soils and surface water bodies have already been developed 40and are being improved upon, the purification of polluted groundwater is still a much too complex and expensive undertaking associated with numerous difficulties and limitations.”
7. In line 52-54, rewrite the sentence “Another approach to groundwater treatment is the creation of in situ geochemical 52barriers using reducing agents, such as zero-valent iron [16, 17] and other additives, that are injected into the reservoirs to create local zones in which metal immobilization
takes place” and merge it with other paragraph.
8. In line 59-62, rewrite the sentence “The key aspect for the successful operation of such barriers is development of microbial biofilms that protect microorganisms from the toxic effects of the polluted environment and allow the microbial community to effectively cope with it [19].”
9. In line 67, reduce the number of citation.

10. For the continuation of the current studies, some previous relevant work should be noted and cited in the introduction section.
11. In lines 82-86, rewrite the sentence.
Please update the experimental section for well understood.
12. The experimental conditions of the article are not well understood. Please follow one of your previous published article, as an example (Safonov, A. V.; Babich, T.L.; Sokolova, D.S.; Grouzdev, D.S.; Tourova, T.P.; Poltaraus, A.B.; Zakharova, E. V.; Merkel, A.Y.; Novikov, A.P.; Nazina, T.N. Microbial Community and in Situ Bioremediation of Groundwater by Nitrate Removal in the Zone of a Radioactive Waste Surface Repository. Front Microbiol 2018, 9, 1985). Make subtitle for a better arrangement of
experimental procedure.
13. In a previous article, some physicochemical and microbiological characteristics were reported.
In the present article, some additional heavy metals are analyzed. Distinguish them using different columns for better understanding. Rewrite the sentence “In this study, a groundwater sample was used with high concentrations of nitrate ions and calcium as major components, as well as Mn, Fe, Ni Sr, Cu, and Zn as the main microelement pollutants (Table 1).” based on table 1.
14. Use the uncertainty or standard error with the same unit in the Table.
15. Mention the chemical name with purity in line 97.
16. Use proper superscript and similar unit in line 104, 133, 134, 139, 161, 163, 194 and all over the text.
17. Use ether short or full abbreviation in line 155.
18. Rewrite lines 172-174, the sentence “Before the start of the measurements, the samples were washed with phosphate-buffered saline and ConA lectin conjugated with the fluorescent dye Alexa Fluor 488 (C11252 Thermo Fisher) in phosphate buffer at a dilution of 1:500.”
Please update the result section to reflect the aim of the article.
19. Rewrite the Table 2 caption.
20. Rewrite the Table 3 caption with full abbreviation of CSLM.
21. Rewrite line 231.
22. Rewrite the Figure 2 caption.
23. line 278-280, rewrite the sentence “As a result of the performed experiments, it was found that the surface of materials, biofilms, and mineral phases formed by microorganisms during their growth all participated in metal immobilization.”

24. Please remove the unnecessary references.
25. Include the error bar in figures 4 and 5