Fouling Identification for Nanofiltration Membrane and the Potential Reduction of Pollutants in the Leachate by Using Fe/Al/PAC Coagulation

Round 1

Reviewer 1 Report

Article entitled Fouling identification for Nano filtration membrane and the potential reduction using Fe/Al/PAC coagulation written by Changwei He, Hui Wang, Luo-chun Wang，Zi-yang Lou, Li Bai, Hai-feng Zong and Zhen Zhou, and submitted to Sustainability journal as a draft no 1066431, deals with an important issue

The article is interesting and could be considered for publication in Sustainability journal. However, while reading I found some statements missing, confusing or unclear. Below I enclose the list of my comments.

As English is not my native language, I am not able to assess language correctness.

The lack of line numbers causes difficulties in indicating the place of corrections.

All abbreviations should be explained when they are used for the first time.

It is worth adding in the title that the research are carried out on real leachates.

“The fouling samples were collected from working incineration plants in Ningbo.” That should be in materials and methods.

The leachate characteristics is given in Table S1. Typical values for this type of wastewater. There are several grams of chloride per liter there. How the influence of chloride on COD was removed? Typically, the maximum chloride content in COD determination is 1000mg/L.

Why BOD was not determined?

While reading the text, you can see that the Authors are practitioners with knowledge and experience in the subject. As a result, there are many mental shortcuts in the text, understandable to people dealing with the topic, but unclear to people with less practice and familiarity with the topic. It is worth extending the description in many places to make it more understandable. An example can be the description of a technology: “The plant employs a typical process concluding anaerobism, a combined two-stage A/O, UF, NF and RO”.

Figure S3. Doses?, Figure S4. pH? Info from Text S2 should be on figure caption for clarification. Why on figures optimal result for each coagulant with optimal conditions are not given (I assume, different doses and pH for each coagulant)?

What was the PAM dose?

How ions content were determined?

Is the dose of the coagulant given per active cation or per total weight of the coagulant?

Coagulation doses are rather small as for industrial practice. Have the authors tried, just for screening, higher doses of coagulants?

Results descriptions and discussion should be expanded. You can see that the experiment was done correctly, but its description is very short and poor. The conclusions, for example, contain information that is difficult to find in the description.

Abstract: Through the pilot scale test, the effluent was connected to the microfiltration membrane and then to the nanofiltration membrane and the practical engineering application is feasible. Pilot scale experiment is not described. From what I understood everything was on a lab scale?

As part of the tests on a larger scale and the implementation suggested in the abstract, do the authors propose some kind of membrane protection between the coagulation and the membranes, e.g. a sand filter? After all, a filtered sample was taken for the determination in the article (“Samples were filtered with 0.45 μm cellulose acetate (CA) filters before the analysis of COD, FTIR, 3D-EEMs and UV/vis”).

Has any economic analysis of the technology costs been carried out, or do the authors find it less important at this stage of research?

The article is interesting. The research has application potential. Based on the comments and general impression, it suggests major revision before the article is finally accepted for publication.

 

 

 

 

 

Author Response

Dear Sir:

        According to your suggestion, I revised my article and made notes in the word article.

        Please review and thank you for your good news.

Reviewer 2 Report

This manuscript presents some practical testing or membrane autopsy results from a incineration leachate treatment plant. However the author did not describe more about the leachate project itself. Such as the COD of leachate is less than 300 ppm, which is quite abnormal of some unclear statements.

Secondly, it seems like a membrane autopsy report, rather than a systematic research article. 

 

Thirdly, FTIR-ATR is commonly used for Thin film membrane surface structure analysis, not sure whether it is FTIR or FTIR-ATR Here? Plus FTIR-ATR database has many typical chemical bonds or molecules. Need deeply explanation. 

 

Fourthly, EDS mapping is also meaningful and should be analyzed to compare the data with peak area. And a close mapping data to show the precise element composition for fouling analysis. 

 

Overall it must be improved to meet the minimum criteria for further assessment. 

Author Response

Dear Sir:

According to your suggestion, I revised my article and made notes in the word article.This research is mainly based on the combination of field and laboratory. The composition of membrane fouling is obtained from the study of membrane fouling, and then actions are taken against the fouling components. The scale is mainly composed of salt scale and mud scale. The double alkali method is considered to remove hardness ions, but the drug consumption is too high in the engineering field, so we should take a step back to study how to remove organic mud scale.

Please review and thank you for your good news.

Round 2

Reviewer 1 Report

This is my second review of this article. Authors answered my questions and cerrected the manuscript. I suggest to accept this article in its present form.

Reviewer 2 Report

The author has well addressed the comments from previous reviewers, with great improvement on the manuscript quality. Now it is ready for acceptance.