Degradation of 2,4-Dichlorophenol by Ethylenediamine-N,N′-disuccinic Acid-Modified Photo-Fenton System: Effects of Chemical Compounds Present in Natural Waters
Round 1
Reviewer 1 Report
Article entitled Degradation of 2,4-dichlorophenol by ethylenediamine-N,N’-disuccinic acid-modified, photo-Fenton system：Effects of chemical compounds present in natural waters, written by Wenyu Huang, Ying Huang, Shuangfei Wang, Hongfei Lin and Gilles Mailhot and submitted to Processes journal as a draft no 1031645 deals with an important issue of pollutants decomposition methods development.
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 literature review on the topic was incomplete. Many laboratories conduct research on the use of the Fenton process and its modifications, such as the photo-Fenton process for the treatment of real wastewater. Additionally, there are practical applications in industrial scale. The literature review on this subject should be supplemented, as well as the review on 2,4-dichlorophenol.
The state of the art on the application of EDDS is not presented. This should be supplemented. In the current version of the article, it is not clearly stated what is a scientific novelty in relation to the literature review.
Fenton and modified Fenton systems are very sensitive to the conditions of the process: pH, doses of reagents, duration of the process. This information is not provided in materials and methods, it needs to be supplemented.
How the process was terminated?
Why was the process carried out in far from optimal conditions (pH), even considered to be one of the worst in terms of the potential effectiveness of the process?
In the article 2,4,6-TCP was also used. Why it is not mentioned in the title?
Why only 1pH value, 1 dose of reagent was used?
Why do the authors give the doses of the reagents in mM? While this is correct, both the amount of 2,4-DCP and HA are given in mg/L. Ions again in mM. It should be unified to one unit.
Have any tests been performed to detect the presence of radicals?
What idea do the Authors have for removing unreacted reagents after the process? Was there enough hydrogen peroxide added to observe its presence after process?
The experiment performed is relatively simple. There are many similar studies done on simple aqueous solutions. Significant shortcomings were found in the literature review and methodology description. Based on these comments and general impression, I suggest rejecting the article.
Author Response
Please see the attachment.
Author Response File: 
Author Response.docx
Reviewer 2 Report
The authors investigate the photodegradation of 2,4-dichlorophenol and 2,4,6-trichlorophenol in a modified photo-Fenton system and also evaluated the influence of organic matter and inorganic ions. Finally real systems were tested.
The results are interesting to the audience although their novelty is low.
Nevertheless, the MS deserves publication upon sddressing the following minor points:
-It could be interesting to include a picture or scheme of the photoreactor employed in the reactions.
-It will also help to discuss the results to have the absorbance spectra of the photoreaction mixture used in the most simple systems (any of those shown in figures 1, 2 or 3) and compared to the absorbance spectrum of those in which natural water bodies were tested.
Author Response
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Author Response File: Author Response.docx
Reviewer 3 Report
Authors wrote that all experiments had been performed in a cylindrical Plexiglas container. This container placed on a homemade photoreactor. I propouse add some comments of this construction or add scheme of this apparatus.
Author Response
Please see the attachment.
Author Response File: Author Response.docx
Round 2
Reviewer 1 Report
This is my second review of this article. The first review was negative. However, the Authors responded to my comments and completed the information. In addition, they provided additional information in response that was missing from the first draft of the manuscript. Based on this, I decided to change my mind. An article may be released for publication as a result of corrections made by the authors.
Reviewer 3 Report
The authors improved manuscript
