Study of the Adsorption of Anionic Surfactants on Carbonate Rocks: Characterizations, Experimental Design, and Parameter Implementation

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

This paper is largely OK but there are nmerous minor comments I have which need to be addressed.

 

Firstly there are a few Portugese words in the text which need to be altered eg Figura 1 line 234

Secondly there are many very short aparagraphs of only a couple of sentences which can be merged.

eg in the introduction paras 1 and and the 3 and 4 can be merged. A new paragraph should really introduce a slightly new topic.

The abstract should be a summary of the paper. there is too much background in the abstract and not enough of the reults or conclusions so abstract needs to be modified.

In abstract there is an abbreviation SCO should this be OCS?

Lines 104 and 105 are repeated below so remove them

I assume that the surfactant solutions are made up in deionised water, so say so as in oil work brine is often used.

Check the cmc valued on line 238 and 239 later you say OCBS has a higher cmc line 250 but the figures quoted here say that this is not the case, one or the other is wrong.

Fig 1 needs attention, firstly the lines through the data points do not seem to be the best fits, especially the linear part on these semi log scales, secondly the arrows indicating the cmc point seem to be the wrong way round have the head pointing to the cmc, personally I think it may be better to have a vertical line droping to the concentration axis actually. what is the meaning of the last character on line 248 in the figure legend?

Also when discussing the work and the linear part of the curve on semi log scales make sure you do not say there is a linear relation between surface tension and concentration as it is not, its linerar between ST and log conc

line 261 the % range does not seem to tally with the data in table 1, also too many decimal points, just quote to nearest whole number in my view.

Line 275, its hard to know why the adsorption of apolar surfactant onto polar calcium carbonate should be higher, please extend the discussion here.

Table 1 has a Portugesse word in it I think

Line 290 say supplementary information rather than Appendix if that is how it will appear in the journal

line 328, I do not see where the 34% mas loss comes from to me thy look more like 50%. Again do not quote to 2 decimal places the data do not warrant that. 

line 368 do you mean carboxyl groups? as carbonates wold be in the rock, next line say what these peaks represent

 

does the peak at 1746 exist  from the figure you say 1795. This peak to me seems to come from the rock as its in the top spectrum as well. You need to align the text with the figure here. Also again in the figure the arrows seem to be the wrong way around.

line 376 suddenly introduces SDS from no where, hopefully there would be a reference you could use here. Also say what SDS is.

I do not really see the point of the zeta potetial data. It needs to have the bare rock as a control. 

do we have an adsorption isotherm as a function of pH?

I do not think the SEMs show anything. I do notthink they show porosity or a thin film of surfactant.

Are they done on the crushed rock?

I would remove them. line 428, natura?

Re the isotherms, I was not aware of the Sips isotherm, which is really looking at the equation a modified version of the Langmuir isothere, as if Beta = 1 then it would be the Langmuir isotherm. So give some more detal as to what Beta is thought to represent? is it due to lateral interactions between the adsorbed molecules? 

Given that the Sips isotherm is the Langmuir isotherm with an extra term, it has to give a better fit, what significance should be put to the fact that beta is much less than 1 for 2 of the surfactants?

Comment on the vastly different ads amounts for the 3 surfactants in fig 7 OCBS is an order of magnitude higher.

In conclusion you refer to a pseudo 2nd order kinetic madel, this is the first time you have used this phrase, what do you mean here.

 

 

 

 

Comments on the Quality of English Language

Its by and large OK apart from the odd Portugesse words

Author Response

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Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

The work “Study of the adsorption of anionic surfactants on carbonate rocks: characterizations, experimental design, and parameter implementation” by Valdivino Francisco dos Santos Borges is devoted to the obtaining carbonate rock sample, its characterization and the study of adsorption properties to three surfactants.

Reviewer’s comments are given below.

1.     It is not clear what “environmentally sustainable surfactants” are.

2.     The second sentence in the text is not clear in meaning.

3.     In the introduction authors should expand how surfactants is use for hydrocarbon and oil recovery.

4.     The Introduction section does not show the novelty of the present research. What exactly caused the choice of these surfactants anyway?

5.      Can crushed and processed rock samples be called as “carbonate rock”? Does such a strong treatment (grinding, washing, heat treatment) lead to a change in sorption properties? And what will happen if similar experiments are carried out on prepared mixtures of chemical substances CaCO3 + MgCO3, for example, that make up rocks?

6.     Line 245. What is “carbon 12”? Formulas of the chemical substances should be given in this case.

7.     Figura 1 = Figure 1. Tables 1 = Table 1. The text needs strong correction and proofreading.

8.     The term apolar is not correct, instead non polar.

9.     The described mechanism of oil sorption on carbonate rocks is unconvincing. A clearer and more understandable explanation is needed about “The ability of an oil to adsorb onto carbonates”. An illustration should be provided.

10.  What is Ensaios in Table 1?

11.  Line 320. “The sandstone was identified as quartz sandstone, with quartz being the predominant 320 component”. Where did sandstone come from if the text talks about limestone rock?

12.  Where in Fig. 2 (XRD) peak corresponding to dolomite (CaMg(CO3)2)?

13.  Line 359: Indexes are should be corrected.

14.  Line 375. “The adsorption efficiency rates exceeded 80%, 375 82%, and 45% for OCS, OCBS, and OMS, respectively, while SDS showed no adsorption”. Why is this sentence in the text? SDS sorption was not carried out.

15.  Fig. 5 is made in very bad resolution. The signatures are practically invisible.

16.  The authors say “Finally, calcination reduced the average particle diameter, enlarging its surface area and, consequently, the contact area with the surfactants. This fact emphasizes the importance of particle size regarding the kinetics of calcination and adsorption". However, obtaining such a porous and finely divided structure was carried out physically. Whereas this is due to the natural porosity of rocks. Perhaps this should be changed in the title of the study – “… on material obtained from carbonate rocks”?

17.  Please, show with arrows in Fig. 6, where surfactant sorption occurred. In Fig. It's worth applying a scalebar.

 

The present manuscript is written very chaotically and requires extensive editing, proofreading of the text and clarification of the research carried out. The authors should justify the novelty of the research, since, in fact, they studied the sorption of three types of surfactants on washed CaCO3. The XRD and FTIR analysis are not very convincing. Characterization of the rock material provides little information about its composition. The sorption process requires clarification and an illustration of the sorption mechanism. It is also not clear whether there is a difference in the sorption of the three surfactants used?

The work can be published only after a number of edits have been made.

Comments on the Quality of English Language

 The text contains a large number of errors and typos, and incorrectly used terms. The article requires editing and proofreading

 

Author Response

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Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

This paper has been significantly improved and in my view can now be accepted

Comments on the Quality of English Language

It could do with a little polishing, but the paper is perfectly understandable, just a little strange in places

Author Response

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Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

After re-reading the article, the reviewer again had the following questions and comments:

 

- The English text requires editing yet. The authors again use of repeated phrases, ambiguous expressions, make mistakes in punctuation. For example, there is a comma in line 205, but not in lines 206 and 207…

Terminology should be uniform. For example, the authors name adsorbent materials, adsorbents, adsorbent (limestone) etc. The names of some sections are unclear... For example, it is not clear what Characterization of Adsorbents in the Rock means, or Adsorption Study: Surfactants-Rock?

Among babassu coconut oil, coconut oil and castor oil, the surfactants in coconut oils showed the highest adsorption efficiencies on carbonates due to their lower polarity compared to the surfactants in saponified castor oil. – the sentence is completely incomprehensible.

L. 277 twelfth carbon = twelfth carbon atom. Line 433 “uneven surface with steps”? There are a lot of small errors and inaccuracies in the text.

L 438. This is discernible from the morphological aspect, which reveals the distribution of the surfactants in the porous medium. The meaning of the text is not obvious.

Absolute disregard for the use of abbreviations; abbreviations are given several times for the same terms.

The experimental part and abstract are poorly written.

Why in Fig. 1 is the only formula? What about other surfactants?

The rock being studied needs to be better characterized. The authors talk only about polarity, a change in which leads to increasing/decreasing of adsorption. However, why is the porosity of the rock, the size after milling and treatment, the presence of impurities and other factors not taken into account?

L 295. How did analysis of Figure 2 help establish that hydrophobic interactions are key? The limestone surface is not an absolutely flat surface; it is porous and defective. Surfactants can stack randomly. The mechanism needs improvement. The authors themselves talk about porosity and surface heterogeneity when describing SEM. This should definitely be taken into account.

It is not clear from Table 1 which samples (1, 2, 3, etc.) were studied? Are there any differences between them? Or are they all the same samples? Then it is worth indicating the experiment number

L 327. And again - XRD of the rock is poorly described. What peak? At what Bragg angle? What is the crystal structure? In Fig. 3 the X axis is not fully labeled.

From the DTA description it is not clear what the peaks indicated in the figures refer to? Is it CO2 that removed or H2O?

The functional groups corresponding to the signed values ​​should be shown on the FTIR spectra.

It is better to combine the fig. 6 a,b,c into one.

SEM analysis is not obvious. It is worth replacing magnification of 500x with scale bar. Arrows is need to show where surfactant putted on the rock. What are the differences in adsorption? It's not too clear at the moment.

The scientific novelty of the work is also questionable. What is it all about? The authors just did the work, the analysis are poorly described, and the adsorption mechanism is not convincing. The article requires significant revision.

Comments on the Quality of English Language

The English text requires editing yet! The authors again use of repeated phrases, ambiguous expressions, make mistakes in punctuation and other...

Author Response

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Author Response File: Author Response.pdf

Round 3

Reviewer 2 Report

Comments and Suggestions for Authors

It is worth saying that the authors have significantly improved their manuscript.

However, in Fig. 5 shows the IR spectrum. Two bands in the region of 2800-3000 cm-1 clearly relate to vibrations of C-H bonds in the surfactants. Therefore, it is worth changing the text in the section. The article may be published after changes are made.

Author Response

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