Evaluation of the Barrier Effect of Polylactic Acid-Modified Membrane on Odours at the Excavated Soil Interface of a Pesticide-Contaminated Site
, Yan Ma 3,†, Xiaoming Du 1,2, Meng Zhang 4, Yi Shi 1,2, Juejun Yao 1,2,* and Weiguang Zhao 1,2,*Round 1
Reviewer 1 Report
In this work the authors studied the barriers effect of bio-based materials like PLA. In my opinion the authors made an excellent work. Moreover, field experiments were very interesting since many authors only focus on lab tests. However, for me, the main weakness of this work consists of the characterization of the materials used in the membranes. Below is a list of questions that authors must attend prior to fully accepting the manuscript.
Q1. I am unsure about the term “odour substances”. In my opinion, I would choose volatile organics compounds (VOCs). However, I am not an expert in this field. Please take this question as an opinion and use the more suitable option.
Q2. PAGE 3 LINE 93: “Exposed strata of the site consist of artificial fill, alluvium, eluvium, and Lower Palaeozoic, from top to bottom.” Did the authors make a study about the soil composition? Or is this common knowledge?
Q3. PLA-modified membrane: please add more information about the polymer processability. That is: equipment used and processing conditions. Also, please add the amount of each component used (PLA, polybutylene adipate terephthalate/butylene terephthalate, calcium peroxide loaded organic intercalated bentonite, and polymer chain extenders).
Q4. Following my prior question, What was the criteria for choosing the formulation used? In case the authors have carried out laboratory tests to optimize the formulation, my recommendation would be to cite these results.
Q5. I assume that the authors employed bentonite to improve the gas barrier properties. This is quite a challenge since these properties depend on the exfoliation degree of the platelets. I recommend a XRD analysis in order to study the intercalation / exfoliation of the clay platelets into the matrix.
Q6. PAGE 4 LINE 17. “The gas transmission rate was 54.7 cm3/(m2·24 h·0.2 MPa)”. Which gas was used in the gas permeability test?
Q7. PAGE 8 LINE 256. “Under the action of a high shear force, the monolayer peeling of the flakes significantly increases the tortuosity of the passage path of odours, and improves the physical barrier ability of the modified membrane to odours, thereby effectively reducing the diffusion flux [33]”. Once again, these behaviors only occur when bentonite exfoliation takes place. Authors should make an XRD analysis and study the d001 peak by Bragg’s Law.
Q8. PAGE 8 LINE 266: “In addition, nanosized calcium peroxide particles were generated between the bentonite-like structures through the in situ reaction process.” How can the authors be sure that nanosized particles were generated? Maybe microscopy studies like SEM would be useful here.
Author Response
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Author Response File: 
Author Response.pdf
Reviewer 2 Report
This paper analyze impact of soil odour using PLA membrane, which more towards application study. The methodology and results sound convincing, so only few recommendations are needed to further improve this manuscript. Can the author comment the degree of fouling given that membrane might have serious fouling issue when using in soil odour removal application? Another comment is that there are too many repeating number in abstract, table 1 and 2, the author should improve demonstration of the number easily after this.
Author Response
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Author Response File: Author Response.pdf
Reviewer 3 Report
Good job. I hope my comments and suggestions are useful to your paper.
Comments for author File: Comments.pdf
Author Response
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Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
I read the authors cover letter and all my questions were attended. Therefore, my recommendation is to accept this manuscript with no further modifications.
