A Comprehensive Review on Forward Osmosis Water Treatment: Recent Advances and Prospects of Membranes and Draw Solutes
Round 1
Reviewer 1 Report
In this manuscript, the authors reviewed the core of water treatment by the forward osmosis technique. I have the following comments:
1. This manuscript is quite very interesting for readers. It is well known that the FO is one of the modified processes of osmosis due to an osmotic pressure gradient, which many previously reported in several papers. However, the reference list is not up to date for the FO method. Several papers have been published in 2022 and 2023, please update the latest literature reviews.
2. Absolutely agreed with the authors that “The membrane material is the core technology in the FO water treatment process…..” However, for better clarify to the reader please mention some type of membrane such as hydrogel, reported by Jamnongkan et al., South African Journal of Chemical Engineering 2021, 35, 14-22, and nanoparticles, reported by Kim et al., Water Science and Technology 2011, 64, 469–476, etc.
3. Please improve the quality of Figure 3(a), the text is not clear.
Author Response
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Reviewer 2 Report
This paper presents a comprehensive review on water treatment by direct osmosis: recent advances and perspectives of extraction membranes and solutes. The topic is interesting and is within the scope of the journal, however the manuscript must improve its presentation. In general, I do not recommend accepting this article in its current form. Following are my detailed suggestions for future improvements, and then the same can be accepted.
abstract graphic
Please build an abstract figure.
Abstract
the abstract of the work must be rewritten in order to present the findings found in the work and also the future perspectives. in addition, this part should describe the importance of this article and how it can contribute to the scientific community. The way it is written looks more like an introduction and not an abstract.
Authors should build a separate item talking about the future prospects and challenges of using this technology. At this point, the possibility of combined processes using other technologies together with reverse osmosis, such as adsorption and photocatalysis, must be addressed.
review english
Author Response
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Reviewer 3 Report
The review is written in good English, its layout is clear and well considered. All parts are important and well presented. Gathered literature is up to date and relevant to the topic.
However, there are some issues that should be addressed in order to improve the quality of the final version of the manuscript.
The main part that should be improved are the graphics. Some of them are of bad quality and thus hard to follow. Detailed information are given below.
Figure 3a is of low quality. Moreover the colors chosen to illustrate dilution degree together with light color of letters makes it impossible to read out the contents of each block in the diagrams. Please choose another color palette and improve quality of this figure.
Figure 4 contains a lot of information. Please consider dividing it into 2 separate figures: one showing fouling and cleaning schemes, and the other one with the alginate membrane cases – it will increase the clarity of presentation.
Figure 10 (a) and (l) are unnecessary. In my opinion they are simple and as they are not described in the manuscript in details, it is enough to provide the reference (as it is in the main text). The interested reader can follow.
Figure 11(A) and line 464: presentation of the synthesis steps in figure without any description in text is just a way of making the article to look better. This do not improve the knowledge of the reader in any way, and if someone is interested in the synthesis itself, will need to read the original paper.
Figure 12(d) also do not provide much interesting information in comparison to other parts of Figure 12.
Figure 13(c) is not given enough care in the manuscript. Authors should either discuss or remove it.
Figure 18(c) and (e): quality of the reprints is poor. The description of the points is hardly readable, especially comparing to the original papers. Authors should improve the quality of those graphs.
Author Response
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Reviewer 4 Report
This is an excellent review paper, worth to be published in International Journal of Environmental Research and Public Health. Forward osmosis is one of this emerging membrane techniques which is developing very fast. Authors presented the most important achievement in FO, indicating also the challenges and perspectives for this separation process. As one of the disadvantages of FO is reverse solute flux, I would suggest Authors to extend this part of the review. In the submitted version, the section 3.3 is too short and too general. There are good papers on that. The general comment on graphics - some of them should be improved or converted into tables (e.g., Fig. 7 - would be much more information in the form of Table; Figs. 9,10, and 20 - too much information over a relatively small space; Fig. 13a i b - in the colorless printout the difference are invisible and poorly legible). Please also try to unify units of the presented values, especially regarding concentrations and fluxes. The data are taken from a number of papers, but one the goals in review papers is to present them in a concise and uniform way.
Recommendation - minor revisions.
Author Response
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Round 2
Reviewer 1 Report
Accepted in this form. However, please check the order of the references list again. I still found something was not correct, i,e., "Figure 18. (a) Appearance of hydrogel beads; (b) reusability of the adsorption capacity of hydrogel 781 beads [110]" It is should be "[114]" not "[110]".
Reviewer 2 Report
The manuscript may be accepted for publication.
