Removal of Phosphorus by Ferric Ion-Rich Solutions Prepared Using Various Fe(III)-Containing Minerals

Round 1

Reviewer 1 Report

This study investigated phosphorus removal by physicochemical proses. The experimental results could be an option for the phosphors removal technology. But, the originality of this study seemed not well statement, instead of the reasonable experimental results. The authors should be explained the research question and the originality of the finding by reviewing the current study. So, it should be said that the manuscript required revision to identify the new finding of this study. 

 

Introduction

The importance of phosphorus removal was well explained in the manuscript. But, literature reviews for the phosphorus removal by the metal irons solution were needed to clarify the originality of this manuscript. 

P2:61 Author explained, “a novel approach should be developed to overcome the disadvantages … s”. But, the idea of the counter measurement for these disadvantages should be explained in the background. 

 

Material and Methods.

Some statement for the experimental setup was not well written. So, more details explanations could be needed for the reader's understanding. 

P3:L105-: Initial pH for the wastewater should be written.

P3:L127-: The model of the XRD should be written as the authors did in other equipment.

 

Results and discussion

Since the research question and originality of this study were not well written in the background, the importance of the results was difficult to understand. 

Specific comments were listed below.

P7:L225-: The phosphorus removal (or sedimentation efficiency) of PAC was influenced by the initial pH. So, T-P removal experiment for PAC should do in optimal. 

P7:L227-: PAC was already explained in the methodology. 

P7:L232-: More discussion should be required, especially the matrix effect in wastewater on T-P removal, and efficiency comparison on other ferric-type coagulation solutions. 

Author Response

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Author Response File: Author Response.pdf

Reviewer 2 Report

1- In section 3.1 lines 44 and 45, the authors mentioned that "whereas almost 37.4% and 34.4% T-P removal was obtained by FeCl₃ and Fe(NO₃)₃" but in fig 1 a and b the the curve indicate percentage around 40% it should correct 

2- Fig 1 a and b the  [PO4 3−-P] in y-axis represented as percentage or as value ? it is not clear  and if it is the same value for metals ((Fe²⁺ , Fe^3+, Mg²⁺, and Al³⁺) (100 before ) I suggest it is necessary to write mention the value after only 

3- (Fig 2 d) is not clear and difficult to explain , could you fit out this figure in two figures ( one magnetite and another for lepidocrocite)>

4- in section 3.3  the authors do not mention  Fe (II) removal, but it has appeared  in Fig 3 b and c 

5- in section 3.3 lines 207, 208, 209 the authors mentioned that pH variation may not have significantly influenced T-P removal in this study" . the reaction  medium was  concentrated acids and the pH values that was  mentioned in fig 4 a and b more than 6.

 

Author Response

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Author Response File: Author Response.pdf

Reviewer 3 Report

The aim of this study was to evaluate removal of phosphorus by ferric ion-rich solutions prepared using various Fe(III)-containing minerals. The topic is important because it concerns the removal of phosphorus from wastewater. The impact of too high a phosphorus concentration on the environment is very significant. This research is important for a number of researchers working in the area of environmental science and wastewater treatment. The manuscript is well structured and organized. However the work needs some enhancements before it can be published. I recommend major revision of the manuscript based on the following comments:

·        One of the main parameters influencing the efficiency of phosphorus precipitation is pH. The paper lacks information on the pH of phosphorus precipitation with the use of various ions (Figure 1). Providing information about the pH is necessary for the correct interpretation of the obtained results. Without this information, it is not possible to correctly interpret the obtained results described in section 3.1. Information on pH is also required in chapter 3.2. It is not sufficient to mention the amount and molarity of the acid used.

Other drawbacks and comments:

- I suggest adding a flowchart describing the whole investigation, research stand and operating parameters to help the readers perceive the main pointsm,

-  please correct indentation of paragraphs: line 142, 167.

 

Author Response

file attached.

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

The authors revised the paper. So, the paper may be acceptable.

Reviewer 3 Report

The author answered the questions. The quality of this manuscript improved much after the revision.