Applicability of Zeolite from the Daubabinsk and Chankanai Deposits as a Sorbent for Natural Waters
and Aktota A. Murzagulova 2
Round 1
Reviewer 1 Report
The manuscript describes Applicability of zeolite from the Daubabinsk and Chankanai 2 deposits as a sorbent for natural waters. This manuscript is organized logically. The article can be published after noted the following:
(1) What is the difference of the sorbents surface after modification in 20% hydrochloric acid?
(2) What is the influence of the pore volume of the sorbents on purification of natural waters?
(3) Some metal oxides sorbents (Separation and Purification Technology 2022,299: 121703; 10.1139/er-2015-0080) for waters purification and monitoring should be cited in the Introduction part.
(4) Some sentences should be polished.
Fairly good.
Author Response
Response to Reviewer 1 Comments
Dear Reviewer!
Thank you for your reviewing and comments to our manuscript. Your significant and correct comments have enabled us to improve our work.
Point 1: What is the difference of the sorbents surface after modification in 20% hydrochloric acid?
Response 1: The Results section includes additions.
The hydrothermal treatment of the zeolite results in a change of the surface groups, the interaction of hydrochloric acid with the zeolite surface causes deprotonation of some of the active groups on the sorbent surface. For example, hydroxyl groups (OH-) can transform into chloride groups (Cl-), which changes the surface charge state. As zeolites have a definite porous structure, which plays an important role in the process of sorption, modification with hydrochloric acid changes the size of pores, their shape as a result of which there is an availability for sorption.
In general, surface modification of zeolite based sorbents using 20% hydrochloric acid leads to changes in their structure, surface properties and adsorption activity [28].
Point 2: What is the influence of the pore volume of the sorbents on purification of natural waters?
Response 2: The Conclusitions section includes additions.
Based on the influence of the pore volume of the sorbents on the treatment of natural waters, the pore volume of zeolite-based sorbents is important for the efficiency of natural water treatment. Porous materials with many microscopic pores adsorb pollutants from water. The larger the pore volume in the modified zeolite, the more surface area is available for interaction with contaminants.
Point 3: Some metal oxides sorbents (Separation and Purification Technology 2022,299: 121703; 10.1139/er-2015-0080) for waters purification and monitoring should be cited in the Introduction part. Some metal oxides sorbents (Separation and Purification Technology 2022,299: 121703; 10.1139/er-2015-0080) for waters purification and monitoring should be cited in the Introduction part.
Response 3: A topical article on our topic, included.
- Mengxue Li, Jianyong Liu, Yunfeng Xu, and Guangren Qian. Phosphate adsorption on metal oxides and metal hydroxides: A comparative review. Environmental Reviews 16 May 2016 https://doi.org/10.1139/er-2015-0080
- Renwu Zhu, Xianbiao Wang, Jared G. Panther, Qiang Wang, Soufian Chakir, Yan Ding, Yuanyuan Huang, Huanting Wang. Micro/nanostructured MgO hollow spheres with selective adsorption performance and their application for fluoride monitoring in water. https://doi.org/10.1016/j.seppur.2022.121703
Point 4: Some sentences should be polished.
Response 4: The article as a whole has been revised, additions included and errors corrected.
Author Response File: 
Author Response.docx
Reviewer 2 Report
In this manuscript, the authors evaluated the effectiveness of using pretreated natural zeolite deposits of Chankanai and Daubabinsk for water treatment. The authors presented some great results for the natural zeolite characterization as well as water analysis for samples before and after treatment. However, the manuscript needs to be reorganized to clearly state the novelty and significance of the current study, as well as the logical flow of the overall storyline. The followings are my comments:
1. Rewrite the abstract. You should summarize the main message of the manuscript in your first sentence, which is not to describe zeolite deposits but to evaluate their effectiveness in water treatment. Water analysis methods are not needed at that level of detail. Instead, please include the novelty and significance of the present study, and new findings/contributions.
2. Throughout the manuscript, ~75% of the text is written as lists. This is highly unrecommended. Do we really need that many lists in this manuscript? I would try to rewrite them in normal paragraphs and only keep the most important one or two as lists. Even if you really want to keep them, please make sure you format lists differently (using bullet points) than normal paragraphs.
3. Introduction lacks background information about the state-of-the-art for natural sorbents. Based on that, the authors will need to add the novelty and significance of the present study. How is the present study different or improved from the previous ones? Why do we need the present study?
4. Information (lines 116-127 and 135-153) in section 2.1 should belong to either background information (introduction) or results. If they are new results from the present study, please move them to the results section and supported them with backup data. If they are from the previous studies, please cite them.
5. If it is already demonstrated in the previous study that zeolites from the Chankanai and Daubabinsk deposits can be used to remove pollution from water (lines 116-117), why is the present study needed?
6. Please describe the methods of using zeolites for water treatment.
7. Please justify the selection of water analysis parameters including total iron, chloride, sulfate content, etc.
8. In the results section, the relevance of information in lines 286-302 and 325-333 is not clear. Are they the results? Are they relevant to zeolites for water treatment? If so, please clearly state the correlation between zeolite structure and its water treatment efficiency and supported it with references or proof. In other words, what structural properties of the zeolite we are looking for to be used as a natural sorbent for water treatment?
9. Lines 347-363 do not belong to the results section.
10. Need references or proof for lines 396-399: "This process modifies the structure and surface properties of the zeolite, increasing its activity and sorption capacity. Treatment of the zeolite in an acidic medium removes ions and other impurities from the surface and internal channels of the zeolite, thus increasing its sorption capacity."
11. Need to evaluate the capacity and regeneration of the zeolite sorbent for water treatment.
12. In the discussion section, please analyze the variability of water treatment effectiveness of different zeolite fractions (0.63 vs. 7.5 mm) and sources (Chankanai vs. Daubabinsk), and correlate back to zeolite chemical and structural characterization results.
13. The logical flow of the entire storyline is very difficult to understand. The authors kept pieces of information here and there but not connecting them. It can be helpful to (i) separate some of the sections into subsections and have a single message for each main subsection, and (ii) add transition sentences or paragraphs.
Minor comments:
1. Missing transition sentences before lines 71, 87, 110, and 334.
2. "The most well-known and widespread method of treating natural water can be attributed to sorption [11]. " (lines 67-68) is repetitive with "The sorption method is one of the best known and most widely used methods of natural water treatment. " (lines 68-69).
3. In the list of natural sorbent's pros and cons, high sorption capacity is its advantage (line 96) and low capacity is its disadvantage (line 103).
4. Each of the water treatment approaches mentioned in the introduction has pros and cons, why is the present study interested in natural sorbent?
5. There are many incomplete sentences throughout the manuscript. Please double-check.
The English language is overall ok. But there are a lot of incomplete sentences. Also, please try to format the lists differently (using bullet points for example) from normal paragraphs.
Author Response
Response to Reviewer 2 Comments
Dear Reviewer!
Thank you for your reviewing and comments to our manuscript. Your significant and correct comments have enabled us to improve our work.
Point 1: Rewrite the abstract. You should summarize the main message of the manuscript in your first sentence, which is not to describe zeolite deposits but to evaluate their effectiveness in water treatment. Water analysis methods are not needed at that level of detail. Instead, please include the novelty and significance of the present study, and new findings/contributions.
Response 1: The abstract section has been corrected to reflect the comments of all reviewers.
Abstract: This article examines the characteristics of zeolites from the Chankanai and Daubabinsk deposits. In the field of water treatment, the purpose of investigating natural zeolite from the Chankanai and Daubabinsk deposits as a sorbent presents new opportunities and prospects, as this raw material is little studied. The effectiveness of the sorbents was assessed based on the results of the water specifications according to the following criteria: methods for determining the total hardness of water; methods for measuring the mass concentration of total iron in water; methods for the determination of chloride in water; methods for the determination of nitrogen-containing substances in water; methods for determining the dry residue content of water; methods for determining the sulphate content of water; on hygiene requirements and water quality control. Zeolite modifications are aimed at improving their adsorption properties, increasing the efficiency of pollutant removal and developing optimal methods of using zeolites in water filtration. Modified zeolite from the Chankanai and Daubabinsk deposits showed high efficiency as a filter. When it is used to treat natural water, which normally contains high hardness and alkalinity, the best results are achieved with zeolite from the Chankanai deposit. In terms of Fe+ and Cl content, the best results are achieved using zeolite from the Daubabinsk deposit.
Point 2: Throughout the manuscript, ~75% of the text is written as lists. This is highly unrecommended. Do we really need that many lists in this manuscript? I would try to rewrite them in normal paragraphs and only keep the most important one or two as lists. Even if you really want to keep them, please make sure you format lists differently (using bullet points) than normal paragraphs.
Response 2: The text has been edited.
Point 3: Introduction lacks background information about the state-of-the-art for natural sorbents. Based on that, the authors will need to add the novelty and significance of the present study. How is the present study different or improved from the previous ones? Why do we need the present study?
Response 3: Background information on the current state of natural sorbents, novelty, relevance are given.
Currently, there are several modern natural sorbents that are widely used to clean water from various pollutants [10 - 11]. Here are some of them:
Activated charcoal: It is one of the most common and effective sorbents for water. Activated charcoal has a large surface area with many pores, allowing it to absorb organic matter, pesticides, chlorine, chemical compounds and other pollutants. It is widely used in commercial drinking water and water supply filters.
Green alumina: Green alumina (aluminium hydroxide) is an effective sorbent for removing toxic metals from water, such as lead, copper, cadmium and arsenic. It has a high adsorption capacity and good chemical stability.
Biosorbents: Biosorbents are materials of biological origin such as bacteria, algae and other micro-organisms that can absorb pollutants from water. Biosorbents are widely used to remove heavy metals, radionuclides and organic compounds from water systems.
Coconut charcoal: Coconut charcoal is obtained from processed coconut remnants. It has a large surface area and high adsorption capacity, making it an effective sorbent for removing organic pollutants, chlorine, phenols and other substances from water.
Cinders and ashes: Cinder and ash from various plants and wood materials are also used as sorbents for water. They can absorb heavy metals, organic substances and other pollutants.
The study of natural zeolite as a sorbent represents a novelty in the field of treatment of various types of water. Modified zeolite from Daubabinsk and Chankanai deposits is poorly studied and there is no industrial production of zeolite-based filters across the CIS.
The significance of the study is to determine the applicability of Daubabinsk and Chankanai zeolite as a sorbent after modification for natural waters.
Point 4: Information (lines 116-127 and 135-153) in section 2.1 should belong to either background information (introduction) or results. If they are new results from the present study, please move them to the results section and supported them with backup data. If they are from the previous studies, please cite them.
Response 4: The text has been changed. Moved to the Introduction section. In the original text, the general characteristics of zeolite were given.
Zeolites have numerous properties, including the ability to remove contaminants from water [19]. One way to use zeolites in water treatment is to create filters based on their properties.
Zeolites have a structure that contains micropores and channels of varying sizes. These pores and channels enable zeolites to effectively trap and remove various contaminants from water, including heavy metal ions, ammonia, pesticides, organic compounds and other substances. They are also able to exchange some ions, such as sodium or potassium, for other ions in the water.
In general, the use of zeolite filters for water treatment has a long history and the technology is widely used in a variety of applications, including domestic water treatment systems, industrial processes and city- and community-scale drinking water treatment.
Some characteristics of zeolite:
Structure and morphology: zeolite has a layered structure resulting from a three-dimensional network of silicon and aluminium oxide frameworks with incorporated cations. This gives the zeolite a micro-porous structure and a high surface activity.
Chemical composition: zeolite contains silicon (Si), aluminium (Al), oxygen (O) and other elements in its chemical composition. Cations such as sodium (Na), potassium (K), calcium (Ca) and magnesium (Mg) can also be present in the zeolite structure.
Sorption properties: zeolite has a high sorption capacity due to its micro-porous structure. It can trap various pollutants, including organic compounds, heavy metals and other harmful substances, making it an effective sorbent for water purification.
Physical properties: zeolite has different physical properties such as different particle sizes, permeability, density and strength. These properties may vary depending on the specific conditions of the deposit and processing.
Applications: zeolite can be used in various fields including natural and drinking water treatment, wastewater treatment, catalysis, agriculture and others. Its sorption properties make it a useful material for removing pollutants and improving water quality [19].
Point 5: If it is already demonstrated in the previous study that zeolites from the Chankanai and Daubabinsk deposits can be used to remove pollution from water (lines 116-117), why is the present study needed?
Response 5: Zeolites have numerous properties, including the ability to remove contaminants from water [19]. One way to use zeolites in water treatment is to create filters based on their properties.
Point 6: Please describe the methods of using zeolites for water treatment.
Response 6: How zeolites can be used for water treatment is given in the introduction.
Point 7: Please justify the selection of water analysis parameters including total iron, chloride, sulfate content, etc.
Response 7: Water quality control is regulated by the Department of Sanitary and Epidemiological Control of Almaty. The water treatment standards presented in this manuscript are legally stipulated in the Sanitary and Epidemiological Station.
Point 8: In the results section, the relevance of information in lines 286-302 and 325-333 is not clear. Are they the results? Are they relevant to zeolites for water treatment? If so, please clearly state the correlation between zeolite structure and its water treatment efficiency and supported it with references or proof. In other words, what structural properties of the zeolite we are looking for to be used as a natural sorbent for water treatment?
Response 8: Lines 286-302 and 325-333 are deleted, will be included in the next article.
Point 9: Lines 347-363 do not belong to the results section.
Response 9: Yes, we agree. Deleted, moved to section 2.2. Methods
Point 10: Need references or proof for lines 396-399: "This process modifies the structure and surface properties of the zeolite, increasing its activity and sorption capacity. Treatment of the zeolite in an acidic medium removes ions and other impurities from the surface and internal channels of the zeolite, thus increasing its sorption capacity."
Response 10: link inserted.
In general, surface modification of zeolite based sorbents using 20% hydrochloric acid leads to changes in their structure, surface properties and adsorption activity [28].
- Bobylev A.E. Synthesis, structure and functional properties of composite sorbents. Cationic KU-2X8-MeS (Me-Cu(II), Zn, Pb)". Dissertation. Yekaterinburg, 2016.
https://elar.urfu.ru/bitstream/10995/40507/1/urgu1588_d.pdf
Point 11: Need to evaluate the capacity and regeneration of the zeolite sorbent for water treatment.
Response 11: Section 2.2. Methods is supplemented by information on the filtration procedure, and a schematic of the installation is presented. In the presented article the data for regenerated spent zeolite have been decided by the co-authors to delete. For information, regeneration of the spent zeolite filter is quite simple, it is rinsing with boiled water or washing with a slightly alkaline solution.
Water filtration. A schematic of the filtration unit is shown in Figure 1.
Figure 1. Schematic diagram of a filter unit
Filtration procedure consisted of the following: a cylindrical polymer tank No.1 receives water with the volume V= 0.03534m3 or 35.34292 liters for 0.2-0.5 min, water passes through the filter No.2 with the volume V= 0.03534m3 for 1.5-10 min and then filtered water is poured into caustic vessels to determine purification degree. The transit time through the filter depends on the Mk (Size modulus) of the modified zeolite.
Point 12: In the discussion section, please analyze the variability of water treatment effectiveness of different zeolite fractions (0.63 vs. 7.5 mm) and sources (Chankanai vs. Daubabinsk), and correlate back to zeolite chemical and structural characterization results.
Response 12: The paper does not aim at chemical and structural characterisation, this will be presented to the next paper in agreement with the co-authors. In this paper the effectiveness of the modified zeolite is evaluated only by the results of the water analysis.
In general, the modified zeolite from the Chankanai and Daubabinsk deposits showed quite excellent performance as a filter. Judging by the purification of natural water, as it is most polluted by hardness 1.24 and alkalinity 0.01, Mk (Size modulus) - 5-2.5 mm zeolite from the Chankanai deposit works better. In terms of Fe+ and Cl content the Daubabinsk zeolite works better, Mk 5-2.5 mm - Fe+ is reduced to 0.02-50, Cl is reduced to 1.11 at Mk 1.25-0.63 mm.
Point 13: The logical flow of the entire storyline is very difficult to understand. The authors kept pieces of information here and there but not connecting them. It can be helpful to (i) separate some of the sections into subsections and have a single message for each main subsection, and (ii) add transition sentences or paragraphs.
Response 13. For section 3. Results include sub-items, transition is included in the text. 3.1. Initial data of the object of study, 3.2. Qualitative indicators of water used to assess the effectiveness of modified zeolite application, 3.3. Preparation of a zeolite-based filter from the Chankanai and Daubabinsk deposits (modification)
Minor comments:
Point 1. Missing transition sentences before lines 71, 87, 110, and 334.
Response 1. LINE 71 CORRECTED, LINE 87 CORRECTED, LINE 110 TEXT DELETED, LINE 334 TEXT CORRECTED.
Point 2. "The most well-known and widespread method of treating natural water can be attributed to sorption [11]. " (lines 67-68) is repetitive with "The sorption method is one of the best known and most widely used methods of natural water treatment. " (lines 68-69).
Response 2. Edited.
Point 3. In the list of natural sorbent's pros and cons, high sorption capacity is its advantage (line 96) and low capacity is its disadvantage (line 103).
Response 3. Edited.
Point 4. Each of the water treatment approaches mentioned in the introduction has pros and cons, why is the present study interested in natural sorbent?
Response 4. Firstly, the applicability of Daubabinsk and Chankanai zeolite as a sorbent for natural waters was of interest to us, as zeolite from these deposits has been little studied as a sorbent. Secondly, the results of the research work are aimed at commercialisation, i.e. the launch of filter stations in regions where there is a shortage of drinking water.
The sorbent based on modified natural zeolite is a material with a number of attractive properties that make it interesting for use in scientific research. Here are a few reasons why zeolites are of interest to researchers:
High sorption capacity: Zeolites have a high surface activity and a microporous structure, which makes them excellent sorbents for various pollutants. They can effectively remove various toxic substances, heavy metals, radionuclides and other pollutants from water, soil and air.
Chemical stability: Zeolites are chemically stable and do not decompose or change their properties when in contact with various media. This makes them durable and reliable materials for sorbing and removing pollutants.
Reuse: Zeolites can be regenerated and reused after saturation with pollutants. This makes them cost-effective and environmentally friendly sorbents. Research is aimed at developing optimal methods for regenerating zeolites and increasing their stability for multiple use.
Wide range of applications: Zeolites can be used in various fields such as water treatment, waste treatment, catalysis, agriculture and others. Research is aimed at expanding the application area of zeolites and optimising their properties for specific applications.
Unique properties: Zeolites have a number of unique properties such as selective sorption, molecular recognition and ion exchange properties. These properties make them attractive for research into the separation and extraction of valuable substances from mixtures or solutions.
Point 5. There are many incomplete sentences throughout the manuscript. Please double-check.
Response 5. Corrected. Edited.
Author Response File: Author Response.docx
Reviewer 3 Report
The manuscript is devoted to the study of the applicability of Daubabinsk and Chankanai zeolite as a sorbent for natural waters. The manuscript is of great theoretical and practical interest, however there are some remarks.
1) Lines 188-189. Authors write: "The method consists in hydrothermal treatment of fractional (granulated) zeolite at 95 – 100 0C " . Authors should describe how the granular zeolite was obtained.
2) In addition, the Authors should describe the procedure for filtering water on zeolite filters, give a drawing of the filter unit, describe what the thickness of zeolite layer was, how long the filter stopped working, how the spent zeolite was regenerated.
3) Line 165: "natural water of Bolshaya Almatinka lake in Almaty (used as a sorbent)" Make a correction!
4) Line 373. What is Mk? Enter an explanation in the manuscript.
5) Tables 5, 7-10 and lines 368, 423, 433, 452, 463, 482, 483 :" Fe+ " What is it? Iron ions have charges 2+ and 3+: Fe2+ , Fe3+.
Comments for author File: 
Comments.pdf
Author Response
Response to Reviewer 3 Comments
Dear Reviewer!
Thank you for your reviewing and comments to our manuscript. Your significant and correct comments have enabled us to improve our work.
Point 1: Lines 188-189. Authors write: "The method consists in hydrothermal treatment of fractional (granulated) zeolite at 95 – 100 0C " . Authors should describe how the granular zeolite was obtained.
Response 1: Information added in section 2.2. Methods. Zeolite modification involves the following work steps:
Step 1 - Preparation of the zeolite: The rock was pre-crushed in a blast crusher (alternatively a ball mill can be used) to the required particle-size ratio (hereinafter referred to as the particle-size ratio).
Step 2 - Preparation of the solution: A 20% hydrochloric acid solution was prepared by diluting concentrated hydrochloric acid in distilled water.
Step 3 - Modification reaction: The zeolite is placed in a hydrochloric acid solution and heated to a temperature of 95-100 °C for 1.5-2 hours.
Step 4 - Filtration and washing: After treatment, the zeolite was extracted from the hydrochloric acid solution and filtered to remove residual acids and other inorganic compounds. The zeolite was then washed with distilled water to remove residual acid reagents and reaction products to a neutral pH.
Step 5 - Drying: The purified zeolite is dried to a constant mass, usually in a muffle kiln, to remove moisture and the liquors formed during washing.
Point 2: In addition, the Authors should describe the procedure for filtering water on zeolite filters, give a drawing of the filter unit, describe what the thickness of zeolite layer was, how long the filter stopped working, how the spent zeolite was regenerated.
Response 2: Section 2.2. Methods is supplemented by information on the filtration procedure, and a schematic of the installation is presented. In the presented article the data for regenerated spent zeolite have been decided by the co-authors to delete. For information, regeneration of the spent zeolite filter is quite simple, it is rinsing with boiled water or washing with a slightly alkaline solution.
Water filtration. A schematic of the filtration unit is shown in Figure 1.
Figure 1. Schematic diagram of a filter unit
Filtration procedure consisted of the following: a cylindrical polymer tank No.1 receives water with the volume V= 0.03534m3 or 35.34292 liters for 0.2-0.5 min, water passes through the filter No.2 with the volume V= 0.03534m3 for 1.5-10 min and then filtered water is poured into caustic vessels to determine purification degree. The transit time through the filter depends on the Mk (Size modulus) of the modified zeolite.
Point 3: Line 165: "natural water of Bolshaya Almatinka lake in Almaty (used as a sorbent)" Make a correction!
Response 3: The object of the study is filter-zeolite as a sorbent. The efficiency of filter-zeolite was evaluated by purification of natural water, Bolshaya Almatinka is the name of the lake.
Point 4: Line 373. What is Mk? Enter an explanation in the manuscript.
Response 4: The designation (Size modulus) is given. The transit time through the filter depends on the Mk (Size modulus) of the modified zeolite.
Point 5. Tables 5, 7-10 and lines 368, 423, 433, 452, 463, 482, 483 :" Fe+ " What is it? Iron ions have charges 2+ and 3+: Fe2+ , Fe3+.
Response 5: In nature, water can contain iron in different forms. The most common iron is 2- and 3-valent iron with a positive ion. When water samples are analysed, the result is recorded as Fe+ (total iron), since the test is carried out according to GOST 4011-72 (Government standard) where the mass concentration of total iron is measured by interaction of iron ions in an alkaline medium with sulphosalicylic acid to form a yellow-coloured complex compound. Colour intensity proportional to the mass concentration of iron. That is, the laboratory does not determine the valence of Fe (2x or 3x) contained in the water, but the total iron content. Water quality control is regulated by the Department of Sanitary and Epidemiological Control of Almaty.
Author Response File: Author Response.docx
Round 2
Reviewer 2 Report
The authors have addressed most of my comments well, except for point 2:
Point 2: Throughout the manuscript, ~75% of the text is written as lists. This is highly unrecommended. Do we really need that many lists in this manuscript? I would try to rewrite them in normal paragraphs and only keep the most important one or two as lists. Even if you really want to keep them, please make sure you format lists differently (using bullet points) than normal paragraphs.
By lists, I mean lines 51-67, 76-89, 107-117, 135-152, 228-300, 351-363, 384-385, 394-413, 423-443, 447-463. Do we really need that much information in the form of lists?
Additional comments:
1. In lines 383-385, "The following parameters can be studied in this assessment: sorption efficiency: Determine ..."
There is only one parameter. Instead of the form of a list, please write this in a single sentence.
2. Line 76, please start "filtering: ..." in the next line.
3. There are many incomplete sentences throughout the manuscript:
"Some characteristics of zeolite:" (line 135)
"Subjects of the study:" (line 167)
"Water filtration." (line 218)
"GOST 4151 - 72 Drinking water (GOST - Government standard)." (line 228)
"GOST 4011-72 Drinking water." (line 236)
And so on..
Need to check for incomplete sentences.
Author Response
Response to Reviewer 2 Comments
Dear Reviewer!
Thank you for your reviewing and comments to our manuscript. Your significant and correct comments have enabled us to improve our work.
Point 1: Throughout the manuscript, ~75% of the text is written as lists. This is highly unrecommended. Do we really need that many lists in this manuscript? I would try to rewrite them in normal paragraphs and only keep the most important one or two as lists. Even if you really want to keep them, please make sure you format lists differently (using bullet points) than normal paragraphs.
By lists, I mean lines 51-67, 76-89, 107-117, 135-152, 228-300, 351-363, 384-385, 394-413, 423-443, 447-463. Do we really need that much information in the form of lists?
Response 1: lines 51-67 – corrected.
There are several modern natural sorbents such as activated carbon, green alumina, biosorbents (bacteria, algae and other micro-organisms), and coconut charcoal as well as ashes and ashes from various plants and wood materials. They effectively remove organic substances, pesticides, chlorine, chemical compounds, toxic metals, radionuclide’s and other pollutants due to their large surfaces, many pores, high adsorption capacity, chemical stability and natural origin, which are widely used to clean water from various pollutants [10 - 11].
Lines 76-89 – corrected.
Using the sorbents listed above, a number of methods are used to treat natural water from pollutants, with both advantages and disadvantages [10-12]. Filtration, coagulation and flocculation and ozonation are common water treatment methods. Filtration is based on passing water through a filter that traps pollutants [12, 13]. Coagulation and flocculation involve the addition of coagulants to combine fine contaminant particles into larger ones, thereby facilitating their removal. Ozonation uses ozone to oxidize and break down pollutants and micro-organisms in water [14, 15]. All methods except filtration have advantages and limitations and require appropriate equipment and costs to operate effectively, the filtration method is the most attractive as it does not require expensive equipment.
Lines 107-117 – corrected
The sorption method has several advantages that make it an important tool in natural water treatment; sorbents can effectively remove a wide range of pollutants, including organic substances, heavy metals, pesticides and other harmful compounds. This allows the sorption method to be adapted to remove specific contaminants by selecting a suitable sorbent and optimizing the process conditions. Some sorbents have a long service life and can be regenerated or reclaimed for reuse. This reduces the cost of purchasing new sorbents and reduces the negative impact on the environment. However, the sorption method also has some disadvantages. Sorbents have a limited capacity to retain pollutants, so periodic replacement or regeneration of the sorbents is required. The sorption treatment process may generate waste that requires further treatment or disposal. This may incur additional costs and have a negative impact on the environment. In general, despite some disadvantages, the sorption method is widely used in industry, utilities and other areas as it provides effective water treatment and helps ensure the safety and quality of water resources.
Lines 135-152 – corrected
In terms of structure and morphology zeolites have a layered structure, which is formed by a three-dimensional network of silicon and aluminium oxide frameworks with included cations, this provides a microporous zeolite structure and high surface activity, the chemical composition of zeolite contains silicon (Si), aluminium (Al), oxygen (O) and other elements in its chemical composition. Cations such as sodium (Na), potassium (K), calcium (Ca) and magnesium (Mg) can also be present in the zeolite structure, the physical properties of the zeolite have different physical properties, such as different particle sizes, permeability, density and strength. These properties may vary depending on the specific conditions of the deposit and processing.
Lines 228-300 – corrected
GOST 4151 - 72 (GOST - Government standard) “Drinking water. Method for determination of total hardness” this standard applies to drinking water and establishes the complex metric method for determination of total hardness. The method is based on the formation of a strong complex compound of Trilon B with calcium and magnesium ions. The volume of the water sample for the determination of total hardness is at least 250 cm3. If the hardness cannot be determined on the day of sampling, a measured volume of water diluted with distilled water 1:1 may be left for determination until the next day [21]. According to GOST 4011-72 “Drinking water. Methods of measurement of mass concentration of total iron” were determined total iron in water, the present standard applies to drinking water and establishes colorimetric methods of measuring mass concentration of total iron. The volume of the sample for measuring the mass concentration of iron shall not be less than 200 cm3. The method is based on the interaction of iron ions in an alkaline medium with sulphosalicylic acid to form a yellow colored compound. The color intensity proportional to the mass concentration of iron is measured at 400-430 nm. The measurement range of the mass concentration of total iron without sample dilution is 0.10-2.00 mg/dm3. In this interval the total measurement uncertainty with probability P = 0.95 is between 0.01 and 0.03 mg/dm3 [22]. Using GOST 4245-72 “Drinking water. Methods for determination of chloride content” determined the amount of chloride in water, the present standard applies to drinking water and establishes methods for determination of chloride (chlorine-ion) content. The volume of the water sample for the determination of chloride content is at least 250 cm3. The method is based on the precipitation of a chlorine ion in a neutral or slightly alkaline medium by silver nitrate in the presence of potassium chromate as an indicator. After precipitation of silver chloride at the point of equivalence, silver chromate is formed, with the yellow coloring of the solution changing to orange-yellow. Method accuracy is 1-3 mg/dm3 [23]. To determine hygienic indicators used GOST 2874-82 “Drinking water. Hygienic requirements and quality control”. This standard defines the epidemic safety of water as determined by the total number of micro-organisms and the number of E. coli bacteria, the toxicological indicators of water quality characterize the harmlessness of its chemical composition [24]. To determine the maximum allowable limit of nitrogen-containing substances used GOST 33045-2014 (ISO 6777:1984, NEQ) “Water. Methods for determination of nitrogen-containing substances”, this standard applies to drinking (including packaged in containers), natural (surface and ground) and waste water and determination of ammonia and ammonium ions (total) with Nessler reagent [25]. The dry residue has been determined according to GOST 18164-72 "Drinking water. Method for determination of dry residue content", this standard applies to drinking water and establishes a weight method for determination of dry residue content. The value of the dry residue characterizes the total content of non-volatile mineral and partly organic compounds dissolved in water (methodology standard - chemistry). Volume of water sample for determination of dry residue not less than 300 cm3 [26] and for determination of sulphates in water GOST 4389-72 "Drinking water. Methods for determination of sulphate content", this standard applies to drinking water and establishes methods for determination of sulphate content. The volume of the water sample for sulphate determination must be at least 500 cm3. The determination of sulphate content is based on the precipitation of ions with barium chloride as barium sulphate in an acid medium. Determination accuracy ±2 mg/dm3 [27].
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The separation into fractions was carried out in order to improve the filtration efficiency of zeolite of different size fractions, which have different properties and sorption ability of the pollutant. The separation into fractions made it possible to optimize the filtration process to capture and remove the largest amount of pollutants from the water, the coarse fraction being used to filter out large particles and sludge, while the fine fraction efficiently sorbed fine pollutants and organic matter. To improve the permeability of the filter, fractional separation of the zeolite also allowed for a more permeable filter. The coarse fraction forms the base of the filter, providing space for free flowing water, while the fine fraction fills in the gaps and provides a surface for sorbing pollutants. Fractional separation allowed the use of different zeolite fractions in different filter layers. This increases the overall capacity of the filter and improves its ability to retain pollutants. Larger fractions in the upper filter layers can prevent premature clogging by smaller fractions below.
Lines 384-385 – corrected
The sorption efficiency of the obtained filters prepared from zeolite fractions of Chankanai and Daubabinsk deposits was evaluated for applicability as a sorbent for water treatment of samples No.1 and No.2, Table 5.
Lines 394-413 – corrected
The following values were found when analyzing the characteristics of drinking water filtered using a zeolite filter from the Daubabinsk field. Water hardness is reduced from an average of 4.8 at baseline to 2.9 at norm 7.0, water alkalinity is reduced from an average of 2.0 at baseline to 0.9, Cl in water is reduced from an average of 14.9 at baseline to 2.1 at norm 350, no trace of in water at baseline 14.6 and no dry residue in water at baseline 28, Fe+ in water is reduced from an average of 400 at baseline to 0.02-50 at norm 350.
An analysis of the characteristics of drinking water filtered using a zeolite filter from the Chankanai deposit showed the following results. Water hardness is reduced from an average of 4.8 in the original to 1.2 with a norm of 7.0, water alkalinity is reduced from an average of 2.0 in the original to 0.4, the amount of Cl in the water is reduced from an average of 14.9 in the original to 1.0 with a norm of 350, no traces of in the water with a norm of 14.6, dry residues in water with a norm of 28 were found, Fe+ in water is reduced from 400 in the original to 0.03 - 75 with a norm of 350.
Lines 423-443 – corrected
For natural water filtered with Daubabinsk zeolite, the following results were obtained. Water hardness is reduced from an average of 1.4 to 0.7 at a norm of 7.0, water alkalinity is reduced from an average of 0.6 to 0.55, Cl in the water is reduced from an average of 2.1 to 1.11 at a norm of 350, no traces of in the water at baseline 15, dry residue in the water at baseline 82.8 is not detected, Fe+ in the water is reduced from an average of 1200 at baseline to 0.02 - 50 at norm of 350.
An analysis of the characteristics of natural water filtered using a zeolite filter from the Chankanai deposit showed the following results. Water hardness is reduced from an average of 1.4 to 1.0 with a norm of 7.0, water alkalinity is reduced from an average of 0.6 to 0.01, Cl in water is reduced from an average of 2.1 to 1.34 with a norm of 350, no traces of in water with a norm of 15, dry residue in water with a norm of 82.8 is not detected, Fe+ in water is reduced from an average of 1200 to 0.03 - 75 with a norm of 350.
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From Tables 7 to 10 we can say that the main indicators of natural and drinking water after filtration with zeolite from the Chankanai and Daubabinsk deposits are several times lower. Both zeolite deposits demonstrate effectiveness. The reduction of water hardness, indicates the zeolite's ability to sorb the ions responsible for water hardness, and results in improved drinking water quality. The decrease in alkalinity of the water suggests that the zeolite is able to sorb alkaline components, which can help to balance the pH value and improve water quality. The decrease in the Cl content of the water indicates that the zeolite effectively sorbs chlorides. The absence of detected traces of and dry residue in the water after zeolite filtration indicates the effective removal of these components. This can be important for removing unwanted pollutants and ensuring water safety. A high Fe+ ion content in the water indicates the presence of iron impurities, which may be undesirable for consumption in addition to reducing the durability of the entire water supply system due to corrosion. The decrease in Fe+ indicates that the zeolite is working successfully as a sorbent.
Additional comments:
Point 1: In lines 383-385, "The following parameters can be studied in this assessment: sorption efficiency: Determine ..."
There is only one parameter. Instead of the form of a list, please write this in a single sentence.
Response 1: The sorption efficiency of the obtained filters prepared from zeolite fractions of Chankanai and Daubabinsk deposits was evaluated for applicability as a sorbent for water treatment of samples No.1 and No.2, Table 5.
Point 2: Line 76, please start "filtering: ..." in the next line.
Response 2: Edited.
Point 3: There are many incomplete sentences throughout the manuscript:
"Some characteristics of zeolite:" (line 135):
Response: In terms of structure and morphology zeolites have a layered structure, which is formed by a three-dimensional network of silicon and aluminium oxide frameworks with included cations, this provides a microporous zeolite structure and high surface activity, the chemical composition of zeolite contains silicon (Si), aluminium (Al), oxygen (O) and other elements in its chemical composition. Cations such as sodium (Na), potassium (K), calcium (Ca) and magnesium (Mg) can also be present in the zeolite structure, the physical properties of the zeolite have different physical properties, such as different particle sizes, permeability, density and strength. These properties may vary depending on the specific conditions of the deposit and processing.
"Subjects of the study:" (line 167):
Response: The subject of the study is zeolite from the Chankanai and Daubabinsk deposits as a filter. To assess effectiveness of zeolite as a filter, the research object is natural water of Bolshaya Almatinka of Almaty city with natural degree of pollution and drinking water of Almaty city.
"Water filtration." (line 218):
Response: The following filter apparatus was used to filter the water, Figure 1.
"GOST 4151 - 72 Drinking water (GOST - Government standard)." (line 228) - corrected
"GOST 4011-72 Drinking water." (line 236) – corrected
Author Response File: Author Response.docx
