Fouling Mitigation in Membrane Distillation Using Pulsation Flow Technique
Round 1
Reviewer 1 Report
This full-length paper contains some interesting aspects which are covered by the authors; however, some information should be clarified. Therefore, the work requires major improvements before publishing in the Journal of Processes. The most important drawbacks which need revision are summarized in the following list:
1. The abstract is too general. The general pattern must be [problem definition] -> [concept] -> [action] -> [results] -> [significance]. This is a good structure, enticing the readers and getting citations.
2. Include quantitative results in the abstract.
3. Highlight the novelty of the study in the last part of the introduction.
4. Was any uncertainty analysis carried out for the work?
5. I encourage you to state the potential application of the new work. The reader gets a better impression of the future application of this technique.
6. Please revise the introduction to emphasize the work's original contribution, the scientific issue the study addresses, and the research gap/problem found.
7. Line 34-35: "Over 35 1800 billion human beings have got access to essential services". Please check the numbers carefully throughout the whole manuscript.
8. The objectives in the introduction section required more revision.
9. Membrane module design should be illustrated/explained with more details, for instance, how the membranes were potted/sealed, what's the thickness of the PVC pipe and membrane, and how the permeate vapour can pass the PVC pipe.
10. Permeate water quality should be assessed regarding salt rejection. The durability of the system should be tested/discussed.
11. The references and citations should be according to journal standards.
12. The conclusion needs revision and some improvements in the language.
13. Regarding The economic study's data and assumptions, I think the Energy demand/m3 water produced should be calculated.
14. Maintenance (membrane clean), and concentrated brine treatment.... should be discussed/assessed.
15. the information provided about insulation and heat losses from the rig (which can be one of the biggest differences in performance at changing scales in these types of units) is not talked about in enough detail, so some further attention should be given to this point in revising the manuscript.
16. In addition, the experiments are performed only over a few-hour period. It is recommended that at least one longer-term experiment is carried out (with replicates) to examine flux decline.
17. Membrane wetting is briefly mentioned and could be expanded upon.
Minor editing of the English language required.
Author Response
Dear Reviewer,
We are deeply appreciative of all the efforts and time to improve the manuscript. We carefully revised the entire manuscript and we tried to reply and consider all your valuable comments Now we are expecting that it may fulfill the expectations of the Processes. We hope that the Proof Draft manuscript is now suitable for online publication.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
This study aimed to investigate the impact of using a pulsatile flow in the feed stream, as opposed to a steady flow, for reducing fouling and flux decline in hollow fiber Direct Contact Membrane Distillation (DCMD). The researchers examined different feed water sources, including distilled water, seawater, and wastewater and found that pulsatile flow enhanced flux for seawater by inducing turbulence while delaying flux decline and improving the overall product of distilled water for wastewater. The results varied for feed water with foulant materials, such as dextran, but overall demonstrated a positive effect of pulsatile flow in mitigating fouling and reducing flux decline in the desalination process.
The research topic is relevant, and its importance is growing every year. The article describes the experimental setup and the research method quite well. The results of the study are presented as quite informative with good graphical visualization.
The article has some weaknesses that need to be improved.
- It would be good to specify other ways of obtaining pure water and mention in the introduction methods of dynamic filtration (rotating or vibrating cylinder, disc, fiber), cross-flow filtration, chemical purification and so on. Explain the advantages of your distillation method over others.
- “The increasing demand for pure water led to its lack of human beings, facilities, and manufacturers to receive it.” This sentence looks strange. Try to rephrase the sentence. It seems that the demand for water has led to a shortage of people to receive it.
- In some places, you need to improve your English. For example: “Desalination techniques are mainly derived FROM thermal and membrane processes. Membrane processes become dominant due TO THEIR low operational cost, lower space requirements and easiness OF operation (3).” Re-read the article text and eliminate the shortcomings.
- In the context of the section "Effect of distilled water flow rate variation as feed on permeates", it is not entirely clear what Amplitude 1 and Amplitude 2 mean? Clarify this moment.
- Change the scale of Figure 13. Try zooming in the plot.
- The conclusions are written in general terms. Add specifics to the conclusions.
The article can be a strong paper based on experimental research, but serious improvements are required.
In some places, you need to improve your English. For example: “Desalination techniques are mainly derived FROM thermal and membrane processes. Membrane processes become dominant due TO THEIR low operational cost, lower space requirements and easiness OF operation (3).” Re-read the article text and eliminate the shortcomings.
Author Response
Dear Reviewer,
We are deeply appreciative of all the efforts and time to improve the manuscript. We carefully revised the entire manuscript and we tried to reply and consider all your valuable comments Now we are expecting that it may fulfill the expectations of the Processes. We hope that the Proof Draft manuscript is now suitable for online publication.
Author Response File: Author Response.pdf
Reviewer 3 Report
The authors studied the effect of using pulsatile flow instead of traditional steady flow on the membrane fouling and flux. This study is interesting; however, the data are not well collected. I would like to ask the authors to revise the following points before accepting it for publication.
1. The introduction part is not well arranged. The authors should provide a more comprehensive literature review in the introduction to establish the context and significance of the research. Highlight the gaps in the current understanding of fouling in membrane distillation and how this study aims to address them.
2. In lines 59-60, the authors said the hollow fiber membrane had a lower packing density, which is not correct.
3. There is an error in line 63.
4. Figure 4 is difficult to understand for readers. What’s the meaning of 0.6 Feed and 0.5 Permeate?
5. The results section should present the data more clearly and comprehensively.
6. The authors should use precise and appropriate scientific terminology throughout the manuscript. Define any acronyms or abbreviations when first mentioned, such as in line 228.
7. The English of the manuscript should be improved.
The English of the manuscript should be improved.
Author Response
Dear Reviewer,
We are deeply appreciative of all the efforts and time to improve the manuscript. We carefully revised the entire manuscript and we tried to reply and consider all your valuable comments Now we are expecting that it may fulfill the expectations of the Processes. We hope that the Proof Draft manuscript is now suitable for online publication.
Author Response File: Author Response.pdf
Reviewer 4 Report
Obviously the overall quality is very low, and many of the figures were not organized into a meaningful figure to illustrate its intrisnic relationship or support its main statement.
The author did not polish the manuscript even leave other's comments there
Most of the referneces are not related, without citing those related articles in the field.
Professional english writing and polishing is recommended
Author Response
Dear Reviewer,
We are deeply appreciative of all the efforts and time to improve the manuscript. We carefully revised the entire manuscript and we tried to reply and consider all your valuable comments Now we are expecting that it may fulfill the expectations of the Processes. We hope that the Proof Draft manuscript is now suitable for online publication.
Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
I recommend publishing the work since the authors adequately address the majority of the criticisms.
Minor editing of the English language required
Reviewer 2 Report
The authors have done serious work on improving the article. Problems with formulations were eliminated, drawings were improved, missing information was added to the conclusions, and literature was added, revealing possible distillation methods and justifying the need for research on membrane distillation using pulsation flow.
Reviewer 3 Report
I agree to publish this article in the existing version.
Reviewer 4 Report
The revised manuscript meet this basic criteria
Needs to be polished again
