Evaluation of the Performance of the Electrocoagulation Process for the Removal of Water Hardness

Round 1

Reviewer 1 Report

This work presents a performance evaluation of the electrocoagulation process for removal of water hardness. It comes under low carbon green tech to remove organic micropollutants from wastewater. It also attempted to evaluate energy consumption applicability of the treatment method and their potential practical implementation for achieving better water quality.

Introduction- There is a lack of recent literature discussion on implementation of water quality evaluation processes pertaining to electrocoagulation.

 What is the rationale for choosing these factors and different levels for the factorial design of experiments? It will give the background to your review article explain the chosen parameters/methods to readers. Kindly cite then and discuss those process investigated in the studies and how the current studies add to the field.

Some other points should be addressed in order to complete and clarify some aspects in the manuscript:-

Abstract: Needs improvement and should contain more quantitative data/results rather than being descriptive in nature.

Line 27: “the water in 25%” …check grammar

Line 40: re-write. Not clear what the author is implying. Write correctly.

Line 43: “the researchers…” The grammar is wrong again. Check the tense of the sentence.

Line 57; “uses…”  check grammar

Line 82: Please specify some coagulants/flocculants

Line 92: “ a recently built…” write properly

Line 99: “used agua salobre artificial. Las cuales….” What on earth is that???

Line 110: Cite re3ference for the method/procedure

Line 116-117: What is the rationale for choosing these factors and different levels for the factorial design of experiments? It will give the background to your review article explain the chosen parameters/methods to readers. Did the authors conducted any one factor experiments to identify ranges for the investigated levels of the two factors?

Table3: report response variable data with SD from the replicate runs as mentioned before that 16 experiments were conducted.

Line 195: Fig 2: Not sure what the authors are trying to illustrate from this fig. Hard to interpret. Why not do a post-hoc analysis like Tukey test and use the compact letter display box plot followed by pair-wise comparison?

Line 198: Fig cited in the text (Fig 5) do not accurately cross-referenced with the fig 3 being discussed in the text

Line 209: Long sentence. Break it down

Line 215: What are the fonts in italics.

Fig 5: Show experimental data points with error bars in the plot. This is not modelling through curve-fitting.

Fig 6: The fig should be self-explanatory. Put experimental condition details in the x-axis to adequately interpret and follow the results. Where are the error bars? Statistical significance between the results needs to be done. For e.g are the results between Exp3- Exp 6 significantly different (p<0.05)?

Line 246: “ section 3.5 title” the authors needs to strictly stick to English language for the manuscript. Check the manuscript thoroughly, found it in many other places throughout the text.

Fig 9: Same comment as fig 5.

Section 3.7 title: correct and re-write

Line 277: “decreases from 13.4 mS/cm to 12.3 mS/cm” statistical significance??

Conclusion: needs to emphasise the implication of this study for practical applications.

Author Response

good morning, the responses of the observations are sent

Author Response File: Author Response.pdf

Reviewer 2 Report

1-      The manuscript must be improved by checking once again English grammar and technical writing.

2-      The first sentence in the abstract should be revised in technical writing and grammar.

3-      Check the repeated words in the keywords.

4-      The introduction part manuscript must be supported by enough recent references.

5-      Photocatalysis and adsorption are superior, affordable and most widely used techniques for the effective treatment of heavy contaminated waters. Then, how electrocoagulation is better than photocatalysis and adsorption? Please, clarify that in the introduction part. The authors can follow the following references for improving the introduction part: (https://doi.org/10.3390/catal12050500) ; https://doi.org/10.1016/j.gsd.2021.100575 ; (https://doi.org/10.3390/ma15134547) ; 

6-      The authors should indicate a clear gap in knowledge which this study seeks to bridge, and potentially contribute to knowledge.

7-      Mention the country of origin of the instruments used in the study

8-      The authors have to improve the presentation of Figure 1.

9-      The caption of Figure 1 must be revised.

10-  The authors should improve the quality of all figures and revise the line weights and font size.

11-  Data Analysis equations should be mentioned in the context.

12-  Correct the English writing error in Section 3.3.

13-  Section 3.3 must be revised. The authors have discussed Figure 3 or Figure 5?

14-  System sustainability is a major concern. When are the cathode and anode replaced? and what effect does this have on the efficiency of the treatment process?

15-  Rewrite the conclusion part (avoid English and grammar errors).

16-  The authors should identify the limitations of this study and the recommended future studies in the conclusion part.

Author Response

good morning, the responses of the observations are sent

Author Response File: Author Response.pdf

Reviewer 3 Report

The findings of this work are of considerable interest and well done. I recommend it to be published after a minor revision. 

1. The novelty needs to refinement and should be highlighted in the introduction part.

2. The Authors should also proofread their manuscript (some spelling and grammar errors).

3. Introduction part, if possible, some important and relative reports about Photocatalysis could helped: https://doi.org/10.1016/j.colsurfa.2021.127753, https://doi.org/10.1016/j.surfin.2022.102006,  https://doi.org/10.1016/j.heliyon.2022.e09652.

4. The conclusion is also not targeted to the important aspects described in the manuscript; please rephrase it.

5. The author should better improve the beauty and quality of the figures in the manuscript.

6. In Materials and method section, please provide the purity of your chosen precursors.

7. In figures 9 and 10, lack of error bar for the obtained data?

Hence, I recommend it accepted for publication after some minor revisions.

Author Response

good morning, the responses of the observations are sent

Author Response File: Author Response.pdf

Round 2

Reviewer 2 Report

Accept.