Agrochemical Contamination and Ageing Effects on Greenhouse Plastic Film for Recycling
Round 1
Reviewer 1 Report
Ageing of greenhouse plastic film due to ultraviolet exposure, wind, and contact with agrochemicals can weaken the structural integrity of the film, preventing its reuse, contributing to the waste produced through agricultural production. Therefore, the authors present a study evaluating the effects of two agrochemicals on the ageing of plastic film used in greenhouse manufacturing. Two agrochemicals, an anti-aphid solution and fungicide, were applied to plastic film that was then artificially aged for two to four weeks. After ageing, the structural integrity of the plastic film was significantly impacted, suggesting the combination of sunlight and agrochemicals significantly reduced the ability to mechanically recycle the film.
Overall, the manuscript is well written, and the results obtained from the experiment support the conclusions drawn by the authors. The main concerns associated with the manuscript are in relation to the structural organization of the introduction. Similarly, there are some revisions that could be made to the figures and tables that would improve the clarity of the data being presented. Specific comments are provided below. It is recommended that the manuscript be accepted for publication after minor revision.
Specific Comments
Sections 2.1-2.2: It is unclear why the information presented in these sections is not included within the Introduction of the manuscript. The information presented in these sections is relevant to the study, but is presented after the main objective of the study. This organization feels as if it disrupts the flow of the manuscript, and it seems that Sections 2.1-2.2 would be better presented in the introduction before the specific objective of the study is described.
Figures 2 and 3: The titles of figures 2 and 3 are unclear. Could they be revised to make it more clear to the reader what data are being presented? Specifically, it is not clear if the variation in maximum strength/elongation at break are being compared to the virgin plastic film or being rated against some specific value? Also, there is no label on the y axis in either figure.
Table 3: The numbers that are presented in Table 3 are not clear. Are these values representing the Carbonyl Index values at 0 and 2 weeks and 0 and 4 weeks, respectively? Or are these values representing a difference in Carbonyl Index over this time period? Please revise to make the meaning of these values clearer.
Line 229-232: How are the authors determining that the effects of UV radiation were dominant in ageing the plastic film? According to the methods section of the manuscript, the plastic film was exposed to one of three treatments: no ageing, ageing after exposure to anti-aphid chemicals, and ageing after exposure to a fungicide. Therefore, it seems that the only conclusion that could be drawn would be with regard to the results were the combined effects of UV radiation and agrochemicals on the integrity of the plastic film as the effect of UV radiation and agrochemicals were not tested separately. Could the authors please provide clarification as to how they arrived at this conclusion?
Author Response
Ageing of greenhouse plastic film due to ultraviolet exposure, wind, and contact with agrochemicals can weaken the structural integrity of the film, preventing its reuse, contributing to the waste produced through agricultural production. Therefore, the authors present a study evaluating the effects of two agrochemicals on the ageing of plastic film used in greenhouse manufacturing. Two agrochemicals, an anti-aphid solution and fungicide, were applied to plastic film that was then artificially aged for two to four weeks. After ageing, the structural integrity of the plastic film was significantly impacted, suggesting the combination of sunlight and agrochemicals significantly reduced the ability to mechanically recycle the film.
Overall, the manuscript is well written, and the results obtained from the experiment support the conclusions drawn by the authors. The main concerns associated with the manuscript are in relation to the structural organization of the introduction. Similarly, there are some revisions that could be made to the figures and tables that would improve the clarity of the data being presented. Specific comments are provided below. It is recommended that the manuscript be accepted for publication after minor revision.
Thank you for the review and comments. We have implemented the minor revisions you have kindly suggested as follows.
Specific Comments
Sections 2.1-2.2: It is unclear why the information presented in these sections is not included within the Introduction of the manuscript. The information presented in these sections is relevant to the study, but is presented after the main objective of the study. This organization feels as if it disrupts the flow of the manuscript, and it seems that Sections 2.1-2.2 would be better presented in the introduction before the specific objective of the study is described.
The structural organization of the introduction has been revised, now limiting the “Introduction” section to some general information only about plastic film used in agriculture and relevant issue connected to its environmental impact. All information relevant to the study – i.e., greenhouse plastic film mechanical properties, ageing, recycling, etc. - have been now homogenized into the following section 2 (The effect of agrochemicals on greenhouse plastic film for recycling), which ends with the presentation of the main objective of the study.
Figures 2 and 3: The titles of figures 2 and 3 are unclear. Could they be revised to make it more clear to the reader what data are being presented? Specifically, it is not clear if the variation in maximum strength/elongation at break are being compared to the virgin plastic film or being rated against some specific value? Also, there is no label on the y axis in either figure.
The titles of figures 2 and 3 (now, 3 and 4, due to the inclusion of a previous figure) have been modified, clearly reporting now that each relevant mechanical property is expressed as the percent variation compared to virgin film (i.e., initial value N0 = 100%). This information has been better clarified also in the previous text, in which these two figures are presented and discussed.
Table 3: The numbers that are presented in Table 3 are not clear. Are these values representing the Carbonyl Index values at 0 and 2 weeks and 0 and 4 weeks, respectively? Or are these values representing a difference in Carbonyl Index over this time period? Please revise to make the meaning of these values clearer.
The numbers presented in Table 3 represent the difference in Carbonyl Index over the relevant time period. Now, they have been accompanied by symbol (+) – which means how much the CI has been increased during that period (2-weeks or 4-weeks long) - and accompanied by the measure unit [%]. This information has been better clarified also in the previous text, in which these numbers are presented and discussed.
Line 229-232: How are the authors determining that the effects of UV radiation were dominant in ageing the plastic film? According to the methods section of the manuscript, the plastic film was exposed to one of three treatments: no ageing, ageing after exposure to anti-aphid chemicals, and ageing after exposure to a fungicide. Therefore, it seems that the only conclusion that could be drawn would be with regard to the results were the combined effects of UV radiation and agrochemicals on the integrity of the plastic film as the effect of UV radiation and agrochemicals were not tested separately. Could the authors please provide clarification as to how they arrived at this conclusion?
The three treatments to which the plastic film has been exposed are:
- ageing after exposure to radiation only;
- ageing after exposure to radiation + anti-aphid chemicals;
- ageing after exposure to radiation + fungicide
This has been reported in the “Discussion” section, that has been enriched through the inclusion of a more elaborate and in-depth discussion as well, particularly focusing on the role of elongation at break, as the technical indicator of the limit for the working life of a plastic film.
Reviewer 2 Report
The article " Agrochemical contamination and ageing effects on greenhouse plastic film for recycling "by Picuno and collaborators is a very interesting study. This study analyzes the effect of two different agrochemicals (anti-aphid or fungicide) on artificially aging and consequently on their mechanical recycling. The article is well written, introduction well argued, but the methods could be more detailed. The results need some improvement, namely in the presentation of results where there is redundancy between tables and figures. The discussion, despite being well written, could be improved, since the authors, instead of discussing their data, present the data of their peers' works in detail. A more elaborate and in-depth discussion would be ideal. Although these data are few but new, they can be a starting point and used for further studies. Since the results are very few and the advance in scientific knowledge is also relative, I would suggest that the article be a Communication, which corresponds to short articles that present groundbreaking preliminary results or significant findings that are part of a larger study over multiple years.
Minor comments
Abstract:
The abstract does not show any results. I believe that the authors should reformulate the abstract in order to present some of the results and, following that, the main conclusions.
Material and Methods:
A better explanation how the agrochemical was sprayed to the plastic film is needed in order to allow others replicate it.
Results:
Figures 2 and 3 are repetition of the results presented in Table 2. Please choose only one way to present the same results.
Author Response
The article " Agrochemical contamination and ageing effects on greenhouse plastic film for recycling "by Picuno and collaborators is a very interesting study. This study analyzes the effect of two different agrochemicals (anti-aphid or fungicide) on artificially aging and consequently on their mechanical recycling. The article is well written, introduction well argued, but the methods could be more detailed. The results need some improvement, namely in the presentation of results where there is redundancy between tables and figures. The discussion, despite being well written, could be improved, since the authors, instead of discussing their data, present the data of their peers' works in detail. A more elaborate and in-depth discussion would be ideal. Although these data are few but new, they can be a starting point and used for further studies. Since the results are very few and the advance in scientific knowledge is also relative, I would suggest that the article be a Communication, which corresponds to short articles that present groundbreaking preliminary results or significant findings that are part of a larger study over multiple years.
Thank you for the review and comments, as well as for your interest about our study, that we are happy you have found very interesting. According to your kind suggestions, section 2. Materials and Methods, has been extended, reporting more information about the selected agrochemicals and their spraying procedure on the plastic film, as well as about the mechanical (tensile) tests on specimens of plastic film. Moreover, in the presentation of results, more information has been now included – both in the text and in the figure captions – to avoid redundancy between tables and figures. We think that this improvement, together with a broader discussion of our data in the following Section 4. Discussion, would increase the advance in scientific knowledge thanks to the results of our research, avoiding to change this article into a Communication.
Minor comments
Abstract:
The abstract does not show any results. I believe that the authors should reformulate the abstract in order to present some of the results and, following that, the main conclusions.
The abstract has been reformulated, so as to briefly present the results about the reduction of mechanical properties in case of contact with agrochemicals, and effect on expected working life and recyclability of the plastic film.
Material and Methods:
A better explanation how the agrochemical was sprayed to the plastic film is needed in order to allow others replicate it.
A more detailed explanation on how the agrochemical was sprayed to the plastic film has been given, by including a photograph of the spraying as well.
Results:
Figures 2 and 3 are repetition of the results presented in Table 2. Please choose only one way to present the same results.
Figures 2 and 3 (now, 3 and 4, due to the inclusion of the previous figure with spraying procedure) report data specifically different from those included in Table 2. Indeed, in Table 2 the absolute values are reported for the two mechanical properties with relevant measure unit (i.e.: Maximum strength [N mm-2] and Elongation at break [%]), while in the two figures each relevant mechanical property has been reported as the percent variation compared to virgin film (i.e., initial value N0 = 100%). This information has been more clarified also in the previous text, in which these two figures are presented and discussed.
Reviewer 3 Report
This work aims to show the mechanical properties of agricultural films exposed to UV and chemical ageing. The manuscript is relevant to the field and presented in a well-structured manner. The experimental design is appropriate. However, It would be advisable to supplement the article with more detailed information:
- an explanation as to why it was chosen those two specific agrochemicals (paragraph from line 142),
- an explanation of the assumptions concerning the number of sprays on the plastic film, line 150 (does it correspond to the real conditions?)
- detailed description of tensile test, sample preparations, standardization etc. (In general, description of method/tests is limited)
It is also recommended to provide a broader discussion on results in chapter 4. The chapter seems more like a description of the current state of the art than a detailed analysis of the results.
Author Response
This work aims to show the mechanical properties of agricultural films exposed to UV and chemical ageing. The manuscript is relevant to the field and presented in a well-structured manner. The experimental design is appropriate. However, It would be advisable to supplement the article with more detailed information:
- an explanation as to why it was chosen those two specific agrochemicals (paragraph from line 142),
Thank you for your review and comments. The reason for having selected these two specific agrochemicals has been now reported in section 3. Materials and Methods.
- an explanation of the assumptions concerning the number of sprays on the plastic film, line 150 (does it correspond to the real conditions?)
As reported in Section 3. Materials and Methods, only one spraying has been applied to plastic film, in order to simulate the more simple application, corresponding to real conditions.
- detailed description of tensile test, sample preparations, standardization etc. (In general, description of method/tests is limited)
Section 3. Materials and Methods, has been extended, even by giving a detailed description of the tensile tests which has been now included, with more details about sample preparation, conditions and standard for the mechanical tests, etc.
It is also recommended to provide a broader discussion on results in chapter 4. The chapter seems more like a description of the current state of the art than a detailed analysis of the results.
A more elaborate and in-depth discussion of our data has been given in Section 4. Discussion, in which some previous researches have been analyzed and discussed within the framework of the results of our research.
Round 2
Reviewer 2 Report
I thank the authors for improving the article and for their explanations. I think that, as a whole, the article was clearer and with useful information for conducting new studies.
