Distribution Characteristics and Genesis of Iron and Manganese Ions in Groundwater of Eastern Sanjiang Plain, China
Round 1
Reviewer 1 Report
Review of manuscript by Wang, Wang, Yang, Yang, Li, and Chen
This manuscript describes geochemical studies of groundwater conducted on the Eastern Sanjiang Plain of China. Forty-one groundwater samples were collected and analyzed for anions, cations, pH, Eh, conductivity, manganese and iron. Gibbs plots, Eh/Ph diagrams and Principle Component Analysis were used to interpret the iron and manganese levels in the groundwater samples.
The experimental design in this study is appropriate for this work and the correct analytical methods were used. Because of the large area of China that was covered by this study, the paper should be published in English where it will reach a larger audience.
The quality of English in this manuscript is inconsistent and must be corrected. The third word of the abstract, “is,” should be replaced with “are,” and is the first of many grammatical errors. A more serious error occurs when the authors state “the easily soluble high-valent iron and manganese oxides in groundwater are reduced” when they should say the “sparingly soluble” or more correctly, the “insoluble high-valent iron and manganese oxides.” Several paragraphs of the manuscript read well, but the numerous style and grammatical errors must be corrected before publication.
Several of the references are poorly chosen. For instance, the first paper by Guo et.al does not adequately demonstrate that divalent iron and manganese are widespread in the Earth’s crust and groundwaters. Many reviews have been written on this topic and these review articles should be cited at the beginning of this manuscript. The authors cite many sources that are published in Chinese when equivalent sources, and more widely available, English articles are available. For instance, the Drinking Water Guidelines by the European Union have similar values to those mentioned in this manuscript, are more widely accepted and quoted, but they are not included as a resource for the reader.
Groundwater samples are typically field-filtered through a 0.45µ filter to distinguish between suspended and dissolved metals. If the samples were not field-filtered, which seems to be the case, the concentrations must be reported as “total metal.” When doing ICP-OES analysis, 1000 PPM Cs must be added to correct for ionization of Na and K in the plasma. The experimental section does not indicate if Cs was added to correct for the ionization interference. The analytical line used for all ICP-OES measurements should be included in Table 1. The instrument the authors used to measure Eh is incorrectly described. I suspect that the instrument is a Hach HQ2200 Portable Multimeter purchased from Cole-Palmer Instrument Company.
The quality of English in this manuscript is inconsistent and must be corrected. The third word of the abstract, “is,” should be replaced with “are,” and is the first of many grammatical errors. A more serious error occurs when the authors state “the easily soluble high-valent iron and manganese oxides in groundwater are reduced” when they should say the “sparingly soluble” or more correctly, the “insoluble high-valent iron and manganese oxides.” Several paragraphs of the manuscript read well, but the numerous style and grammatical errors must be corrected before publication.
Author Response
Dear reviewer,
We gratefully appreciate your valuable comment, which has significantly raised the manuscript’s quality and enabled us to improve the manuscript. Each comment brought forward by you was accurately incorporated and considered. The comments have been responded point by point, and revisions are indicated. The changes in the revised manuscript are highlighted in red.
Comment 1: The quality of English in this manuscript is inconsistent and must be corrected. The third word of the abstract, “is,” should be replaced with “are,” and is the first of many grammatical errors. A more serious error occurs when the authors state “the easily soluble high-valent iron and manganese oxides in groundwater are reduced” when they should say the “sparingly soluble” or more correctly, the “insoluble high-valent iron and manganese oxides.” Several paragraphs of the manuscript read well, but the numerous style and grammatical errors must be corrected before publication.
Reply: Thank you for pointing out the error. We have corrected it (line 11, 23 and 283). At the same time, we have also read the whole text many times and made more than 20 modifications for the grammatical errors you put forward. Because there are many minor changes, it is inconvenient to mark them all. Later, we will also take seriously the revision suggestions put forward by the language editor. I am sorry for the trouble caused by our lack of formal grammar.
Comment 2: Several of the references are poorly chosen. For instance, the first paper by Guo et.al does not adequately demonstrate that divalent iron and manganese are widespread in the Earth’s crust and groundwaters. Many reviews have been written on this topic and these review articles should be cited at the beginning of this manuscript. The authors cite many sources that are published in Chinese when equivalent sources, and more widely available, English articles are available.
Reply: We have replaced and supplemented the references. First of all, as for the first cited literature you mentioned, we have added several related literatures as supplements. At the same time, according to your reasonable suggestions, we will also replace part of Chinese literature with similar English literature to improve accessibility. Finally, we also added more references to better support relevant scientific opinions. The number of references increased from 35 to 51.
Comment 3: For instance, the Drinking Water Guidelines by the European Union have similar values to those mentioned in this manuscript, are more widely accepted and quoted, but they are not included as a resource for the reader.
Reply: As a contrast and supplement, we have quoted the relevant EU standards as you suggested (line 40), which will indeed allow more readers to find the familiar iron and manganese content limits.
Comment 4: Groundwater samples are typically field-filtered through a 0.45µ filter to distinguish between suspended and dissolved metals. If the samples were not field-filtered, which seems to be the case, the concentrations must be reported as “total metal.”
Reply: Thank you for your question. Actually, to investigate the metal ion concentration in groundwater, we filtered the water sample on site. Sorry, we didn't make that clear. We have explained this in more detail in the revised manuscript (line 184-187).
Comment 5: When doing ICP-OES analysis, 1000 PPM Cs must be added to correct for ionization of Na and K in the plasma. The experimental section does not indicate if Cs was added to correct for the ionization interference. The analytical line used for all ICP-OES measurements should be included in Table 1.
Reply: In accordance with test method requirements, Cs was added to correct for ionization interface. We added a description of this step (line 189). Meanwhile, we added a column in Table 1 for the wavelength of each ion in ICP-OES measurements.
Comment 6: The instrument the authors used to measure Eh is incorrectly described. I suspect that the instrument is a Hach HQ2200 Portable Multimeter purchased from Cole-Palmer Instrument Company.
Reply: We verified the equipment used to test eh values in the field. It was SmarTROLL MP, In-Situ, Colorado, USA. (Line 178)
Reviewer 2 Report
The authors in their work analyze water in wetlands for the origin of manganese and iron in it.
Notes:
1. The structure of the article should have a clear consistent structure. The author needs:
1.1. In the introduction, it is necessary to clearly state the task of the study. In the future, according to the article, the problem posed must be solved.
1.2. In the "overview" section, it is necessary to consider existing technologies for solving the problem
2. There are too many sections and subsections in the article. The confusion begins. The author needs to single out "introduction", "problem statement", "review of existing methods", "methodology for solving the problem", "example", "discussion", "conclusions" to structure the article approximately according to this structure.
3. There is no research methodology in the work. Authors need to explicitly present the results. At the moment it is not clear what happened in the end? Part of the results in the middle of the article, part at the end.
4. In the conclusions, the result 1 and 3 was not initially set for the study. Are these side effects or main ones? This must be specified.
5. Clause 4.2.4. Don't you think that this is also a very significant result of the study. Why is it not in the waters?
6. In the discussion section, there is no critical assessment of the study; positive and negative aspects are not noted. The ways of applying these studies are not shown.
7. As part of this study, I recommend that you read and include in your review the following works:
https://doi.org/10.3390/w15040770
https://doi.org/10.1109/ElConRus54750.2022.9755601
Conclusion. The topic is undeniably relevant. The conducted research makes a significant contribution to the scientific and technical field. However, the study is poorly presented. The author needs to revise the article. I consider it inappropriate to reject this article, since this study, if revised, can be very useful for the scientific community.
Author Response
Dear reviewer,
We gratefully appreciate your valuable comment, which has significantly raised the manuscript’s quality and enabled us to improve the manuscript. Each comment brought forward by you was accurately incorporated and considered. The comments have been responded point by point, and revisions are indicated. The changes in the revised manuscript are highlighted in red.
Comment 1: The structure of the article should have a clear consistent structure. The author needs: (1) In the introduction, it is necessary to clearly state the task of the study. In the future, according to the article, the problem posed must be solved. (2) In the "overview" section, it is necessary to consider existing technologies for solving the problem.
Reply: Thank you for your constructive comments. We have reorganized the content of the introduction. (1) We have summarized the research methods used in relevant studies and the problems solved (line 75-95); (2) we have clearly proposed the problems (objective) that this study tries to solve (line 98-107).
Comment 2: There are too many sections and subsections in the article. The confusion begins. The author needs to single out "introduction", "problem statement", "review of existing methods", "methodology for solving the problem", "example", "discussion", "conclusions" to structure the article approximately according to this structure.
Reply: In order to make the structure of the full text more reasonable, we adjusted and merged the chapters to make it clearer. The contents of 4.1, 4.2, and 4.2.4 are merged into 4.1 in the revised draft, and the remaining chapters are presented in sequence. As mentioned above, the introduction section has been reorganized, according to the structure that “background”, “problem statement”, “review of existing methods”, ”examples”, “object of this research”.
Comment 3: In the conclusions, the result 1 and 3 was not initially set for the study. Are these side effects or main ones? This must be specified.
Reply: The purpose of the research was not described in detail in the original manuscript. For this reason, we added relevant content at the end of the introduction to form a clear correspondence between the conclusion and the purpose of the research.
Comment 4: Clause 4.2.4. Don't you think that this is also a very significant result of the study. Why is it not in the waters?
Reply: Clause 4.2.4, “Analysis of water chemical index factor” in the original manuscript is correlation analysis, which only analyzes the strength of correlation between water quality parameters from the perspective of statistics. In essence, this method is a dimensionality reduction analysis and does not consider hydrogeochemical factors. Therefore, it is usually regarded as a preliminary analysis and cannot be directly conclusive. Therefore, this section is merged with 4.1 and is no longer a separate section.
Comment 5: In the discussion section, there is no critical assessment of the study; positive and negative aspects are not noted. The ways of applying these studies are not shown.
Reply: At the end of the paper, the significance of this research is summarized, and the necessary research content not involved in this research is prospected.
Comment 6: As part of this study, I recommend that you read and include in your review the following works:
https://doi.org/10.3390/w15040770
https://doi.org/10.1109/ElConRus54750.2022.9755601
Reply: We read the article you recommended and added it to the references (No. 29 and 30). Thank you for your help.
Round 2
Reviewer 2 Report
all comments have been removed.
