Efficiency of Combined Processes Coagulation/Solar Photo Fenton in the Treatment of Landfill Leachate
, Jorge Trilleras 3, Gustavo E. Barros 3, Arturo J. González-Solano 2 and Henry Maury-Ardila 2Round 1
Reviewer 1 Report
The illustrations are not enough; graphs or diagrams are required that reflect the comparative characteristics of the experimental results. This will greatly facilitate the understanding of the material. Some figures require quality improvement, including an increase in the font of the inscriptions. There are other comments, which are given in the attached file. See below only some of them:
1. The authors did not provide the initial and final chemical composition of leachates, but only some physico-chemical parameters. The change in the concentration of iron in the solution after the experiment with the addition of FeCl3 did not considered. It is also interesting to find out what the content of Al will be after processing using PAC. It is necessary to compare the initial and final composition of the solutions with the standards of Colombia and WOS (for example, MPC) for drinking or at least domestic water in all regulated indicators. It may be that the use of the proposed reagents, although it will reduce the COD, will increase the total mineralization of water and the concentration of a number of chemical elements in them.
2. It is unclear what the scientific novelty of the work. Coagulation / Sedimentation Experiments using PAC and FeCl3 have already been described and applied. On page 7, the authors compare their results with those already published by other authors, including comparing experimental conditions, dosages, etc. It looks so that the authors simply repeated what was published elsewhere in the use of this method. It is necessary to specify what exactly is the originality of the presented work (reagents, conditions, a unique object, etc.).
3. The standards (regulations) are not given, according to which it is necessary to evaluate the effectiveness of the proposed methods.
4. Many parameters e.g. COD, BOD, DOC etc. are not deciphered, which complicates the understanding of the text. The phrase "COD removal" should be replaced in the whole text by “reduction of COD”.
Comments for author File: 
Comments.pdf
Author Response
Response to Reviewer 2 Comments
Point 1: The authors did not provide the initial and final chemical composition of leachates, but only some physico-chemical parameters. The change in the concentration of iron in the solution after the experiment with the addition of FeCl3 did not considered. It is also interesting to find out what the content of Al will be after processing using PAC. It is necessary to compare the initial and final composition of the solutions with the standards of Colombia and WOS (for example, MPC) for drinking or at least domestic water in all regulated indicators. It may be that the use of the proposed reagents, although it will reduce the COD, will increase the total mineralization of water and the concentration of a number of chemical elements in them.
Response 1: In the sanitary landfill located in Atlantico (Colombia), the coagulation process (PAC coagulant) is used without optimization of operational conditions and low efficiency of COD reduction. The starting point of this work was to use leachate treatment already studied, in order to demonstrate to the authorities responsible for sanitary landfill that other processes can be coupled with high efficiency and not very high cost. Because each leachate has particular characteristics and conditions, it was necessary to carry out a study of optimization of the variables that could affect the process. COD was the response variable and was evaluated all the time. Measurements of other parameters were not performed, except for aluminum. Line 550, content of Al after processing using PAC was presented. The concentration of iron in the solution after the experiment with the addition of FeCl3 was not considered, however, increase amount of iron in the leachate increases the efficiency of the reduction of COD was observed. Line 539-546, compare the initial and final composition of the solutions with the standards of Colombia. Recently we are advancing studies with natural coagulants precisely to avoid increase the total mineralization of water and the concentration of a number of chemical elements in them.
Point 2: It is unclear what the scientific novelty of the work. Coagulation / Sedimentation Experiments using PAC and FeCl3 have already been described and applied. On page 7, the authors compare their results with those already published by other authors, including comparing experimental conditions, dosages, etc. It looks so that the authors simply repeated what was published elsewhere in the use of this method. It is necessary to specify what exactly is the originality of the presented work (reagents, conditions, a unique object, etc.).
Response 2: Lines 74-95, originality of this work was presented. Lines 203-208, the use of PAC and FeCl3 in the coagulation/sedimentation experiments were explained. Lines 361-372, the efficiency of the coagulation/sedimentation process with PAC and FeCl3 at optimal conditions was compared with the efficiency of the coagulation/sedimentation process with PAC currently used the sanitary landfill located in Atlantico-Colombia.
Point 3: The standards (regulations) are not given, according to which it is necessary to evaluate the effectiveness of the proposed methods.
Response 3: Lines 376-381 and 539-546, methods were evaluated according to regulations.
Point 4: Many parameters e.g. COD, BOD, DOC etc. are not deciphered, which complicates the understanding of the text. The phrase "COD removal" should be replaced in the whole text by “reduction of COD”.
Response 4: The parameters were deciphered. The phrase “COD removal” was replaced in the whole text by “reduction of COD”
Point 5: Line 19 - Avoid using abbreviations in the Abstract.
Response 5: The abbreviations were removed in the Abstract.
Point 6: Line 57 - Decipher, please, at the first mention in the text.
Response 6: Line 60, the abbreviations were deciphered and mentioned first in the text.
Point 7: Line 69 - Please provide more references regarding this method.
Response 7: Line 71, more references were provided.
Point 8: Line 71 - Please clarify what the novelty of the proposed method is.
Response 8: At lines 74-95 explains the proposed method is.
Point 9: Line 97, Table 1.
Response 9: Line 100, Table 1 was added.
Point 10: Line 98, Can be deleated.
Response 10: Line was deleated.
Point 11: Lines 109–112, Manufacturer, city, country. Purity.
Response 11: Lines 126-134, requested information was added.
Point 12: Line 117, Change to values.
Response 12: Line 138, line was rephrased.
Point 13: Line 119-123 Manufacturer, City, Country. Accuracy and precision.
Response 13: Lines 139-151, requested information was added.
Point 14: Line 120, Describe the methodology in more detail, please provide references.
Response 14: Lines 141-144, requested information was added.
Point 15: Line 135, Please explain the formula and provide references.
Response 15: Lines 163-164, requested information was added.
Point 16: Line 145, Please, explain formulas.
Response 16: Lines 171-174 and 180-182, requested information was added.
Point 17: Line 156, Reference.
Response 17: Line 189, reference was added.
Point 18: Line 185, Manufacturer, City, Country. Accuracy and precision.
Response 18: Line 228, requested information was added.
Point 19: Line 195, Please explain why the pH is exactly 3.
Response 19: Lines 245-247, requested information was added.
Point 20: Line 197, How did you control this parameter?
Response 20: Lines 248-249, answer to this question was added.
Point 21: Line 218, Please, rephrase or explain the process.
Response 21: Line 304-306, line was rephrased.
Point 22: Change removal by reduction.
Response 22: Term was changed.
Point 23: Line 293, Please specify what the standard COD means? Provide a reference to the standard.
Response 23: Lines 376-381, line was rephrased and reference was added.
Point 24: Line 302, Why? mass ratio R=[H2O2]/[Fe2+]) between 5 and 20 was used
Response 24: Lines 389-392, answer to this question was added.
Point 25: Line 304, Artificially forced? Please clarify.
Response 25: Line 393, line was rephrased.
Point 26: Line 336, Small and fuzzy figure. Figure 4
Response 26: Line 442, figure was changed.
Point 27: Line 363-364, It is difficult to understand the physical meaning of these parameters. A2, B2
Response 27: Line 467-472, line was rephrased.
Point 28: Line 385, Please, check stoichiometric coefficient.
Response 28: Line 510, stoichiometric coefficient was checked.
Point 29: Line 397, Please clarify what the novelty is. For example, in a combination of two known methods.
Response 29: Lines 516-524, line was rephrased for clarity.
Point 30: Line 401, 404 Please provide a comparison with the requirements for the landfill leachates in Colombia.
Response 30: Lines 539-546, comparison with the requirements for the landfill leachates in Colombia was provided.
Point 31: Line 411 Please, specify which one treatment exactly.
Response 31: Lines 547-550, line was rephrased.
Point 32: Line 412 Specify the region, please. Please, specify, which one?
Response 32: Line 551, region was specified.
Reviewer 2 Report
I suggest the acceptance of this paper for publication. I would suggest the following:
1- Rewrite the abstract in more comprehensive way
2- The figures (Pareto Chart), can be explained and why the authors prefered them. What make them more important than the normal way of showing the results. or:
3- I suggest that they change the way they presented there results to make them more clear and highlight the importance and the novelty of their work.
Author Response
Response to Reviewer 2 Comments
Point 1: Rewrite the abstract in more comprehensive way.
Response 1: Rewrite the abstract was done.
Point 2: The figures (Pareto Chart), can be explained and why the authors prefered them. What make them more important than the normal way of showing the results.
Response 2: Lines 292-313 and 327-338, the figures (Pareto Chart) were explained. These figures were used only for the coagulation/sedimentation experiments in order to explain the effect of the factors on the response. Lines 442 and 511, the figures of section solar photo-Fenton experiments with PAC coagulant pre-treated and ferrioxalate-induced solar photo-Fenton process with FeCl3 coagulant pre-treated were changed by response surface plot to evaluate the relationship between the experimental factors and the response measured according to the selected criteria.
Point 3: I suggest that they change the way they presented there results to make them more clear and highlight the importance and the novelty of their work.
Response 3: Change the way to present the results and show the novelty of this work were done.
Round 2
Reviewer 1 Report
Dear Authors,
Send you the Review on the manuscript “Efficiency of Combined Processes Coagulation/Solar Photo Fenton in the Treatment of Landfill Leachate”.
Thank you for the significant effort to improve the manuscript, accurate consideration of all the comments, corrections of technical errors. It is important that you emphasize the originality and novelty of the results. Remarks only about the quality of the figures remain (blurry and small inscriptions, some of the figures illustrating the results can be combined). I recommend accepting the manuscript in present form at the discretion of the Honored Editors.
Best regards,
Nataliya Yurkevich
