Preparation of Fenton Catalysts for Water Treatment
Round 1
Reviewer 1 Report (Previous Reviewer 1)
This manuscript discusses the preparation of the Fenton catalyst used to degrade the methylene blue dye in the presence of light. the catalyst via impregnation the metal ions Fe, Cu, Ce, and Mn on active carbon and finally calcinated at different temp. (500-1000). calcination method. the prepared catalysts were characterized using different techniques such as SEM, XPS, BET, XRD, TGA, DLS…. Besides, the synthesized method were optimized by controlling the sintering temp, metal ions and there ratios, and concentration of metal ions.
1. In section 3.1.1, the authors mentioned that at the first stage in TGA, the loss is about 15%, which was related to evaporated water and partial decomposition of inorganic salts.
a- the authors should provide a reference for this information
b- According to section 2.2, the metals nitrate are the only inorganic salts that are used; therefore, the authors should state that the loss of weight is related to the partial decomposition of nitrate, which is expected to decompose to HNO3. refers to the following reference https://doi.org/10.1039/C5RA03103F.
c- In line 128, the authors stated “but it can ensure that the metal is reduced”. This sentence is not clear. Is the metal ions or the metal reduced?
2. In Figure 4, what cps (y-axis unit) stand for?
3. According to table 3, the % of carbon in blank AC is around 87 and the rest element is about 13% with a specific surface area is 890 m2/g. while, at 900C, the % of carbon is ~49%, Fe and Cu ~46%, and the other elements is about 5%, with a specific surface area 899 m2/g. This information indicate that the % of carbon in the prepared catalyst was reduced by about 40% and the % of the metal increased around 40% (if we consider the % of Fe and Cu alone). How do both materials give the same adsorption–desorption behaviour and same surface area?
4. Besides that, the SEM image showed very large particles compared to the mother material which are an alloy or metals – according to the authors- how could a material consisting of 40% of metals give the same BET as the porous AC? The reviewer cant understand these two points!
5. In line 229-232 the authors mentiom that 43.3°, 50.4°, and 74.6°, consistent with the standard XRD diffraction peaks of Fe–C and Cu. Based on what the authors state that? Mention a reference.
6. In all the discussion the authors mention alloy. How the authors be sure that the alloy formed? A TEM image with a d-spacing is required to prove that.
7. In line 306, there are two sets of AC-loaded Fe/Cu > AC-loaded Fe/Cu one of them should contain Ce.
8. In line 311, what is the idea behind the final sentence “Efficient catalysts were prepared by loading with other metals.” It seems it is in the wrong place.
9. Figure 10, the y-axis unit should be only % removal. If the authors calculated the rate, or the authors should provide the equation used to calculate the % of the removal rate.
10. Figure 11 and their discussion are not accepted and are wrong. how the authors compared different sets with different degradation and different times. The authors should fixed one of the paramter then compare according to the other one.
11. In section 3.3.1, the authors did not mention the volume of the Fe and Cu that were added. Since the authors mentioned in section 2.2 that they added a different solid amount. In this section 3.3.1 they should mention the volume beside the conncentration.
12. It is important to include a blank experiment, evaluating the catalysts' activity without H2O2 and the degradation of MB with only H2O2.
13. Several mandatory experiments are missing in the manuscript, for such experiment I suggest the authors to check the following references and cite them in the manuscript: 10.1021/acscatal.0c01713,
10.3390/catal11010107
a- The blank experiment: the degradation of MB under light alone
b- The degradation of MB using the AC and prepared catalyst in the absence of the H2O2
c- The absorption of MB under dark in the presence of the catalyst and MB
14- when the color of MB is removed for the medium this not mean that all the organic compound was minerlizied. what about the by products of this Fenton reaction.
this manuscript need some english editing
Author Response
Thank you for your review. Please find attached the specific response.
Author Response File: 
Author Response.pdf
Reviewer 2 Report (New Reviewer)
The research results are interesting and could be published, but the paper is not written at a scientific level. It is necessary either to make major corrections or to reject the paper, and when it is rewritten, to send it to the journal again. Some of the guidelines for correction of Manuscript are:
- Abstract and Conclusion should be improved.
- The first sentence should not be written in the Abstract: "In the heterogeneous Fenton reaction, a solid catalyst reacts with H2O2 to generate highly oxidizing free radicals, thereby degrading organic pollutants in aqueous solutions."
- What is written in the first paragraph of the conclusion is not written in the Conclusion. The conclusion should be written generally (descriptively), so that the quality of the results and their possibilities are highlighted.
- Chemical reactions are not written in the 1. Introduction. It should be written in the theoretical part of the paper.
- The contents of Tables 1 and 2 are not written in the form of tables. 2. Experimental should be written differently.
- 3. Results and Discussion refers to the results and very little to the discussion. It should be improved.
- References in the text are somewhere in parentheses in the index above, and somewhere in parentheses without being in the index. It should be repaired according to the Journal's instructions.
- There are too many figures, 18. Some of them can be presented tabularly.
In other words, the whole paper should be written again in the way that scientific papers are written.
Author Response
Thank you for your review. Please find attached the specific response.
Author Response File: Author Response.pdf
Reviewer 3 Report (New Reviewer)
Dear authors,
The manuscript catalysts-2591920 presents the preparation of catalysts based on activated carbon (AC) loaded with metal compounds (Cu, Mn, Fe and Ce) with improved fenton-catalytic activity toward the degradation of methylene blue (MB) dye. The manuscript was carefully presented, the introduction is well written and the objective of the work was clearly shown. The authors investigated different parameters in the photocatalytic tests and used different techniques to characterize the materials.
The manuscript brings some interesting results, however the authors sometimes miss the opportunity to present motivation to better support the ideas and findings. In some sections the results are not well discussed, and this should be improved and more scientific background included in the revised version. In addition, the results should be compared with data previously reported in literature. I have some remarks that the manuscript would benefit and impact the readers if they are appropriate addressed.
1) The catalytic activity of the materials was investigated toward the MB dye degradation. However, in the end of the introduction the authors emphasize that the MB compound used as model pollutant and the conditions employed in the catalytic tests were chosen to determine the optimal solution for sewage treatment. It is important to have in mind that sewage is more complex and different types of pollutants can be found in it. I would consider exclude this or emphasize that the studies were carried out to determine the optimal solution for the degradation of organic pollutants (specially dyes) in water.
2) Experimental section.
a. There are some mistakes in the name and formula of the chemicals in Table 1. Please check all and correct where it is appropriate. For instance: According to the formula, copper chloride “dihydrate” is not correct.
b. In the Table 2, the authors give the location of the producer of all the equipment used in the studies. The authors should include the Company of each equipment not only the model, for instance: “Shimadzu” XRD-6000 X-ray diffractometer (Japan), etc. In addition, the authors analyzed the samples by thermal analysis (TGA/DSC), but it is not included in the Table.
c. For the characterization techniques, the authors must detail the conditions of the measurements.
3) Results:
a. In order to understand the amount of impregnated solution on AC, the TGA of blank AC must be included and discussed accordingly.
b. In the surface element analysis, some variations in the intensity of the peaks are observed. It was found that the blank AC presents some impurities in the composition, especially Al and Si. The intensity of the peaks related to these two elements substantially increased in the samples sintered at 800 and 900 ºC. Why?
c. In the XRD results, the authors mention that metal oxides are possibly formed at 1000 ºC and the particles became excessively aggregated. There some small diffraction peaks around 2theta = 30º and 35º, but they were not mentioned in the discussion. Are these peaks related to some oxide materials formed during the sintering? Also, include the ICDD file number for Fe-C and Cu.
d. In the discussion of the XPS data, there are some missing references and comparison with the literature. For instance, the authors state that “the presence of Cu+ at 932.4 eV promotes the formation of hydroxyl radicals and improved the degradation efficiency”. The authors must add more scientific background to support the statement.
e. The Cu 2p XPS spectrum (2p3/2 and 2p1/2) can be fitted into two peaks as shown in Figure 8. The authors mention that three species of copper exist in the loaded AC sample. To avoid misunderstanding, revise the discussion and assign all the species to all the fitted peak in the deconvoluted XPS spectra (Fe 2p, Cu 2p, Ce 3d and Mn 2p). Thus, the reader can follow better the interpretation of the data.
f. The authors mention that the presence of the loaded metals improve the formation of hydroxyl radicals and, therefore, the photocatalytic activity. In order to prove this, authors should include at least tests oh photohydroxylation of terephthalic acid. This is a simple method to evaluate the hydroxyl radicals formation.
g. As the specific surface area (SBET) is an important factor that play a role in photocatalysis and black/loaded AC samples present a very large surface area, this can play a role in the adsorption of MB dyes. What is the adsorption contribution of such materials in the studied process?
Author Response
Thank you for your review. Please find attached the specific response.
Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report (Previous Reviewer 1)
After considering the revised manuscript catalysts-2591920, it is clear that the authors try to enhanced the manuscript according to the reviewers' comments. However, several points of the reviewer's comments are not covered in an acceptable manner. In my opinion, the manuscript still needs some corrections before it can be accepted for publication in the Catalysts journal.
1. Comment 3. I agree with the authors that the SEM-EDS analysis provides information about the surface structure of the material and measures its elemental composition at a depth of about 10 microns on the surface. However, this analysis in material science is used to get an approximate idea about the elemental composition of the overall material. Therefore, I still believe that – at least- the adsorption–desorption behavior should be different between the AC and the synthesis material.
2. Comment 9. The y-axis in Figure 10 still “removal rate”, so it is not corrected as the authors stated in his answer.
3. Comment 10. The author's answer is not accepted.
4. Comment 13 c. According to the authors answer “In the absence of light and H2O2, the concentration of MB remained almost unchanged”. This data is not accepted. It is well known the AC adsorption capacity towards the MB as well as the organic pollutants is very high. I still recommend performing a blank experiment for the adsorption of MB in the presence of AC and the modified AC alone.
5. Again, the removal rate can’t be %. Please revise all the y-axis in your figures.
6. The English writing the EPR section is very bad. Please revise it.
7. Also, in the EPR section, the quartet signal under light belong to the formation of the hydroxyl radical, while the signal that appears in the dark in the presence of 900 C loaded AC+H2O2 is belong to more than one spin adduct being simultaneously produced and overlapping. Please enhance your discussion in this part. The authors are encouraged to review the following references and cite them in the text (https://doi.org/10.3390/ catal11121423, https://dx.doi.org/10.1021/acscatal.0c01713).
8. Comment 14. The mechanism of the photocatalytic degradation of MB is changed according to the formed active species in the medium. By changing the catalyst in the medium, a different active species will be formed, thus, different degradation mechanisms will take place. there is no guarantee that the MB will be degraded in the same manner as the authors mentioned in their answer.
The writing language of the new section (EPR section) is not accepted.
Author Response
Please refer to the attachment for modification suggestions.
Author Response File: Author Response.pdf
Reviewer 2 Report (New Reviewer)
For the paper catalysts-2591920-peer-review-v2, I make the following comment:
- Colleagues should answer each reviewer's question more carefully.
- Colleagues should write a separate theoretical part from the first sentence of the Abstract (Line 8,9), the Introduction from Line 50 to 77 and the Conclusion from Line 452 to 457, which would be right after the Introduction
- Regarding BET, give an answer to the reviewer's question...
Author Response
Please refer to the attachment for modification suggestions.
Author Response File: Author Response.pdf
Reviewer 3 Report (New Reviewer)
Dear authors,
The manuscript is better descriptive and the addition of new data give a better support to the objective as the EPR analysis. Therefore, I can recommend it for publication. However, in the proof editing I would suggest that the authors assign the XPS peaks accordingly for all the cations present in the samples (Figure 8). Also, also verify the subscripts in chemical formula, for instance in Methylene blue C16H18ClN3S•3H2O.
Best regards
Author Response
Please refer to the attachment for modification suggestions.
Author Response File: Author Response.pdf
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
In this manuscript, the authors conducted modifications on active carbon by loading it with various metal ions (Fe, Cu, Ce, and Mn) using the impregnation calcination method. The synthesized catalysts were optimized by controlling the calcination temperature, metal ratios, and concentration of metal ions. Different physiochemical techniques were employed to characterize the synthesized materials. The activity of these materials towards methylene blue dye degradation was evaluated using a heterogeneous Fenton reaction.
However, the revision of this manuscript appears to be confusing. The structure and design of the manuscript should be aligned with the Catalysts journal style, taking the following points into consideration:
a) Correct the numbering of figures, tables, and section divisions.
b) Section 3, "Catalyst Characterization," does not fit under the experimental part or the results and discussion part. This confuses readers because the authors have presented results and discussions related to characterization within this section, as well as discussing results that are yet to be presented in later sections. To improve this, it is suggested that the authors include a brief paragraph regarding the characterization methods in the experimental part (as section 2.2). Then, merge section 3 (as section 3.1) at the beginning of the results and discussion part (part 3), after removing all the results that will be discussed later.
c) After the characterization, keep section 4.1 (which will be section 3.2), but ensure that all the reaction conditions are mentioned. Currently, there is no information in this section about the experimental conditions. As the authors have determined the most active material to be used in the Fenton reaction, it is suggested to move section 4.5 (Effect of H2O2 concentration on MB degradation) immediately after section 4.1, which will then become section 3.3. After that, address all the optimization conditions of the catalysts.
d) Section 4.3 is particularly confusing, as the authors mentioned in line 291 that they used a tungsten lamp as part of the reaction. This raises the question of whether the authors performed a Fenton reaction or a Photo-Fenton reaction, as there is a significant difference between the two. Clarification is needed in this section.
e) The reaction conditions for most of the experiments' results are missing, along with information about the blank experiments.
Besides the previous notes, the revised manuscript should also address the following comments:
- While the introduction is presented in an interesting and attractive manner, there are some areas that could be enhanced as follows:
a) In line 29, the authors mentioned, "Chemical, physical, and biological methods are commonly used to treat difficult-to-degrade organic compounds in industrial wastewater." It is suggested to provide examples for each of these methods, such as adsorption and advanced oxidation processes. The authors are recommended to review and cite this reference: https://doi.org/10.3390/catal11030317.
b) In line 32, before discussing the Fenton method, a brief explanation of advanced oxidation processes should be provided, mentioning methods like UV/H2O2, Fenton reaction, Photo-Fenton reaction, and Heterogeneous photocatalysis. The authors should then describe their method and highlight its advantages compared to other methods. It is suggested to review and cite the following references in the text: https://doi.org/10.1021/acs.chemrev.1c00527, https://doi.org/10.1007/s10311-018-0738-3, https://doi.org/10.1016/j.jenvman.2022.114822.
c) As there are many reviews in the literature discussing similar work, the authors are advised to add some of them and highlight the advantages of their research compared to other researchers.
- The novelty of the work must be clearly indicated to emphasize the scientific soundness and merit of the study.
- In the experimental part, section 2.2, in line 90, it is not clear what the authors mean by "until the AC quality was stable."
- In lines 90-91, the authors mentioned, "The dried AC-loaded catalyst was placed in a tube furnace under nitrogen protection for 1 h to obtain the catalysts loaded with Fe, Cu, Mn, and Ce." This sentence is not clear. The authors should specify in this sentence that the synthesized catalysts were calcined at different temperatures to obtain the catalysts loaded with Fe, Cu, Mn, and Ce.
- It is suggested to transfer section 3 to the results and discussion part. Therefore, a small paragraph describing the methods of catalyst characterization should be added to the experimental part.
- The procedure of the catalytic reaction should be added to the experimental part.
- Figure 3-1 appears blurry and requires revision.
- The first paragraph (lines 95-100) is not clear, and the writing language is of poor quality.
- According to the authors' procedure to prepare the catalysts, they did not mention whether the catalysts were washed before and after drying and loading with the metal salts. There might be a probability of the formation of nitrate salts again before and after calcination, as shown in Figure 3-1 (i.e., the white particles in this figure).
- The numbering style of the figures in the manuscript is incorrect.
- The sentence in lines 119-120 requires a reference.
- Also, the sentence in lines 121-123 needs a reference.
- In line 123, the authors mentioned that the optimal sintering temperature was determined to be between 800 and 900 °C. It is unclear based on which data the authors obtained this result, as the SIM image provides no data for such results.
- In lines 141-143, the authors mentioned that the calcination process at 900°C does not affect the AC structure, but they should address the porosity of the material.
- The surface area values in Table 3-1 should be provided with standard deviation.
- In line 216, please provide a reference for the mentioned sentence.
- In line 217, the authors state, "The addition of Ce increased the specific surface area, changed the material morphology," contradicting the earlier mention in section 3.2 that the surface area was not affected after loading.
18. I believe that the loading of the metal on the catalyst's surface will impact the surface area. Therefore, if possible, I suggest that the authors repeat their measurements for the surface area.
19. Please review table 4-1, as the element symbols appear to be incorrect.
- In section 4.1, the authors should mention the concentration of MB and whether H2O2 was used.
- It is important to include a blank experiment, evaluating the catalysts' activity without H2O2 and the degradation of MB with only H2O2.
- In section 4.2.1, (a) the experimental conditions, such as the concentration of the dye, temperature, calcination temperature, amount of catalysts, and H2O2 concentration, should be mentioned. (b) Additionally, clarify the degradation values. I suggest replacing the time axis with the percentage of degradation in the graph. It appears that the degradation may not reach 100% based on the results presented in figure 4-1.
- In line 272, the authors mentioned the removal rate, but figure 4-3 shows the concentration vs. time. Please provide the removal percentage or the degradation rate or amount (removal moles).
- Section 4.2.3 should be revised according to the comments provided in points 23 and 24.
- In section 4.4, the data presented in figure 4-7 shows the percentage of removal (removal or degradation %), not the rate of removal percentage. Hence, the graph and the text should be updated. A thorough revision of the entire manuscript is needed regarding this point.
- If the authors provided the data in figure 4-9 with an error bar, it would show whether there is a significant difference between using 1 or 5 mM H2O2. Please provide the error bars and mention the number of repetitions for all the experiments in the caption throughout the manuscript.
27. Since the authors performed ICP-MS in this study to assess the leaching of metals, they should also determine the percentage of the loaded metals on the surface of AC, as it provides to the authors and the other researchers with very important data.
28. Get its English edited very carefully.
29. Provide better-quality figures.
30. Also, check the typos throughout the manuscript during revision submission.
Comments for author File: Comments.pdf
several typos throughout the manuscript should be revised
Author Response
Thank you for your valuable feedback. I have carefully revised the manuscript according to your suggestions and will also consider your suggestions for relevant experiments in our future work.
Author Response File: Author Response.pdf
Reviewer 2 Report
The overall design of the work is correct and has a systematically characterization and testing of the catalysts synthetized, although it is not particularly original as it is based in accumulation of synergies already known.
The main problem with the manuscript is that it has several problems about results interpretation. Following I will list the main issues founded:
- The authors give for valid that the catalyst should have the metals in form of alloys for being stable and effective as catalysts. This is nothing obvious considering that the mechanism listed by the authors is ion mediated, and there is not reference that said that. At most, it can be used as a conclusion after the characterization of the catalysts has been done. And the term atomization for ions reduction to metal is not correct.
- BET surface areas either increase after loading or have little effect. Can´t be both. Authors should list the uncertainty of the measurement to understand which is the case.
- There are several misconceptions regarding XRD. It is not based in absorption processes. And a diffractogram is not a spectrum. The intensity of a diffractogram is not related to the size of particles (you could relate it to FWHM at most).
Fe-Cu alloys have the have the same diffraction patterns than metal structures? Why authors are so sure that they have alloys? Some explanations regarding this should be done.
- In the same line, XPS characterization has a lot of misconceptions. Signals are not absorption peaks. What is “unit number spectrum”?
The baselines of the spectra are not well done (particularly the one of Cu2p, it can´t be over the signal). Ce3d and Mn2p peak fitting doesn´t match with the signal. Satellites synthetics peaks are too wide (in Ce3d there are 2 signals with the same energies). And is not possible to differentiate Cu(II) and Cu(I) with the differences of Eb of the peaks (they are very similar). You can use either Auger or satellites for that.
Moreover, there is a very serious error: If you have a doublet, if you have two species in 2p3/2 signal, you should have two species in 2p1/2.
Lastly, I don´t see the changes in Eb of Fe and Cu with calcination temperature, but a decrease in signal (maybe it exists, but it can´t be visualized in figure 3.6). An At% calculation should have been done, to see if metal signal diminution is accompanied with an increase in AC signal. And having fewer but bigger particles doesn´t explain signal diminution.
- Impurities in AC hardly explain the degradation observed. Possibly you are having an adsorption of MB. Have you done tests W/O H2O2? In general, MB degradation experiments details are not well described.
- Fe/Cu ratios evaluation are not clear. There is not only a ratio variation, but a total ion variation. Particularly, authors said that groups 7,8 and 9 have similar performance, have different Fe/Cu ratio, and they conclude that the ratio is the main factor (and not total Fe concentration).
- The discussion in 4.4 assumes a lot of things that doesn´t correspond with characterization results. Nothing indicate there is an alloy formation of the 4 metals, neither that at high calcination temperatures they are “more firmly bound”. And why being bound firmly is better for catalysis performance?
- If there are no difference in efficiency with [H2O2], why 5mM is optimal?
Other problems:
- Manuscript is too long. Introduction repeats some concepts several times. And 14 SEM figures is too much.
Recommendation:
- Make a reinterpretation of the results based on a correct analysis of characterizations.
English per se is not the problem, but the misuse of chemical terms.
Author Response
Thank you for your valuable feedback. I have carefully revised the manuscript according to your suggestions and will also consider your suggestions for relevant experiments in our future work.
Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
In this revised manuscript, it is clear that the authors did not enhance the manuscript according to the reviewers' comments. In my opinion, the manuscript still needs serious corrections before it can be accepted for publication in the Catalysts journal.
Since the authors do not provide a clear indication of the place of their answers for each point of the reviewer’s comments and did not show all the corrections that they made inside the manuscript, many of the reviewer’s comments were not revised. However, the reviewer checks carefully the revised manuscript and finds that the revised manuscript still needs major revisions are necessary for covering the following points.
1- The answer to comment 2 should be addressed in the manuscript, not for the reviewer.
2- Comment 3, should be addressed in the manuscript. Besides, the authors mentioned in their answer to the reviewer “ Until the moisture and other substances evaporate completely”, what are the other substances? In the reaction medium, there are just water and salts!
3- Comment 5 was not addressed in the revised version
4- The authors should read comment 4 carefully, it is still not addressed in the revised version
5- Comment 8, the writing language of the first paragraph in section 3.1.1 is still very poor. It should be rewritten.
6- Comment 9, the reviewer completely agrees with the authors, but what about the calcination at 500 and 600 C?
7- Comment 11, the authors should give a reference after the mentioned paragraph in the manuscript, to support their hypothesis.
8- In comments 12 and 13, the authors discussed results not yet presented. Therefore, you can remove this sentence or provide a reference that discussed similar results to support your discussion. The author’s answer to this point is not clear.
9- Comment 17, since the authors did not provide the number of new lines or comment for each answer inside the revised manuscript, the reviewer did not distinguish the author’s answer for this comment!
10- The reviewer’s answer for comment 18 is incorrect, please check the following articles which discuss the effect of the loading metal on the surface area for the active carbon and TiO2 10.1016/j.jiec.2019.03.004, 10.3390/catal11010107.
11- Section 3.3.1 is discussed in the wrong way and graph 8 is presented in the wrong way also. The author’s discussion is based on the time of degradation, however, the % of degradation is different between materials!
12- The answer of comment 21 is incorrect. The data in Figure 15 does not present any information about the blank experiments.
13- Comment 22, the answer is accepted.
14- Comment 27, it is mandatory to this manuscript to provide the weight % of the loaded metal, otherwise, the results in this manuscript will stay without meaning.
15- Comment 27, the answer is not clear.
the writing language must be enhance
Reviewer 2 Report
The authors have not corrected the following problems found in the original version.
- The XRD technique is based on X-ray diffraction, not absorption. It is a different phenomenon. X-ray absorption is another technique, not related to DRX. For this reason, XRD results are diffractograms, not spectra. Check with an expert in the art to help you write this part, the language used is incorrect and also results interpretation.
- I have never read the expression "unit number spectrum" in XPS. If you have an article that uses this terminology, please cite it.
- XPS spectra are ok, not particularly noisy or weak. They are just poorly adjusted. You can use two regions to fit Cu with Shirley's background. Doublets should be used as a constraint, same for FWHM. Curve fitting is done with conceptual problems related to the physics involved. Please consult with an expert in the technique.
- Carbon adsorption is quite common, it has its own kinetics and cannot be ruled out without making a blank in the absence of H2O2. It is a short experiment.
English lenguage is not the main issue, but the missuse of chemical and physical terms
