Adsorption of Pyraclostrobin in Water by Bamboo-Derived and Pecan Shell-Derived Biochars
Round 1
Reviewer 1 Report
Comments for Editor and Authors
In the present study the authors have evaluated the adsorption performance of biochar prepared from pecan shells and bamboo for pyraclostrobin in aqueous solution. They have evaluated the experimental parameters to obtain the best adsorption conditions. The adsorption behaviors of pyraclostrobin onto developed adsorbents have been investigated in terms of kinetics, isotherms and thermodynamics evaluation.
Although various adsorbents for the adsorption of pyraclostrobin have been developed in the literature, biochar prepared from pecan shells and bamboo was used for the first time for this purpose. Therefore, this study is new and is thought to contribute to the literature. I think it is appropriate to publish the current study in Sustainability after considering the major comments given below.
1. In abstract in line 20-22 “Characterization, kinetics, isotherms, thermodynamics, and factor analyses indicate that the pseudo-second-order kinetics and Freundlich model are the most suitable for both types of biochar.” This statement needs to be revised. Because the suitability of the kinetic and isotherm models cannot be determined by characterization and thermodynamic studies.
2. In line 103, how the ash elimination from biochar is carried out should be explained in a more detailed.
3. Why are the Langmuir isotherm parameters KL and qm not given in the Table S2? The important parameter that reveals the effectiveness of the adsorbent in adsorption studies is the adsorption capacity. Capacity is determined either by working at a single and high adsorbate concentration. Or, by working at different adsorbate concentrations, Langmuir isotherm model should be applied and the capacity should be determined. For isotherm experiments, the initial adsorbate concentration was studied in the very low range (0.1-1.5 mg/L). In this case, the capacity of the adsorbents cannot be determined. The obtained capacity value should be compared with other adsorbents used for pyraclostrobin adsorption in the literature.
4. What is the limit of detection value and linear range of ultra performance liquid chromatography mass spectrometry/mass spectrometry for pyraclostrobin analysis? It should be specified.
5. In line 168, the unit of biochar mass should be corrected as “g”.
6. In 2.6 Data processing title, The statements given in lines 204 to 218 are not related to the manuscript. It should be deleted.
7. It is seen that the correlation coefficients obtained for the pseudo first-order kinetic model are also high enough. When only the R2 values are examined, it is noticed that both models are suitable. Another parameter that should be taken into account to decide the suitability of the kinetic model is the closeness of the experimental qe to the theoretical qe values. Therefore, the experimental qe values should be added to the Table S1 and compared with the qe values obtained from the models.
8. The quality of the figures is very low and not clear. It should be improved.
9. In line 325 “The value of 1/n was < 1, indicating that the primary mechanism was physical adsorption” However the n value obtained from the Freundlich isotherm model does not give an idea about the adsorption mechanism. A value of 1/n less than 1 indicates the suitability of the adsorption process. Please revise the statement. On the other hand to decide whether the adsorption is physical or chemical, the Dubinin-Raduskevich isotherm model is used.
10. In line 334, please delete “adsorbed” from “adsorbed ΔH and ΔS can…” and in line 337 please “G” should be written as “ΔG”. In line 349 and 354 “absorption” should be changed as “adsorption”.
11. The authors examined only the effect of inorganic ionic strength in the current study. However, in real water samples, there are many organic compounds besides NaCl and pyraclostrobin. Therefore, the effect of an organic compound on the adsorption efficiency of pyraclostrobin could also be evaluated.
12. Has the reusability of adsorbents been tested? Determining how many times it is used with and without desorption can improve the quality of the work done.
Comments for author File: 
Comments.pdf
Author Response
Please see the attachment.
Author Response File: 
Author Response.docx
Reviewer 2 Report
Kongtan Yang et al. reported “Adsorption of Pyraclostrobin in Water by Bamboo-Derived and Pecan Shell-Derived Biochars”. The work is publishable after addressing the following minor issues.
1. Briefly include other methods for the removal of pesticide residues in the introduction section.
2. In the material part % purity of the chemical is missing.
3. Data calculation and Isothermal models section verified with references. Read and cite the below reported literature which will be helpful to improve the manuscript further. Molecules 2023, 28, 1081 (https://doi.org/10.3390/molecules28031081) and Separation and Purification Technology 316 (2023) 123678 (https://doi.org/10.1016/j.seppur.2023.123678)
4. SEM images should be explain more in detail with references. What will be the effect of porosity on the adsorption studies?
5. For the Hydrophobicity confirmation contact angle experiment should be conducted of all designed materials.
6. The adsorption capacity is very low of the present materials. comparative table with other material reported for the Pyraclostrobin adsorption should be included in the revised manuscript.
7. The conclusion should be improved.
8. Check the grammatical and spelling mistakes throughout the manuscript.
Minor editing of English language required
Author Response
Please see the attachment.
Author Response File: Author Response.docx
Reviewer 3 Report
Adsorption of Pyraclostrobin in Water by Bamboo-Derived and Pecan Shell-Derived Biochars
In present work, Authors have successfully developed material for the treatment of Pyraclostrobin by adsorption process.
Let me tell you authors have well described the work with proper data.
The work can be accepted with considering following comments
Comment 1 Authors are suggested to put data about Pyraclostrobin, like structure, pKa value and other information whatever available. With knowing pka of adsorbate, interaction can be more prominent way describe.
Comment 2 Authors suggested to show reusability study if they have done. If not done it is advisable to do.
Comment 3 Authors are suggested to include isotherm and kinetic data in main manuscript, it is necessary for readers.
Comment 4 Authors are also advised to make a comparison table show where their material stands in compare with other literature.
I wish all the best to authors
Comments for author File: Comments.pdf
Author Response
Please see the attachment.
Author Response File: Author Response.docx
Reviewer 4 Report
This manuscript investigated one pesticide removal by bamboo and pecan shell derived biochars. The experiment is quite fundamental and the results are as expected. Please revised followed by these suggestions:
(1) L122-123 why the author determine to dose 50 mg adsorbent with 50 mL of the water?
(2) L204-217 should be removed. It is the template.
(3) L202-203 is there any statistics used in this experiment?
(4) All the figures specially Fig 3 and Fig 5 are far too small to be seen, please make sure it is readable.
(5) L164 how did the author change the inorganic ion strength? Please clarify.
(6) The author seems to investigate the impact of particle size of the biochar, initial adsorbent dosage, inorganic ionic strength, and pH on the adsorption capacity. However, there is no concluded information in the conclusion section.
No specific English language improvement is needed.
Author Response
Please see the attachment.
Author Response File: Author Response.docx
Reviewer 5 Report
The work deals with the adsorption of pyraclostrobin fungicide from water by biochars based on bamboo and pecan shell and deashing products. The authors performed the characterization of the sorbents, focused on many aspects of the adsorption of the mentioned substance – kinetics of the process, adsorption isotherms, the effect of particle size, pH, salinity of the solution and other relevant aspects of the process.
The text is concise, clearly designed, the results provided are clearly described and analyzed, the results achieved are straightforwardly interpreted.
I have the following minor comments about the work:
The introduction talks about the properties and occurrence of pyraclostrobin in water during its use, in my opinion, from the point of view of water management, it is appropriate to mention and add further physico-chemical data and its stability/biodegradability.
Line 204 – 218: It doesn't belong here - ? some residue from template/instructions…
Figure 3: difficult to read even when zooming the pdf; conceivably arrange „2x4“ instead of „4x2“
To paragraph 3.3 / Table S2 / Figure S3: Although the goal of the behavior study was defined input concentrations of 0.1 – 1.5 mg/l of target compound, I think that the construction of an isotherm from only 4 experimental points (then R2 comes out very well) is less common. At the same time, it would be good to state/justify that the use of higher input concentrations is technically limited by the solubility of the target substance in water.
Line 349: typo absorption → adsorption
Figure 5: enlarge, difficult to read even when the pdf is zoomed
In conclusion: Economically advantageous - although the production process will cost something, it would be appropriate to state in what way the tested biochar is better compared to biochar made from other raw materials, also of a natural waste material.
Author Response
Please see the attachment.
Author Response File: Author Response.docx
Round 2
Reviewer 1 Report
Dear Editor,
I have reviewed the manuscript entitled “Adsorption of Pyraclostrobin in Water by Bamboo-Derived and 2 Pecan Shell-Derived Biochars” once more. The authors have made an effort to improve the manuscript, and also they made most of the changes necessary. However, a situation that is overlooked is given below. I recommend that this paper can be published in Sustainability after considering the following one comment;
· Linear range is not a linear equation. Linear range is approximately like working range. This range is the concentration range between LOD and end point of the linearity in calibration graphs. For example, it should be given as 0.005-1.2 mg/L. In this context the linear range given in line 173 should be revised and corrected.
Author Response
We are very grateful for your comments on the manuscript. According to your advice, we amended the relevant part of the manuscript. Your questions were answered below.
Comments 1: Linear range is not a linear equation. Linear range is approximately like working range. This range is the concentration range between LOD and end point of the linearity in calibration graphs. For example, it should be given as 0.005-1.2 mg/L. In this context the linear range given in line 173 should be revised and corrected.
Response 1: Thank you for pointing this out. We strongly agree with this comment. Therefore, we have modified it to “The linear equation within the range of 0.005–0.5 mg·L−1 is y = 2,194,609.8304 x + 2,833.2255 (R² = 0.9997), and the LOD and LOQ of the pyraclostrobin on the instrument are 0.001 mg·L−1 and 0.005 mg·L−1 respectively.” in lines 174–176.
Reviewer 4 Report
The author has addressed my concerns. Just one minor issue, Figure 2's caption and figure are not together, please revise in the final version.
Author Response
We are very grateful to your comments for the manuscript. According with your advice, we amended the relevant part in manuscript. Your questions were answered below.
Comments 1: The author has addressed my concerns. Just one minor issue, Figure 2's caption and figure are not together, please revise in the final version.
Response 1: Thank you for pointing this out. We strongly agree with this comment. Therefore, we have moved the figure to make it connected to the title.
