Development of an Air Filter to Remove Fine Dust from Indoor Air Using a Traditional Korean Paper, ‘Hanji’
Siegfried Denys
Round 1
Reviewer 1 Report
Comments and Suggestions for AuthorsThe content is described quite succinctly and provides a clear overview of the research. The introduction section introduces the problem of air pollution in East Asia, the use of Hanji paper as a filter material, and the development of AC-embedded Hanji filters. The methods section explains how the filters were produced, and the results section presents data on the filters' efficiency and dust removal capacity.
The paper effectively discusses the characteristics and performance of both Hanji filters and AC-embedded Hanji filters, providing data to support the findings. The study appears to be well-structured and informative, and it offers valuable insights into the potential of natural materials for air filtration
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Reviewer 2 Report
Comments and Suggestions for AuthorsI have read the article entitled “Development of an Air Filter to Remove Fine Dust from Indoor 2 Air Using a Traditional Korean Paper, 'Hanji'” Changes need to be made to the manuscript before acceptance.
· Introduction; add cellulose studies as a filter or composite cellulose with activated carbon.
· Materials and Methods: Add microscope data.
· Evaluate the porosity of the Hanji filter and the activated carbon filter.
· What are the wettability properties of the filter with and without activated carbon?
· Generally, with the use of filters with nanoparticles, there is a release of these. Perform a test to calculate the percentage of release of activated carbon.
· The size of the filter influences the adhesion of the dust, did you only use the 30 cm × 40 cm measurement?
Comments on the Quality of English Language
Please, check spaces and punctuation marks and nomenclature
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Reviewer 3 Report
Comments and Suggestions for AuthorsI have carefully read the manuscript entitled “Development of an Air Filter to Remove Fine Dust from Indoor Air Using a Traditional Korean Paper, 'Hanji'” by Soyoung Baek, Suho Kim, Kwang Soo Kim, Younghan Yoon and Jiyeol Bae to Sustainability.
The aim of this manuscript was to evaluate the applicability of a filter material made from Traditional Korean Paper, ‘Hanji’ for removal of fine dust from the air. Both ‘pure’ Hanji and activated carbon impregnated Hanji were tested for pressure loss and fine dust removal efficiency when filtering contaminated air.
In general, the objective of the paper is clear. However, some issues were noticed during this review. The main issue is related to the methodology and the link between the results and the performed experiments. The Materials and Methods section is rather limited and it is often unclear which specific experiments in M&M correspond to each result presented in Results & Discussion. Hence, the M&M section should be extended and the details should be revised so that every result presented in the manuscript has a corresponding part in M&M, and no new experiments are introduced in Results & Discussion. This will improve clarity and reproducibility. The main issues encountered are pointed out in more detail below.
1. In sections 2.1 and 2.2 the production process of Hanji and the Hanji filter are described. However, it is unclear to what stage in the Hanji production process is referred to by ‘the dried Hanji’ in the first sentence of section 2.2 (line 93), considering that at the end of section 2.1, the Hanji is diluted in water (line 89).
2. In the Results & Discussion section filters with varying cellulose content are mentioned. It is unclear how this was done in M&M.
3. Line 110-111: How are these larger filters produced?
4. At the end of section 2.2 (line 112-119) an experiment is described in a very concise way. For the sake of clarity, I would advice to split this section in two; one describing the production of the filter and one describing the aerosol removal efficiency experiment. Additionally, more info is necessary to ensure reproducibility of the experiment. Finally, it should be elucidated to which section in Results & Discussion this experiment relates.
5. The description of the experiment in section 2.4 could be improved by including more details to enhance reproducibility. Adding a schematic representation of the setup would lead to more clarity. Furthermore, adding more details will clarify the difference between the ‘aerosol removal efficiency experiment’ and the ‘field application as a semi-pilot experiment’ and how these experiments relate to the presented results.
6. In section 3.3 (line 270), data of fine dust removal tests at different particle sizes for AC embedded filters could be included and discussed (comparable to Fig. 9).
The discussion could be extended to emphasize the impact of the technology. For instance, the authors could enhance the comparison with conventional air filters by expanding it beyond the scope of pressure loss and including a quantitative comparison to offer readers a more comprehensive understanding (line 213-214). Another example is line 178-182; the (dis)advantages of the roll form could be discussed more elaborately. The conclusion contains some information that was not presented before, this should be avoided.
Next to the remarks above, there are some issues with consistency and clarity throughout the manuscript. It is recommended to reread the manuscript carefully to correct the mistakes. Below, a non-exhaustive list of the specific inaccuracies encountered is given together with some other comments and suggestions.
1. Make sure to refer to all the figures and tables in the text by using the figure number.
2. Fig. 1 and Fig. 2 can be merged to save some space.
3. Fig. 5: The level of magnification and a scale bar are missing.
4. Fig. 6: The velocity units are inconsistent with the text (line 173-174). Also the given numbers are inconsistent with line 189 and Table 1 (7 cm/s). Please check all given numbers and units to make sure they are correct and consistent.
5. Fig. 8 and Fig. 10: Please define CMS.
6. Line 172-174: Would it be useful to provide the concentrations as average ± standard deviation? Additionally, you could compare the removal efficiency of the filter at each linear velocity?
7. Line 187-190: How were these properties measured/calculated?
8. Table 1
a. In this table it is not clear what is meant by ‘Linear value’.
b. ‘25 mm H2O head loss’: Is this because of the filter itself or because of the captured dust (also line 190)?
9. Line 199: Is the cellulose content of 1.2 g correct (3.1 mg/cm² * 324 cm² = 1.0 g)?
10. Line 207-210: The explanation of the relationship between porosity and pressure loss is unclear. Why do you observe no further increase in pressure loss? Extra data of pressure loss at higher AC content should be included.
11. Line 211: ‘not statistically significant’: Give more info on the statistical calculation performed and the resulting p-value. In Fig. 7 the pressure loss does seem to increase with the linear velocity?
12. Line 218 and 270: Two times section number 3.3
13. Line 275-276: ‘consistently above 98% from the start’: This is not true for 0.4 g of AC, see Fig.10a.
14. Line 281-284: This is not in line with what is shown in Table 2.
15. Line 308-309: ‘cellulose does not dissolve in water’ contradicts with line 63: ‘high water solubility’.
Comments on the Quality of English Language-
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Reviewer 4 Report
Comments and Suggestions for AuthorsTitle: Development of an Air Filter to Remove Fine Dust from Indoor Air Using a Traditional Korean Paper, 'Hanji
The paper presents an economical and environmentally friendly solution for addressing the fine dust problem in indoor environments, using 'Hanji,' a traditional Korean paper. This innovative approach holds significant potential for large-scale applications.
The paper is well-written and can be accepted with minor changes.
1. In the abstract, the name of the "natural material" can be mentioned (line 14).
2. The introduction does not include a literature review. Are there any prior works that explore similar concepts, such as the use of Hanji as filters or its incorporation into other materials? If relevant, please include.
3. In the materials section, please include the names and companies of all chemicals used, such as Activated Carbon, t-BuOH, polyamine, etc.
4. Polyamine has not been motioned in the schematic graph (Figure 3).
5. What type of Microfiltration (MF) membrane was used for the filtration process?
6. In the introduction, it is stated that cellulose is hydrophilic (lines 62-64); however, in the conclusion, it is mentioned that it does not dissolve in water (line 308). please clarify.
7. How much is the Contact time of AC and filter to prepare an AC-embedded Hanji filter?
8. How many times AC-embedded Hanji filter can be reused?
Comments on the Quality of English LanguageThe English language is fine, it just needs minor editing.
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Round 2
Reviewer 2 Report
Comments and Suggestions for AuthorsThe authors responded to all my observations and therefore accepted the manuscript.
Reviewer 3 Report
Comments and Suggestions for Authors- Line 118: ‘linear value’ should be ‘linear velocity’?
- Section 3.1: Carefully check the units used to indicate the linear velocity, for example:
o Line 187: 483-713 cm/s
o Line 191-192: 483-713 m/s
o Figure 5: numbers and units on the figure itself and in the caption
o Line 208 and Table 1: 7 cm/s
- Line 301-302: ‘The dust adhesion on the filter increased with the increased content of Hanji and AC’ à in Table 2 the weight of adhered dust decreases when the Hanji content increases from 1.2 g to 1.8 g.
- Conclusion: where is the following stated in the results?: “1) When producing the Hanji filter, the appropriate Hanji content per unit area to ensure porosity and minimal head loss was 51 g/m2. For the AC-embedded Hanji filter, the appropriate Hanji content per unit area was 31 g/m2, and the AC content was 31 g/m2.”
Comments on the Quality of English Language-
