Water Purification Using Active Charcoal with Microbes and Chelated Iron Soaked into Its Micropores

Round 1

Reviewer 1 Report

the authors presented new and interesting data on the purification of various waters, including wastewater from nitrates. According to the presented results, the authors were able to develop a new purifier, the production of which can be carried out almost immediately on an industrial scale.

Despite this, the reviewer has some comments regarding the form of presentation of the results.

1.  To subsection 2.7: Nitrate control is very difficult. Wouldn't it be easier to use nitrate-selective electrodes?

2. To subsection 3.2: In the text, the authors say that the initial concentration of nitrates was 150 mg/kg, and the starting point in Fig. 3 refers to 200 mg/kg. Where is right? What are the units of measurement for the x axis in Fig. 3?

3. For what purpose do the authors include a mathematical description of the curves for the removal of nitrate ions from various liquid media? If you use mathematics, you must describe each variable from a physical or chemical point of view. What are α and β? What is their physical meaning?

4. In subsections 3.2-3.4, the authors present graphs of non-time dependence. nevertheless, the authors continue to present a mathematical description (formula) that includes the parameter t. What is its physical meaning in these sections?

5. The discussion section is more like a summary of the Introduction. The reviewer invites the authors in this section to consider/suggest possible mechanisms for the removal of nitrate ions from aqueous media. Can the sorption process be considered as one of the possible ways to remove these ions and why?

The comments presented do not reduce the level of the work presented, but will help to better understand the controversial issues.

Author Response

Dear Reviewer，

Thank you very much for taking the time to review this manuscript. Please find the detailed responses attached and the corresponding revisions highlighted in the re-submitted files.

Best

Xiaoyong

Author Response File: Author Response.pdf

Reviewer 2 Report

In this manuscript the removal of nitrates from wastewater, using active charcoal with microbial liquid and chelated iron soaked into its micropores, was tested. However the following points should be addressed before consideration:-

1- The methods lack details regarding the preparation and characterization of Bamboo charcoal.

2- In Section 2.2, please clarify is it "charcoal" or "activated charcoal" you used the two terms.

3- In section 2.3, please specify in which phase did you use ACMI, liquid or solid.

4- Sentence in lines 75 & 76, is misleading, please rephrase.

5- What do you mean by "first half and second half" in lines 86-87.

6- In section 2.3, the amount of ACMI was expressed in mL and in Fig 2, the y axis, the nitrate is expressed in mgkg^-1, please unify.

7- In section 3.2, it is stated that "the nitrate concentration was 150 mg/kg while in Fig. 3, the initial concentration was 200mg/kg, which is the correct concentration?

8- In line 204, it is written that the nitrate concentration decreased from 200mg/kg (please correct units) to 70mg/kg, while in Fig. 4 it shows that the initial concentration was 150mg/kg, which one is the correct value?

9- to strengthen the work, cost analysis and cost comparison is required, also required, removal efficiency comparison with different adsorbent in removing nitrates from wastewater.

10- Much of the discussion section belong to the introduction section, please re-write and re-organize.

11- There is no conclusions section?

12- Please correct the year format of references 5&8.

The English of the manuscript should be improved, please check spelling and grammar as well.

Author Response

Dear Reviewer，

Thank you very much for taking the time to review this manuscript. Please find the detailed responses attached and the corresponding revisions highlighted in the re-submitted files.

Best

Xiaoyong

Author Response File: Author Response.pdf

Reviewer 3 Report

In this research article, authors studied the removal of nitrates by an activated charcoal material with beneficial microbes and chelated nano-iron absorbed in its micropores as well as the effect of removing nitrate, and water purification. The authors conducted a number of experiments, the methods were described, and the results were well analyzed and presented. Besides, the information, analysis, and discussion provided by this paper are clear. Considering a minor revision, the following points need to be checked and corrected carefully.

In the introduction section:

Page 2, Line 74, Please Superscript the Fe^2+,  and subscript the Fe2O3.

Page 2, Line 79. Please define the "COD" as it,s first appearance in the text. 

Page 3, Line 117. Why degree sign (^oC) is underlined?

Page 3, Line 124. Use superscript for "m^2". 

Define the "ACMI" as its first appearance. 

Page 4. Line 176. Please write the equations with numbers and define them accordingly. 

Please compare your results with the recent studies. 

The discussion part is too lengthy. Please shrink it and include your main findings. 

Overall, the writing of the manuscript needs to be improved further. 

Author Response

Dear Reviewer，

Thank you very much for taking the time to review this manuscript. Please find the detailed responses attached and the corresponding revisions highlighted in the re-submitted files.

Best

Xiaoyong

Author Response File: Author Response.pdf

Round 2

Reviewer 2 Report

The quality of the manuscript has significantly improved. No additional comments.

minor editing is required