Effects of UV Light Treatment on Functional Group and Its Adsorption Capacity of Biochar

Round 1

Reviewer 1 Report

Dear editor,

Thanks for inviting me to review this manuscript titled “Effects of UV light treatment on functional group and its adsorption capacity of biochar”. In this manuscript, the effect of UV treatment on biochar was evaluated. The results are of practical interest. Thus I recommend this manuscript be considered for publication after some revisions.

--Table 3 is an image format? Very unclear.

--There is an error in the format of the reference, please check it carefully.

--Conclusion section: The third point is suggested to be added. The fourth point "UV pre-treatment is the most effective method to enhance the adsorption capability of biochar", where in the text can be concluded that UV is the best treatment method? It is suggested to add the comparison of other adsorbents for VOCs treatment in the text.

--The innovation point of the manuscript is not clear and it is suggested to add it in the introduction section to highlight the innovation point of the article.

Author Response

Dear reviewer, 

Thank you very much for your precise comments. 

-Table 3 is an image format? Very unclear.

-> Answer:  We improved the quality

--There is an error in the format of the reference, please check it carefully.

-> Answer: We checked on more time about the reference format. 

--Conclusion section: The third point is suggested to be added. The fourth point "UV pre-treatment is the most effective method to enhance the adsorption capability of biochar", where in the text can be concluded that UV is the best treatment method? It is suggested to add the comparison of other adsorbents for VOCs treatment in the text.

-> Answer: we changed the text as following: 

4. UV pre-treatment is demonstrated to be an effective method for enhancing the adsorption capability of biochar. Additionally, simultaneous irradiation during the penetration process further increases the adsorption capability. These findings suggest that UV treatment holds great potential for improving the adsorption performance of biochar

--The innovation point of the manuscript is not clear and it is suggested to add it in the introduction section to highlight the innovation point of the article.

-> Answer: We added the following in the introduction.

However, the previous researches didn’t investigate its mechanism and how to use for optimized process of biochar upgrading thoroughly. For industrial utilization of biochar as an alternative of activated carbon, economic UV treatment process based on surface reforming reaction theory should be introduced.

Author Response File: Author Response.pdf

Reviewer 2 Report

In this manuscript, aiming the adsorption by biochar, authors investigated the effect of surface and near-surface functionality and structure of biochar on the adsorption performance. Comprehensive characterizations have been performed. In general, it is an interesting work and the conclusion is supported by the experimental and results. However, there are still some issues to be addressed. A moderate revision is suggested before its acceptance.

1.     One or two sentences are required at the beginning of abstract to present the background or aim of this work.

2.     More solid data should be provided in abstract section.

3.     More background on the preparation, properties, and application of biochar should be provided in introduction with some recent supporting articles: Journal of Bioresources and Bioproducts, 2022, 7(2): 109-115; etc.

4.     Some figures should be modified with a better readability, especially the quite small and unclear texts.

5.     Table 3 should be rebuilt to have a better readability. Please also recheck other tables.

6.     The figure caption should not be placed in the table, such as Fig. 9.

7.     To further show the novelty of this work, it is better to make a table in the main manuscript to compare the absorption performance with other materials. Please consider the following articles: Colloids and Surfaces A: Physicochemical and Engineering Aspects, 131726, 2023; Molecules 28 (8), 3492, 2023; e-Polymers 22 (1), 399-410, 2022; etc.

8.     In order to demonstrate this journal is the right journal for your paper and also the connection of your paper to the composite community, it would be good to include some latest papers published in this journal as references.

Author Response

Dear Reviwer, 

Thanks for your precise comment and oppinin. 

1. One or two sentences are required at the beginning of abstract to present the background or aim of this work.

-> Answer: following text inserted in the begining of abstract. 

This study aimed to investigate the impact of UV treatment on the surface functionality and adsorption capacity of biochar, with the goal of enhancing its effectiveness as an adsorbent for toluene.

And also in the end of introduction, following is added. 

However, the previous researches didn’t investigate its mechanism and how to use for optimized process of biochar upgrading thoroughly. For industrial utilization of biochar as an alternative of activated carbon, economic UV treatment process based on surface reforming reaction theory should be introduced.

1. More solid data should be provided in abstract section.

-> Answer: Following texts are added in the abstract. 

The main reason of adsorption capacity increase by UV-treatment is functional group formation, of which rate is linearly increase with pre-treatment energy until 11 W·hr/g_biochar, while after, the increase rate is slow.

1. More background on the preparation, properties, and application of biochar should be provided in introduction with some recent supporting articles: Journal of Bioresources and Bioproducts, 2022, 7(2): 109-115; etc.

-> Answer: We found that paper is related with water treatment, which is not related with air treatment. As you know, the adsorption model is strongly dependent on media type, so we think the paper is not directly related with our paper, and it does not show the recent trend on biochar for VOC cleaning. We also think the references that we found show recent indormation of the VOC removal in the air. 

1. Some figures should be modified with a better readability, especially the quite small and unclear texts.

-> Answer: Fig. 1, 2, 4,6 and Table 3 have been improved. 

1. Table 3 should be rebuilt to have a better readability. Please also recheck other tables.

-> Answer: Fig. 1, 2, 4,6 and Table 3 have been improved. 

1. The figure caption should not be placed in the table, such as Fig. 9.

-> Answer: Fig. 1, 2, 4,6 and Table 3 have been improved. 

1. To further show the novelty of this work, it is better to make a table in the main manuscript to compare the absorption performance with other materials. Please consider the following articles: Colloids and Surfaces A: Physicochemical and Engineering Aspects, 131726, 2023; Molecules 28 (8), 3492, 2023; e-Polymers 22 (1), 399-410, 2022; etc.

-> Answer: Thanks for your kind introduction. However, unfortunately, these papers are for water treatment. As our research is on VOC removal in air, they are not directly related. 

1. In order to demonstrate this journal is the right journal for your paper and also the connection of your paper to the composite community, it would be good to include some latest papers published in this journal as references.

-> Answer: We think the references that we found show recent indormation of the VOC removal reaction in the air. 

Author Response File: Author Response.pdf