Environmental Sustainability of the Removal of Alpaca Fiber Dye Using a Thermally Modified Sludge from a Drinking Water Treatment Facility

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

This paper studied the dye removal (Bordeaux B) performance by thermal modified DWTS. Several methods were used to characterize the DWTS physicochemical. The paper is interesting and meaningful. The following question can be addressed.

 

1 The Figures 1a，1b, and 1c are not arrange in order in the Figure.

 

2 The plot of N2 adsorption and desorption of the sample in Figure is not related to the BET model. The pore size distribution of the sample should be given.

 

3 In Figure 11, the kinetic model can be plotted as the line to fit the data.

 

4 The scaleplate in Figure 15 is not clear enough.

 

5 The innovation point of this paper should be emphasized in the title, and introduction part.

 

6 In the Abstract, the key measurement data and conclusions should be given and highlighted.

 

Comments on the Quality of English Language

Extensive editing of English language required.

Author Response

General comment: This paper studied the dye removal (Bordeaux B) performance by  thermal modified DWTS. Several methods were used to characterize the DWTS physicochemical. The paper is interesting and meaningful. The following question can be addressed.

Answer: Thank you for your positive comment.

 

Comment 1. The Figures 1a, 1b and 1c are not arrange in order in the Figure.

Answer: Thanks for your comments. The Figures were arranged.

 

Comment 2. The plot of  N₂ adsorption and desorption of the sample in Figure is not related to the BET  model. The pore size distribution of the sample should be given.

Answer: Thank you so much for your comment. The information was corrected. At this moment, the authors can only report the average pore diameter pag. 12. Pag 13: “It would be demonstrated that both samples do not have micro and/or mesopores of considerable volume in their structure, which means that they are not very porous materials”.

 

Comment 3. In Figure 11, the kinetic model can be plotted as the line to fit the data.

Answer: Figure 11 was improved.

 

Comment 4. The scaleplate in Figure 15 is not clear enough.

Answer: Thanks for your comment. The scaleplate in Figure 15 was improved.

 

Comment 5. The innovation point of this paper should be emphasized in the title, and introduction part.

Answer: Thanks for your comment. The title and introduction were improved. New Title: “Environmental Sustainability in the Removal Process of Dye used in Alpaca Fiber Dying Using a Thermal Modified Sludge from a Drinking Water Treatment Facility”.  Additional information (Introduction): “This study gives value to the waste obtained in the coagulation flocculation process (waste sludge) in order to remove an emerging organic agent (Bordeaux B). The sustainability of the process leads to a circular economy which represents a great environmental contribution”.

 

Comment 6. In the abstract, the key measurement data and conclusions should be given and highlighted.

.Answer: Thanks for your comment.The abstarct was improved. Additional information : “The best removal efficiency was at 500 °C (R=85.57±0.76 %, q max = 37.45±0.14 mg/g) which compared to other unconventional adsorbents are more reliable and competitive”.

Reviewer 2 Report

Comments and Suggestions for Authors

This study investigates the use of thermally modified drinking water treatment sludge (DWTS) for the removal of Bordeaux B dye from water. The research is relevant and contributes to the field of water treatment and waste valorization. However, there are several areas that require improvement:

- Ensure consistency in terminology throughout the manuscript.

Introduction section

- Provide a clearer rationale for using DWTS specifically for dye removal.

- Include a more focused literature review on recent advancements in using DWTS for water treatment.

 

Methodology section:

- Provide more details on the exact composition of the DWTS used.

- Explain the rationale behind the choice of activation temperatures.

 

Results and Discussion section:

- Compare your findings more extensively with similar studies in the literature.

- Discuss the implications of your results for real-world applications.

- Address any unexpected results and propose explanations.

- Improve Figures quality (300 dpi or higher) for better clarity. 

- Consider using different colors or symbols to distinguish between data points more easily.

- Add a brief discussion on the potential scalability and economic feasibility of this method.

- Clearly state the limitations of the study.

 

Conclusions section

- Make the conclusions more concise and focused on the significance of the results.

- Clearly state how your findings contribute to the broader field of water treatment and waste valorization.

- Discuss the practical implications of your research.

- Suggest future research directions based on your findings.

Comments on the Quality of English Language

Moderate editing of English language required

Author Response

General comment: This study investigates the use of thermally modified drinking water treatment sludge (DWST) for the removal of Bordeaux B dye from water. The research  is relevant and contributes to the field of water treatment and waste valorization. However, there are several areas that require attention.

Answer: Thank you for your positive comment.

 

Comment 1. Ensure consistency in terminology throughout the manuscript.

Answer: Thanks for your comments. The manuscript was revised.

 

Introduction section:

Comment 2. Provide a clearer rationale for using DWTS specifically for dye removal.

Answer: Thank you so much for your comment. The use of this sludge as adsorbent had been reported for several authors. Pag: 2: “Improving the physical and chemical characteristics of the soil , raw materials or additives in the construction industry [4,7], coagulants or adjuvants in water purification processes [8,9] or adsorbent of various contaminants such as phosphorus [10], heavy metals and metalloids [11,12], emerging pollutants [13] and dyes [14,15]”. Gadekar MR, Ahammed MM. Modelling dye removal by adsorption onto water treatment residuals using combined response surface methodology-artificial neural network approach. Journal of Environmental Managementfebruary 1^st, 2019,  2019;231:241–8 and Tony MA. Zeolite-based adsorbent from alum sludge residue for textile wastewater treatment. Int J Environ Sci Technol. May 1^st, 2020;17(5):2485–98. Pag 2 “Therefore, using the waste generated by various local industries, such as DWTS, to remove textile dyes from wastewater, is a cheap, sustainable and efficient solution which has been developed and researched for some years now [14,15,21–27]”.

 

Comment 3. Include a more focused literature review on recent advancements in using DWTS for water treatment.

Answer: Literatuure on recient advancent using DWTS for water treatment has been included:

• Nihade Bensitel, Khadija Haboubi, Fatima-Zahra Azar, Yahya El Hammoudani, Aouatif El Abdouni, Chaimae Haboubi,  Fouad Dimane, Achraf El Kasmi, Potential reuse of sludge from a potable water treatment plant in Al. Water Cycle 2023.
• Mohamed F. Soliman M. Nageeb Rashed · Abeer Ali Ahmd. Treatment Plant for Adsorption of Methylene Blue Dye- Water Air Soil Pollut (2023) 234:228.

 

Methodology section:

Comment 4. Provide more details  on the exact composition of the DWST used.

Answer: Thanks for your comment. This extended information is presented in the results from pag 5 to 12.

 

Comment 5. Explain the rationale behind the choice of activation temperatures

Answer: Thanks for your comment. The reason is explaned in pag 4: “The activation temperatures, time and sludge calcination conditions were defined based on the results shown in a previous research by Laib et al. [25], Nageeb Rashed et al. [26] and Tony [15] and exploratory tests were developed in the laboratory”.

 

Results and discussion section:

Comment 6. Compare your findings more extensively with similar studies in the literature.

.Answer: Thanks for your comment. The comparison with other studies was made on Pag 16.

 

Comment 7 Discuss the implications of your results for real – world applications.

Answer: Thanks. This point is very important Its discussion was done on pages 25 to 26.

 

Comment 8. Address any unexpected results and propose explanations.

Answer: Thanks. Effectively, It has been incluyed in the limitations section on pag 26.

 

Comment 9. Improve Figures (300 dpi or higher) for better clarity.

Answer: Thank you for your comment, yes, it is possible.

 

Comment 10. Consider using different colors or simbols to distinguish between data points more easily.

Answer. Thanks, yes, some Figures were improved.

 

Comment 11. Add a brief discussion on the potencial scalability and economic feasibility of this method.

Answer. Thank you. It has been included in the “limitation section” pag 26.

 

Comment 12. Clearly state the limitations of the study.

Answer. Thank you. It has been included in the “limitation section” pag 26.

 

Conclusions section.

Comment 13.  Make the conclusions more consice and focused on the significance of the results.

Answer:   Thanks. Conclusions were improved: Aditional information: “The best removal efficiency was at 500 °C (R=85.57±0.76 %, q max = 37.45±0.14 mg/g) which compared to other unconventional adsorbents are more reliable and competitive”.

 

Comment 14. Clearly  state how your findings contribute to the broader field of warter treatment and waste.

Answer: Thanks. The following information was added: “These findings suggest that the T-500 is capable of removing the “Bordeaux B” dye, efficiently and that its production could become even more economical if drying or thickening systems were implemented in the DWTP. These results showed that the implementation of the sludge as adsorbent in optimal conditions would contribute to the circular economy in water treatment processes (without environmental liabilities)”  

 

Comment 15. Discuss the practical implications of your research.

Answer: Thank you for your comment. The practical implications were considered.

 

Comment 16. Suggest future research directions based on your findings.

Answer.

 

Final comment. English Language was revised.

Reviewer 3 Report

Comments and Suggestions for Authors

This study with sufficient experiments and testing, may provide some insightful opinions for future applications. some comments for author to consider

a) Mechanism explanation with proper citation and methodologies used in previous literatures should be enhanced and explained in details 

b) The overall manuscript does not show its meet the sustainability targets or evaluation criteria. can you add more explanations to justify it?

c) Similar results in many other studies were reported, so can you make proper comparison with those related articles to justify the novelty and rationale properly?

d) Proper citation should be made with concentrating on most related ones 

Comments on the Quality of English Language

NO

Author Response

General comment: This study with suffient experiments and testing, may provide some insightful opinions for future applications. Some comments for author to consider.

Answer: Thank you for your positive comment.

 

Comment a. Mechanism explanation with proper citation and methodologies used in previous literatures should be enhanced and explained in details.

Answer: Thanks for your comments. The  mechanism is described on pages 16 to 17.

 

Comment b. The overall manuscript does not show its meet the sustainability targets or evaluation criteria can you add more explanations to justify it?

Answer: Thank you so much for your comment. Aditional information was aditioned: “. Therefore, four main criteria for sustainability support this study: environmental (dye removal and used of the residual sludge without environmental liabilities), economic (adsorbent production cost), social (increasing employment), and technical sustainability (innovation in the thermal process)”. Pag 2.

 

Comment c. Similar results in many other studies were reported, so can you make proper comparison with those related articles to justify the novelty and rationale properly??.

Answer: Thanks. This information is analyzed on in pag 24 to 25. This study was compared with nine (9) similar where this research obtained satisfactory and competitive results. Because it is a waste generated in the water treatment process and the mineral wealth of its composition, the preparation costs as an adsorbent decreases, increasing its efficiency.

 

Comment d. Proper citation should be made with concentrating on most related ones.

Answer: Thanks for your comment. Citation was revised.

 

Round 2

Reviewer 2 Report

Comments and Suggestions for Authors

The authors have addressed many of the previous comments and improved the manuscript. However, there are still some areas that could be further enhanced:

- The discussion section could be strengthened by providing more in-depth analysis of the results and their implications. Compare your findings more extensively to other studies using different types of adsorbents for dye removal.

- The conclusions could be more concise and focused on the key findings and their significance. Avoid repeating details from the results.

- Consider adding a brief section on future research directions based on your findings.

- Ensure all figures are high quality (300 dpi or higher) for publication.

 

Comments on the Quality of English Language

Some minor language editing is still required throughout the manuscript to improve clarity and flow.

Author Response

General comment: The authors have addressed many of the previous comments and improved the manuscript. However, there are still some areas that could be further enhanced:

 

1. The discussion section could be strengthened by providing more in-depth analysis of the results and their implications. Compare your findings more extensively to other studies using different types of adsorbents for dye removal.

Answer: Thank you for your comment. The discussion was strengthened. Information added: Wakkel et al. [65] researched about the ability of date seeds to absorb basic violet 3 (BV3) dyes through a simple drying and spraying process where they managed to eliminate 98% BV3. Kushwaha & Agarwal [66] investigated the potential use of a waste generated by the metal industry called jarosite which has metals, metal oxides and silica in its composition; Therefore, when crushed and dried, it was able to remove up to 92.5% of the methylene blue (MB) dye under its optimal conditions. Sitab et al. [68] also investigated the removal capacity of the MB dye by using a thermally modified waste from the leather tanning industry, obtaining a 99.9 mg/g maximum adsorption capacity with an 88.8%. removal efficiency at pH 12 Şentürk & Alzein [67] researched about the use of pistachio shell as an adsorbent to remove the Basic blue 41 (BB ​​41) dye from textile wastewater effluents, obtaining a maximum adsorption capacity in batch mode of 21.8. mg/g and 41.77 mg/g in an adsorption column. By comparing the maximum adsorption capacity and the removal percentage of T-500 with other adsorbents, it is possible to infer that raw materials of inorganic composition offer a significant advantage compared to those of organic composition. This may be due to the fact that the large number of electrically charged particles is much greater in inorganic compounds than in organic ones, generating a better interaction with the dyes and a greater number of active sites Page 25.

2. The conclusions could be more concise and focused on the key findings and their significance. Avoid repeating details from the results.

Answer: Thank you for your comment.

3. Consider adding a brief section on future research directions based on your findings.

Answer:Thank you for your comment. It was done. Information added:

 

Future directions

Based on the results shown in this paper, it is possible to provide new information inside the circular economy in water post-stabilization companies; Likewise, the treat-ment of wastewater from the textile industry has minimum considerations to be able to decide the use of new adsorbent materials that purify their wastewater. The results shown give rise to new research focused on the use of T-500 in a column adsorption system under continuous conditions, estimating the efficiency of the adsorbent through the analysis of desorption cycles, backwashing and the use of real textile water waste.

The results obtained here allow to establish some parameters for future research con-cerning the use of these sludges as a catalyzing support in the adsorption and degrada-tion of emerging contaminants (TiO₂ for example). These also can be used in the area of civil engineering (brick, asphalt and cement manufacture, among others).. Page 27

4. Ensure all figures are high quality (300 dpi or higher) for publication.

Answer: Thank you for your comment. All figures were improved with 300 dpi

 

Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

The author has addressed the comments and make an improvement on the manuscript to meet the basic criteria 

Comments on the Quality of English Language

Polishing of writing skills in proper language is strongly recommended

Author Response

Response to Reviewer 3. Round 2

Comments and Suggestions for Authors: The author has addressed the comments and make an improvement on the manuscript to meet the basic criteria.

Answer: Thank you four your kind comment.

Comments on the Quality of English Language: Polishing of writing skills in proper language is strongly recommended.

Answer: English Language was revised by an expert.