Advanced Graphene-Based Technologies for Antibiotic Removal from Wastewater: A Review (2016–2024)

Round 1

Reviewer 1 Report

Dear author,

This paper reviews publications that highlight progress in the application of graphene-based technologies for the removal of antibiotics from wastewater between 2020 and 2024. The manuscript provides a detailed background on the topic and research area, well-supported by relevant references. Overall, I find this work interesting and worthy of publication. However, I have some concerns that need to be addressed before it can be accepted.

1. Part 2: Antibiotics in wastewater: Graphene-Based Materials are clearly effective in removing antibiotics from wastewater; however, based on current regulations, there are alternatives that can meet the effluent quality requirements and are more economical. Please include regulations regarding MDC (Maximum Allowable Concentration) values of antibiotics in wastewater, along with additional evidence that supports the idea of graphene applications as a potential main direction for the future. 

2. Which specific antibiotics are most effectively removed using Graphene-Based Materials? What are their concentrations in wastewater?

3. Please ensure that all acronyms are introduced with their full forms upon first appearance in the manuscript, followed by the abbreviated form in parentheses. Use the abbreviated form thereafter. Go through the entire manuscript for similar minor errors.

All the typos and grammar need to be checked thoroughly in the manuscript.

Author Response

Reviewer 1

 

Major comments

This paper reviews publications that highlight progress in the application of graphene-based technologies for the removal of antibiotics from wastewater between 2020 and 2024. The manuscript provides a detailed background on the topic and research area, well-supported by relevant references. Overall, I find this work interesting and worthy of publication. However, I have some concerns that need to be addressed before it can be accepted.

Response: The authors gratefully acknowledge the reviewer’s insightful observations and constructive suggestions.

 

1. Part 2: Antibiotics in wastewater: Graphene-Based Materials are clearly effective in removing antibiotics from wastewater; however, based on current regulations, there are alternatives that can meet the effluent quality requirements and are more economical. Please include regulations regarding MDC (Maximum Allowable Concentration) values of antibiotics in wastewater, along with additional evidence that supports the idea of graphene applications as a potential main direction for the future.

Response: The authors gratefully acknowledge the reviewer’s insightful observations and guidance. In response, three new paragraphs have been added (appended below) to the section titled "Challenges, Potential Solutions, and Mitigation Strategies" to address the issues raised.

“GBMs have demonstrated remarkable efficacy in removing antibiotics from wastewater, offering a promising solution to this pressing environmental issue. However, given the current regulatory landscape, specifically the maximum allowable concentration (MAC) values for antibiotics in wastewater, alternative methods that are more cost-effective and can still meet effluent quality standards are often preferred. Ac-cording to environmental protection agencies, the MAC values for antibiotics in wastewater generally range between 0.01 and 1 µg/L, depending on the antibiotic type and the environmental impact.

 

While alternatives such as activated carbon or biological treatments may meet these regulatory requirements at a lower cost, graphene-based technologies are emerging as viable long-term solutions. Compared with traditional materials, the unique properties of graphene, such as a high surface area, excellent adsorptive capabilities, and the potential for functionalization, provide superior antibiotic removal efficiency.

 

The future direction of wastewater treatment could lean heavily towards graphene-based materials, especially as the costs of production decrease and regulations potentially tighten to require more advanced removal techniques. As more research substantiates the long-term environmental safety and effectiveness of these materials, they may become the preferred choice for meeting stringent effluent standards. Further-more, the multifunctionality of graphene, such as its use in catalytic degradation and its potential for regeneration, makes it a sustainable and scalable solution for antibiotic removal in wastewater. “

2. Which specific antibiotics are most effectively removed using Graphene-Based Materials? What are their concentrations in wastewater?

Response: Sincere appreciation is expressed for the reviewer’s careful attention.

Graphene-based materials (GBMs) are highly effective at removing several antibiotics from wastewater. Key antibiotics include:

Tetracycline (TC): Found at 1-100.0 µg/L [1], GBMs can remove up to 99%.[2]

Sulfamethoxazole (SMX): Detected at 0. 0.6 to 16 µg/L [3], GBMs achieve 90% removal. [4]

Amoxicillin (AMX): Found at even at 171 mg/L [5], with up to 80% removal.[6]

 

1. Xiong, Y.; Hozic, D.; Goncalves, A.L.; Simões, M.; Hong, P.-Y. Increasing Tetracycline Concentrations on the Performance and Communities of Mixed Microalgae-Bacteria Photo-Bioreactors. Algal Research 2018, 29, 249–256, doi:10.1016/j.algal.2017.11.033.
2. Lin, X.; Zhao, J.; Zhang, Y.; Li, Y.; Liao, Y.; Zhang, H. Graphene Oxide Structure-Oriented NM88B/GO/SA Aerogel for Highly Efficient Degradation of Dye and Antibiotic Wastewater. J Polym Environ 2024, 32, 2091–2104, doi:10.1007/s10924-023-03119-y.
3. Borsetto, C.; Raguideau, S.; Travis, E.; Kim, D.-W.; Lee, D.-H.; Bottrill, A.; Stark, R.; Song, L.; Cha, C.-J.; Pearson, J.; et al. Impact of Sulfamethoxazole on a Riverine Microbiome. Water Research 2021, 201, 117382, doi:10.1016/j.watres.2021.117382.
4. Karaolia, P.; Michael-Kordatou, I.; Hapeshi, E.; Drosou, C.; Bertakis, Y.; Christofilos, D.; Armatas, G.S.; Sygellou, L.; Schwartz, T.; Xekoukoulotakis, N.P.; et al. Removal of Antibiotics, Antibiotic-Resistant Bacteria and Their Associated Genes by Graphene-Based TiO2 Composite Photocatalysts under Solar Radiation in Urban Wastewaters. Applied Catalysis B: Environmental 2018, 224, 810–824, doi:10.1016/j.apcatb.2017.11.020.
5. Meng, L.-W.; Li, X.; Wang, K.; Ma, K.-L.; Zhang, J. Influence of the Amoxicillin Concentration on Organics Removal and Microbial Community Structure in an Anaerobic EGSB Reactor Treating with Antibiotic Wastewater. Chemical Engineering Journal 2015, 274, 94–101, doi:10.1016/j.cej.2015.03.065.
6. Rajapaksha, P.; Orrell-Trigg, R.; Truong, Y.B.; Cozzolino, D.; Truong, V.K.; Chapman, J. Wastewater Depollution of Textile Dyes and Antibiotics Using Unmodified and Copper Oxide/Zinc Oxide Nanofunctionalised Graphene Oxide Materials. Environ. Sci.: Adv. 2022, 1, 456–469, doi:10.1039/D2VA00059H.

 

3. Please ensure that all acronyms are introduced with their full forms upon first appearance in the manuscript, followed by the abbreviated form in parentheses. Use the abbreviated form thereafter. Go through the entire manuscript for similar minor errors.

Response: The authors sincerely appreciate the reviewer’s thoughtful critiques. The revised manuscript has been carefully reviewed to address and resolve the issues with acronyms.

 

 

 

Detail comments

All the typos and grammar need to be checked thoroughly in the manuscript.

Response: Thank you for your valuable feedback. The revised manuscript has been thoroughly reviewed for typos and grammatical issues using Curie (https://www.aje.com/curie/).

 

Author Response File: Author Response.docx

Reviewer 2 Report

This manuscript reviews the application of graphene in the field of antibiotic removal from wastewater, and indeed provides some application examples. However, as a review academic paper, there is still a certain insufficient in this manuscript

(1) The manuscript should briefly introduce graphene and its production methods, as this section does not align with the main theme of the manuscript.

(2) As a review manuscript, the author simply listed 14 applied papers, which is far from enough. There are many research achievements in the field of antibiotic wastewater treatment using graphene.

(3) Suggest the author to focus on analyzing the role of graphene materials in antibiotic wastewater treatment rather than simply listing other people's experimental results.

(4) A review manuscript should present its own views on the development trends in the field.

Author Response

Reviewer 2

 

Major comments

This manuscript reviews the application of graphene in the field of antibiotic removal from wastewater, and indeed provides some application examples. However, as a review academic paper, there is still a certain insufficient in this manuscript.

Response: The authors appreciate the insightful feedback on the manuscript. The authors are grateful for the recognition of the application examples related to the use of graphene in antibiotic removal from wastewater. The authors took the comments seriously and worked to enhance the manuscript by addressing the identified insufficiencies.

 

 

Detail comments

(1) The manuscript should briefly introduce graphene and its production methods, as this section does not align with the main theme of the manuscript.

Response: The reviewer’s insightful observations and constructive suggestions are gratefully acknowledged by the authors. In response, the introduction of graphene and its synthesis processes has been shortened as recommended (Wordcount reduced from 1754 to 1112).

 

 

(2) As a review manuscript, the author simply listed 14 applied papers, which is far from enough. There are many research achievements in the field of antibiotic wastewater treatment using graphene.

Response: Sincere appreciation is expressed for the reviewer’s careful attention and thoughtful suggestions for improving the manuscript. The preparation of the review paper adhered to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines 2020, as outlined in Section 3, "Research Methods," where all eligible papers are discussed. To increase the number of papers considered, an open search was conducted, revealing that the earliest report according to PRISMA guidelines was from 2016. This paper has been included in the revised version, bringing the total number of discussed papers to 15.

 

 

(3) Suggest the author to focus on analyzing the role of graphene materials in antibiotic wastewater treatment rather than simply listing other people's experimental results.

Response: The reviewer’s insightful observations and constructive suggestions are gratefully acknowledged by the authors. In response, a paragraph has been added to the end of Section 4 (appended below), illustrating the role of graphene materials in antibiotic wastewater treatment.

“Thus, GBMs play a pivotal role in removing antibiotics from wastewater through various mechanisms, including photocatalytic degradation, adsorption, catalytic activation of inorganic peroxides, and electrochemical oxidation. In photocatalysis, graphene enhances the efficiency of semiconductor catalysts by improving charge separation and increasing the generation of ROS, which degrade antibiotics. Its high surface area and functional groups enable strong adsorption of antibiotic molecules, facilitating their removal. Additionally, graphene acts as a catalyst in the activation of inorganic peroxides, generating ROS through Fenton-like reactions that break down antibiotics. In electrochemical oxidation, the excellent conductivity of graphene promotes direct electron transfer and ROS formation, further enhancing antibiotic degradation. These diverse functions make graphene materials highly effective for antibiotic removal, although challenges remain in scaling their use for practical applications.”

 

 

(4) A review manuscript should present its own views on the development trends in the field.

Response: The authors respectfully disagree with the reviewer’s comments. A review manuscript should not present its own views on the development trends in the field, as the primary objective of a review is to provide an unbiased and comprehensive synthesis of existing research, rather than to advance personal opinions. The role of a review is to objectively evaluate the current state of knowledge by analyzing, summarizing, and critically assessing the findings from various studies. Introducing personal views can bias the interpretation of the literature, potentially leading to a distorted understanding of development trends and hindering the reader’s ability to form independent conclusions.

Moreover, review manuscripts are valued for their ability to offer a balanced, evidence-based perspective, allowing readers to navigate complex research landscapes. Including subjective views could detract from this goal, as it might prioritize the author’s interpretations over the breadth of existing evidence. Instead, a well-constructed review should present the trends in the field based on factual data and research consensus, leaving room for readers to engage with the material without being swayed by the author's personal perspectives.

 

Author Response File: Author Response.docx

Reviewer 3 Report

In this review paper, “Advanced Graphene-Based Technologies for Antibiotic Removal from Wastewater: A Review (2020-2024),” the authors present a review regarding utilizing several graphene-based materials for antibiotic removal from wastewater. The review is presented systematically, and the discussion and conclusion are formative. It is recommended that it be accepted after minor revisions.

The following are my suggestions:

1.     The manuscript needs an introduction section that details the novelty of this work compared to other reviews on the same topic. Besides, what methodology was used in finding, screening, and selecting the references for discussion? (database from Scopus or Web of Science).

2.     In the abstract, the authors stated, "Functionalised graphene materials and graphene integrated with other substances, like metal oxides and polymers, have enhanced performance in antibiotic removal through mechanisms including adsorption and photocatalysis." I recommend that the authors discuss the advantages and limitations of these two methods in removing antibiotics.

3.     The authors should discuss antibiotics' adsorption mechanisms. What are the different antibiotic adsorption interaction mechanisms on graphene-based materials?

 

4.   What about the limitations of graphene-based materials after use to remove antibiotics? And how can they avoid the health and environmental pollution risks from these materials?

see major comments 

Author Response

Reviewer 3

 

Major comments

In this review paper, “Advanced Graphene-Based Technologies for Antibiotic Removal from Wastewater: A Review (2020-2024),” the authors present a review regarding utilizing several graphene-based materials for antibiotic removal from wastewater. The review is presented systematically, and the discussion and conclusion are formative. It is recommended that it be accepted after minor revisions.

Response: Thanks are extended to the reviewer for highlighting this important issue and offering helpful recommendations.

 

 

The following are my suggestions:

 

1. The manuscript needs an introduction section that details the novelty of this work compared to other reviews on the same topic. Besides, what methodology was used in finding, screening, and selecting the references for discussion? (database from Scopus or Web of Science).

Response: The reviewer’s detailed analysis and thoughtful critique are sincerely appreciated.

An introduction section has been incorporated in the revised manuscript in accordance with the suggestion of the reviewer.

A new Section 3, “Research Methods,” has been added to the revised manuscript, detailing the analysis conducted in accordance with PRISMA guidelines.

However, the search string “TITLE(graphene AND wastewater AND antibiotic)” did not yield any review articles in the Scopus database; thus, no comparison could be made.

 

2. In the abstract, the authors stated, "Functionalised graphene materials and graphene integrated with other substances, like metal oxides and polymers, have enhanced performance in antibiotic removal through mechanisms including adsorption and photocatalysis." I recommend that the authors discuss the advantages and limitations of these two methods in removing antibiotics.

Response: The authors thank the reviewer for the insightful query. The following paragraphs have been incorporated into the section 4 as per the suggestion.

“Antibiotic removal from wastewater is a critical environmental challenge, and two promising approaches, adsorption and photocatalysis, leverage the unique properties of graphene to address this issue effectively. Adsorption offers a straightforward method for removing antibiotics by capturing contaminants on the graphene surface, benefiting from the high surface area and tunable chemical properties of functionalized graphene. This method is highly effective, especially for a wide range of antibiotics, and allows for simple operation without requiring light sources or complex equipment. However, adsorption has limitations, such as potential saturation of the material, which reduces its effectiveness over time and necessitates regeneration processes that may degrade the material’s performance.

 

Photocatalysis, on the other hand, introduces an additional advantage by degrading antibiotics rather than merely trapping them, breaking them down into less harmful substances using light energy. Graphene combined with metal oxides, like TiO₂ or ZnO, enhances this process due to improved electron transfer, which increases photocatalytic efficiency. Despite this, photocatalysis requires external energy input (light) and specific conditions to function optimally, which can limit its application in large-scale or low-resource settings. Moreover, the potential release of toxic byproducts during degradation is a concern. Thus, while both methods offer significant potential for antibiotic removal, their practical implementation should carefully consider these performance trade-offs.”

 

3. The authors should discuss antibiotics' adsorption mechanisms. What are the different antibiotic adsorption interaction mechanisms on graphene-based materials?

Response: Appreciation is extended to the reviewer for highlighting this important issue and offering helpful recommendations. The following paragraph has been incorporated into the section "Challenges, Potential Solutions, and Mitigation Strategies," as per the suggestion.                 

“GBMs adsorb antibiotics through various interaction mechanisms, which include π‒π stacking, hydrogen bonding, electrostatic interactions, van der Waals forces and hydrophobic interactions. π-π stacking occurs between antibiotics with aromatic rings and the delocalized π-electron system of graphene. Hydrogen bonding forms between functional groups in antibiotics and oxygen-containing groups on graphene oxide, whereas electrostatic interactions depend on the charge of both antibiotics and functionalized graphene surfaces and are influenced by pH. Van der Waals forces contribute to the weaker, nonspecific adsorption, and hydrophobic interactions that occur between the hydrophobic portions of antibiotics and the graphene surface. These diverse mechanisms enable GBMs to efficiently adsorb a wide range of antibiotics, making them highly effective in wastewater treatment applications.”

 

 

 

 

4. What about the limitations of graphene-based materials after use to remove antibiotics? And how can they avoid the health and environmental pollution risks from these materials?

Response: Gratitude is expressed to the reviewer for identifying this significant issue and providing constructive recommendations. In accordance with the suggestion, the subsequent paragraphs have been included in the section "Challenges, Potential Solutions, and Mitigation Strategies."

 

“GBMs are highly effective at removing antibiotics from wastewater because of their large surface area and versatile adsorption mechanisms. However, despite their efficiency, several limitations arise after their use, particularly concerning environmental and health risks. Key challenges include the regeneration of these materials for reuse, potential secondary contamination, and risks posed by the release of nanomaterials into the environment. Without proper management, these issues could undermine the environmental benefits of using GBMs in wastewater treatment.

 

To mitigate these risks, several strategies are being explored. Safe disposal methods, such as encapsulating GBMs to prevent antibiotic and nanomaterial leakage, are essential for preventing secondary pollution. Improved regeneration technologies, such as green chemical processes or thermal treatments, can extend the life of GBMs without compromising their adsorption capacity. Research into biodegradable graphene composites also offers a future solution for reducing the long-term risks associated with nanomaterials. These approaches are critical for ensuring that GBMs remain a safe and sustainable option for wastewater treatment.”

Author Response File: Author Response.docx

Round 2

Reviewer 2 Report

After careful revision and supplementation, the content of manuscript has been greatly enriched and meets the acceptance criteria for review papers, and can be accepted.

After careful revision and supplementation, the content of manuscript has been greatly enriched and meets the acceptance criteria for review papers, and can be accepted.