Vermibiochar: A Novel Approach for Reducing the Environmental Impact of Heavy Metals Contamination in Agricultural Land

Round 1

Reviewer 1 Report

The presented manuscript “Vermibiochar: a novel approach for reducing the environmental impact of heavy metals contamination in agricultural land” explores the latest and state-of-the-art progress in Vermibiochar for heavy metal remediation from agricultural land. Moreover, the authors summarized the source of heavy metal in the agricultural fields and their impacts. The manuscript presented is a fairly good-organized work. However, some issues require to be addressed scientifically. I recommend minor revisions.

 

1.     The abstract need to be better organized. Do not use abbreviations in the abstract.

2.     Remove the full stop from the end of the title (Vermibiochar: a novel approach for reducing the environmental impact of heavy metals contamination in agricultural land.)

3.     Grammar needs to be improved significantly.

4.     Please make sure to define each acronym at its first use. Check through the entire manuscript to make sure it is defined at the first use.

 

5.     The quality of Figure 4 is poor. Please provide good quality images.

1. Grammar needs to be improved significantly

2. Please make sure to define each acronym at its first use. Check through the entire manuscript to make sure it is defined at the first use

Author Response

Reviewer #1

1. The abstract need to be better organized. Do not use abbreviations in the abstract.
2. Remove the full stop from the end of the title (Vermibiochar: a novel approach for reducing the environmental impact of heavy metals contamination in agricultural land.)
3. Grammar needs to be improved significantly.
4. Please make sure to define each acronym at its first use. Check through the entire manuscript to make sure it is defined at the first use.

Ans.: We appreciated the careful examination of our work made by Reviewer #1. The abstract is now better organized, and all other suggested minor points have been addressed, accordingly, as evidenced within the text.

 

5. The quality of Figure 4 is poor. Please provide good quality images.

Ans.: We have replaced Figure 4 with good quality image.

Reviewer 2 Report

The review, entitled " Vermibiochar: a novel approach for reducing the environmental impact of heavy metals contamination in agricultural land" reports an interesting work on the very important topic of heavy metal removal from soil and water, as an environmentally friendly approach. The paper summarizes valuable information in its figures and tables, and contains a lot of work. The manuscript needs several revisions before it can be published. Therefore, please improve or clarify the following points:

1. The introduction should be broader and should also note activated carbon, MOFs and natural products such as chitosan for the removal of heavy metals. In this respect, I recommend using as references some important papers in this domain: https://doi.org/10.1080/01496395.2017.1340953, https://doi.org/10.1016/j.jece.2022.109131,https://doi.org/10.1007/s10661-020-8162-0

2. Did the combined VC and BC improve the biochemical status of B. integerrima, introduced in the first line of Table 3,  is selective only for Cd ions, or other heavy metals were not investigated in the research

3. Also, in Table 3 some adsorption capacities should be introduced, instead of (or as supplementary information beside) removal %.

4. It is necessary to discuss the selectivity of vermibiochars for heavy metals.

5. Please insert one more section and discuss the practical application value on an industrial scale? Also comparing with other adsorbents, such as activated carbon, MOFs, and natural products, used in scientific research will be welcome.

6. The homogeneity of the reference section needs to be improved. Some journal names are abbreviated, some are not. (ex. Reference nr. 9, 43), Reference nr. 25, 45, 59, and so on, are incomplete. Please see the instructions on the following page:                https://www.mdpi.com/journal/sustainability/instructions

Based on these, I advise the authors to rectify the above-mentioned issues, and I hope to re-evaluate the revised manuscript.

Author Response

Reviewer #2:

1. The introduction should be broader and should also note activated carbon, MOFs and natural products such as chitosan for the removal of heavy metals. In this respect, I recommend using as references some important papers in this domain: https://doi.org/10.1080/01496395.2017.1340953, https://doi.org/10.1016/j.jece.2022.109131,https://doi.org/10.1007/s10661-020-8162-0

Ans.: We appreciated the careful examination of our work made by Reviewer #2. We have explained the role of activated carbon, MOFs and chitosan for heavy metals reduction by citing the suggested articles, as evidenced within the text (lines 46 - 66).

 

2. Did the combined VC and BC improve the biochemical status of B. integerrima, introduced in the first line of Table 3, is selective only for Cd ions, or other heavy metals were not investigated in the research

Ans.: We appreciated the careful examination of our work made by Reviewer #2. The cited research focused only on the alleviation of Cd stress (NOT all heavy metals) by using VC and BC and minimized its uptake and improved biochemical status of B. integerrima.

 

3. Also, in Table 3 some adsorption capacities should be introduced, instead of (or as supplementary information beside) removal %.

Ans.: We appreciate the Reviewer’s suggestions. We have added the adsorption capacity of some heavy metals along with the metal’s removal efficiency by earthworms.

 

4. It is necessary to discuss the selectivity of vermibiochar for heavy metals.

Ans.: We appreciated the careful examination of our work. We have further explained the selectivity of vermibiochar, prepared by different sources of biochar, for heavy metals as evidenced within the text (lines 447 - 453).

 

5. Please insert one more section and discuss the practical application value on an industrial scale? Also comparing with other adsorbents, such as activated carbon, MOFs, and natural products, used in scientific research will be welcome.

Ans.: We appreciated the careful examination of our work. We have discussed the industrial application of vermibiochar as compared to other absorbent as evidenced within the text (lines 454 - 461).

 

6. The homogeneity of the reference section needs to be improved. Some journal names are abbreviated, some are not. (ex. Reference nr. 9, 43), Reference nr. 25, 45, 59, and so on, are incomplete. Please see the instructions on the following page: https://www.mdpi.com/journal/sustainability/instructions

Ans.: We appreciated the careful examination of our work. All suggested minor points have been addressed, accordingly, as evidenced within the text.

Reviewer 3 Report

The paper is relevant, original and well-described.

In my opinion:

A. section 2.1.3 should be expanded (maybe consider the implementation of permeable reactive barriers as a mitigation strategy for acid main drainage waters as example)

B practical aspects of the implementation of the biochar should be included: how is mixed, life time of the soil, possible release?

C information about its footprint is necessary. 

D why radionuclides are not considered?

 

 

English is ok but few wordings are ''italianisms'' such like menace (minacciare)... harm would sound more scientific, sounded and appropriate. 

Author Response

Reviewer #3:

2. section 2.1.3 should be expanded (maybe consider the implementation of permeable reactive barriers as a mitigation strategy for acid main drainage waters as example)

Ans: we thank the reviewer for his careful examination of our work and suggestions. The section 2.1.3 explains the impact of heavy metals on aquatic life, not their mitigation strategies. However, we have further described the aquatic environment pollution caused by acid mine drainage water and their impact on aquatic life (lines 246 - 258).

 

B practical aspects of the implementation of the biochar should be included: how is mixed, life time of the soil, possible release?

C information about its footprint is necessary.

Ans: We appreciate the reviewer’s suggestion about our work. We have further explained the mixing of biochar and lifetime of biochar in soil is evidenced in the text (lines 94 - 108)

 

D why radionuclides are not considered?

Ans: We appreciate the reviewer’s suggestion about our work. On the other hand, this review focuses on the heavy metal’s remediation of agricultural land not considering specifically radionuclides. We have stated this aspect in the introduction of the revised paper. 

Reviewer 4 Report

The authors have summarised reported findings on the topic of the use of earthworms in combination with biochar, as a bulking agent, for the immobilization of heavy metals in agricultural soil. The manuscript is well-written and well-structured.

Vermicomposting with biochar can reduce the bioavailability of heavy metals, but as heavy metals are accumulated in the biochar, there is a concern about their leaching back into the soil. Have there been any reported investigations on the stability of biochar in soil?

Author Response

Reviewer #4:

Vermicomposting with biochar can reduce the bioavailability of heavy metals, but as heavy metals are accumulated in the biochar, there is a concern about their leaching back into the soil. Have there been any reported investigations on the stability of biochar in soil?

Ans: We appreciate the Reviewer’s suggestions. We described the stability of biochar in soil in relation to heavy metals adsorption (lines 94 - 100).

Round 2

Reviewer 2 Report

 

The authors have spent a lot of effort to further improve the manuscript, and they answered all of my questions well. Thus, I would recommend the Editor to consider an acceptance for publication in Sustainability.