Removal of Volatile Organic Compounds by Means of a Felt-Based Living Wall Using Different Plant Species

Round 1

Reviewer 1 Report

Title:

Removal of volatile organic compounds by means of a felt- based living wall using different plant species

 

Objective:

The purpose of this study is to evaluate the efficiency of five species planted in living wall modules to remove VOCs for IAQ improvement and to assess if the type of contaminant had any influence.

 

Comments:

This is a rather straightforward study. There is not much issue with it other than the fact that the manuscript is rather short. Please consider the following:

Provide a more comprehensive review in the literature section

Figures would be useful. Such as bar/line charts of VOC reduction over time, photos of experiment setup.

Insert table of all equipment used, including measurement range, accuracy, etc.

Nomenclature: After initial introduction of Spahtiphyllum wallisii, plant species should be S. wallisii, not Spa-walli

Does the soil have any influence on the amount of VOC reduction? Discuss.

Add a conclusion section, summarising findings, limitations and possibilities for future work

Author Response

This is a rather straightforward study. There is not much issue with it other than the fact that the manuscript is rather short. Please consider the following:

Provide a more comprehensive review in the literature section

Though we appreciate the reviewer’s suggestion, we wanted to keep the introduction simple, given that there are recent and very detailed reviews on the topic that the reader can use to acquire more information. For instance, we cited Dela Cruz et al. (2014) and Bandehali et al. (2021) among others.

Figures would be useful. Such as bar/line charts of VOC reduction over time, photos of experiment setup.

Figure 1 was added, detailing how the test was set up, showing the sealed chamber and the instruments used for the measurements.

Figure 2 shows the module used during the tests together with the distribution of the three plants. Five modules were used, one per species.

Figure 3 has been inserted showing the evolution of the reduction of TVOCs for each of the species, in the case of n-hexane (A) and formaldehyde (B) as time elapses.

Insert table of all equipment used, including measurement range, accuracy, etc.

Table 1 was inserted, in which the instruments used during the tests are detailed, taking into account the model and description of each one of them.

Nomenclature: After initial introduction of Spahtiphyllum wallisii, plant species should be S. wallisii, not Spa-walli

The nomenclature of the plants has been changed throughout the document, to avoid confusion, leaving the scientific name.

Does the soil have any influence on the amount of VOC reduction? Discuss.

A brief paragraph was added about the influence that the rhizosphere microbial community present in the soil has on the reduction of VOCs as well as the direct adsorption (lines 253-256).

Add a conclusion section, summarising findings, limitations and possibilities for future work

A conclusion section summarising findings and pointing out the limitations of our work and possible future studies was added (lines 258-268).

Reviewer 2 Report

There is often limited space indoors to provide the amount of vegetation needed to improve air quality. Thus, living walls can be considered as a viable solution . They also contribute to improving the aesthetical component and offer psychological benefits associated with indoor vegetation.

This study confirms that plants contribute to the improvement of indoor air quality  by reducing the concentration of VOCs. The effect is higher the longer the air is in contact  with the plants. However, the efficiency in this reduction was different depending on  the contaminant and on the species used.

The authors received good results, but their presentation in the article should be improved. I lacked the justification for the reliability of the results, why everything is summarized in tables, and where there are graphs, diagrams. The picture could show how the plants are arranged and what they look like.

 

Author Response

There is often limited space indoors to provide the amount of vegetation needed to improve air quality. Thus, living walls can be considered as a viable solution. They also contribute to improving the aesthetical component and offer psychological benefits associated with indoor vegetation.

This study confirms that plants contribute to the improvement of indoor air quality by reducing the concentration of VOCs. The effect is higher the longer the air is in contact with the plants. However, the efficiency in this reduction was different depending on the contaminant and on the species used.

The authors received good results, but their presentation in the article should be improved. I lacked the justification for the reliability of the results, why everything is summarized in tables, and where there are graphs, diagrams. The picture could show how the plants are arranged and what they look like.

The reliability of the results was supported by the replications performed for each experiment and by comparing our results with the obtained with other authors (see the discussion section).

Figures 1, 2 and 3 have been inserted. Figure 1 details how the test was carried out, showing the sealed chamber and the instruments used for the measurements. Figure 2 shows the module used during the tests together with the distribution of the three plants. Five modules were used, one per species. Figure 3 has been inserted showing the evolution of the reduction of TVOCs for each of the species, in the case of n-hexane (A) and formaldehyde (B) as time elapses. 

Reviewer 3 Report

The paper is interesting, clear and well organized. It falls within the scope of the Journal. I suggest to the authors, to add a couple of pictures/photos of the experimental tests/equipments. These can help the potential reader to better follow the descriptions of the campaign reported in the paper.

Author Response

The paper is interesting, clear and well organized. It falls within the scope of the Journal. I suggest to the authors, to add a couple of pictures/photos of the experimental tests/equipments. These can help the potential reader to better follow the descriptions of the campaign reported in the paper.

Two photographs showing the experimental setup and a table detailing the equipment used were added according to Reviewer 1 recommendations.