Accumulation Assessment of Mo4+, Pb++, and Cu++ in the Acidic Water of Copper Mines with Lemna minor and Lemna gibba
Round 1
Reviewer 1 Report (New Reviewer)
Comments and Suggestions for AuthorsOverall, the study offers a thorough analysis of the experiment carried out to look at Lemna gibba and Lemna minor's accumulation capacities in acid mine fluids from copper mining operations. Both the technique and the results are presented in an understandable manner. Still, there are a few places in which the paper could be strengthened.
1. More background information about the significance of mining activities in contaminating aquatic habitats and the significance of developing effective techniques for pollutant removal could be included in the introduction.
2. Although the experimental design is described, additional information should be given regarding the size of the reactors, the amount of water and plant material used, and any particular conditions that were upheld throughout the experiment (such as nutrient availability and light intensity).
3. To assess the significance of the variations between the experimental and control samples, statistical analysis of the data would be helpful.
4. A more thorough examination of the processes by which Lemna minor and Lemna gibba gather Mo, Pb, and Cu from the acid mine fluids could be done in the discussion section. Furthermore, it might be investigated how these results might affect environmental remediation in general and the field of phytoremediation in particular.
5. The study's main conclusions should be briefly summarized in the conclusion, along with the importance of the findings in relation to environmental pollution.
6. To give readers a more comprehensive understanding of the study's implications, suggestions for future research directions or possible uses of the findings could be included.
7. Some sentences are difficult to read because they are long and complicated. Clarity would be increased by using simpler language and dividing difficult concepts into smaller, easier-to-understand sections.
8. Cite more recent references to boost the context and applicability of the research.
In general, addressing these issues would improve the paper's overall quality and increase its significance to the fields of phytoremediation and environmental science.
Author Response
Reviewer 1
Overall, the study offers a thorough analysis of the experiment carried out to look at Lemna gibba and Lemna minor's accumulation capacities in acid mine fluids from copper mining operations. Both the technique and the results are presented in an understandable manner. Still, there are a few places in which the paper could be strengthened.
- More background information about the significance of mining activities in contaminating aquatic habitats and the significance of developing effective techniques for pollutant removal could be included in the introduction.
It was added
It is known that the large amounts of waste and waste generated over the years as a result of mining activities still constitute a permanent source of pollution for surface and groundwater in the region. This situation causes the negative effects of water quality on organisms living in aquatic ecosystems to reach frightening levels [23].
- Although the experimental design is described, additional information should be given regarding the size of the reactors, the amount of water and plant material used, and any particular conditions that were upheld throughout the experiment (such as nutrient availability and light intensity).
All details were given in 2.3. Analytical Method
As detailed by Tatar and Obek [32], each reactor contained 500 grams of plants, with dimensions of 70x35x30 cm (Fig. 2), L. gibba in one reactor and L. minor in the other. Throughout the experiment, the plants were fed with fresh water by the reactors, which continuously flowed 1.28 L sec−1 of acid mineral water (Fig. 2).
- To assess the significance of the variations between the experimental and control samples, statistical analysis of the data would be helpful.
I don't know this details. Only I added p < 0.05 values to my analyses results
- A more thorough examination of the processes by which Lemna minor and Lemna gibba gather Mo, Pb, and Cu from the acid mine fluids could be done in the discussion section. Furthermore, it might be investigated how these results might affect environmental remediation in general and the field of phytoremediation in particular.
I benefited from the articles on the accumulation of these metals in recent years and added the summaries of these studies to the discussion section.
- The study's main conclusions should be briefly summarized in the conclusion, along with the importance of the findings in relation to environmental pollution.
It was added to conclusion;
In this study, the daily accumulation performances of Mo, Pb and Cu in L. gibba and L. minor growing in acidic mineral waters of Maden copper deposit were examined and the following results were found;
- To give readers a more comprehensive understanding of the study's implications, suggestions for future research directions or possible uses of the findings could be included.
I made similar suggestions for future research recommendation in last sentences of the conclusion
- Some sentences are difficult to read because they are long and complicated. Clarity would be increased by using simpler language and dividing difficult concepts into smaller, easier-to-understand sections.
I corrected some long and complicated sentences in text
- Cite more recent references to boost the context and applicability of the research.
I also added a few recent references to text
In general, addressing these issues would improve the paper's overall quality and increase its significance to the fields of phytoremediation and environmental science.
Thank you very much for the positive comments and great contribution.
Author Response File: 
Author Response.pdf
Reviewer 2 Report (New Reviewer)
Comments and Suggestions for AuthorsDear Author,
the subject of the submitted manuscript is important due to the contamination of water with heavy metals and its monitoring. Before acceptance, I have requested major revision, please see the comments below.
Introduction
Please write - as in the case of Mo - why Pb and Cu are harmful to health and what are their permissible doses.
Methods
Why haven't other metals been tested e.g. Ni, Cu, Au, Co and Ag, although the Author states that there are significant resources in the Maden mine deposits.
What was the control sample?
How it was calculated how many liters of water containing these metals were purified by these plants in a week.
Results
Line 136 - What does it mean “taken from 35”?
Have correlations between Mo, Pb and Cu removal been calculated between Lemna species?
Figures
Figures 4-6 - describe what the abbreviations LM and LG mean.
What does the column mean in the figures? Is SE marked?
Tables
Table 1 is difficult to read. Please correct it. What does DL mean in table 1?
References
In more than 40% of the articles, the year of publication is more than 10 years old.
Please format the references as required by the journal - the year of publication is missing in several items.
The manuscript requires checking by a native speaker due to numerous linguistic errors.
Author Response
Reviewer 2
Dear Author,
the subject of the submitted manuscript is important due to the contamination of water with heavy metals and its monitoring. Before acceptance, I have requested major revision, please see the comments below.
Introduction
Please write - as in the case of Mo - why Pb and Cu are harmful to health and what are their permissible doses.
The appropriate content of Cu in plants is essential both for the health of the plant and for the nutrient supply to man and animals. Certain plant species can collect very high quantities of Cu in their tissues and are highly tolerant of elevated Cu concentrations. All plants naturally contain lead (Pb), although its exact function in metabolism is unknown. They came to the conclusion that a concentration of 2–6 μg/kg should be adequate if Pb is needed by plants. Consequently, Pb has garnered a lot of attention lately as a significant metallic compound that contaminates the environment and a component that is harmful to plants [23]. Yet, as with all elements, exposure to high doses of Mo, Cu and Pb can be detrimental to animal, human and plant health [24].
Methods
Why haven't other metals been tested e.g. Ni, Cu, Au, Co and Ag, although the Author states that there are significant resources in the Maden mine deposits.
Sasmaz Kislioglu (2023) studied these metals (Ag, Au, and As) in this copper deposits in this article
What was the control sample?
The control samples are Lemna gibba and Lemna minör samples analyzed before starting the experiment
How it was calculated how many liters of water containing these metals were purified by these plants in a week.
To find out how much water the Lemna minör plant cleans on the 8th day, the control concentration (2.16 mg kg-1) is subtracted from the 8th day Lemna minör concentration (169 mg kg-1). Then, the resulting value is divided to the water Mo value (30 μg L-1) in one liter of water (=169.000-2.160/30) to find out how many liters of water (5561 L.) the plant cleans Mo. L. gibba removed molybdenum in 274 L of acidic mineral water at the end of the 6th day of the study.
Results
Line 136 - What does it mean “taken from 35”?
This data was taken from Sasmaz Kislioglu [45]
Have correlations between Mo, Pb and Cu removal been calculated between Lemna species?
No, Metal removal between Lemna species was calculated separately
Figures
Figures 4-6 - describe what the abbreviations LM and LG mean.
It was added to text: Mo accumulation ratios by L. gibba (LG) and L.minor (LM).
What does the column mean in the figures? Is SE marked?
It is standard deviation ratios for each plant
Tables
Table 1 is difficult to read. Please correct it. What does DL mean in table 1?
It was enlarged
References
In more than 40% of the articles, the year of publication is more than 10 years old.
Please format the references as required by the journal - the year of publication is missing in several items.
Please format the references as required by the journal - the year of publication is missing in several items.
The references were corrected
The manuscript requires checking by a native speaker due to numerous linguistic errors.
Author Response File: Author Response.pdf
Round 2
Reviewer 2 Report (New Reviewer)
Comments and Suggestions for AuthorsThe manuscript has been revised according to the reviewer's instructions, but minor revision is needed. The improvement should be in the English language.
The manuscript requires checking by a native speaker due to numerous linguistic errors.
Author Response
It was corrected with English editing ID: english-78544
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
Comments and Suggestions for AuthorsSee attached review
Comments for author File: Comments.pdf
Reviewer 2 Report
Comments and Suggestions for AuthorsThe manuscript (water-2864012) concerns the assessment of the ability of Lemna gibba and Lemna minor to accumulate molybdenum, lead and copper from the acidic water of copper mine. In my opinion, the research results presented in this work can potentially be used in practice, however, the similarity of this article to another one, already published in the Water, raises serious doubts. Reviewed manuscript is very similar in structure, language style and other elements to a previously published article by another author (Merve Sasmaz Kislioglu, Removal of Ag, Au, and As from Acid Mine Water Using Lemna gibba and Lemna minor - A Performance Analysis, Water 2023, 15(7), 1293; https://doi.org/10.3390/w15071293).
Below is a description of elements that are very similar or identical in both articles.
- The vast majority of references listed in the References section are the same as those in article of Merve Sasmaz Kislioglu. Moreover, the first 10 references are identical references, arranged in the same order.
- The content and structure of the first and half of the second paragraph of the Introduction are the same in both articles. Differences between articles result from the use of synonyms or different sentence structures.
The revied manuscript
“Acid mine drainage, or AMD for short, is a common occurrence in both current and abandoned mines, whether open-pit or underground. Sludge ponds, quarries, pit lakes, tailing dumps, tailing dams, stockpiles, iron ore haul highways, and mine waste dumps are additional locations where AMD can be discovered [1,2]. Because of its high pH and heavy metal content, AMD is challenging to cure and presents serious risks on human health and the environment. If AMD is discharged without receiving the appropriate care, long-term environmental problems and damage may arise [3-5]. Particularly in sulfide mines, acidic water is produced as a byproduct of mining and subsequent processes. This water can have a drop in heavy metal ion concentration from thousands or hundreds of milligrams to a few milligrams. Because heavy metals pollute the air, land, and water, as well as taint food and drink, they can cause a wide range of illnesses in both people and animals. Therefore, it is a significant task and a known scientific truth that heavy metals may be removed or reduced from the air, soil, and water. One of the hardest challenges in contemporary mining has been acid mine waters [6].
Heavy metals have large atomic weights and a density five times higher than that of water [7]. They were divided into two categories by Gergen and Harmanescu [8]. Rai et al. [9] claim that metals including Mo, Pb, Cu, Cd, Hg, Ni, As, Au, Ag, and Cr have contaminated soil, water, and air widely and have no good effect on plants or animals. Animals and plants require some metals (Fe, Cu, Zn, Co and Mn), although high amounts of these metals can be harmful. Therefore, one of the primary issues affecting aquatic plants and animals is still heavy metal contamination [10]. Certain metals include As, Tl, Hg, Pb, Cr, and Cd are an especially concerning for public health because of their high hazardous levels [7].”
Previously published article
“Acid mine drainage (AMD) is commonly found around both active and abandoned mining areas, whether they are underground or open pit. Secondary sources of AMD include sludge ponds, pit lakes, quarries, haul roads, iron ore stockpiles, tailing dams, tailing dumps and mine waste dumps [1,2]. Due to its high concentration of heavy metals and pH levels, AMD can be difficult to treat and poses significant risks to human health and the environment. Discharging AMD without proper treatment can cause long-term environmental pollution and problems [3–5]. Acid mineral water is produced as a result of production and subsequent activities, particularly in sulfide mines. The concentration of heavy metal ions in this water can decrease from several hundred or even thousands of milligrams to just a few milligrams per liter. Heavy metals can lead to various diseases in humans and animals by polluting the air, soil, and water as well as through drinking water and contaminated food. Consequently, removing and reducing heavy metals from the air, soil, and water is a significant task and a scientific reality. Acid mine waters have been one of the most challenging problems of modern mining activities [6].
Heavy metals have a density five times greater than that of water and have high atomic weights [7], and Gergen and Harmanescu classified them into two groups [8]. According to Rai et al. [9] metals such as Ag, Au, As, Ni, Pb, Hg, Cd, and Cr have no beneficial role in plants and animals and cause widespread water, air, and soil contamination. While some metals such as Zn, Mn, Cu, Fe, and Co are essential for animals and plants, excessive concentrations of these metals can be toxic. As a result, heavy metal contamination remains one of the main problems affecting animals and plants in aquatic environments [10]. Certain metals including Cd, Cr, Pb, Hg, Tl, and As are a particularly concerning for public health due to their high toxicity [7].”
- The content of the Materials and Methods section in both articles is mostly the same.
Figures 2 and 3 in the reviewed manuscript correspond to Figure 2 (a) and (b) in the previously published article (no references inserted).
All the data presented in this section of the reviewed manuscript indicate that the results presented are part of the experiment described in the previously published article. It can therefore be concluded that the results of a single experiment, reported in the previously published article, were artificially divided into two articles. In my opinion, if one experiment was conducted, all important results obtained during the experiment should be published and analyzed in one article.
- The structure of the Results section is the same in both articles.
The difference is limited to the fact that the bioaccumulation of other elements was analyzed. In my opinion, if during the experiment plant samples were analyzed using ICP-MS, the concentrations of all important elements should be measured and bioaccumulation should be analyzed in the context of the concentrations of all measured elements. Such a study would provide an overview of the entire bioaccumulation process in Lemna minor and Lemna gibba exposed to a specific wastewater.
In the reviewed manuscript, the results are anecdotal evidence. Only an artificially selected part of the experimental results is presented and cannot be used for scientific analysis. Moreover, analyzing the content of the currently reviewed and previously published articles, it can be assumed that the results regarding other elements are intended for the next publication, which will make it difficult for readers to analyze the experiment.
My other comments on the manuscript.
- There is no information regarding the novelty of the presented research. What is the novelty of the presented research?
- The Material and Methods section is described too briefly and should be improved (for example, more information should be added about the reagents used, the digestion method, the equipment used, and the ICP-MS measurement procedure).
- The results of the element determinations were presented imprecisely, i.e., no information was provided whether they referred to ash, dry mass or fresh mass.
- According to the author, during the first four days of the experiment copper accumulation by Lemna minor was very high (12668 ppm). Such a high value of accumulated copper should be confirmed using an additional method, e.g., SEM-EDS.
- The data in Table 1 are presented is in a way that is difficult to read.
- The manuscript contains editing errors, e.g., line 66: incorrect notation of the degree sign; line 108: uncompleted sentence; line 138: the superscript is missing in the L-1 notation; line 234: the full stop isn’t at the end of the sentence; line 253: the word “low” is repeated.
Considering the above, I recommend rejecting the manuscript.
Reviewer 3 Report
Comments and Suggestions for AuthorsDear author, please add the following notes to the manuscript:
1. It is necessary to correct punctuation errors in the text.
2. It is required to indicate the valency of the elements.
3. Please indicate methods for recycling waste phytomaterials, as well as specifically on the topic of research.
4. Please provide data on the speed limit for the mandatory cleaning result.
5. Should any racks reduce each of the heavy metal readings? Indicate the standards on this topic
6. What are the permissible pH values ​​and pollutants (heavy metals) for the existence of L.gibba and L.minor
7. What is the period of complete restoration of the reservoir with this method of phytoremediation?
In addition, it is necessary to strengthen the scientific component on the research topic
Reviewer 4 Report
Comments and Suggestions for AuthorsLemna minor and Lemna gibba are aquatic vegetation that have been fairly well studied for wastewater bioremediation. The publication would be improved if the introduction provides a more detailed analysis of the application of L. gibba and L. minor for biosorption and bioaccumulation of heavy metals based on global experience.
I believe that it would also be useful to analyse the toxicity tests of Lemna minor and Lemna gibba in relation to various heavy metals and the acidity of the wastewater, which are also known in world practice.
