Resistance of Untreated and Torrefied Medium-Density Fiberboard (MDF) Residues to Xylophage Fungi

Round 1

Reviewer 1 Report

The manuscript is focused on the investigation and evaluation of the resistance of untreated and torrefied MDF panels to xylophage fungi. In general, the manuscript is well-written and structured, but needs some improvements before acceptance for publication in the Forests Journal. Please, see below my comments on your work:

Lines 3-4: I would recommend to revise the title a bit by replacing “in natura” with “untreated”, it will be more clear.

In general, the abstract (lines 13 to 23) and the keywords (line 24) are relevant to scope of the manuscript.

Line 13: The first sentence of the abstract is too general and should be revised/replaced.

In the keywords, I’d recommend to add also ‘medium-density fibreboards” and “xylophage fungi”

Lines 29-30: “The residues generated by the use of MDF panels are a problem…” – this statement is not clear as it is, please revise/explain. In addition to energy purposes, there are many successful examples related to recycling of waste/discarded MDF panels. Please add some information, supported by relevant references. Please check the following examples:

https://doi.org/10.1007/s12649-021-01391-4

https://doi.org/10.3390/f11060613

https://doi.org/10.1016/j.matpr.2021.12.025

https://doi.org/10.1007/s00107-021-01739-6

In general, the Introduction part is well-written and informative, and provides a relevant background of the research. It can be further extended based on the comments given above. This is needed to increase the scientific soundness of the work.

Line 65: the sample dimensions should be given as 18 mm x 18 mm x 18 mm, please revise.

Line 66: please provide relevant information on the equipment used for performing the heat treatment.

Line 68: “…were torrefied and torrefied…” – probably a typo mistake, please revise. It should be “for 20, 30, and 40 minutes” and not “during”.

Line 70: Figure 1 caption – it should be “MDF samples in natura…”.

Line 94: please use only the common abbreviation MDF instead of the full term “medium-density fibreboard”

Overall, the Materials and Methods section is well written but should be further elaborated based on the comments above.

The results of the study are detailed, informative, and properly discussed with previously reported works in the field.

In general, the Conclusion part (lines 181-187) reflects the main findings of the manuscript. However, they should be extended by adding information about the practical applications of the results obtained as well as the perspectives for future research in the field.

The References cited are appropriate to the topic of the manuscript, but they are not properly formatted. Please refer to the Instructions for Authors for the proper way of formatting your references.

Author Response

Reviewer 1

All changes suggested by this reviewer are highlighted in red.

The manuscript is focused on the investigation and evaluation of the resistance of untreated and torrefied MDF panels to xylophage fungi. In general, the manuscript is well-written and structured, but needs some improvements before acceptance for publication in the Forests Journal. Please, see below my comments on your work:

Lines 3-4: I would recommend to revise the title a bit by replacing “in natura” with “untreated”, it will be more clear.

The suggestion was accepted, the term was changed throughout the manuscript. Changes are marked in red.

In general, the abstract (lines 13 to 23) and the keywords (line 24) are relevant to scope of the manuscript.

Ok

Line 13: The first sentence of the abstract is too general and should be revised/replaced.

The sentence has been changed

The use of waste wood panels can be an option for renewable energy generation

In the keywords, I’d recommend to add also ‘medium-density fibreboards” and “xylophage fungi”

The suggestion was accepted. Changes are marked in red.

Lines 29-30: “The residues generated by the use of MDF panels are a problem…” – this statement is not clear as it is, please revise/explain. In addition to energy purposes, there are many successful examples related to recycling of waste/discarded MDF panels. Please add some information, supported by relevant references. Please check the following examples:

https://doi.org/10.1007/s12649-021-01391-4

https://doi.org/10.3390/f11060613

https://doi.org/10.1016/j.matpr.2021.12.025

https://doi.org/10.1007/s00107-021-01739-6

The sentence has been rewritten and references have been added

In general, the Introduction part is well-written and informative, and provides a relevant background of the research. It can be further extended based on the comments given above. This is needed to increase the scientific soundness of the work.

Line 65: the sample dimensions should be given as 18 mm x 18 mm x 18 mm, please revise.

The suggestion was accepted. Changes are marked in red in the manuscript.

Line 66: please provide relevant information on the equipment used for performing the heat treatment.

The authors decided to add a reference with the details of the operation of the roaster

Line 68: “…were torrefied and torrefied…” – probably a typo mistake, please revise. It should be “for 20, 30, and 40 minutes” and not “during”.

The suggestion was accepted. Changes are marked in red in the manuscript.

Line 70: Figure 1 caption – it should be “MDF samples in natura…”.

The sentence was changed to

Figure 1. Sample of MDF untreated and after torrefaction (40 minutes).

Line 94: please use only the common abbreviation MDF instead of the full term “medium-density fibreboard”

The suggestion was accepted. Changes are marked in red in the manuscript.

Overall, the Materials and Methods section is well written but should be further elaborated based on the comments above.

The results of the study are detailed, informative, and properly discussed with previously reported works in the field.

In general, the Conclusion part (lines 181-187) reflects the main findings of the manuscript. However, they should be extended by adding information about the practical applications of the results obtained as well as the perspectives for future research in the field.

The sentence was added in the conclusion

 “Torrefaction is an effective technique to reduce the incidence of fungi and can be used to increase the storage time of biomass without loss by xylophages.”

The References cited are appropriate to the topic of the manuscript, but they are not properly formatted. Please refer to the Instructions for Authors for the proper way of formatting your references.

The references have been reviewed

Reviewer 2 Report

The article "Resistance of in natura and torrefied medium-density fiberboard (MDF) residues to xylophage fungi" presented insightful knowledge on evaluating the resistance of medium-density fibreboard (MDF) panels in natura and torrefied to biological attack by the xylophage fungi of the white rot Irpex lacteus and Trametes versicolor and the brown rot Postia placenta.

My comments are:

·       The paper's originality is high, with a similarity index of 9% to the published work

·       The abstract is incomplete. The abstract should include a brief background/introduction, objective, methods, quantitative results, discussion, and conclusion. Some of the parts are missing. Please improve it.

·       The state-of-the-art written in the introduction of the paper is improper and too brief. Please improve it.

·       The experimental procedure is justified and comprehensive according to this study.

·       The results are presented with proper TABLES and FIGURES.

·       However, compared to the references, the results obtained are not significant.

·       The discussion section is not clear.

·       The conclusion is not written properly.

·       The citation and reference format are wrong. The authors should revise it according to the FORESTS Journal.

·       The manuscript should go for English checking. Many grammatical errors were detected.

·       The article lacks major scientific soundness. Thus, the article can be considered after addressing the below comments in the revision (major revision).

Please check the specific comments below:

1.     Title: The title is relevant to the content. The authors can keep it as it is.

2.     Abstract:

a.     The brief quantitative results and discussion are missing in the abstract. Revise this accordingly.

3.     Introduction:

a.     Please write 'medium-density fiberboard' consistently throughout the manuscript.

b.     The introduction does not have a storyline, and the research gap is missing. The authors should revise this.

c.     The authors should expand the introduction about the MDF-rich nitrogen content and their resistance. The following articles could be used in the introduction:

·       Visual inspection of surface mold growth on medium-density fiberboard bonded with oxidized starch adhesives. Wood Material Science & Engineering (2022): 1-8. https://doi.org/10.1080/17480272.2022.2073828

·       Hydrolytic removal of cured urea–formaldehyde resins in medium-density fiberboard for recycling. Journal of Wood Chemistry and Technology 38, No. 1 (2018): 1-14. https://doi.org/10.1080/02773813.2017.1316741

4.   Materials and Method:

a.     Page 2. Line 61. Revise to "medium-density fibreboard (MDF) residues..." The full name comes first and is then followed by its abbreviation.

b.     Page 2. Line 61. Please write the MDF's detailed specifications, such as the density, adhesive, MDF's size, the MDF plant, location, and country.

c.     FIGURE 1. The images of 20 and 30 minutes of torrefied MDF are missing. Please add it for better clarity.

d.     Page 3. Line 76. Why the TGA's initial temperature is 100°C? Some low molecular weight compounds and moisture are degraded below 100°C.

e.     The chemical characterizations to obtain the results in TABLE 1 are missing in the methods. The authors should write the methods briefly, concisely, and clearly.

5.       Results and discussion:

a.     FIGURE 2. The X and Y labels and units are wrong. Revise to "Mass loss (%) and Temperature (°C)." In addition, the legends are missing, and the fonts are not in similar sizes. Which line belongs to mass loss, and which belongs to derivative mass loss? Revise this accordingly.

b.     TABLE 2. Revise weight loss to ‘mass loss’ for consistency.

c.     Please check the writing. The space is inconsistent.

d.     Page 5. Line 127. What is MDP?

e.     Page 6. Please add images of the MDF after attacked by T. versicolor, P. placenta, and Irpex lacteus.

6.     Conclusions

a.     Please expand the conclusion by briefly discussing the results of mass losses (%) of MDF residues in natura and torrefied to resist the attack of xylophagous fungi.

7.     References

Revise the references according to the FORESTS Journal.

Comments for author File: Comments.docx

Author Response

Reviewer 2

All changes suggested by this reviewer are highlighted in yellow.

My comments are:

Please check the specific comments below:

1. Title: The title is relevant to the content. The authors can keep it as it is.

 Ok

2. Abstract:
3. The brief quantitative results and discussion are missing in the abstract. Revise this accordingly.

 The abstract has been rewritten, changes are marked in yellow in the manuscript.

3. Introduction:
4. Please write 'medium-density fiberboard' consistently throughout the manuscript.

The change has been accepted; the changes have been marked in yellow. The term has been standardized to MDF.

1. The introduction does not have a storyline, and the research gap is missing. The authors should revise this.

The introduction has been rewritten, changes are marked in yellow in the manuscript.

1. The authors should expand the introduction about the MDF-rich nitrogen content and their resistance. The following articles could be used in the introduction:

• Hydrolytic removal of cured urea–formaldehyde resins in medium-density fiberboard for recycling. Journal of Wood Chemistry and Technology 38, No. 1 (2018): 1-14. https://doi.org/10.1080/02773813.2017.1316741

            The References have been added in the manuscript

4. Materials and Method:
5. Page 2. Line 61. Revise to "medium-density fibreboard (MDF) residues..." The full name comes first and is then followed by its abbreviation.

The term has been standardized to MDF.

2. Page 2. Line 61. Please write the MDF's detailed specifications, such as the density, adhesive, MDF's size, the MDF plant, location, and country.

The information has been added to the manuscript. “The MDF panel was produced in Brazil, with eucalyptus wood bonded with thermo-setting synthetic resin, which melt with the action of temperature together with pressure.”

1. FIGURE 1. The images of 20 and 30 minutes of torrefied MDF are missing. Please add it for better clarity.

Unfortunately, we do not have these images.

3. Page 3. Line 76. Why the TGA's initial temperature is 100°C? Some low molecular weight compounds and moisture are degraded below 100°C.

Few wood substances are degraded at this temperature, so much so that this temperature is used in basic density tests. Therefore, any changes in MDF do not influence the results.

1. The chemical characterizations to obtain the results in TABLE 1 are missing in the methods. The authors should write the methods briefly, concisely, and clearly.

A reference was used. The methodology can be accessed in the work of de Castro et al 2021.

5. Results and discussion:
6. FIGURE 2. The X and Y labels and units are wrong. Revise to "Mass loss (%) and Temperature (°C)." In addition, the legends are missing, and the fonts are not in similar sizes. Which line belongs to mass loss, and which belongs to derivative mass loss? Revise this accordingly.

The term mass was retained, as the axis in the graph refers to the amount of remaining mass, not the mass that was lost.

2. TABLE 2. Revise weight loss to ‘mass loss’ for consistency.

The suggestion was accepted

1. Please check the writing. The space is inconsistent.
2. Page 5. Line 127. What is MDP?

MDP is (Medium Density Particleboard), the information has been added to the manuscript

6. Page 6. Please add images of the MDF after attacked by T. versicolor, P. placenta, and Irpex lacteus.

 Unfortunately, we do not have these images.

6. Conclusions
7. Please expand the conclusion by briefly discussing the results of mass losses (%) of MDF residues in natura and torrefied to resist the attack of xylophagous fungi.

The conclusion has been revised

7. References

Revise the references according to the FORESTS Journal.

The references have been reviewed.

Reviewer 3 Report

Manuscript ID: forests-2101771

Title: Resistance of in natura and torrefied medium-density fiber-3 board (MDF) residues to xylophage fungi
 

Reviewer comments: 

This manuscript has been the focus on Resistance of in natura and torrefied medium-density fiber-3 board (MDF) residues to xylophage fungi. Therefore, could you consider some points below for further improvement.

1.           General:

Referring to the previous study title, "Resistance of in natura and torrefied wood chips to xylophage fungi," what are the major differences with this current manuscript? Compared to the prior application, it appears that there was less originality (wood chips).

2.           Abstract:

The abstract has been written well. Otherwise, can the author describe in the text the residue properties of natura MDF to justify the significant results achieved? Please describe accordingly.

3.           Introduction:

a)       What are the discussion from the previous study related? The author should have discussed detail and deliberate the discussion on the resistance of in natura and torrefied for more understanding on current or previous issues.

b)      The motivation or objective of this manuscript are not clear enough.

4.           Methodology:

The author should explain the flow of the research (Research Flow) in the context of the research methods (qualitative and quantitative) to help the reader understand the hypothesis for a specific process or phenomenon that has been observed during research. The discussion or explanation of each parameter highlighted was weak, please improve!

5.           Results & discussion:

a)   Sections 3 - The authors should consider detail explanation due the tabulated data generated via the approach method with more informatics arrangement (Figure 2, Table 2 & 3). Not enough discussion, please improve!

b)  The paper is a train of tests, without explaining the outcome and the mechanistic reason behind observations. It is similar to a technical report frequently engineers use in production lines rather than a research article. What is the significant of the overall discussion? Please improve!!

6.           References:

a)     Too many discrepancies on the format used, please recheck the format references of the journal and improve!

Comments for author File: Comments.docx

Author Response

Reviewer 3

All changes suggested by this reviewer are highlighted in green.

This manuscript has been the focus on Resistance of in natura and torrefied medium-density fiber-3 board (MDF) residues to xylophage fungi. Therefore, could you consider some points below for further improvement.

1. General:

Referring to the previous study title, "Resistance of in natura and torrefied wood chips to xylophage fungi," what are the major differences with this current manuscript? Compared to the prior application, it appears that there was less originality (wood chips).

2. Abstract:

The abstract has been written well. Otherwise, can the author describe in the text the residue properties of natura MDF to justify the significant results achieved? Please describe accordingly.

The summary has been restructured

3. Introduction:
4. a)What are the discussion from the previous study related? The author should have discussed detail and deliberate the discussion on the resistance of in natura and torrefied for more understanding on current or previous issues.

The introduction was restructured.

1. b)The motivation or objective of this manuscript are not clear enough.

The objective of the work was rewritten.

“This work aimed to evaluate the resistance of MDF (medium density fiberboard) pan-els, untreated and torrefied, to biological attack by the xylophage fungi of the white rot Irpex lacteus and Trametes versicolor and the brown rot Postia placenta”

4. Methodology:

The author should explain the flow of the research (Research Flow) in the context of the research methods (qualitative and quantitative) to help the reader understand the hypothesis for a specific process or phenomenon that has been observed during research. The discussion or explanation of each parameter highlighted was weak, please improve!

The methodology was restructured.

5. Results & discussion:
6. a)Sections 3 - The authors should consider detail explanation due the tabulated data generated via the approach method with more informatics arrangement (Figure 2, Table 2 & 3). Not enough discussion, please improve!

Work discussion has been improved

1. b)The paper is a train of tests, without explaining the outcome and the mechanistic reason behind observations. It is similar to a technical report frequently engineers use in production lines rather than a research article. What is the significant of the overall discussion? Please improve!!

Work discussion has been improved

6. References:
7. a)Too many discrepancies on the format used, please recheck the format references of the journal and improve!

          The references have been reviewed

Reviewer 4 Report

Manuscript ID: forests-2101771

Title: Resistance of untreated and torrefied medium-density fiberboard (MDF) residues to xylophage fungi

Minor Revisions

This manuscript analyzes the resistance of MDF panels residues, untreted and torrefied at 300 °C for 20, 30 and 40 minutes, to the xylophagous fungi of the white rot, Irpex lacteus and Trametes versicolor, and that of the brown rot, Postia placenta.

After 12 weeks of exposure, the mass loss of the samples attacked  by T. versicolor and P. placenta was similar in all treatments, except the MDF untreted with greater mass losses by the fungus Irpex lacteus.

Must be admitted that the article does not introduce novelty aspects but it broadens the knowledge in the discussed scope. Is an interesting topic and the manuscript is well prepared clear and relevant for the field with correct methods and reasonable discussion of the results. The introduction provide sufficient background and include the most relevant references. The conclusions are not clearly presented and needs to be refined. The English language needs a moderate revision.

Therefore, I would recommend some corrections:

Line 66 – Chek the reference [24] or [29]

Line 78 – Chek the reference [24] or [29]

Line 124 – Correct (Figure 3) to (Figure 2)

Line 189 – Check this sentence (30 minutes by the Irpex lacteus) or (30 min by the Tramets versicolor)

Author Response

Reviewer 4

All changes suggested by this reviewer are highlighted in yellow.

Line 66 – Chek the reference [24] or [29]

The error has been fixed

Line 78 – Chek the reference [24] or [29]

The error has been fixed

Line 124 – Correct (Figure 3) to (Figure 2)

The error has been fixed

Line 189 – Check this sentence (30 minutes by the Irpex lacteus) or (30 min by the Tramets versicolor)

The sentence has been changed

The intensity of torrefaction increased the resistance of the MDF residue to rot fungi, the losses caused by the attack by the fungus Irpex lacteus and Postia placenta were lower in the material torrefied for 30 and 20 minutes, respectively.

Round 2

Reviewer 2 Report

1.       FIGURE 1. Why don't the authors have the images of 20 and 30 minutes of torrefied MDF? This is your research.

2.       Page 6. Please add images of the MDF after attacked by T. versicolor, P. placenta, and Irpex lacteus. You can see the example from this article.

·         Visual inspection of surface mold growth on medium-density fiberboard bonded with oxidized starch adhesives. Wood Material Science & Engineering (2022): 1-8. https://doi.org/10.1080/17480272.2022.2073828

Author Response

Reviewer 2

All changes suggested by this reviewer are highlighted in red.

1. FIGURE 1. Why don't the authors have the images of 20 and 30 minutes of torrefied MDF? This is your research.

The authors opted for a photo with the most intense treatment, 40 minutes of torrefaction. Unfortunately, we do not have pictures of samples treated for 20 and 30 minutes.

2. Page 6. Please add images of the MDF after attacked by T. versicolor, P. placenta, and Irpex lacteus.You can see the example from this article.

Unfortunately we do not have photos of samples infected by the fungi.

3. Visual inspection of surface mold growth on medium-density fiberboard bonded with oxidized starch adhesives. Wood Material Science & Engineering (2022): 1-8. https://doi.org/10.1080/17480272.2022.2073828

The reference was added in the manuscript

Reviewer 3 Report

Reviewer 3

All changes suggested by this reviewer are highlighted in green.

This manuscript has been the focus on Resistance of in natura and torrefied medium-density fiber-3 board (MDF) residues to xylophage fungi. Therefore, could you consider some points below for further improvement.

1. General:

Referring to the previous study title, "Resistance of in natura and torrefied wood chips to xylophage fungi," what are the major differences with this current manuscript? Compared to the prior application, it appears that there was less originality (wood chips).

-No response

2. Abstract:

The abstract has been written well. Otherwise, can the author describe in the text the residue properties of natura MDF to justify the significant results achieved? Please describe accordingly.

Answer: The summary has been restructured

- The author has just highlighted the content without making any changes to the text manuscript.

3. Introduction:

a) What are the discussion from the previous study related? The author should have discussed detail and deliberate the discussion on the resistance of in natura and torrefied for more understanding on current or previous issues.

Answer: The introduction was restructured.

- The author has just highlighted the content without making any changes to the text manuscript.

b) The motivation or objective of this manuscript are not clear enough.

Answer: The objective of the work was rewritten. “This work aimed to evaluate the resistance of MDF (medium density fiberboard) pan-els, untreated and torrefied, to biological attack by the xylophage fungi of the white rot Irpex lacteus and Trametes versicolor and the brown rot Postia placenta”

- The motivation cannot reflect the importance and necessity of this work. There is no clear reason why this work is done! Which aspect of literature in this area was missing that encouraged authors to do this work? Plenty of works in this regard are neglected in the literature review, and I'm sure there could be some improvement to highlight from previous studies to affect this study.

4. Methodology:

The author should explain the flow of the research (Research Flow) in the context of the research methods (qualitative and quantitative) to help the reader understand the hypothesis for a specific process or phenomenon that has been observed during research. The discussion or explanation of each parameter highlighted was weak, please improve!

Answer: The methodology was restructured.

- The author has just highlighted the content without making any changes to the text manuscript.

5. Results & discussion:

a) Sections 3 - The authors should consider detail explanation due the tabulated data generated via the approach method with more informatics arrangement (Figure 2, Table 2 & 3). Not enough discussion, please improve!

Answer: Work discussion has been improved

- The author has just highlighted the content without making any changes to the text manuscript.

Author Response

Reviewer 3

All changes suggested by this reviewer are highlighted in green.

This manuscript has been the focus on Resistance of in natura and torrefied medium-density fiber-3 board (MDF) residues to xylophage fungi. Therefore, could you consider some points below for further improvement.

1. General:

Referring to the previous study title, "Resistance of in natura and torrefied wood chips to xylophage fungi," what are the major differences with this current manuscript? Compared to the prior application, it appears that there was less originality (wood chips).

This article evaluated torrefied MDF residues, in this case, the material has woodreatments and has other impregnated substances, such as adhesives, therefore, which can affect its performance in roasting and its resistance against fungi, which justifies the need to evaluate this biomass.

2. Abstract:

The abstract has been written well. Otherwise, can the author describe in the text the residue properties of natura MDF to justify the significant results achieved? Please describe accordingly.

Mdf panel composition added in manuscript abstract

“The MDF panels were produced using eucalyptus wood and bonded with thermosetting synthetic resin, under high temperature and pressure.”

3. Introduction:
4. a) What are the discussion from the previous study related? The author should have discussed detail and deliberate the discussion on the resistance of in natura and torrefied for more understanding on current or previous issues.

We added information about previous studies with this theme.

“The intensity of fungus attack varies according to the wood treatment. Torrefaction increased the resistance of wood chips to attack by Trametes sp. and P. ostreatus, reducind the mass loss from 1.63 and 2.78% to 0%, respectively (Castro et al., 2019). Torrefaction of eucalyptus, pine and coffee husk at 290˚C decrease the mass loss against Trametes versicolor and Coniophora Puteana attack in at least 18% and 22%, respectively (de Faria et al., 2021).

1. b) The motivation or objective of this manuscript are not clear enough.

Answer: The objective of the work was rewritten. “This work aimed to evaluate the resistance of MDF (medium density fiberboard) pan-els, untreated and torrefied, to biological attack by the xylophage fungi of the white rot Irpex lacteus and Trametes versicolor and the brown rot Postia placenta”

- The motivation cannot reflect the importance and necessity of this work. There is no clear reason why this work is done! Which aspect of literature in this area was missing that encouraged authors to do this work? Plenty of works in this regard are neglected in the literature review, and I'm sure there could be some improvement to highlight from previous studies to affect this study.

The last paragraph of the introduction was rewritten

The large amount of waste generated in the production of MDF demands an alterna-tive for its use. Studies for energy generation focus on parameters such as calorific value and energy efficiency, however, in the storage of this material, it is subject to fungal attack, which can make its use unfeasible. This topic is understudied. This work aimed to evalu-ate the resistance of MDF (medium density fiberboard) panels, untreated and torrefied, to biological attack by the xylophage fungi of the white rot Irpex lacteus and Trametes versicolor and the brown rot Postia placenta.

4. Methodology:

The author should explain the flow of the research (Research Flow) in the context of the research methods (qualitative and quantitative) to help the reader understand the hypothesis for a specific process or phenomenon that has been observed during research. The discussion or explanation of each parameter highlighted was weak, please improve!

The methodology has been restructured, changes are marked in green.

5. Results & discussion:
6. a) Sections 3 - The authors should consider detail explanation due the tabulated data generated via the approach method with more informatics arrangement (Figure 2, Table 2 & 3). Not enough discussion, please improve!

The discussion of chemical changes in the torrefied material has been improved.